BIO FINAL EXAM

Created by geektothebone 

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Which of the following statements is INCORRECT?

Melanin provides protection against ultraviolet (UV) radiation.
Keratinocytes produce a fibrous protein to protect the epidermis.
Langerhans cells activate the immune system.
Tactile cells anchor the skin to the body.

Tactile cells anchor the skin to the body.

This is the incorrect statement. Tactile cells, in conjunction with their sensory nerve endings, function as touch receptors. The hypodermis, not tactile cells anchors skin to the body.

Which of the following does NOT protect the skin from bacteria?

cathelicidins
defensins
the low pH of the skin
dermcidin
the temperature of the skin

the temperature of the skin

Correct
The temperature of the skin does not protect the skin against bacteria. In fact, the temperature of the skin is ideal for many types of bacteria.

Which skin appendages aid in cooling the body to prevent overheating on a hot day or during intense exercise?


eccrine sweat glands
apocrine sweat glands
sebaceous glands
ceruminous glands

Eccrine sweat glands

Correct
Eccrine (merocrine) sweat glands produce a watery secretion (called sweat) that is released onto the surface of skin in response to elevated body temperature. As body heat is used (thus removed) to convert the water of sweat to water vapor, body temperature decreases; this is called evaporative cooling.

Which structures of the dermis give rise to friction ridges (fingerprints)?

epidermal ridges
dermal papillae
flexure lines
dermal ridges

Dermal ridges

Correct
Dermal ridges cause the overlying epidermis to form epidermal ridges. Collectively these ridges are called friction ridges

Hair and nails are made primarily of calcium.

True
False

False

Correct
The primary component of hair and nails is hard keratin (not calcium), produced by keratinocytes.

A needle would pierce the epidermal layers of the forearm in which order?

basale, spinosum, granulosum, corneum
basale, spinosum, granulosum, lucidum, corneum
granulosum, basale, spinosum, corneum
corneum, granulosum, spinosum, basale

corneum, granulosum, spinosum, basale

Melanocytes and keratinocytes work together in protecting the skin from UV damage when keratinocytes ________.

maintain the appropriate temperature so the product of the melanocyte will not denature
accumulate the melanin granules on their superficial portion, forming a UV-blocking pigment layer
provide the melanocyte with a protective shield against abrasion
maintain the appropriate pH in order for the melanocyte to synthesize melanin granules

accumulate the melanin granules on their superficial portion, forming a UV-blocking pigment layer

What is the most important role of the arrector pili muscles in humans?

Cause the hair follicle to stand erect
Help retain heat
Defense
Force sebum out of the hair follicle to the skin surface

Cause the hair follicle to stand erect

Sudoriferous (sweat) glands are categorized as two distinct types. Which of the following are the two types of sweat glands?

sebaceous and merocrine
eccrine and apocrine
holocrine and mammary
mammary and ceruminous

eccrine and apocrine

Apocrine glands, which begin to function at puberty under hormonal influence, seem to play little role in thermoregulation. Where would we find these glands in the human body?

beneath the flexure lines in the body
in the palms of the hands and soles of the feet
in the axillary and anogenital area
in all body regions and buried deep in the dermis

in the axillary and anogenital area

Burns are devastating and debilitating because of loss of fluids and electrolytes from the body. How do physicians estimate the extent of burn damage associated with such dangerous fluid loss?

by using the "rule of nines"
by observing the tissues that are usually moist
through blood analysis
by measuring urinary output and fluid intake

by using the "rule of nines"

We are told that every surface we touch is teeming with bacterial cells, and bacteria are found in the pools we swim in, the water we wash with, and on the hands of friends. Why are we not inundated with bacterial infections on our skin?

Not all bacteria are harmful or thrive on the skin.
The low pH of the skin secretions retards the multiplication of bacteria on the skin.
All of these answers are correct.
Many bacteria are killed by bactericidal substances in the sebum and sweat.

All of these answers are correct.

Hyaline cartilage ________.

is the rarest of the skeletal cartilages
is found on the ends of bones that form movable joints
forms "shock-absorbing" pads between the vertebrae
gives shape to the external ear

is found on the ends of bones that form movable joints

The axial skeleton includes the ________.

bones of the arms
hip bones
ribs
bones of the legs

ribs

Choose the FALSE statement.

Long bones include all limb bones except the patella.
Sesamoid bones form within certain tendons.
Irregular bones include the vertebrae and hip bones.
The sternum is an example of a flat bone.

Long bones include all limb bones except the patella.

Osteoclasts ________.

form skeletal cartilage
calcify bone matrix
break down bone
form new bone

break down bone

Correct
Osteoclasts are bone-breaking (bone-resorption) cells.

The epiphyseal plate is ________.

where long bone lengthening occurs
the long axis of a bone
where yellow bone marrow is produced
the site of red bone marrow production

where long bone lengthening occurs

Correct
Long bones elongate from growth at the epiphyseal plate, a layer of hyaline cartilage between the epiphyses and diaphysis of long bones

What indicates that a long bone has reached its adult length?

the presence of osteoblasts
the presence of hyaline cartilage on the ends of the bone
the presence of osteons
closure of the epiphyseal plate

closure of the epiphyseal plate


Correct
The epiphyseal plate is a zone of hyaline cartilage between the epiphysis and diaphysis of a long bone. When the cartilage is replaced with bone and the plate closes (becoming an epiphyseal line), the bone has reached its maximum length.

What is the final stage in the healing of a bone fracture?

formation of a bony callus
formation of a fibrocartilaginous callus
bone remodeling
formation of a hematoma

bone remodeling

Correct
In order, here are the stages of bone fracture healing: (1) formation of a hematoma, (2) formation of a fibrocartilaginous callus, (3) formation of a bony callus, and (4) bone remodeling.

The structure of bone tissue suits the function. Which of the following bone tissues is adapted to support weight and withstand tension stress?

irregular bone
spongy bone
trabecular bone
compact bone

compact bone

The periosteum is secured to the underlying bone by dense connective tissue called ________.

Volkmann's canals
the struts of bone known as spicules
perforating (Sharpey's) fibers
a bony matrix with hyaline cartilage

perforating (Sharpey's) fibers

The structural unit of compact bone (osteon) resembles the growth rings of a tree trunk.

True
False

True

Each consecutive bone lamella has collagen fibers that wrap in alternating directions.

True
False

True

Why, or why not, is swimming recommended as an exercise to prevent osteoporosis?

Swimming is not recommended to prevent osteoporosis, as it is not considered a weight-bearing exercise.
Swimming is recommended to prevent osteoporosis, as it is considered a weight-bearing exercise.
Swimming is not recommended to prevent osteoporosis, as forces are applied in all directions on the bones simultaneously in swimming.
Swimming is recommended to prevent osteoporosis, as forces are applied in all directions on the bones simultaneously.

Swimming is not recommended to prevent osteoporosis, as it is not considered a weight-bearing exercise.

The ________ articulate(s) with the hip bones of the pelvis.

thoracic vertebrae
coccyx
sacrum
lumbar vertebrae

Sacrum

Correct
The sacrum articulates with the hip bones of the pelvis

If a herniated disc in the lumbar region is treated by surgically removing the intervertebral disc and doing a bone graft between the adjoining vertebrae, one of the consequences might be _________.

reduced flexibility of the spine in the lower back
gradual growth of a replacement intervertebral disc in the space between the vertebrae
increased shock absorbance qualities in the intervertebral discs located immediately above and below the graft in order to compensate for the removal of the herniated disc
All of the listed responses are correct.

reduced flexibility of the spine in the lower back

Correct
The intervertebral disc and space that it occupies provides room for vertebral bodies of adjacent vertebrae to flex and extend the vertebral column (spine).

The ribs that attach to the sternum are called ________.

floating ribs
true ribs
vertebral ribs
false ribs

true ribs

Correct
The superior seven rib pairs, called true ribs, attach directly to the sternum by individual costal cartilages.

Choose the FALSE statement.

The female pelvis is tilted further forward than the male pelvis.
The pelvic outlet is narrower in a female than in a male.
The female pelvis is thinner than that of a male.
The pubic arch is broader in the pelvis of a female than in the pelvis of a male.

The pelvic outlet is narrower in a female than in a male.

Correct
This is false; the pelvic outlet is narrower in a male than in a female. The female pelvis is modified for childbearing; it is wider, shallower and lighter than the male pelvis. The male pelvis has thicker/heavier bones with more prominent bone markings, acetabula that are larger and closer together, and a narrower, heart-shaped pelvic inlet.

Which of the following does NOT form part of the thoracic cage?

clavicle
thoracic vertebrae
sternum
ribs

clavicle

Correct
The clavicle is a part of the pectoral girdle; it does not form part of the thoracic cage.

How are the male and female pelves different?

The female pelvis has thicker bones with more prominent bone markings.
The pelvic inlet is heart-shaped in the male.
The male pelvis is usually wider, shallower, and lighter.
The acetabula are larger and closer together in the female.

The pelvic inlet is heart-shaped in the male.

Correct
The female pelvis is modified for childbearing; it is wider, shallower and lighter than the male pelvis. The male pelvis has thicker/heavier bones with more prominent bone markings, acetabula that are larger and closer together, and a narrower, heart-shaped pelvic inlet.

Which is the largest, longest, and strongest bone in the body?

os coxa
tibia
fibula
femur

Femur

Correct
The femur is the largest, longest, and strongest bone in the body. Its durable structure reflects the stress exerted on the femur as it bears the weight of the body when standing, walking, or running.

Which of the following bones is a part of the appendicular skeleton?

sternum
hyoid bone
mandible
humerus

Humerus

Correct
The humerus is part of the appendicular skeleton.

What is the major function of the intervertebral discs?

string the vertebrae together
absorb shock
prevent hyperextension of the spine
prevent hyperextension

absorb shock

The layman's name for the scapula is the collarbone.

True
False

False

The antebrachium is composed of which of the following two bones?

the humerus and the radius
the scapula and the clavicle
the radius and the ulna
the humerus and the clavicle

the radius and the ulna

The articulation that most closely resembles a hinge in the body involves which bones?

humerus-radius
femur-fibula
femur-tibia
humerus-ulna

humerus-ulna

The fibula is the major weight-bearing bone of the leg.

True
False

False

Describe fibrous joints.

Correct
In all three joints, bones are directly connected by dense fibrous tissue to form a joint lacking a cavity.

Functional classification of joints is based on ________.

the amount of movement allowed by the joint
whether a joint cavity is present
the size of the joint
the location of the joint

the amount of movement allowed by the joint

Correct
Functional classification is based on the amount of movement allowed by a joint. Structural classification focuses on the material binding the bones together, and whether a joint cavity is present.

Which of the following refers to a joint that is immovable?

diarthrosis
synarthrosis
synovial
amphiarthrosis

synarthrosis

Correct
Synarthroses are immovable joints and include sutures and syndesmoses.

Which of the following is NOT a factor that contributes to joint stability?

shape of the articulating surfaces
number and positioning of reinforcing ligaments
amount of muscle tone applied to tendons that cross the joint
amount of synovial fluid in the joint cavity

amount of synovial fluid in the joint cavity

Correct
The amount of synovial fluid in the joint cavity is not a factor that contributes to joint stability. The major role of synovial fluid is to lubricate the joint surfaces of freely movable (synovial) joints

The shoulder and hip are examples of ________.

condylar joints
pivot joints
plane joints
ball-and-socket joints
hinge joints

ball-and-socket joints

Correct
The shoulder and hip are examples of ball-and-socket joints.

Which of the following is NOT a structural feature of synovial joints?

reinforcing ligaments
bone ends united by fibrocartilage
bone ends covered with hyaline cartilage
a fluid-filled joint cavity

bone ends united by fibrocartilage

Correct
In synovial joints, bone ends are covered, but not united with cartilage. Hyaline (articular) cartilage covers the bone ends. The fibrocartilage found in some synovial joints, such as the knee joint, provides additional cushioning between opposing bone ends.

Which movement increases the angle between articulating bones?

adduction
extension
flexion
supination

extension

Correct
Extension involves movement along the sagittal plane that increases the angle between the articulating bones and typically straightens a flexed limb or body part.

Which joint has sacrificed stability to provide great freedom of movement?

elbow
ankle
knee
shoulder

shoulder

Correct
In the shoulder joint, stability has been sacrificed to provide the most freely moving joint in the body. The articulating bones provide minimal joint stability because of the size and "fit" of the articulating surfaces. The major stabilizing forces are soft tissue, in particular the tendons of the rotator cuff muscles (via muscle tone).

Fibrous joints are classified as ________.

hinge, saddle, and ellipsoidal
pivot, hinge, and ball and socket
symphysis, sacroiliac, and articular
sutures, syndesmoses, and gomphoses

sutures, syndesmoses, and gomphoses

In symphysis joints the articular surfaces of the bones are covered with ________.

hyaline cartilage
synovial membranes
tendon sheaths
fibrocartilage

hyaline cartilage

Articular cartilage found at the ends of the long bones serves to ________.

form the synovial membrane
produce red blood cells (hemopoiesis)
attach tendons
provide a smooth surface at the ends of synovial joints

provide a smooth surface at the ends of synovial joints

Bending your head back until it hurts is an example of ________.

flexion
extension
circumduction
hyperextension

hyperextension

What is moving a limb away from the median plane of the body along the frontal plane called?

adduction
inversion
abduction
dorsiflexion

abduction

Which of the following is CORRECTLY paired?

skeletal muscle: voluntary control
smooth muscle: striated
cardiac muscle: voluntary control
cardiac muscle: nonstriated

skeletal muscle: voluntary control

Correct
Correct; skeletal muscle is under voluntary control.

Which muscle characteristic describes the ability of muscle to respond to a stimulus?

extensibility
elasticity
contractility
excitability

excitability

Correct
Excitability, also termed responsiveness, is the ability to receive and respond to a stimulus, For example, skeletal muscle contracts in response to receiving chemical stimulation by a neurotransmitter called acetylcholine (ACh).

The cross bridge cycle is a series of molecular events that occur after excitation of the sarcolemma. What is a cross bridge?

ATP bound to a myosin head
Troponin bound to tropomyosin
A myosin head bound to actin
Calcium bound to troponin

A myosin head bound to actin

Correct
Yes! As soon as the activated myosin head forms a cross bridge with actin, the power stroke begins.

What structure is the functional unit of contraction in a skeletal muscle fiber?

The triad
The junctional folds of the sarcolemma
The cross bridge
The sarcomere

The sarcomere

Correct
Yes! A sarcomere is a regular arrangement of thin and thick myofilaments that extends from one Z disc to the next. A myofibril consists of a series of sarcomeres.

Calcium ions couple excitation of a skeletal muscle fiber to contraction of the fiber. Where are calcium ions stored within the fiber?

Calcium ions are stored in the sarcoplasmic reticulum.
Calcium ions are stored in the mitochondria.
Calcium ions are stored in the nuclei.
Calcium ions are stored in the transverse tubules.

Calcium ions are stored in the sarcoplasmic reticulum.


Correct
Yes! Sarcoplasmic reticulum is the specific name given to the smooth endoplasmic reticulum in muscle fibers. The sarcoplasmic reticulum is very elaborate in skeletal muscle fibers, allowing for significant storage of calcium ions.

After a power stroke, the myosin head must detach from actin before another power stroke can occur. What causes cross bridge detachment?

Acetylcholine binds to receptors in the junctional folds of the sarcolemma.
ATP binds to the myosin head.
ADP and inorganic phosphate are bound to the myosin head.
Calcium ions bind to troponin.

ADP and inorganic phosphate are bound to the myosin head.

Correct
Yes! The binding of ATP to the myosin head weakens the bond between myosin and actin, forcing the myosin head to detach. ATP also provides the energy for the next power stroke.

How does the myosin head obtain the energy required for activation?

The energy comes from the hydrolysis of GTP.
The energy comes from oxidative phophorylation.
The energy comes from the hydrolysis of ATP.
The energy comes from the direct phosphorylation of ADP by creatine phosphate

The energy comes from the hydrolysis of ATP.

Correct
Yes! Myosin is a large, complex protein with a binding site for actin. It also contains an ATPase. The energy released during the hydrolysis of ATP activates the myosin head.

What specific event triggers the uncovering of the myosin binding site on actin?

Calcium ions bind to troponin and change its shape.
Calcium release channels open in the sarcoplasmic reticulum, and calcium levels rise in the sarcoplasm.
Sodium ions bind to troponin and change its shape.
Calcium ions bind to tropomyosin and change its shape.

Calcium ions bind to troponin and change its shape.

Correct
Yes! The shape change caused by the binding of calcium to troponin shifts tropomyosin away from the myosin binding sites on actin.

When does cross bridge cycling end?

Cross bridge cycling ends when ATP binds to the myosin head.
Cross bridge cycling ends when calcium ions are passively transported back into the sarcoplasmic reticulum.
Cross bridge cycling ends when sufficient calcium has been actively transported back into the sarcoplasmic reticulum to allow calcium to unbind from troponin.
Cross bridge cycling ends when calcium release channels in the sarcoplasmic reticulum open.

Cross bridge cycling ends when sufficient calcium has been actively transported back into the sarcoplasmic reticulum to allow calcium to unbind from troponin.

Correct
Yes! The sarcoplasmic reticulum contains Ca2+-ATPases that actively transport Ca2+ into the SR. Without Ca2+, troponin returns to its resting shape, and tropomyosin glides over and covers the myosin binding sites on actin.

In a neuromuscular junction, synaptic vesicles in the motor neuron contain which neurotransmitter?

serotonin
acetylcholine (ACh)
norepinephrine
dopamine

acetylcholine (ACh)

Correct
Yes, acetylcholine is the neurotransmitter found in neuromuscular junctions

When an action potential arrives at the axon terminal of a motor neuron, which ion channels open?

voltage-gated potassium channels
voltage-gated sodium channels
chemically gated calcium channels
voltage-gated calcium channels

voltage-gated calcium channels

Correct
Yes, the action potential opens voltage-gated calcium channels and calcium rushes into the axon terminal, leading to the release of the neurotransmitter.

What means of membrane transport is used to release the neurotransmitter into the synaptic cleft?

exocytosis
a protein carrier
a channel

exocytosis

Correct
Yes, the synaptic vesicles (where the neurotransmitter is stored) merge with the membrane and release the neurotransmitter by exocytosis.

The binding of the neurotransmitter to receptors on the motor end plate causes which of the following to occur?

Binding causes chemically gated potassium channels to open in the motor end plate.
Binding of the neurotransmitter causes chemically gated sodium channels to open in the motor end plate.
Binding causes voltage-gated sodium channels to open in the motor endplate.
Binding causes potassium voltage-gated channels to open in the motor endplate.

Binding of the neurotransmitter causes chemically gated sodium channels to open in the motor end plate.

Correct
Yes, sodium enters the cell and causes depolarization. A small amount of potassium also leaves the motor end plate.

How is acetylcholine (ACh) removed from the synaptic cleft?

a reuptake pump on the axon terminal
acetylcholinesterase (AChE; an enzyme)
diffusion away from the synaptic cleft

acetylcholinesterase (AChE; an enzyme)

Correct
Yes, this enzyme is present in the synaptic cleft and breaks down acetylcholine.

The action potential on the muscle cell leads to contraction due to the release of calcium ions. Where are calcium ions stored in the muscle cell?

terminal cisternae of the sarcoplasmic reticulum
T tubule
sarcolemma
cytosol

terminal cisternae of the sarcoplasmic reticulum

Correct
Yes, calcium is stored in the terminal cisternae of the sarcoplasmic reticulum until it is released by an action potential.

The epimysium continuous with the tendon that connects the muscle to a bone?

True or false?

True

Correct
The dense connective tissue of the epimysium is continuous with the tendon that connects the muscle to a bone.

Actin is the chief component of the thin myofilaments.

True or false?

Correct
Actin is the chief component of the thin myofilaments.`

Calcium Ions bind to troponin to expose the actin for the cross bridge cycle.

True or false?

True.

Correct
Binding of calcium by troponin (B) removes the blocking action of tropomyosin along the thin myofilament. This allows myosin to bind to actin and form the cross bridge illustrated in this figure.

The smallest contractile unit of a muscle fiber is ________.

troponin
the sarcomere
the elastic filament
the myofilament

the sarcomere

Correct
The sarcomere is the smallest contractile unit of a muscle fiber, and the smallest functional unit of muscle. A sarcomere is the region of a myofibril between two successive Z discs; it primarily consists of thin and thick myofilaments.

The distance between Z discs ________ during muscle contraction.

decreases
increases
decreases and then increases
stays the same

decreases

Correct
During muscle contraction, the distance between Z discs decreases as the thin myofilaments slide across thick myofilaments, toward the M line in the center of each sarcomere. As the sarcomeres shorten, the myofibrils and, thus the myofibers shorten (contract).

The sliding filament model of contraction states that ________.

during contraction the thin myofilaments slide past T tubules so that the Z discs are overlapping
during contraction the thin myofilaments slide past the thick myofilaments so that calcium ions can be released from the sarcoplasmic reticulum
during contraction the thin myofilaments slide past the thick myofilaments so that the actin and myosin myofilaments no longer overlap
during contraction the thin myofilaments slide past the thick myofilaments so that the actin and myosin myofilaments overlap to a greater degree

during contraction the thin myofilaments slide past the thick myofilaments so that the actin and myosin myofilaments overlap to a greater degree


Correct
The sliding filament model of contraction states that during contraction, the thin myofilaments slide past the thick myofilaments so that actin and myosin myofilaments overlap to a greater degree. In a relaxed muscle fiber, the thick and thin myofilaments overlap only at the ends of the A band.

Which organelle contains the contractile elements found in skeletal muscle?

myofibril
sarcoplasmic reticulum
sarcolemma
glycosome

myofibril

Correct
The myofibrils contain the contractile elements of skeletal muscles, the sarcomeres. The sarcomeres contain even smaller rod-like structures called myofilaments.

The type of muscle found in the walls of most hollow organs is ________.

unitary smooth muscle
cardiac muscle
skeletal muscle
multi unit smooth muscle

unitary smooth muscle

Correct
Smooth muscle is generally classified as being either unitary smooth muscle or multi unit smooth muscle. The type of muscle found in the walls of most hollow organs is unitary smooth muscle.

Rigor mortis occurs because ________.

sodium ions leak into the muscle causing continued contractions
the cells are dead
proteins are beginning to break down, thus preventing a flow of calcium ions
no ATP is available to release attached actin and myosin molecules

no ATP is available to release attached actin and myosin molecules

What is the functional unit of a skeletal muscle called?

the sarcoplasmic reticulum
a myofibril
a sarcomere
a myofilament

a sarcomere

Which of the following is the correct sequence of events for muscle contractions?

muscle cell action potential, neurotransmitter release, ATP-driven power stroke, calcium ion release from SR, sliding of myofilaments
neurotransmitter release, muscle cell action potential, motor neuron action potential, release of calcium ions from SR, sliding of myofilaments, ATP-driven power stroke
motor neuron action potential, neurotransmitter release, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke, sliding of myofilaments
neurotransmitter release, motor neuron action potential, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke

motor neuron action potential, neurotransmitter release, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke, sliding of myofilaments

Which of the following is NOT one of the basic functions of the nervous system?

control the activity of muscles and glands
integration of sensory input
regulation of neurogenesis
monitor changes occurring both inside and outside the body

regulation of neurogenesis

Correct
Most active during pre-natal development, neurogenesis (formation of neurons) is the process by which neurons are generated from neural stem cells. It is not one of the basic functions of the nervous system.

Which of the following allows us to consciously control our skeletal muscles?

the parasympathetic division of the autonomic nervous system
the sympathetic division of the autonomic nervous system
the somatic nervous system
the afferent division of the nervous system

the somatic nervous system

Correct
The somatic nervous system is composed of somatic motor nerve fibers that conduct impulses from the central nervous system to skeletal muscles. It is often referred to as the voluntary nervous system because it allows us to consciously control our skeletal muscles.

What part of the nervous system performs information processing and integration?

sympathetic nervous system
central nervous system
parasympathetic nervous system
somatic nervous system

central nervous system

Correct
The central nervous system, which consists of the brain and spinal cord, is the integrating and control center of the nervous system. It interprets sensory input and dictates motor output based on reflexes, current conditions, and past experience.

What part of the neuron receives signals?

The dendrites and soma of the cell receive signals from other neurons.

Which area, on a neuron, would contain an abundance of vesicles containing neurotransmitter?

Correct
Neurotransmitters are stored in synaptic vesicles within axonal terminals for release into the synaptic cleft.

Which of the following peripheral nervous system (PNS) neuroglia form the myelin sheaths around larger nerve fibers in the PNS?

oligodendrocytes
Schwann cells
satellite cells
astrocytes

Schwann cells

Correct
Schwann cells (also called neurolemmocytes) surround all nerve fibers in the PNS and form myelin sheaths around the larger fibers. Myelin protects and electrically insulates nerve fibers, and it increases the transmission speed of nerve impulses.

Which of the following is the conducting region of the neuron?

dendrites
soma
terminal boutons
axon

axon

Correct
Functionally, the axon is the conducting region of the neuron. It generates nerve impulses and transmits them, typically away from the cell body, along the plasma membrane, or axolemma.

Which of the following is NOT a difference between graded potentials and action potentials?

Graded potentials can result from the opening of chemically gated channels; action potentials require the opening of voltage-gated channels.
Spatial summation is used to increase the amplitude of a graded potential; temporal summation is used to increase the amplitude of an action potential.
Greater stimulus intensity results in larger graded potentials, but not larger action potentials.
Graded potentials occur along dendrites, whereas action potentials occur along axons.

Graded potentials can result from the opening of chemically gated channels; action potentials require the opening of voltage-gated channels.
Spatial summation is used to increase the amplitude of a graded potential; temporal summation is used to increase the amplitude of an action potential.

Which of the following types of neurons carry impulses away from the central nervous system (CNS)?

afferent
association
motor
sensory

motor

Correct
Motor, or efferent, neurons carry impulses away from the CNS to the effector organs (muscles and glands) of the body periphery.

Ions are unequally distributed across the plasma membrane of all cells. This ion distribution creates an electrical potential difference across the membrane. What is the name given to this potential difference?

Threshold potential
Resting membrane potential (RMP)
Positive membrane potential
Action potential

Resting membrane potential (RMP)

Correct
Yes! The resting membrane potential is the baseline potential that can be recorded across the plasma membrane of an excitable cell prior to excitation.

Sodium and potassium ions can diffuse across the plasma membranes of all cells because of the presence of what type of channel?

Ligand-gated channels
Voltage-gated channels
Sodium-potassium ATPases
Leak channels

Leak channels


Yes. Leak channels for Na+ and K+ are ubiquitous, and they allow for the diffusion of these ions across plasma membranes.

On average, the resting membrane potential is -70 mV. What does the sign and magnitude of this value tell you?

The inside surface of the plasma membrane is much more negatively charged than the outside surface.
The inside surface of the plasma membrane is much more positively charged than the inside surface.
The outside surface of the plasma membrane is much more negatively charged than the inside surface.
There is no electrical potential difference between the inside and the outside surfaces of the plasma membrane.

The inside surface of the plasma membrane is much more negatively charged than the outside surface.

Correct
Yes! The inside surface of the plasma membrane accumulates more negative charge because of the presence of Na+ and K+ gradients and the selective permeability of the membrane to Na+ and K+.

The plasma membrane is much more permeable to K+ than to Na+. Why?

There are many more voltage-gated K+ channels than voltage-gated Na+ channels.
Ligand-gated cation channels favor a greater influx of Na+ than K+.
There are many more K+ leak channels than Na+ leak channels in the plasma membrane.
The Na+-K+ pumps transport more K+ into cells than Na+ out of cells.

There are many more K+ leak channels than Na+ leak channels in the plasma membrane.

Correct
Yes! More leak channels translates into more leakiness. Thus the outward flux of K+ is greater than the inward flux of Na+.

The resting membrane potential depends on two factors that influence the magnitude and direction of Na+ and K+ diffusion across the plasma membrane. Identify these two factors.

The presence of concentration gradients and voltage-gated channels
The presence of concentration gradients and Na+-K+ pumps
The presence of a resting membrane potential and leak channels
The presence of concentration gradients and leak channels

The presence of concentration gradients and leak channels

Correct
Yes! The concentration gradient and the large number of K+ leak channels allow for rather robust K+ diffusion out of a cell. In contrast, the concentration gradient and the relatively few Na+ leak channels allow for much less Na+ diffusion into a cell.

What prevents the Na+ and K+ gradients from dissipating?

Na+ cotransporter
Na+ and K+ leaks
Na+-K+ ATPase
H+-K+ ATPase

Na+-K+ ATPase

Correct
Yes! Also known as the Na+-K+ pump, or simply the pump, this transporter moves three Na+ out of the cell and two K+ into the cell for every ATP it hydrolyzes. This pumping action prevents the Na+ and K+ gradients from running down as these ions passively move through leak channels.

How is an action potential propagated along an axon?

Stimuli from the graded (local) potentials from the soma and dendrites depolarize the entire axon.
An influx of sodium ions from the current action potential depolarizes the adjacent area.
An efflux of potassium from the current action potential depolarizes the adjacent area.

An influx of sodium ions from the current action potential depolarizes the adjacent area.

Correct
Yes, the influx of sodium ions depolarizes adjacent areas, causing the membrane to reach threshold and cause an action potential. Thus, the action potential is regenerated at each new area.

Why does the action potential only move away from the cell body?

The areas that have had the action potential are refractory to a new action potential.
The flow of the sodium ions only goes in one direction—away from the cell body

The areas that have had the action potential are refractory to a new action potential.

Correct
Yes, sodium channels are inactivated in the area that just had the action potentia

The velocity of the action potential is fastest in which of the following axons?

a large unmyelinated axon
a small unmyelinated axon
a small myelinated axon

a small myelinated axon

Correct
Yes, the myelination acts as insulation and the action potential is generated only at the nodes of Ranvier. Propagation along myelinated axons is known as saltatory conduction.

The small space between the sending neuron and the receiving neuron is the

vesicle.
synaptic cleft.
synaptic terminal.
neurotransmitter.
calcium channel.

synaptic cleft.

Correct
The synaptic cleft is the small space between the sending neuron and the receiving neuron.

A molecule that carries information across a synaptic cleft is a

neurotransmitter.
synapse.
receiving neuron.
sending neuron.
synaptic cleft.

neurotransmitter.

Correct
Neurotransmitter molecules carry information across a synaptic cleft.

When calcium ions enter the synaptic terminal,

neurotransmitter molecules are quickly removed from the synaptic cleft.
they cause an action potential in the sending neuron.
the inside of the receiving neuron becomes more negative.
they cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron.
the inside of the receiving neuron becomes more positive.

they cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron.

When neurotransmitter molecules bind to receptors in the plasma membrane of the receiving neuron,

the receiving neuron becomes more negative inside.
the receiving neuron becomes more positive inside.
ion channels in the plasma membrane of the sending neuron open.
ion channels in the plasma membrane of the receiving neuron open.
vesicles in the synaptic terminal fuse to the plasma membrane of the sending neuron.

ion channels in the plasma membrane of the receiving neuron open.

If a signal from a sending neuron makes the receiving neuron more negative inside,

the sending neuron becomes more positive inside.
the receiving neuron is less likely to generate an action potential.
the receiving neuron immediately generates an action potential.
the sending neuron becomes more negative inside.
the receiving neuron is more likely to generate an action potential

the receiving neuron is less likely to generate an action potential.

Correct
If the receiving neuron is more negative inside, it is less likely to generate an action potential.

Unmyelinated fibers conduct impulses faster than myelinated fibers.

True
False

False.

Correct
Myelinated fibers (axons bearing a myelin sheath) conduct nerve impulses rapidly, whereas unmyelinated fibers conduct impulses more slowly. Note that myelin sheaths are associated only with axons; dendrites are always nonmyelinated.

What component of the reflex arc determines the response to a stimulus?

sensory neuron
effector
receptor
integration center

integration center

Correct
The integration center receives sensory information (input), determines the proper response, and then signals the appropriate effector(s) to produce the response.

Which of the choices below describes the ANS?

motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands
sensory neurons that convey information from somatic receptors in the head, body wall, and limbs and from receptors from the special senses of vision, hearing, taste, and smell to the CNS
motor fibers that conduct nerve impulses from the CNS to skeletal muscles
sensory and motor neurons that supply the digestive tract

motor fibers that conduct nerve impulses from the CNS to smooth muscle, cardiac muscle, and glands

The overlapping functions of the nervous system are sensory input, integration, and motor output.

True
False

True

The autonomic nervous system is under voluntary control; whereas, the somatic nervous system is involuntary.

True
False

False

The part of a neuron that conducts impulses away from its cell body is called a(n) ________.

Schwann cell
axon
dendrite
neurolemma

axon

Myelination of the nerve fibers in the central nervous system is the job of the oligodendrocyte.

True
False

True

If bacteria invaded the CNS tissue, microglia would migrate to the area to engulf and destroy them.

True
False

True

What does the central nervous system use to determine the strength of a stimulus?

origin of the stimulus
frequency of action potentials
type of stimulus receptor
size of action potentials

frequency of action potentials

Saltatory conduction is made possible by ________.

diphasic impulses
large nerve fibers
the myelin sheath
erratic transmission of nerve impulses

the myelin sheath

Which of the following is not true of graded potentials?

They increase amplitude as they move away from the stimulus point.
They can form on receptor endings.
They can be called postsynaptic potentials.
They are short-lived.

They increase amplitude as they move away from the stimulus point.

In myelinated axons the voltage-regulated sodium channels are concentrated at the nodes of Ranvier.

True
False

True

__________ forms a liquid cushion for CNS structures.

Cerebrospinal fluid
The dura mater
The pia mater
The blood-brain barrier

Cerebrospinal fluid


Correct
Cerebrospinal fluid (CSF), found in and around the brain and spinal cord, forms a liquid cushion that gives buoyancy to CNS structures. By floating the jellylike brain, the CSF effectively reduces brain weight by 97% and prevents the delicate brain from crushing under its own weight. CSF also protects the brain and spinal cord from blows and other trauma. Additionally, although the brain has a rich blood supply, CSF helps to nourish the brain, and there is some evidence that it carries chemical signals (such as hormones and sleep- and appetite-inducing molecules) from one part of the brain to another.

Nerves that only carry impulses away from the central nervous system (CNS) are called __________.

afferent nerves
sensory nerves
motor nerves
mixed nerves

motor nerves

Correct
Nerves that only carry impulses away from the CNS are motor (efferent) nerves.

__________ are collections of neuron cell bodies associated with nerves in the peripheral nervous system (PNS).

Nuclei
Myelin sheaths
Ganglia
Fascicles

Ganglia

Correct
Ganglia are collections of neuron cell bodies associated with nerve fibers in the PNS, whereas nuclei are collections of neuron cell bodies in the CNS.

Another name for sweat glands is

sudoriferous glands

The two types of sweat glands are

eccrine and apocrine

Modified sweat glands that produce ear wax are called

ceruminous glands

Modified sweat glands that produce milk are called

mammary glands

The scientific name for oil glands is__________ these glands secrete oils and ___________

sebaceous gland; cell fragments

Secretions of the oil glands are stimulated by:

hormones or androgens

Small muscles at the base of hair follicles that contract to form goose bumps are called:

arrector pili

The part of the hair that shows is the _______ and the part of the dermis is called the _______

shaft; root

There are 3 concentric layers of the hair they are called: ____, ____, ____

The medulla, the cortex and the cuticle

The cells responsible for producing the pigment that results in hair colour are called

melanocytes

The functions of nails include: protection and scratching or identification and diagnosis

protection and scratching

Sweat is normally acidic or basic

acidic

The sweat gland that cause the body odour are found in the aural and pedal or axillary and anogenial regions

axillary and anogenial regions

Nails are modified from the epidermis/dermis/hypodermis

epidermis

What is sweat composed of?

Water, metabolic wastes, dermicidin, vitamin C and antibodies.

What are the main functions of muscle?

1. Movement. i.e walking.
2. Posture i.e able to sit up straight
3. Stabilize joints i.e knees won't buckle when exposed to pressure.
4. Generate heat i.e shivering
5. Protect internal organs i.e rectus abdominus
6. Regulate digestive functions i.e digestion of food w. smooth muscle.

What are the functional characteristics of muscle?

1. Excitability i.e can react to a stimulus
2. Contractility i.e can shorten
3. Extensibility i.e can extend
4. Elasticity i.e similiar to C and Exten

What are the main function of skin?

1. Protection:
i. Physical:tight junctions "water proofing"
ii:Chemical: Acid mantle low pH of sking. Dermicidin. Melanin prevents UV damage. Defensins kill bacteria. Cathelcidins prevent A strepococcus.
iii. Biological: Dendritic-->antigens>lymphocytes. Dermal macrophages.
2. Body temp-Dialation and constriction of blood vessels.
3. Cutaneous sensation-sensory receptors.
4.Blood resovoir: 5% of blood held in skin.
5. Metabolic functions: VIT D SYNTYH 4 BONE FORMATION.
6. Excretion: nitrogenous wastes, salts and oils.

What are the main functions of bone?

1. Support: gives organs support.
2 Protection: cranium/spinal cord.
3. Locomotion: muscles use as levers.
4. Hematopoeisis: Blood cell formation.
5. Mineral storage: Calcium and phosphorus.
6. Triglyceride: fat storage (YBM)
7. Hormone production: Osteocalcin.

Three main functional classifications of joints?

1. Fibrous (skull)
i. sutures, syndesmosis, gomphosis.
2. Cartilaginous (vertebrae)
3. Synovial: (elbow)

Three functional classifications?

1. Synarthrosis: IMMOVABLE (skull suture)
2. Amphiarthrosis: SLIGHTLY MOVABLE (Pubic symphsis)
3. Diarthrosis: FREELY MOVABLE. (Hip)

Three things that affect joint stability?

1. Size of articular surface. (Hip joint)
2. Ligament (B 2 B)
3. Tendons surrounding (M 2 B)

Name the types of joints in the body.

1. Plane joint. (Gliding, Noniaxial) (intercarpal joint)
2. Hinge joint ( Flexion/extension. Uniaxial) (elbow joint)
3. Pivot joint (rotation, uniaxial) ) (proximal radioulnar joints)
4. Condylar joint (F&E, A&A, biaxial) (wrist joints)
5. Saddle joint ( F&E, A&A, biaxial) (carpometacarpal joint of thumb)
6. Ball and socket (ALL, Multiaxial) (shoulder)

Name the functional classification of muscles.

1. Prime movers: Main muscle used.
2. Synergists: Stabilize muscles for prime mover.
3. Antagonist: Capable of the opposite action.
4. Fixators: stabilize joints.

What are the characteristics for naming muscles?

1. Location (intercostals)
2. Shape (deltoid=triangle)
3. Relative size (gluteus maximus)
4. Direction of muscle fibers (rectus abdominis)
5. # of origins (biceps femoris)
6. # of attachments (sternocleidomastoid0
7. Function of muscle (extensor carpi radialis)

What are the patterns of fascicle arrangements and examples.

1. Circular: Arrangement in a circle (orbicularis oris)
2. Convergent: fascicles converge to one tendon (pectoralis major)
3. Parallel: fascicles run along the long axis of the muscle (sartorius)
4. Fusiform: fasicles run along the long axis but are thicker. (biceps brachii)
5. Pennate: 3 forms
i: Unipennate: fascicles run down one side of the tendon. (extensor digitorum longus)
ii: Bipennate: fascicles run down opposite sides of the tendon. (rectus femoris)
iii. Multipennate: fascicles run down all sides of the tendon. (deltoid)

Which of the following best defines anatomy?
It is the study of how the body parts work and carry out their life-sustaining activities.
It is the study of the structure of body parts and their relationships to one another.
It is the study of all chemical reactions that occur within body cells.
It is the study of tissues.

It is the study of the structure of body parts and their relationships to one another.

Correct
Anatomy is the study of the structure of body parts and their relationships to one another.

Which of the following is the simplest level of structural organization in the human body?
tissue
chemical
cellular
organismal

Chemical
Correct
The simplest level of the structural hierarchy is the chemical level; chemicals (molecules) can be combined to form the structures of a cell

The study of large body structures, visible to the naked eye, such as the heart is called ________ anatomy.
developmental
microscopic
systemic
gross

gross

Which organ systems function as control systems, communicating with other cells/organs to regulate their activities?
nervous and endocrine systems
cardiovascular and endocrine systems
cardiovascular and digestive systems
nervous and cardiovascular systems

nervous and endocrine systems

Correct
Communication within the body is essential for homeostasis. Communication is accomplished chiefly by the nervous and endocrine systems, the body's control systems.

Which level of structural organization is considered to be the highest level?
organismal
cellular
chemical
organ

organismal


Correct
The highest level of organization is the organism, the living human being, Thus, the organismal level represents the sum total of all structural levels working together to keep us alive

A structure that is composed of two or more tissue types that work together to perform specific functions for the body is a(n) ________.
complex cell
organ
organ system
complex tissue

organ

A tissue consists of groups of similar cells that have a common function.
True
False

True

Which of the following represents the correct order in which the components interact in a homeostatic control system?
the effector, the stimulus, and the receptor
the receptor, the control center, and the effector
the variable, the receptor, and the set point
the receptor, the stimulus, and the effector

the receptor, the control center, and the effector

Correct
Regardless of the factor or event being regulated-the variable-all homeostatic control mechanisms are processes involving at least three components that work together. The first component, the receptor, is a sensor that monitors the environment and responds to changes by signaling (providing input to) the control center. The control center compares the input to the set point, which is the level or range at which a variable is to be maintained, and signals the appropriate effector(s). The effector produces the effect (change) that counteracts the initial problem (stimulus).

Lungs carry out an excretory function.
True
False

True

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