together with blood vessels, nerves, sensory organs, the skin & associated structures form this
epidermis, dermis & subcutaneous layer
the 3 layers of the skin
Outermost portion of skin, protection from wear and tear, injury, and harmful substances; composed mostly of stratified squamous epithelium, avascular, composed of stratum corneum & stratum basale
stratum basale, or stratum germinativum
the deepest layer of epidermis, closest to the dermis, constantly dividing & producing new epithelial cells, which are pushed upward toward skin surface
uppermost layer of epidermis or horny layer of the epidermis formed by the migrated, flattened cells of the basal layer.This layer consists of dead keratinized cells that are interwoven and closely packed. These cells are constantly being shed and are completely replaced with new cells from below; found on face, soles of the feet, & palms of the hands
fibrous protein that helps give the epidermis its protective properties
shedding of dead skin cells
a dark pigment that colors the skin & protects it from sunlight's harmful rays; it is produced by melanocytes in the deepest layer of the epidermis
skin, hair, middle coat of eyeball, iris of eye & in certain tumors
where is melanin found in the body?
irregular patches of melanin are called
The middle layer of the skin, has a framework of elastic connective tissue & well supplied with blood vessels and nerves, location for sebaceous (oil) glands, sweat glands, hair follicles & sensory receptors
Projections from dermis into epidermis. Increase surface area of the dermis and stratum germinativum. Form ridges in epidermis and form fingerprints and footprints
subcutaneous layer (hypodermis or superficial fascia)
underneath and supporting the dermis, this connects the skin to the underlying muscles, consists of loose connective tissue & large amounts of adipose (fat) tissue, helps to regulate body temperature.
sebaceous (oil) glands
saclike glands, ducts open into hair follicles and secrete sebum to keep hair and skin lubricated and provide protection against both bacteria and drying
sweat (sudoriferous) glands
coiled glands located in the dermis & subcutaneous tissue that vent directly to the skin surface or through hair follicles; release perspiration to cool body by evaporation, eliminate some soluble wastes
Most widely distributed sweat glands that regulate body temperature by releasing a watery secretion that evaporates from the surface of the skin
oily secretion, lubricates the skin & hair & prevents drying
babies are born with this covering (resembles cream cheese) produced by sebaceous glands "cheesy varnish"
modified sebaceous glands, are associated with the eye lashes & produce a secretion that lubricates the eyes
apocrine sweat glands
located mainly in the arm pits & groin area, these glands become active at puberty & release their secretions through hair follicles in response to emotional stress & sexual stimulation; body odor develops from the action of bacteria in breaking down these materials
ceruminous (or cerumen) glands
in the ear canal that produce ear wax
at the edge of eyelids
in the breasts
composed of keratin, develops in the follicle, grows from base of follicle
follicle, shaft, root & errector pili muscle
errector pili muscle
attached to most hair follicles is a thin band of involuntary muscle, when a person is frightened, or cold this muscle contracts, raising the hair & forming "goose bumps" on the skin "hair raiser"
palms of hands, soles of feet, lips, nipples & parts of external genitalia
the part of hair that projects above the skin
the portion below the skin
root, cuticle.lunula, nail plate & free edge
the structure of the nail in order, starting with proximal end
What is the name of the system that comprises the skin & all of its associated structures?
epidermis & dermis
Moving from the superficial to the deeper layer, what are the names of the 2 layers of skin?
loose connective tissue & adipose (fat) tissue
What is the composition of the subcutaneous layer?
the sebaceous glands
What is the name of the skin glands that produce an oily secretion (sebum)?
What is the scientific name for the sweat glands?
What is the name of the sheath in which a hair develops?
keratin & sebum
What 2 substances produced in the skin help to prevent dehydration?
dilation (widening) & constriction (narrowing) of blood vessels & evaporation of perspiration from the body surface
What 2 mechanisms involving the skin are used to regulate temperature?
functions of the integumentary system
protection against infection, protection against dehydration (drying), regulation of body temperature & collection of sensory information
this is the skin's main pigment, helps to protect against sunlight's damaging UV radiation
is a hereditary disorder that impairs melanin production, resulting in lack of pigment in skin, hair & eyes
is the pigment that carries oxygen in red blood cells, gives blood its color & is visible through vessels in the dermis
is paleness of the skin, often caused by reduced blood flow or reduction in hemoglobin, as occurs in cases of anemia
is diffuse redness caused by increased blood flow to the skin
the skin may take on a bluish discoloration when there is not enough oxygen in circulating blood
the presence of carotene, usually in excess amounts, in the blood; yellowish red skin discoloration caused by excessive intake of carrots & other orange vegetables
yellow discoloration of the skin, mucous membranes, and whites of the eyes, caused by excessive levels of bilirubin in the blood (hepatitis, immaturity of liver in newborn)
is any wound or local damage to tissue
a surface lesion
a raised lesion
redness of the skin
macule, papule, vesicle & pustule
the 4 surface lesions
flat (neither raised nor depressed) spot = freckle
small, elevated lump in the skin, as in some stages of chicken pox or 2nd stage of syphilis; pimple
A blister or small fluid filled sac as seen in some stages of chickenpox or shingles eruption
a blister (vesicle) filled with pus
excoriation, laceration, ulcer & fissure
the 4 deeper lesions of skin
a scratch into the skin
irregular wound caused by tearing of the skin
a sore associated with disintegration & death of tissue (it goes all the way through skin)
a crack in the skin
superficial, superficial partial thickness, deep partial thickness & full thickness
what are the 4 different ways that depths of tissue destruction are categorized?
superficial- 1st degree burn
involves the epidermis only, skin is red & dry; minimal pain
deep partial thickness- 2nd degree burn
involves the epidermis & dermis, the tissue may be blistered with weeping surface or dry because of sweat gland damage. These burns may be less painful because of nerve damage
full thickness- 3rd degree burn
involves the full skin & sometimes subcutaneous tissue & underlying tissues as well, tissue is broken, dry, pale or charred. These injuries may require skin grafting & loss of digits or limbs
the rule of nines
this method is used to estimate percentages of body surface area (BSA) in treatment of burns
depth of the burn & extent of body surface involved
What 2 factors are used to assess the severity of burns?
cells of the stratum corneum contain large amounts of a protein called
apocrine sweat glands
sweat glands located in the axillae & groin
the name of the muscle that raises the hair (goose bumps) is called
a dark-colored pigment that protects the skin from ultraviolet light is called
an indication of damage, a mark on the skin that is left after a cut or other wound has healed
a medical term that means "scar"
protection against infection, protection against dehydration, temperature regulation, and sensation.
what are the 4 most important functions of the skin?
melanin, hemoglobin & carotene
What are some pigments that impart color to the skin?
nutrition, blood supply, infection & age
4 factors that affect healing of skin
epithelial & connective tissue
What 2 categories of tissues repair themselves most easily?
a general term referring to any skin disease
inflammation of the skin
atopic dermatitis or eczema
intense itching & skin inflammation; is a chronic, inflammatory skin disorder with a genetic predisposition of asthma and hay fever, or allergies to irritants
a chronic, recurrent skin disease marked by silvery scales covering red patches, papules, and/or plaques on the skin that result from overproduction and thickening of skin cells; common sites of involvement are the elbows, knees, genitals, arms, legs, scalp, and nails
the most common form of cancer in the United States
is a malignant tumor of melanocytes, originates in a mole or birthmark anywhere on the body
skin condition that occurs most frequently during the teenage years at varying levels of severity. It is caused by obstruction of a hair follicle due to overgrowth of sebum and keratin debris, an overproduction of oil due to enlarged oil glands, and bacteria known as pimples- usually found on face, chest, and back
highly contagious skin infection caused by streptococci or staphylococci organisms; marked by pustules that rupture and become crusted--most often occurs around the mouth and nostrils; honey-crusted lesions
herpes simplex virus
causes the formation of watery vesicles (cold sores & fever blisters) on skin & mucous membranes; Two Types.-Type 1 causes lesions around the nose & mouth & Type 2 is responsible for genital infections, often reoccuring
disease caused by the same organism that causes chickenpox in children; infection follows nerve pathways, producing small, vesicular skin lesions along the course of nerve
a skin lesion caused by a virus of the human papillomavirus group; usually a raised bump
another name for wart, an epidermal tumor caused by human papilloma virus (genital warts)
a fungal infection of the skin, resembles a worm shape: ringworm of the body
fungal scalp infection
contagious skin disease caused by an itch mite burrowing under the skin
baldness, is an expression of heredity & aging; influenced by male sex hormones
A hypersensitivity to a substance that does not normally cause a reaction.
hives (wheals), is an allergic reaction characterized by temporary appearance of elevated red patches
reaction to one's own tissue
pemphigus, lupus erythematosus & scleroderma
What are the 3 autoimmune disorders that involve the skin?
An autoimmune disorder in which the immune system produces antibodies against specific proteins in the skin and mucous membrane. These antibodies produce a reaction that leads to a separation of skin cells; is fatal unless treated by methods to suppress the immune system
a chronic, inflammatory, autoimmune disease of connective tissue (skin or joints), "butterfly rash" across the nose & cheeks
a disease that involves overproduction of collagen with thickening & tightening of the skin; hardening of the skin
skin lesions that appear where the body rests on skin that covers bony projections
What is the name for a cancer of the skin's pigment producing cells?
the skeletal system
is made up of 206 bones, joints and supporting connective tissue; divided into 2 parts= axial & appendicular
ribs & skull (cranium)
where are flat bones found?
carpals of wrist, tarsals of ankle
where are short bones found?
arms & legs
where are long bones found?
the narrow shaft of a long bone
the central portion -marrow cavity; the open area within the center of diaphysis of long bone
this marrow is found at the ends of long bones & at the center of others, manufactures blood cells
this found chiefly in the central cavities of long bones; composed of mostly fat
The thick fibrous membrane covering the entire surface of a bone except its articular cartilage. It contains osteoblasts (bone-forming cells), osteoclasts (bone destroying cells), nerve fibers, and blood & lymphatic vessels. Ligaments & tendons attach to this
a thinner membrane that lines the bone's marrow cavity, contains cells that aid in the growth & repair of bone tissue
the specialized tissue forming the bones.
compact bone & spongy bone
2 types of bone tissue
is hard & dense; makes up the main shaft of a long bone & outer layer of other bones; located in rings of bone tissue called haversian canal (contains nerves & blood vessels)
the structure of a long bone
has a long, narrow shaft, the diaphysis & 2 irregular ends, the epiphyses, the medullary cavity has yellow bone marrow
spongy bone (cancellous)
it is made of a meshwork of small, bony plates filled with red marrow; it is found at the epiphyseal ends of long bones & center of other bones
the conversion of cartilage to bone
bone-building cells; immature cells, manufacture matrix which is material located between cells- matures into osteocytes
material located between the cells
a fibrous protein that gives the tissue strength & resilience
around the time of birth, secondary bone- forming centers develop across the ends of the long bones
developed from WBC, responsible for resorption or breakdown of bone tissue; necessary for bone remolding & repairs
mature bone cells, consists of collagen, maintain & repair the existing bone matrix
long bone formation
cartilage begins to turn into bone, epiphyseal plates develop across bone ends, bones continue to lengthen, bones stop lengthening, bone resorption & formation continues
head, process, condyle, crest & spine
What are the 5 different bone markings that are projections?
a rounded, knoblike end separated from the rest of the bone by a slender region, the neck
a large projection of a bone, such as the superior process of the ulna in the forearm that creates the elbow
a large, rounded articular process
a distinct border or narrow ridge, often rough, such as over the top of the hip bone
a sharp projection from the surface of a bone, such as a spine of the scapula (shoulder blade)
foramen, sinus, fossa & meatus
What are the 4 different bone markings that are depressions or holes?
a hole that allows a vessel or nerve to pass through or between bones
a cavity or hollow space, most commonly, an air-filled chamber found in some skull bones. These sinuses are named for the bones in which they are located
a depression on a bone surface
a short channel or passageway, usually the external opening of a canal. An example is the channel in the skull's temporal bone that leads to the inner ear
what are the centers for secondary growth of long bone called?
help to form joints, are points for muscle attachments & allow passage of nerves and blood vessels
What are some functions of bone markings?
axial skeleton & appendicular skeleton
How are the bones of skeleton divided?
axial skeleton (body's "axis")
consists of 80 bones- bony framework of the head & trunk
appendicular skeleton (body's "appendages")
consists of 126 bones & forms the framework for the extremities (limbs), shoulders & hips
single bone forming forehead, roof of eye socket, contains frontal sinuses
located in the frontal bone just above the eyebrows; an infection here can cause severe pain in this area,communicate with the nasal cavities,
Cavities within cranial and facial bones near the nasal cavity
paired bones forming most of the top & sides of cranium
paired bones forming part of side & base of skull; each bone has a bony prominence behind the ears that is called a mastoid process; each mastoid process contains mastoid sinus
of the temporal bone projects downward immediately behind the outer ear. It is a place for muscle attachments & contains air cells that make up the mastoid sinus
is a light, fragile, single bone located between eye orbits (E for eye) forming superior part of nasal septum, contains ethmoid sinus
single bone forming the skull base anterior to the temporal bones, contains sphenoid sinus, contains saddlelike depression called sella turcica which holds & protects the pituitary gland (superior view, resembles a bat with its wings extended)
single bone forming the posterior skull & base, contains foramen magnum for passage of spinal cord
located at the base of occipital bone, is a large opening through which the spinal cord communicates with the brain
flat, immovable joints which unite the skull bones: sagittal, coronal & lamboid
coronal suture, squamous suture, lambdoid suture & sagittal suture
What are the 4 most prominent cranial sutures?
coronal suture (C for crown)
suture joins the frontal bone with the 2 parietal bones along the coronal plane
squamous suture (S for side)
suture joins the temporal bone to the parietal bone on the cranium's lateral surface
lambdoid suture (L for lay back)
suture joins the occipital bone with the parietal bones in posterior cranium
suture joins the 2 parietal bones along the superior midline of cranium, along the sagittal plane
single bone forming the lower jaw, is the skull's only movable bone
paired bones fuse midline forming the upper jaw & anterior hard palate (roof of mouth), each bone contains a maxillary sinus, that communicates with the nasal cavity
paired bones forming the "cheek bones"
paired bones forming the bridge of the nose
paired bones, each about the size of a fingernail, form anterior medial wall of eye orbit
single bone, shaped like the blade of a plow, forms the inferior part of nasal septum
paired bones forming posterior hard palate
inferior nasal conchae
paired bones located along lateral walls of nasal cavities
bones of the middle ear that carry sound vibrations, composed of the malleus (hammer), incus (anvil), and stapes (stirrup). The stapes connects to the oval window, which transmits the sound vibrations to the cochlea of the inner ear.
the 1st bone in the middle ear, shaped like a hammer, the handle-like part of it is attached to the tympanic membrane, the headlike part is connected to the 2nd bone-the incus
the 2nd bone in middle ear, is shaped like an anvil (an iron block used in shaping metal)
the innermost bone in middle ear is shaped like the stirrup of a saddle, the base of this is in contact with inner ear
tongue is attached to this bone; U-shaped bone at the base of the tongue that supports the tongue muscles
anterior & posterior fontanels
bone formations are incomplete "soft spots" on the infant's skull, closes at about 18 months
drum shaped anterior portion serves as the weight-bearing part; disks of cartilage between vertebral bodies absorb shock & provide flexibility, linked together by ligaments
C1 to C7 are located in the neck
the 1st cervical vertebra, supports the head, nods the head, the skull rocks on this at the occipital bone
axis (C2) or dens
the 2nd cervical vertebra, projects into the atlas as a pivot point ; absence of vertebrae body allows for extra movement of head; only cervical vertebrae have a hole in transverse process on each side
only the cervical vertebrae have this hole on each side to accomodate blood vessels & nerves that supply the neck & head
thoracic vertebrae (T1 to T12)
located in the chest, they are larger and stronger than the cervical vertebrae and have longer spinous process that points downward; second set of 12 vertebrae; they articulate with the 12 pair of ribs to form the outward curve of the spine; posterior ends of 12 pairs are attached to thoracic vertebrae
lumbar vertebrae (L1- L5)
located in the small of the back
sacrum (sacral vertebrae)
it is formed by the fusion of 5 vertebrae (S1-S5), a triangler bone below the last lumbar vertebra; completes the bony part of bony pelvis
Coccyx or tail bone (coccygeal vertebrae)
formed by 4 fused vertebrae, is a small triangle-shaped bone that attaches to the bottom of the sacrum
the middle of the chest (connects the ribs), breastbone
12 pairs of ribs
the bones of the thorax form a cone shaped cage, these form the bars of this cage; these bones enclose & protect the heart, lungs & other organs in thorax
"handle", superior part of the sternum that joins laterally on the right & left with a clavicle (collarbone)
this is the slight elevation where the manubrium joins the body of the sternum; it can be easily felt as a surface landmark
this is used as a landmark for CPR to locate the region for chest compression, the inferior portion of the sternum
first 7 pairs of ribs, attach directly to sternum by costal cartilages
(8-12) 3 pair of ribs that do not attach to the sternum, they connect (costal cartilage) to the rib directly above them
2 pair of false ribs that do not attach to anything at their anterior ends
the spaces between the ribs
vertebral column & bones of the thorax (ribs & sternum)
What bones make up the skeleton of the trunk?
cervical vertebrae, thoracic vertebrae, lumbar vertebrae, sacrum & coccyx
What are the 5 regions of the vertebral column?
clavicle & scapula
the 2 bones of the shoulder girdle
another name for clavicle
another name for scapula
bone linking the scapula and sternum
either of two flat triangular bones one on each side of the shoulder= Shoulder blade
arm or upper limb
the upper extremity
the arm bone, bone extending from the shoulder to the elbow
ulna & radius
the 2 forearm bones
a process that forms the point of the elbow
palm of hand & knuckles
in anatomic position, this bone lies on the medial side of the forearm in line with the little finger (little bone W/ little finger)
in anatomic position, this bone lies laterally, above the thumb (fat bone w/ fat finger)
ilium, ischium & pubis
the 3 pelvic bones
forms the upper, flared portion of pelvic bone
is the curved rim along the ilium's superior border, it can be felt just below the waist
is the lowest & strongest part of pelvis
at the posterior of the pelvic outlet is used as a reference point during childbirth to indicate the progress of the presenting part down birth canal
helps support trunk weight when a person sits down
forms the anterior part of the os coxae
joint becomes more flexible late in pregnancy to allow for passage of baby's head during childbirth
socket for the femur, the deep socket that holds the head of the femur (thigh bone) to form the hip joint
the difference in female pelvis
is adapted for pregnancy & childbirth, lighter in weight, ilia are wider & flared, pubic arch is wider in female, pelvic opening is wider & more rounded, lower diameter, pelvic outlet is larger, sacrum & coccyx are shorter & less curved
"shin bone" stronger weight bearing bone (big bone- big toe side)
the lateral leg bone to tibia, does not reach knee joint (little bone- little toe side)
in step; ball of foot
disorder of bone formation, lack of ca++ salt deposits & decrease bone protein, increase breakdown bone tissue without increase in deposit of new bone by osteoblasts, bones become fragile & break easily, involves spine, pelvis & long bones- most postmenopausal female(decreased estrogen levels), Caucasian & Asian females
reduction in bone density to below average levels
bone tissue softens due to lack of calcium salt formation; causes- vitamin D deficiency, renal disorders, liver disease.
when osteomalacia occurs in children; is usually caused by a deficiency of vitamin D
another name for a tumor
osteosarcomas & chondrosarcomas
the 2 tumors of bone
most commonly occurs in a young person in a bone's growing region, especially around the knee
arises in cartilage & usually appears in midlife
is a inflammation of bone caused by pyogenic (pus producing) bacteria (strep, staph) enter blood stream because there is break in skin
infection may spread to bones, especially the long bones of the extremities & wrist & ankle bones
TB- tuberculosis of the spine; infected vertebrae are weakened & may collapse, causing pain, deformity, & pressure on spinal cord
kyphosis, lordosis & scoliosis
the 3 spinal curvatures
an exaggeration of the thoracic curve, "hunchback"
an excessive lumbar curve, "swayback" common in pregnant or overweight woman
a lateral curvature of the vertebrae column, most common type
a simple bone fracture with no open wound
a broken bone protrudes through the skin or an external wound leads to a broken bone
one side of the bone is broken & the other is bent
there is more than 1 fracture line & the bone is splintered or crushed
(articulation) is an area of junction or union between 2 or more bones
fibrous, cartilaginous & synovial joints
the 3 main joint types
the bones in this type of joint are held together by fibrous connective tissue- example is a suture between bones on skull= immovable
the bones in this joint are connected by cartilage- example the joints between the bodies of the vertebrae
the bones in this type of joint have a potential space between them called a joint cavity, which contains a small amount of synovial fluid, most of the body joint are this type
thick, colorless fluid, resembles uncooked egg white and is secreted by the membrane that lines the joint cavity.
immovable joint (fibrous- sutures)
slightly movable (cartilaginous- joints between vertebrae)
freely movable (synovial- gliding, hinge, pivot, condyloid, saddle& ball & socket joints)
bands of fibrous connective tissue, help stabilize & reinforce joints at various points
is a congenital deformity in which there is an opening in the roof of the mouth owing to faulty union of the maxillary bones
a common disorder in which the tendons & ligaments that support the foot's long arch are weakened, flattening its curve
flexion, extension, abduction, & adduction
4 kinds of angular movement
bending motion that decreases angles between bones, as in bending the fingers to close the hand
straightening motion that increase the angle between bones, as in straightening the fingers to open the hand
movement away from the midline of body, as in moving the arm straight out to the side
movement toward the midline of the body, as in bringing the arm back to its original position beside the body
turns palms up or forward, as if holding a "bowl of soup"
turn palms down
turns sole inward, so that it faces the opposite foot
turns the sole outward, away from body
foot is bent upward at the ankle, as walking on heels
the toes point downward, as on toes like a ballerina
gliding, hinge, pivot, condyloid, saddle & ball-&-socket joints
6 types of synovial joints
two relatively flat bone surfaces slide over each other with little change in joint angle; found in tarsals and carpals
allows forward or backward motion, the joint that moves like a door, found in legs, fingers and toes
one bone rotates in a ring of another, allows rotation only, joint between atlas and axis of cervical spine or proximal joint between the radius & ulna that allows rotation of forearm
oval-shaped projection of 1 bone fits into a oval-shaped depression on another bone, allows movement in 2 directions: flexion & extension / abduction & adduction (examples are joints between metacarpal bones & proximal phalanges of fingers)
one bone fits into a saddle-like depression on another bone, allows movement in 3 directions: flexion & extension, abduction & adduction, & rotation (examples are wrist & thumb)
a ball-like surface of 1 bone fits into deep cuplike depression in another bone. It allows the greatest range of motion in 3 directions, as in circumduction (examples are shoulder & hip joints)
is a derangement of joint parts: ball-and-socket has the greatest tendency to dislocate
is the wrenching of a joint with rupture or tearing of ligament; more severe than strains
an injury to muscle tissue resulting from overstretching.
the disks between the vertebrae of the spine consist of an outer ring of fibrocartilage & a central mass known as the nucleus pulposus; this central mass protrudes through a weakened outer cartilaginous ring into the spinal canal & puts pressure on spinal cord or nerves producing back spasms or pain along sciatic nerve that travels through the leg
inflammation of joints
aka DJD (degenerative joint disease) usually occurs in elderly people as a result of normal wear & tear; occurs mostly in joints in weight bearing hips, knees & spinal column
is a crippling condition characterized by joint swelling in hands & feet, articular cartilage is gradually destroyed & joint cavity develops adhesions; shares characteristics of autoimmune disorders where antibodies produced attack the body's own tissues
septic (infectious) arthritis
arises when bacteria spread to involve joint tissue, usually by way of the bloodstream (examples are invasive medical procedure, illegal drug use, injections) pathogens: staph, strep & neiserria
overproduction of uric acid (normally excreted in the urine) deposited as masses around the joints, the joints become inflamed & extremely painful; commonly affects big toe but can involve any joint, commonly seen in men past midlife
caused by herniated disks, kidney infections, strains on the lumbosacral joint, infections or tumors & elderly osteoarthritis
a type of lighted instrument known as an endoscope that a physician uses to examine injured joints & can also repair them surgically
a tapping procedure done to drain or remove fluid from a joint
the shaft of a long bone is called the:
osteon (or haversian system)
the structural unit of compact bone is the:
red bone marrow manufactures:
bones are covered by connective tissue membrane called:
bone matrix is produced by:
a rounded bony projection
a sharp bony prominence
a hole through bone
a bony depression
an air-filled bony cavity
smooth, cardiac & skeletal
the 3 types of muscles
wall of hollow organs, vessels, respiratory, passageways; tapered at each end, branching networks, nonstriated; involuntary control= produces peristalsis; contracts & relaxes slowly; may sustain contraction
wall of heart, branching networks; special membranes (intercalated disks) between cells; single nucleus; LIGHTLY STRIATED, involuntary control= pumps blood out of heart; self-excitatory but influenced by nervous system & hormones
attached to bones, long & cylindrical; multinucleated; HEAVILY STRIATED, voluntary control, produces movement at joints; stimulated by nervous system; contracts & relaxes rapidly
abdominal muscles are attached to other muscles & facial muscles are attached to the skin
what are the 2 exceptions in muscles being connected to bones?
what constitutes the largest amount of body's muscle tissue making up 40 % of total body weight?
movement, maintenance of posture & generation of heat
the 3 primary functions of muscular system
movement of skeleton
muscles attached to bones & contract to change postion of bones & joints
maintenance of posture
a steady partial contraction of muscle, known as muscle tone helps keep the body in position
generation of heat
muscles generate most of the heat needed to keep the body at 37 degrees celsius; heat is a natural by product of muscle cell metabolism; example- when we shiver (rapid small contraction) this causes the muscles to boost their heat output
fascicles, endomysium, perimysium,& epimysium= all of these form the tendon
are individual muscles arranged in bundles held together by fibrous connective tissue
deepest layer of this connective tissue surrounds the individual fibers in the fascicles
is a connective tissue layer around each fascicle
is a connective tissue shealth that encases the entire muscle, this forms the innermost layer of the deep fascia
the tough, fibrous sheath that encloses & defines a muscle
a band of connective tissue that attaches a muscle to a bone
nerve impulses coming from the brain & spinal cord stimulate skeletal muscle fibers (traveling away from the CNS)
traveling toward the CNS
a single neuron & all the muscle fibers it stimulates comprise
movements of eyes- tying shoe laces, holding a pencil
small motor units are used in fine motor coordination, give an example
maintaining posture, walking, or swinging tennis racquet
large motor units are used for what
neuromuscular junction (NMJ)
the point at which a nerve fiber contracts a muscle cell
a chemical released from the neuron to stimulate the muscle fiber
a neurotransmitter that, among its functions, triggers muscle contraction
a point of communication between a neuron & another cell
space between nerve cells where chemical transmitters act to move impulses from one neuron to the next.
motor end plate
the muscle cell's receiving membrane
the spreading wave of electric current; it calls the muscle cell into action
important property of muscle tissue; a muscle fiber's capacity to undergo shortening, become thicker
thin & light filaments of protein found in skeletal muscles
thick & dark filaments of protein found in skeletal muscles; these give skeletal muscle its striated appearance
a contracting subunit of skeletal muscle, it consists of a band myosin filaments & actin filaments on each side of them. the myosin molecules are shaped like 2 golf clubs twisted together with their paddle-like heads projecting away from the sarcomere's center,the actin molecules are twisted together like 2 strands of beads, each bead having a myosin binding site
myosin head connects thick filaments and thin filaments during a contraction
sliding filament mechanism
thin filaments slide over thick filaments simultaneously on each side of sarcomeres; shortens sarcomeres and muscle fibers, produces force that contracts the muscle
troponin & tropomyosin
Regulatory proteins that recognize calcium as the signal to allow actin and myosin to interact with each other.
the summary of events in a muscle contraction
1) ACh is released from a neuron ending into the synaptic cleft at the NJM.
2) ACh binds to the muscle's motor end plate & produces an action potential.
3) the action potential travels to the SR (sarcoplasmic reticulum).
4) the SR (sarcoplasmic reticulum) releases calcium into the cytoplasm.
5) calcium shifts troponin & tropomyosin so that binding sites on actin are exposed.
6) myosin heads bind to actin, forming cross-bridges.
7) using stored energy, myosin heads pull actin filaments together within the sarcomeres & the cell shortens.
8) new ATP is used to detach myosin heads & move them back to position for another "power stroke."
9) muscle relaxes when stimulation ends & the calcium is pumped back into the SR.
the neuromuscular junction (NMJ)
what is the name of the special synapse where a nerve cell makes contact with a muscle cell?
what neurotransmitter is involved in the stimulation of skeletal muscle cells?
excitability & contractility
what are the 2 properties of muscle cells that are needed for response to a stimulus?
actin & myosin
what filaments interact to produce muscle contraction?
what mineral is needed for interaction of the contractile filaments?
all muscle contraction requires energy in the form of ---, most of this energy is produced by the oxidation ("burning") of nutrients within the cell's mitochondria, especially the oxidation of glucose & fatty acids
a chemical reaction that involves the loss of an electron. Oxidation often involves the addition of oxygen and the loss of hydrogen ions.
metabolic process that does not require oxygen
Metabolic processe that require oxygen
stores additional oxygen, is similar to hemoglobin in blood, but is located specifically in muscle cells
the storage form of glucose, a polysaccharide made of multiple glucose molecules that can be broken into glucose when needed by muscle cells
fatty acids are stored as this, formed into fat droplets, these droplets can be broken down into fatty acids when needed by muscle cells
stores energy; similar to ATP in that it has a high energy bond that releases energy when it is broken; this energy is used to make ATP for muscle contraction when muscle cell has used up its ATP
Produced in muscles during rapid exercise when the body cannot supply enough oxygen to the tissues, causes muscle fatigue
muscles operating anaerobically are in a state of
the tone or tension within the muscle remains the same, but the muscle length changes & the muscle bulges as it accomplishes work
concentric & eccentric contractions
the 2 types of isotonic contractions
a muscle as a whole shortens to produce movement; picking up a book
the muscle lengthens as it exerts force; slowly lowering book
Muscle contraction which results in increased tension but the length does not alter, for example, when pressing against a stationary object.
what compound is formed in oxidation of nutrients that supplies the energy for contraction?
What acid accumulates during anaerobic metabolism?
isotonic & isometric
what are the 2 main types of muscle contraction?
the less movable attachment
the body part that the muscle puts into action
3rd class lever
of the 3 classes of levers, which 1 represents the action of most muscles?
any muscle that performs a given movement
the muscle that produces a movement opposite to that of the agonist "against" , a muscle that relaxes while another contracts
"helping" muscles, they work with the agonist to accomplish a movement "together"
Muscle that has the principal responsibility for a given movement
1st class, 2nd class & 3rd class
3 classes of levers
1st class lever
the fulcrum is located between the resistance & effort; a seesaw or scissors
2nd class lever
lever has the resistance located between the fulcrum & the effort; a wheelbarrow or a mattress lifted at 1 end
3rd class lever
the effort is between the resistance & fulcrum. a forceps or tweezers
3) applied by muscle
musculoskeletal system as a lever system
muscles of the head
orbicularis oculi, orbicularis oris, levator palpebra superioris, buccinator, temporalis & masseter
the muscles of facial expression include ring-shaped "orbit" around the eyes & lips
the muscles surrounding the eye; closes eye
encircles mouth; closes lips
levator palpebrae superioris
lifter of the eyelid; opens eye (is the anatagonist for the orbicularis oculi)
fleshy part of cheek; flattens cheek; helps in eating, whistling & blowing wind instruments
above & near ear; closes jaw
at the angle of jaw; closes jaw
muscles of the neck
sternocleidomastoid & trapezius
along lateral neck, to mastoid process; flexes head; rotates head toward opposite side from muscle
Stiff neck caused by spasmodic contraction of the muscles of the neck; wryneck
located at the posterior neck, where it helps to hold the head up
muscles of upper extremities
trapezius, latissimus dorsi, pectoralis major, serratus anterior, deltoid, biceps brachii, brachialis, bracioradialis & triceps brachii
posterior neck & upper back to clavicle & scapula; raises shoulder & pulls it back; superior portion extends & turns head
middle & lower back, to humerus; extends & adducts arm behind back
superior, anterior chest, to humerus; flexes & adducts arm
inferior to axilla on lateral chest, to scapula; moves shoulder forward; aids in raising arm, punching or reaching forward
covers shoulder joint, to lateral humerus; abducts arm; flexes & extends arm at shoulder
anterior arm along humerus, to radius; flexes forearm at elbow & supinates the forearm & hand
deep to biceps brachii, inserts at anterior elbow joint; forceful flexor of forearm
lateral forearm from distal end of humerus to distal end of radius; flexes forearm at elbow
posterior arm, to ulna; extends forearm to straighten upper extremity
muscles of respiration
diaphragm & intercostal muscles
the most important muscle involved in act of breathing; forms the partition between the thoracic cavity above & the abdominal cavity below.
are attached to & fill the spaces between the ribs; the external & internal intercostals run at angles in opposite directions, contraction of intercostal muscles elevates the ribs, thus enlarging the thoracic cavity from side to side & anterior to posterior
muscles of abdomen & pelvis
external oblique, internal oblique, transversus abdominis, rectus abdominis & levator ani
exterior abdominal wall muscles
in the middle
the innermost abdominal muscles
of anterior abdominal wall
pelvic floor; aids defecation
muscles of lower extremities
gluteus maximus, sartorious, quadriceps femoris, rectus femoris, vastus medialis, vastus lateralis, vastus intermedius, hamstring group & gastronemius
superficial buttock, to femur; extends thigh
crosses anterior thigh, from ilium to medial tibia; flexes thigh & leg (to sit crossed legged)
anterior thigh, to tibia; extends leg
part of quadriceps group, extends leg at knee
inner front thigh muscle; extends leg
lateral to rectus femoris, extends leg
vastus intermedius (deep)
part of quadriceps group,extends leg
Largest Muscles of the calf, posterior leg, to calcaneus; plantar flexes foot (ballerina)
the largest tendon in the body, attaches the gastrocnemius muscle to the heel bone
is a sudden & involuntary muscular contraction which is always painful
a spasm of the visceral muscles, severe abdominal pain
convulsion or seizure
if spasms occur in a series
strong, painful muscle contractions, especially of the leg & foot
to waste away from lack of use; wasting or decrease in the size of a muscle when it cannot be used
group of disorders in which there is deterioration of muscles that still have intact nerve function; causes weakness & paralysis
a chronic progressive disease characterized by chronic fatigue and muscular weakness (especially in the face and neck) drooping of the eyelids(ptosis) is a common early sign
muscle aches, tenderness, and stiffness along with fatigue and sleep disorders, difficult to diagnose and no cure
an inflammation of muscle tendons & their attachments
pain & soreness along the tibia "shin bone"
carpal tunnel syndrome
involves the tendons of the flexor muscles of the fingers as well as the nerve supplying the hand & fingers, numbness & weakness of the hand is caused by pressure on the medial nerve as it passes through a tunnel formed by the carpal bones of the wrist
individual muscle fibers are arranged in bundles called
the point at which a nerve fiber contacts a muscle cell is called:
a contraction in which there is no change in muscle length but there is a great increase in muscle tension
a term that means "muscular pain"
a disease characterized by chronic muscular fatigue due to defects in neuromuscular transmission
extends vertebrae column to produce erect posture
elevate ribs & enlarge thoracic cavity
aids in defecation