Fundamentals of Biology II Chapter 32


Terms in this set (...)

biological form
biological function
cells organized into this
tissues organized into these functional units
organ systems
groups of organs that work together
digestive system components
mouth, pharynx, espohagus, stomach, intestines, liver, pancreas anus
digestive system function
food processing (ingestion, digestion, absorption, elimination)
circulatory system components
heart, blood vessels, blood
circulatory system functions
internal distribution of materials
respiratory system components
lungs, trachea, other breathing tubes
respiratory system functions
gas exchange (uptake of oxygen, disposal of carbon dioxide)
immune and lymphatic system components
bone marrow, lymph nodes, thymus, spleen, lymph vessels, white blood cells
immune and lymphatic system functions
body defense; fighting infections and cancer
excretory system components
kidneys, ureters, urinary bladder, urethra
excretory system functions
disposal of metabolic wastes; regulation of osmotic balance of blood
endocrine system components
pituitary, thyroid, pancreas, adrenal, other hormone secreting glands
endocrine system functions
coordination of body activities; digestion and metabolism
reproductive system components
ovaries or testes and associated organs
reproductive system functions
nervous system components
brain, spinal cord, nerves, sensory organs
nervous system functions
coordination of body activities; detection of stimuli and formulation of responses to them
integumentary systems components
skin and its derivatives (hair, claws, skin glands)
integumentary system functions
protection against mechanical injury, infection, dehydration; thermoregulation
skeletal system components
skeleton; bones, tendons, ligaments, cartilage
skeletal system functions
body support, protection of internal organs, movement
muscular system components
skeletal muscles
muscular system functions
locomotion and other movement
animal tissue types
epithelial, nervous, connective, muscle
epithelial tissue
covers outside of body and lines organs and cavities; barrier against mechanical injury, pathogens, fluid loss, active interfaces with environment
lines intestines; secretes digestive juices and absorbs nutrients
nervous tissue
receipt, processing, transmission of information
receives nerve impulses from other neurons via its cell body and dendrites; transmit impulses to neurons, muscles, other cells via axons
glial cells
nourish, insulate, replenish neurons and in some cases moderate neuron function
muscle tissue
skeletal, smooth, cardiac; contain actin and myosin for contraction
skeletal muscle
attached to bones by tendons, voluntary, striated
smooth muscle
spindle shaped cells, walls of many organs, involuntary
cardiac muscle
striated, forms contractile wall of heart
connective tissue
cinsists of cells scattered through an extracellular matrix, often consisting of a web of fibers embedded in a liquid, jellylike, or solid foundation
secrete fiber proteins
engulf foreign particles and cell debris
loos connective
holds skin and other organs in place
fibrous connective
found in tendons and ligaments
adipose tissue
stores fat
consists of cells and cell fragments suspended in plasma
provides flexible support in the spine and elsewhere
hard mineral of calcium, magnesium, and phosphate ions in a matrix of collagen
uses internal mechanisms to control internal change in the face of external fluctuation; otters
allows internal condition to change in accordance with external changes; bass
interstitial fluid
fluid that surrounds body cells
steady state
set point
maintaining a variable, such as body temperature or solute concentration, at or near a particular value
human homeostasis
body temperature of 37 degrees C, blood pH within 0.1 unit of 7.4, blood glucose concentration 70-110 mg per 100 mL of blood
fluctuations in the variable above or below the set point
control center generates output that triggers this after receiving a signal from the sensor; helps return variable to set point
negative feedback
control mechanism that reduces the stimulus
process by which animals maintain an internal temperature within a normal range
warmed mostly by heat generated by metabolism; humans, mammals, birds
gain most of their heat from external sources; amphibians, many fish, nonavian reptiles, most invertebrates
widening of superficial blood vessels
reduces blood flow and heat transfer by decreasing the diameter of superficial vessels
countercurrent exchange
transfer of heat or solutes between fluids that are flowing in opposite directions
sensors for thermoregulation here; group of nerve cells functions as a themrostat; releasing and inhibiting hormones; regulates anterior pituitary
elevated body temperature in response to a bacterial or viral infection
endocrine system
signaling molecules released into the bloodstream by endocrine cells are carried to all location in the body
nervous system
neurons transmit signals along dedicated routes connecting specific locations in the body
signaling molecules broadcast throughout the body by the endocrine system
a gland located behind the stomach; insulin and glucagon
first part of small intestine
pituitary gland
at the base of the hypothalamus
anterior pituitary
hormonal signals from the hypothalamus trigger the synthesis and release of hormones from here; these hormones regulate other endocrine glands
posterior pituitary
oxytocin, ADH
pineal gland
thyroid gland
thyroid hormone T3 and T4, calcitonin
thyroid hormone
stimulates and maintains metabolic processes
lowers blood calcium level
parathyroid glands
raises blood calcium level
estrogen, progestins
stimulate uterine libing growth, promote development and maintenance of female secondary sex characteristics
promote uterine lining growth
support sperm formation, promote development and maintenance of male secondary sex characteristics
stimulates contraction of uterus and mammary gland cells
promotes retention of water by kidneys; influences social behavior and bonding
adrenal medulla
epinephrine and norepinephrine
epinephrine and norepinephrine
raise blood glucose level, increase metabolic activities, constrict certain blood vessels
adrenal cortex
glucocortioids, mineralocorticoids
raise blood glucose level
promote reabsorption of Na+ and excretion of K+ in kidneys
lowers blood glucose level
raises blood glucose level
positive feedback
reinforces a stimulus, leading to an even greater response; circulating oxytocin, stimulating contractions during birth
signal transduction
series of changes in cellular proteins that converts the extracellular signal to a specific intracellular response
homeostasis is the
maintenance of a relatively constant and optimal internal environment
Negative feedback is a method of homeostatic control that _____.
ensures that conditions in an organism do not vary too much above or below their set points
Which of the following primarily involves heat transfer by convection?

As you lie on the sand, you can feel the sun's warm rays on your skin.
After sunset, you can feel heat from the warm pavement.
The water in the lake is so cold that your legs become numb.
You roll down the car window to allow the cool breeze to blow through.
You sweat profusely as you mow the lawn on a hot summer day.
You roll down the car window to allow the cool breeze to blow through.
A countercurrent heat exchanger enables an animal to _____.
reduce the loss of body heat to the environment
Receptors for nonsteroid hormones are located in _____.
association with a cell's plasma membrane
which of these is a nonsteroid hormone?

both estrogen and testosterone
epinephrine and oxytocin
epinephrine and oxytocin
How do nonsteroid hormones differ from steroid hormones?
nonsteroid hormones act via signal transduction pathways; steroid hormones do not act via signal transduction pathways
Which of these extracellular signal molecules could diffuse through a plasma membrane and bind to an intracellular receptor?

The primary reason steroid hormones usually act slowly is that _____.
they turn genes on or off and it takes time for gene products to build up or become depleted
Steroid hormone-receptor complexes act in _____.
The hormone epinephrine causes opposite effects in two populations of target cells because _____.
each set of target cells has different receptor-transduction mechanisms
In their mechanism of action, a difference between lipid-soluble and water-soluble hormones is that _____.
lipid-soluble hormones bind to an intracellular receptor and this hormone-receptor complex binds to DNA
Oxytocin secretion and milk release from the mammary glands of lactating female mammals are initiated by _____.
the physical sensation of the baby sucking at the nipple
hormones are
chemical signals between cells, transported in blood or hemolymph
Which of the following would increase the rate of heat exchange between an animal and its environment?

feathers or fur
blubber or fat layer
wind blowing across the body surface
countercurrent heat exchanger
wind blowing across the body surface
Homeostasis typically relies on negative feedback because positive feedback
drives processes to completion rather than to a balance point
In a physiological system operating with positive feedback, _____.
a change in a variable will amplify rather than reverse the change
An animal may be a regulator for one environmental variable...
...but a conformer for another
Why are marine fish essentially living in a desert, from an osmotic standpoint?
Marine fish are losing water to the environment. They are surrounded by water, by after drinking the water, they have to excrete the salts.
Osmoregulatory mechanisms of freshwater fish include
salt uptake in gills and water excretion in urine.
What problem does a freshwater fish have to deal with?
Excess water constantly entering their body (via gills). They have to excrete the water.
Which of these is an osmoconformer?
Freshwater flatworms
Ray-finned fish
Order in water requirements from least to greatest

Uric Acid
Uric Acid < Urea < Ammonia
Order in energy requirements from least to greatest

Uric Acid
Ammonia < Urea < Uric Acid
A decrease in the volume of urine excreted would be expected following
an increase in aquaporin channels in collecting duct.
Name that tissue: Blood
Name that tissue: Hypothalamus
Which of the following is an example of a negative feedback response?

As the uterus contracts in labor and delivery, more oxytocin is released to intensify uterine contractions

Meerkats bask in the sun in the cool mornings but avoid the sun during the heat of the day

Sexual stimulation leads to sexual arousal

nursing baby stimulates the release of oxytocin, which causes letdown of milk
Meerkats bask in the sun in the cool mornings but avoid the sun during the heat of the day
Why use the endocrine system instead of the nervous system?
Endocrine: more gradual, systemic changes
Oxytocin, the milk-release hormone secreted from nerve endings (axon terminals) in the posterior pituitary gland, is synthesized in
Organ X produces hormone A, which stimulates target cells Y to produce product Z. Negative-feedback regulation is best represented by observing that
source X has receptor proteins for Z; Without receptors for Z, the source of A (organ X) would not have the idealized feedback mechanism.
How can a hormone effect cells differently?
Different receptors Different signal transduction pathways
Hormones are transported throughout the circulatory system, but they affect only specific tissues or cells because
only the target cells have receptors for the hormone.
homeostasis requires this; the process by which animals control solute concentration in the interstitial fluid and balance water gain and loss
process that rids the body of nitrogenous metabolites and other metabolic waste products
osmotic pressure; total solute concentration expressed a osmolarity, that is, moles of solute per liter of solution
to be isoosmotic with its surroundings; all are marine animals; way to maintain water balance
way to maintain water balance; control internal osmolarity independent of environment; enables animals to live in environments that are uninhabitable for osmoconformers, such as freshwater and terrestrial habitats
very toxic, in part because its ion interferes with oxidative phosphorylation; many species expend energy to convert it to a less toxic compound, either urea or uric acid, prior to excretion
transport epithelia
both osmoregulation and metabolic waste disposal rely on this; one or more layers of epithelial cells specialized for moving particular solutes in controlled amounts in specific directions; arranged in tubular networks with extensive surface areas; some face outside, while others line channels connected to outside by opening on body surface
in vertebrates, it is the product of a metabolic cycle that combines ammonia with carbon dioxide in the liver; very low toxicity
uric acid
insects, land snails, many reptiles, including birds, excrete this as primary nitorgenous waste; relatively nontoxic and does not readily dissolve in water; it can be excreted as a semisolid paste with very little water loss; more energetically expensive
hydrostatic pressure drives this; the excretory tubule collects a filtrate from the blood. water and solutes are forced by blood pressure across the selectively permeable membranes of a cluster of capillaries and into the excretory tubule
water and small solutes (salt, sugars, amino acids, nitrogenous wastes) cross the epithelial membrane and form this solution
recovers useful molecules and water from the filtrate and returns them to the body fluids; valuable solutes like glucose, certain salts, vitamins, hormones, and amino acids, are reabsorbed by active transport
non essential solutes and wastes are left in the filtrate or are added to it by this; occurs by active transport
functions in osmoregulation and excretion; consist of tubules; transport and store urine
urine produced by each kidney exits through this duct
urinary bladder
the 2 ureters drain into this common sac; during urination, urine is expelled from here
empties urine to the outside near the vagina or through the penis; sphincters near the junction regulate urination
renal cortex
outer part of the kidney; supplied with blood by a renal artery and drained by a renal vein; tightly packed excretory tubules and associated blood vessels lie in here
renal medulla
inner part of the kidney; supplied with blood by a renal artery and drained by a renal vein; tightly packed excretory tubules and associated blood vessels lie in here
renal pelvis
collects urine from the excretory tubules and passes it to the urinary bladder
weave back and forth across the renal medulla and cortex; functional units
cortical nephrons
reach only a short distance into the medulla; most of the nephrons are these
juxtamedullary nephrons
extend deep into the medulla; essential for production of urine that is hypeosmotic to body fluids
each nephron has a single long tubules and a ball of capillaries called this
Bowman's capsule
blind end of the tubule forms a cup-shaped swelling called this; surrounds the glomerulus; filtrate is formed when blood pressure forces fluid from the blood in the glomerulus into the lumen of this
proximal and distal tubule
2 of the 3 main regions of the nephron
loop of Henle
1 of the 3 main regions of the nephron; a hair pin turn with a descending limb and an ascending limb
collecting duct
receives processed filtrate from many nephrons and transports it to the renal pelvis
peritubular capillaries
branches of the efferent arteriole; surround the proximal and distal tubules
vasa recta
hair pin shaped capillaries that serve the renal medulla and surround the loop of Henle
flatworms have these excretory systems; form a network of dead end tubules; the tubules branch throughout the body, which lacks a coelom or open cavity; serve in osmoregulation
flame bulbs
cellular units in a faltworm; cap the branchesof each protonephridium; each has a tuft of cilia; during filtration, the beating of the cilia draws water and solutes from the interstitial fluid through the flame bulb, releasing filtrate into the tubule network
malpighian tubules
screte certain solutes and wastes into the lumen of the tubule; the filtrate passes through the digestive tract and water absorption by osmosis follows; in insects and terrestrial arthropods
afferent arteriole
each nephron is supplied with blood by this; an offshoot of the renal artery that branches and forms capillaries of the glomerulus
efferent arteriole
capillaries converge as they leave the glomerulus and form this