Chapter 12: Animal Systems and Homeostasis Flashcards
homeostasis
the physiological condition in which the body maintains stable internal conditions
countercurrent exchange
the opposite flow of adjacent fluid that maximizes heat transfer, or transfer rates between fluids
set point
the optimal value of a physiological variable
positive feedback
a homeostatic response to a stimulus in which the effector exaggerates the stimulus
negative feedback
a homeostatic response to a stimulus in which the effector removes the stimulus
endotherms
organisms that use internal energy to maintain a constant body temperature (ex: mammals and birds)
ectotherms
organisms that use external energy or behavior to maintain body temperature (ex: reptiles or invertebrates)
histology
the microscopic structure of plant and animal tissues, and the branch of biology that studies this
matrix
an embedding material
collagen
common protein present in connective tissues
phagocytosis
the process in which a cell engulfs extracellular particles by surrounding them with extensions of the plasma membrane
lacuna
a gap or cavity
Haversian system
a unit of bone consisting of concentric layers of bone, a central Haversian canal with a blood vessel, and a system of microscopic interconnecting canals
sphincter
a circular muscle that surrounds an opening and regulates entry and exit
peristalsis
the rhythmic, involuntary contraction of the digestive tract
neuron
a cell type in nervous tissue that is specialized to initiate and transmit nerve impulses
neuroglia
a group of cells associated with neurons that perform various support functions (hint: “neuron glue”)
zymogen
inactive form of a digestive enzyme
villi
the finger-like projections lining the small intestine fundamental to absorption
lacteal
a small vessel of the lymphatic system that transports lymph
chylomicrons
small globules (formed in the epithelial cells of the small intestine) composed of fats mixed with cholesterol and coated with special proteins
enterogastrones
hormones secreted by the wall of the duodenum
egestion
getting rid of left over, undigested materials
excretion
getting rid of a metabolic product, such as CO2
mutualistic symbiont
the smaller participant in a relationship that benefits both organisms
cnidaria
a phylum of radially symmetrical organisms including the jellyfish, anemones, and corals
polychaetes
a member of a class of mostly marine worms (Polychaeta) in the phylum Annelida
negative pressure breathing
a ventilation system that works like a suction pump that pulls air into the lungs
diaphragm
the sheet of visceral muscle that separates the thoracic cavity from the abdominal cavity
myoglobin
an oxygen-storing protein similar to hemoglobin that is exclusively found in muscles
buffer
a substance that minimizes changes in pH by adding or removing H+ from the solution
EKG
output from a medical procedure which measures electrical impulses in the heart
endothelium
inner lining of tightly packed cell
sphygmomanometer
instrument used to measure blood pressure
collagen
the most abundant protein in the body. It forms strong fibers involved in the clotting process.
metabolism
the sum of all catabolic (breakdown) and anabolic (synthesis) reactions in the body
urea
nitrogenous waste that is metabolized by bacteria and forms ammonia
deamination
the removal of an amino group from a molecule
renal
of or pertaining to the kidneys
nephron
the functional unit of the kidney consisting of a long tubule and associated capillaries
interstitial fluid
the fluid filling the space between cells in vertebrate
pus
a fluid containing dead white blood cells
leukocyte
white blood cell
erythrocyte
red blood cell
antigen
any chemical that is foreign to an organism and that causes an immune response; an antibody generator
effector cells
lymphocytes that do not further differentiate
clonal selection theory
the scientific theory in immunology that explains the functions of cells (lymphocytes) of the immune system in response to specific antigens invading the body
CD4
a cell-surface protein found on helper T cells that enhances the interaction between an antigen presenting cell (macrophage) and the helper T cell
interleukin I
a protein secreted by antigen-presenting macrophages that activates the helper T
cytokines
proteins or peptides that stimulate other lymphocytes
vaccine
a harmless variant of a pathogen that stimulates an immune response against the actual pathogen
introns
non-coding sequences found within genes
mesentery
a large, tangled mass of blood vessels in the small intestine, which allow food to be absorbed into the bloodstream and feul the body
signal transduction pathways
mechanisms that link a chemical or mechanical stimulus to a cellular response
tropic hormones
hormones targeted towards other endocrine glands
menstrual cycle
a reproductive cycle in higher female primates characterized by the shedding of the nonpregnant endometrium
estrous cycle
a reproductive cycle characterized by the reabsorption of the nonpregnant endometrium
dendrites
fibrous extensions of a nerve cell that receive input
myelin sheath
formed from Schwann cells wrapped around an axon
reflex
inborn, automatic response
synapse
the space between the dendrite of one neuron and the axon of another neuron
voltage
a difference in potential
depolarization
an electrical state that takes place when the inside of a cell is made less negative relative to the outside than at the resting potential
voltage-gated ion channels
passageways made of protein that allow ions to enter and exit the cell under certain conditions
threshold potential
the membrane potential (voltage) at which the gates swing open
endorphin
neurotransmitter that acts as a natural painkiller
ganglion
an aggregation of nerves external to the brain or spinal cord
central nervous system (CNS)
a nervous system made up of a brain along with one or two longitudinal nerve cords
brain
a concentration of ganglia in one location of an animal’s body, usually the head
autonomic
describes a body function that occurs automatically
neuromuscular junctions
regions where neurons and muscles meet
T tubules
deep infoldings of the plasma membrane into the interior of a muscle cell
tropomyosin
a long protein that blocks myosin binding sites on the actin filament
rhodopsin
the most ubiquitous light-sensing protein in animals
statolith
“stationary stone”; a structure acquired from the environment (usually a grain of sand) that stimulates mechanoreceptors in the statocyst or other balance organ in some invertebrates
otoliths
“ear stones”; structures made of calcium carbonate in the vertebrate ear that aid in the detection of movement
cupula
a gelatinous organ that functions in maintaining balance
middle ear
the region of the ear between the tympanic membrane and the oval and round windows, containing the malleus, incus, and stapes, the bones that conduct and amplify sound vibrations
inner ear
the fluid-filled cochlea that conducts sound vibrations and contains the basilar membrane, the basis for pitch discrimination, and the organ of Corti that translate vibration into nerve impulses
organ of Corti
a structure in the inner ear containing hair cells that translate vibration into action potential in the auditory nerves
action potential
a rapid change in the membrane potential of an excitable cell
