Chapter 40: Animal anatomy and physiology Flashcards
physiology
biological function; how things work
surface area to volume ratio
constrains the size, exchange of resources, and energy; greater size=smaller SA:vol
increase in cell number implications
requires an increase in complexity
interstitial fluid
fluid around cells linked to exchange surfaces by other fluids
hierarchical organization of animal bodies
tissue, organs, organ systems
4 major tissue types
epithelial, connective, muscular, and nervous
epithelial tissue
closely packed cells lining surfaces; barrier against injury, infection, dehydration
cells forms of epithelial tissue
- simple squamous: thin and leaky; diffusion surfaces
- columnar: tight cell-cell junctions; line intestines
- stratified squamous: layers of cells; outer sloughed off as new cells arise; line abraded surfaces
- cuboidal: built for secretion; glands, kidneys
connective tissue
bind and support other tissues of the bond
composition of connective tissue fibers
proteins: collagen and/or elastin
major types of connective tissue
- loose connective tissue
- cartilage
- fibrous connective tissue
- adipose tissue
- blood
- bone
nervous tissue
convert external stimuli to electronic impulses, conduct impulses
neurons
have long extensions (axons) to action potentials
glia
associated cells that protect and nourish neurons
muscle tissue
contractile cells with actin and myosin filaments; most abundant, uses most energy
types of muscle tissue
- skeletal: voluntary movements; striated
- smooth: involuntary movements; non striated
- cardiac: involuntary heartbeats; striated
nervous system
sends point-to-point messages, short duration
endocrine system
broadcast message, tissues respond; longer duration
homeostasis
relatively constant internal environment
negative feedback loops
used to regulate; response attenuates stimulus (like thermostat)
set point
normal range; deviation leads to correction
sensor
senses stimulus and leads to a response
hypothalamus
body’s ‘thermostat’; leads to physiological changes
mechanisms for thermoregulation
radiation, conduction, convection, evaporation
insulation
fur, feathers, fat, etc.
circulatory adaptations for thermoregulation
vasodilation: increase blood flow, increase heat exchange
vasoconstriction: decreases blood flow, decrease heat exchange
concurrent exchange: reduce heat loss; cooled blood of extremities flows back past warm arteries
evaporative heat loss
heat carried away by water vapor
acclimization
changing anatomy/physiology to better suit environment (reversible), ie. added insulation in the winter
ectotherms
control body temperature behaviorally; non-bird reptiles and amphibians
endotherms
lose heat to their environment; warmer than the air
thermogenesis
make more heat thru muscle contraction (shivering)
bioenergetics
how animals allocate energy for different functions
heterotrophs
energy comes from food
metabolic rate
amount of energy used per unit time
basal metabolic rate
minimum metabolic rate
effect of size on metabolic rate
larger animals have more mass and use more energy, but small animals require more energy per mass than large animals
torpor
physiological state of very low metabolic rates
hibernation
long-term torpor during winter cold
estivation
summer torpor to survive high temps and low water
