BIOL 373 midterm #1

Question 1

What is Physiology

Answer 1

The science of the function of living systems

Question 2

Function is

Answer 2

why, why does this system occur

Question 3

Process is

Answer 3

how, how does a system work

Question 4

Homeostasis

Answer 4

maintenance of a relatively stable internal environment, oscillation around a set point

Question 5

Walter cannon

Answer 5

flight or fight response, expanded on benards concept of homeostasis

Question 6

local versus reflex control

Answer 6

local: cells near site of change initiate response

reflex control: cells at a distant site control response, ex. blood pressure changes cells from other places can initiate reflex response, brain evaluates change and initiates response in reflex control

Question 7

response loop

Answer 7

afferent input, stimulus, sensor, output signal efferent, target, response

Question 8

feedback mechanisms

Answer 8

negative feedback- stabilizes variables, feedfoward control- anticipates control, positive feedback - reinforces stimulus

Question 9

electrical signals

Answer 9

restricted to nerve and muscle cells

Question 10

chemical signals

Answer 10

secreted into extracellular fluid, responsible for most communication

Question 11

cell to cell communication: long range endocrine

Answer 11

if cell has a receptor to that hormone then there will be a response

Question 12

cell to cell communication: neural

Answer 12

electrical signals travel down neuron, turn into chemical signal then transmit to next cell

Question 13

cell to cell communication: neuro endocrine

Answer 13

electrical signal travels down neuron, reaches end and is secreted into blood

Question 14

what is a target cell

Answer 14

only cells that have receptors for that signal will respond to it

water soluble- hydrophillic- lipophobic- suface receptor. need receptor to get in to pass membrane

water insoluble - hydrophobic - lipophillic- intracellular receptor can just go in

Question 15

signal pathways

Answer 15

-one ligand may have different types of receptors
-cells can change response to signals by changing receptor number or sensitivity
-receptors show saturation, competition, specificity

Question 16

epinephrine with alpha and beta receptors

Answer 16

alpha receptor and epinephrine vessel constrict
beta receptor and epinephrine vessel dilates

Question 17

agonist and antagonist

Answer 17

agonist will mimic
antagonist will block

Question 18

GPCR

Answer 18

are on when GTP and alpha is not attached to beta-gamma

are on when GDP and alpha is attached to beta gamma

alpha subunit can turn itself off by hydrolyzing GTP to GDP

Question 19

G protein lasts as long as…

Answer 19

as long as alpha and beta-gamma subunits are free and alpha subunit is bound to GTP