Student Introduction 1 Homeostasis

Question 1

what is the definition of homeostasis

Answer 1

process of maintaining a relatively constant/stable internal environment in spite of changing external environments

Question 2

define external environment

Answer 2

outside body

Question 3

define internal environment

Answer 3

inside body, outside cells, extracellular fluid

Question 4

define intracellular environment

Answer 4

inside cells, cytoplasm, intracellular fluid

Question 5

what is dynamic constancy

Answer 5

levels change over short periods of time but remain relatively constant over long periods of time

Question 6

what does cellular homeostasis rely on

Answer 6

components of extracellular fluid

Question 7

what are the two types of extracellular fluid

Answer 7

local and systemic

Question 8

what does local ECF utilize

Answer 8

paracrine and autocrines

Question 9

what does systemic ECF utilize

Answer 9

nervous system and endocrine system

Question 10

what is the function of local ECF

Answer 10

maintain function of tissue

Question 11

what is the function of systemic ECF

Answer 11

maintain function of heart and brain

Question 12

what happens in homeostasis if input is greater than output

Answer 12

shuttled to storage to maintain ECF pool

Question 13

what happens in homeostasis if output is greater than input

Answer 13

released from storage to maintain ECF pool

Question 14

explain the flowchart outlining a systemic homeostatic process mediated by NS

Answer 14

stimulus -> reflex receptor -> afferent pathway -> integrating center ->efferent pathway -> effector -> effector response -> feedback regulation -> stimulus

Question 15

explain the flowchart outlining a systemic homeostatic process mediated by the ES

Answer 15

stimulus -> reflex receptor -> integrating center -> efferent pathway -> effector -> effector response -> feedback regulation -> stimulus

Question 16

explain the flowchart outlining a systemic homeostatic process mediated by the ES

Answer 16

stimulus -> reflex receptor -> integrating center -> efferent pathway -> effector -> effector response -> feedback regulation -> stimulus

Question 17

why doesnt the ES have an afferent pathway

Answer 17

because the reflex receptor is located at the integrating center

Question 18

what does the reflex receptor do

Answer 18

detects changes in the concentration of substances in the ECF

Question 19

what is the threshold stimulus in the reflex receptor

Answer 19

minimum change required to activate reflex receptor

Question 20

what does the threshold stimulus determine

Answer 20

amplitude of normal range

Question 21

what is the reflex receptor made of

Answer 21

can be cluster of cells, individual cells, cell parts or molecules in membrane or cytoplasm of cell

Question 22

what is the setpoint defined as

Answer 22

mean of fluctuations

Question 23

what is the normal range a function of

Answer 23

sensitivity of the reflex receptor

Question 24

what does a narrow range of values tell you about the sensitivity

Answer 24

the sensitivity is high

Question 25

what does the afferent pathway do

Answer 25

carries information from reflex receptors to integrating center

Question 26

what are the types of neurons in the afferent pathway

Answer 26

sensory neurons

Question 27

what is the function of the integrating center

Answer 27

receives stimulus, analyzes information and generates appropriate response

Question 28

what is the integrating center in the endocrine system? nervous system?

Answer 28

endocrine system- endocrine gland
NS - brain and spinal cord

Question 29

what is the function of the efferent pathway

Answer 29

carries commands from the integrating center to effectors

Question 30

what carries the signals in the efferent pathway in the endocrine system? NS?

Answer 30

ES- hormones
NS- motor neurons

Question 31

what is the effector

Answer 31

any cells affected by the efferent pathway (change in function)

Question 32

what are the two levels of the effector response and what are they

Answer 32

1. local effector response- how the cell (effector) function is changed by the efferent pathway
2. systemic effector response- how ECF (whole body) changed by local effector response

Question 33

what is feedback regulation

Answer 33

how systemic effector response changes the function of the reflex receptor

Question 34

what are the types of feedback and what do they do

Answer 34

1. negative feedback- decreases activity shutting off pathway (homeostatic); values fluctuate around the set point
2. positive feedback- increases activity further activity pathway (non-homeostatic)

Question 35

what are the 2 principles of the homeostatic process

Answer 35

tonic level of activity and antagonistic control

Question 36

what is the tonic level of activity

Answer 36

at rest, a homeostatic pathway is neither completely shut off or fully active

Question 37

what is antagonistic control and give example

Answer 37

a single systemic effector response is controlled by two different efferent pathways but in opposite directions
ex: glucose is controlled by insulin and glucagon

Question 38

what is the function of the jaw unloading reflex

Answer 38

protective reflex that occurs when jaw is suddenly unloaded during mastication if something is hard that youre eating

Question 39

what is the mechanistic vs teleological explanation

Answer 39

mechanistic describes how something happens (physiology), teleological describes why something happens (lamens explanation)

Question 40

what is the difference between equilibrium and steady state

Answer 40

steady state requires energy input to maintain balance

Question 41

which type of feedback is considered homeostatic

Answer 41

negative feedback