Introduction Homeostasis

Question 1

homeostasis

Answer 1

process of maintaining a relatively constant/stable internal environment (set point) in spite of changing external environments

Question 2

set point

Answer 2

the level the body is trying to maintain

Question 3

external environment

Answer 3

outside the body

Question 4

internal environment

Answer 4

inside body, outside cells

ECF

Question 5

intracellular environment

Answer 5

inside cells, cytoplasm

ICF

Question 6

homeostasis is important for

Answer 6

cell function

Question 7

examples of homeostasis

Answer 7

BP
[Na]
[Glu]
[K]
pH
body h2o 
BT

Question 8

homeostatic processes restore — to the ECF following disturbance

Answer 8

balance

Question 9

dynamic constancy

Answer 9

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

Question 10

homeostasis is a — process

Answer 10

dynamic, not static 
steady state (requires energy input) vs equilibrium

Question 11

physiological variables can change dramatically over a 24 hour periods, but

Answer 11

the system is still in overall balance

Question 12

when homeostasis is maintained, we refer to —, when it is not, awe refer to —

Answer 12

physiology

pathophysiology

Question 13

levels of homeostasis (2)

Answer 13

cellular

extracellular

Question 14

cellular homeostasis (4)

Answer 14

functions of each cell
cytoplasm of single cell
necessary for normal cell function
relies on components of extracellular fluid

Question 15

extracellular fluid homeostasis (3)

Answer 15

environment outside of the cell
necessary for normal cell function
local vs systemic

Question 16

local (3)

Answer 16

restricted to one tissue space
utilizes paracrine and autocrines
maintain function of tissue

Question 17

systemic (3)

Answer 17

involves entire body
utilizes nervous system and endocrine system
maintain function of heart and brain

Question 18

endocrine system sequence (3)

Answer 18

hormone secreting gland cell
hormone in blood vessel
target cells in one or more distant places in the body

Question 19

nervous system sequence (4)

Answer 19

nerve cell
electrical signal
NT
neuron or effector cell in close proximity to site of NT release

Question 20

paracrine sequence (3)

Answer 20

local cell
paracrine substance
target cells in close proximity to site of release of paracrine substance

Question 21

autocrines sequence (3)

Answer 21

local cell
autocrine substance
autocrine substance acts on same cell that secreted the substance

Question 22

flowchart outlining systemic homeostatic process mediated by NS or ES

Answer 22

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

Question 23

stimulus (3)

Answer 23

 First Domino
 Changes in ECF Composition, Body Temperature, BP, etc.
 Changes in [substances]ECF
- Na+, K+, Ca++
- H+ (pH)
- Glucose, O2, CO2
- Endocrine (hormones) and neural (neurotransmitters)

Question 24

reflex receptor (3)

Answer 24

 Detects changes in [substance]ECF
 Threshold Stimulus (Sensitivity) - Determines
amplitude of normal range
 Can be Cluster of cells, individual cells, cell parts or
molecules in membrane or cytoplasm of cell

Question 25

normal range

Answer 25

as long as value is WNR it is considered a normal value

Question 26

afferent pathway (3)

Answer 26

 Carries information from Reflex Receptors to Integrating Center  NS Reflexes only  Sensory Neurons

Question 27

why is the afferent pathway NS reflexes only?

Answer 27

not ED bc the reflex receptor is in the integrating pathway (dont need it)

Question 28

Integrating Center (3)

Answer 28

 Receives stimulus, analyzes information and generates appropriate response  ES = Endocrine Gland  NS = Brain/Spinal Cord

Question 29

Efferent Pathway (3)

Answer 29

 Carries commands from integrating center to effectors  ES = Hormones (travel via blood)  NS = Motor neurons

Question 30

Effector

Answer 30

Any cell affected by Efferent Pathway (change in function)

Question 31

two levels of the effector response

Answer 31

local effector response | systemic effector response

Question 32

Local Effector Response

Answer 32

how cell (effector) function is changed by the Efferent Pathway

Question 33

Systemic Effector Response

Answer 33

how ECF (whole body) changed by local effector response

Question 34

Different Efferent Pathways can create the same systemic effector response while having

Answer 34

different local effector responses

Question 35

Feedback Regulation

Answer 35

How Systemic Effector Response changes the function of the Reflex Receptor

Question 36

types of feedback regulation (2)

Answer 36

negative | positive

Question 37

Negative Feedback

Answer 37

decreases activity shutting off pathway (homeostatic); values fluctuate around the set point

Question 38

Positive Feedback

Answer 38

increases activity further activating pathway (non-homeostatic)

Question 39

which feedback is more common?

Answer 39

negative