mod 1 - intro to physiol. & homeostasis

Question 1

define physiology

Answer 1

study of the normal functioning of a living org. & its component parts (including all chem. & phys. processes)
- “knowledge of nature” - aristotle

Question 2

physiology is a __________ science
- elaborate

Answer 2

integrated science
- interdisciplinary

Question 3

define emergent properties

Answer 3

proprieties that exist within complex systems that can’t be explained by knowing each system independently
- e.g.: emotions, intelligence, memory etc

Question 4

levels of organizations
- smallest to largest

Answer 4

1. molecules
2. cells
3. tissue
4. organ
5. organ system

Question 5

how many types of specialized cells & what are they?

Answer 5

4 types
- epithelial cells
- connective tissue cells
- neurons
- muscle cells

Question 6

define tissue

Answer 6

collection of cells carrying out related functions
- groups of cells

Question 7

define organ

Answer 7

formation of tissues into a structural & functional unit

Question 8

how many types of tissue make up an organ?

Answer 8

2+ types of tissue

Question 9

define organ system

Answer 9

integrated groups of organs
- made up of multiple types of organs

Question 10

function is a ________ approach

Answer 10

teleological approach (the “why”)
- looking @ the end goal

Question 11

mechanism is a __________ approach

Answer 11

mechanistic approach (the “how”)
- break down process to the basics

Question 12

physiology focuses on a _________ approach

Answer 12

mechanistic approach (the “how”)

Question 13

define homeostasis

Answer 13

ability to maintain a relatively stable internal environment in spite of exposure to external variability

Question 14

___________ & _____________ are key principles in physiology

Answer 14

homeostasis & regulation of the internal environment

Question 15

who coined the term homeostasis?

Answer 15

walter cannon (1929)

Question 16

t/f: homeostasis is a static state

Answer 16

f: it’s dynamic (variable change)
- ex: blood pressure, body temp, ion/molecule concentration etc

Question 17

disease typically enters when:

Answer 17

homeostasis is disrupted & the body’s homeostasis mechanisms can’t bring the values back to normal
- body enters a “diseased state”

Question 18

external changes that can lead to a pathophysiological state

Answer 18

• toxic chemicals
• physical trauma
• foreign invaders (bact. or viruses)

Question 19

internal changes that can lead to a pathophysiological state

Answer 19

• abnormal cell growth
• autoimmune disorders
• genetic disorders

Question 20

define pathophysiological state

Answer 20

abnormal physiological state
- body is unable to maintain homeostasis

Question 21

what is considered the internal environment?

Answer 21

extracellular fluid (ECF) around cells
- buffer between cells & ext. environ.

Question 22

internal environ. of the body is a ______________

Answer 22

dynamic steady state
- material constantly moving back & forth, between ext. environ., ECF & ICF

Question 23

define law of mass balance

Answer 23

the amount of a substance in the body is to remain constant - any gain must be offset by an equal loss

Question 24

equation for law of mass balance

Answer 24

mass balance = existing body load + intake/metabolic prod. - excretion/metabolic removal

Question 25

T/F: ECF is relatively easy to monitor

Answer 25

T: ex. - Plasma

Question 26

the goal of a dynamic steady state is a _______

Answer 26

stable disequilibrium - main the DSS of the body’s compartments

Question 27

how do we maintain homeostasis in the body?

Answer 27

control systems

Question 28

define control systems

Answer 28

the mechanisms that exist within the human body to maintain homeostasis

Question 29

define dynamic steady state

Answer 29

the internal environ. is in a relatively steady state but is dynamic in that materials are constantly moving back & forth between the extracellular & intracellular fluid

Question 30

regulated variables are kept within _________ by _____________

Answer 30

regulated variables are kept within a NORMAL RANGE by CONTROL MECHANISMS

Question 31

how many types of control systems are there

Answer 31

2 types - 1. Local - 2. Reflex

Question 32

4 general parts of a control system (in order)

Answer 32

1. Input signal 2. Integrating center 3. Output signal 4. Response

Question 33

define input signal

Answer 33

sense change in a variable from homeostatic state

Question 34

integrating center step

Answer 34

signal input change goes to integrating center (takes in/registers change)

Question 35

output signal step

Answer 35

integrating center creates an output signal/response

Question 36

response step

Answer 36

response created by the output signal, tries to return to the variable to a normal homeostatic state

Question 37

define local control system (& example)

Answer 37

within a small area of body - restricted to tissues or cells involved - ex: reduced O2 lvls in tissue

Question 38

reflex control system uses ___________

Answer 38

long distance signalling - any long distance pathway that uses the NERVOUS & ENDOCRINE system or both

Question 39

reflex control system can be broken into ____ parts

Answer 39

2 parts - 1. Response loop - 2. Feedback loop

Question 40

Reflex control system pathway (in order)

Answer 40

1. Stimulus 2. **Sensor** 3. Input signal 4. Integrating center 5. Output signal 6. **Target** 7. Response

Question 41

feedback loop function

Answer 41

modulated response loop - feeds back to ultimately influence the input

Question 42

how many types of reflex control systems

Answer 42

3 types - 1. Negative feedback - 2. Positive feedback - 3. Feedforward control

Question 43

reflex control can be _______

Answer 43

antagonistic - controlled in both directions (ex: body’s dual control of heart rate)

Question 44

define set point

Answer 44

ideal value/range of variables for a physiological parameter

Question 45

define negative feedback

Answer 45

pathway that opposes/removes the signal (stimulus) - shuts off response loop

Question 46

negative feedback loop function & example

Answer 46

stabilize a system - HOMEOSTATIC (acts to stabilize a system) - can restore initial state - CANNOT PREVENT INITIAL DISTURBANCE - ex: rising blood glucose lvl

Question 47

define positive feedback loop

Answer 47

reinforcer a stimulus to drive the system away from a normal value rather decreasing or removing it

Question 48

positive feedback loop function & example

Answer 48

NOT homeostatic - needs intervention (event outside loop) to cease the response loop - ex: blood clotting, delivering a baby

Question 49

define feedforward control & example

Answer 49

reflexes that allow the body to predict a change is about to occur - ex: saliva reflex (thought/anticipation of food causes salivation)

Question 50

T/F: setpoints vary from person to person

Answer 50

T: setpoint vary from person to person due to genetics, or constant exposure to a new condition

Question 51

define biorhythms & example

Answer 51

variables that change predictably & create retreating patterns/cycles of changes - predictable cyclical changes - ex: circadian rhythm

Question 52

what is considered the “internal environ.” of the body?

Answer 52

extracellular fluid (ECF) - acts as buffer & bathes all cells in body

Question 53

T/F: homeostasis is ONLY maintained in the body using reflex control systems?

Answer 53

F: Homeostasis is maintained by both local & reflex control systems

Question 54

a negative feedback loop will:

Answer 54

oppose/remove stimulus to return a variable to it’s normal value