Chapter 1: Homeostasis Flashcards Preview

ONLINE PHYSIOLOGY > Chapter 1: Homeostasis > Flashcards

Flashcards in Chapter 1: Homeostasis Deck (51):
1

Physiology

the study of how the body functions. Many levels and integration (work together)

2

Pathophysiology

the physiologic basis of disease

3

Levels of organization

1) chemical
2) organelles
3) cells
4) tissues
5) organs
6) organ systems
7) organisms

4

Chemical level of organization

most simple level

5

Cells

basic structural and functional units of life (differentiate during development)
- 4 main types: muscle, nerve, connective tissue, and epithelial

6

Muscle cells

contract and generate movement

7

Nerve cells

initiate and conduct electrical signals

8

Connective Tissue Cells

connect, anchor, and support structures in the body

9

Epithelial Cells

- Selective, secretion, and absorption of ions and organic molecules and for protection.
- Cover and line the body's surface.
- Make glands and form absorptive cells in intestines and kidneys

10

Tissues

Groups of differentiated cells with similar properties
- 4 types: muscle (skeletal muscle/cardiac muscle/smooth muscle), nerve tissue, connective tissue, epithelial

11

Muscle Tissues

- contract and generate movement of certain muscles
- 3 types: skeletal, cardiac, smooth

12

Skeletal muscle tissue

movement of entire body

13

Cardiac muscle tissue

contraction of the heart

14

Smooth muscle tissue

movement of internal organs

15

Nerve tissue

makes up brain, spinal cord, and nerves

16

Connective tissue

bone, cartilage, and blood

17

Epithelial tissue

covers and lines body and lines organs and intestines

18

Organs

structures composed of 2+ tissues that perform a specific function and usually have a recognizable shape (i.e. heart, brain, lungs, liver, kidneys)

19

Functional Units of Organs

responsible for performing actual function of the organ (i.e. the nephron of a kidney)

20

Organ systems

collection of organs that work together to perform an overall function

21

Organism

most complex level of organization. Collection of organ systems that work together.

22

Internal environment

fluids that surround the cells and exist in blood

23

Fluid compartments

extracellular and intracellular

24

Extracellular fluid

- outside the cell
- plasma component: 20-25% fluid in blood vessel
- interstitial fluid: 75-80% directly surrounds cells

25

Intracellular fluid

fluid within cells

26

Compartmentilization

achieved via barriers (regulation of the movement of substances between compartments)
- capillary membrane only lets certain things through

27

Body water

- 55-60% body weight in males (less in females because more fat and fat has less water in it)
- 2/3 body water is intracellular, 1/3 extracellular

28

Homeostasis

- Maintenance of relatively stable internal environment
- physiology variables maintained in narrow range of 'normal' that fluctuates around a setpoint
- compensatory mechanisms restore conditions
- dynamic process. Detects and responds to deviations in physio variables

29

Negative feedback

- MOST COMMON
- response moves variable in opposite direction of original stimulus
- moves back toward normal setpoint

30

Positive feedback

- exacerbates effect of original stimuli
- accelerates a physiological pro
- pregnant lady increases uterine contractions

31

Feedforward Regulation

- produces responses that improve the speed of homeostatic responses and minimizes deviation of the regulated variable from the set point
- anticipates changes in regulated variables
- minimizes distance to setpoint

32

Resetting of set points

- not all set points are static
- some may change or be reset for health purposes (i.e. get fever to kill viruses)

33

Homeostatic control systems

- are reflexes

34

Reflex and reflex arcs

- reflex: specific involuntary responses to a particular stimulus
- reflex arc: pathway mediating the reflex with 3 components (receptor, integrating center, and effector)

35

Stimulus

change in environment

36

Receptor

detects change from stimuli
- very specific

37

integrating center

recieves input from receptor and determines the change need to be made to fix it.
- determines the response

38

Effector

produces the response that changes the variable (usually a muscle or gland)

39

Response

actual response/change that occurs

40

Organ system that controls homeostasis

- nervous and endocrine systems

41

Nervous system control of homeostasis

nerve reflexes

42

Endocrine system control of homeostasis

hormones that circulate through blood and stimulate specific target cells
(i.e. endocrine systems = integrating center and hormones = effectors)

43

Four chemical messengers that maintain homeostasis

hormones, neurotransmitters, paracrine substances, and autocrine substances

44

Hormones and Neurotransmitters

systemic levels

45

Paracrine substances

- locally
- paracrine released into the interstitial fluid by cells and effect nearby cells

46

Autocrine substances

affect the cells that release them

47

Three states of total-body balance

- negative balance
- positive balance
- stable balance

48

Negative balance

- loss exceeds gain (amount decreases overall)

49

Positive balance

- gain exceeds loss (amount increases overall)

50

Stable balance

- gain equals loss (amount stays the same)

51

pool

- body's readily available quantity of substance (amount present in ECF)
- total amount of substance in body depends on the relative rates of net gain and net loss for particular substance
- pool concentration depends on both total amount of substance in the body and upon exchanges of the substance within the body
- potential inputs and outputs can effect the pool of a material