Metabolism (class 1)

Question 1

What is physiology? (3 elements ish)

Answer 1

study of normal functioning of a living organism and its component parts
- NOT pathology

Question 2

Organization of “life” (7 levels)

Answer 2

Atoms < molecules < cells < tissues < organs > organ systems < organisms

Question 3

what are characteristics of life? (4)

Answer 3

• reproduce
• evolve
• adapt to environment
• convert food to energy to do work = metabolism

Question 4

definition of tissues
- 4 types

Answer 4

collection of similar types of cells
1. epithelial
2. connective
3. muscular
4. nervous

Question 5

definition of organs

Answer 5

different tissues come together to perform specific function
ie: kidney, stomach

Question 6

what are the 10 organ systems in the body?

Answer 6

1. integumentary (skin)
2. musculoskeletal
3. respiratory (pulmonary)
4. digestive (gastrointestinal)
5. urinary (renal)
6. reproductive
7. circulatory (cardiovascular)
8. nervous
9. endocrine
10. immune

Question 7

what is homeostasis?
what does it mean?

Answer 7

maintenance of a relatively stable internal environment
- relatively stable = not a fixed number! always a range that fluctuates
- internal environment = extracellular fluid

Question 8

3 critical variables for homeostasis

Answer 8

1. environmental factors that affect cells
2. materials for cell’s needs
3. factors cells use to communicate with one another

Question 9

what is pathophysiology?

Answer 9

study of body functions in a disease state (when there is a failure to maintain homeostasis)

Question 10

2 fluids that make up the body’s internal environment

Answer 10

1. extracellular fluid: watery internal environment that surrounds the cells –> serves as a buffer zone between outside world and ICF –> needs to be kept relatively stable
2. intracellular fluid (ICF): fluid within cells

Question 11

body fluids = __% of BW
–> separation between intra and extracellular fluid?
–> ECF than separates into what?

Answer 11

60%
- 2/3 ICF vs 1/3 ECF
- ECF –> intravascular vs extravascular fluid
- extravascular –> interstitial vs transcellular fluid

Question 12

is homeostasis equilibrium or dynamic steady state? explain.

Answer 12

dynamic steady state! NOT equilibrium
- materials are constantly moving between 2 compartments
- no net movement between compartments
- concentrations maintained at different levels between 2 compartments
VS equilibrium: implies composition of compartments are identical

Question 13

long-distance vs short distance signaling for homeostasis control: name?

Answer 13

• long distance = reflex control/ signaling control–> response loop + uses nervous and/or endocrine systems –> 2 or more systems are involved
• short distance = local control –> restricted to a tissue or cell

Question 14

7 steps of a feedback loop

Answer 14

stimulus –> sensor –> input signal –> integrating center –> output signal –> target –> response

Question 15

negative vs positive vs feedforward loops

Answer 15

• negative = homeostatic –> stabilize variable –> response counteracts stimulus, shutting off the response loop
• positive = NOT homeostatic –> reinforce variable (ie pregnancy, child birth)
• feedforward = allows body to anticipate change: response before it changes (saliva before you eat, digestive juices before eating)

Question 16

Circadian rhythms in humans examples (3)

Answer 16

• body temp: lowest in early morning and highest in early evening
• plasma cortisol: lowest during sleep and peaks at awakening
• blood sugar: high after eating, low when fasting

Question 17

Give 1 physiological example of negative and positive feedback loop

Answer 17

Negative:
- body temp 38°C –> sweat to cool off
- blood sugar levels increase –> secrete insulin to make sugar to into cells –> decreases blood sugar levels
Positive:
- birth contractions: pressure on cervix sends signal to continue contracting which pushes baby even more on cervix