homeostasis

Question 1

homeostasis

Answer 1

The maintenance of a stable internal environment of the body

Question 2

what are the 3 components homeostasis interacts with?

Answer 2

1. receptor (free nerve ending)
   - senses the change
2. integrator (brain)
   - receives the information, judges the response, and stimulates the response
3. effector (a muscle or a gland)
   - restores the balance

Question 3

negative feedback

Answer 3

triggers the response that reverses the initial change, and reverts the variable back to set-point

Question 4

positive feedback

Answer 4

triggers the response that causes more change in the same direction

Question 5

hydrophobic vs hydrophilic

Answer 5

hydrophobic: fat soluble substances passes through the membrane

hydrophilic: substances do not pass through the membrane

Question 6

what are several different type of cell communications?

Answer 6

1. gap junctions
   - directly from cell to cell
   - local
   - anatomic location
2. synaptic
   - across the synaptic cleft
   - local
   - anatomic location & receptors
3. paracrine & autocrine
   - diffusion of interstitial fluid
   - locally diffuse
   - receptors
4. endocrine
   - circulating body fluids
   - general receptors

Question 7

diffusion

Answer 7

random movement of particles of a solute from an area of higher concentration to an area of lower concentration

• ALWAYS move down the concentration gradient
• small intestine to blood

Question 8

bulk flow

Answer 8

movement via differential pressure changes

• blood in arteries, vessels, and capillaries
• blood to brain
• mouth to small intestine

Question 9

osmosis

Answer 9

spontaneous net movement of water through semipermeable membrane into a region higher of solute concentration

Question 10

what is the charge outside and inside of the molecule?

Answer 10

outside = positive charge
inside = negative charge

Question 11

exocytosis

Answer 11

membrane bound vesicle from the cytoplasm makes contents within the membrane and contents spill into the extracellular fluid

• release of neurotransmitters by a neuron

Question 12

endocytosis

Answer 12

substances collect along the surface of the plasma membrane and engulfs, fusing the membrane and creating a membrane vesicle

• cholesterol uptake of the cell