CH. 8 Homeostasis

Question 1

What is the importanc eof homeostasis

Answer 1

Essential for maintaining the body’s internal environment for the proper functioning of the human body
Allows for chemical reactions of the body to progress normally

Question 2

What are three conditions in the body that are regulated by homeostasis

Answer 2

Blood pressure
Proper concentration of gases, nutrients, and salts
Body temperature

Question 3

define internal environment

Answer 3

the environment in which cells are found and is thus defined as the fluid inside the body, but outside of cells.

Question 4

How do substances move between compartments

Answer 4

in ECF: plasma –> interstitial –> lymph
plasma and interstitial can exhange with ICF

Question 5

define stressor

Answer 5

Any stimulus that causes an imbalance in the
internal environment
can be internal (nutrient levels, high blood pressure)
can be external (lack of oxygen, extreme temps)

Question 6

What is a feedback loop?

Answer 6

A mechanism to deal with stress in order to regain
homeostasis. Can be either positive or negative
contains:
input/stressor
receptor
control center
effector
output

Question 7

describe a negative feedback loop

Answer 7

a negative feedback loop is when the output is the opposite of the input. one example is the body’s reaction to extreme cold external temperatures.

input - body temperature is too cold
receptor - cold thermoreceptors
control center - hypothalamus
effector - shivering, hormone release, vasoconstriction
output - internal body temperature rises

Question 8

describe a positive feedback loop

Answer 8

A condition where the output is stronger, more
amplified than the input, one example is childbirth

input - baby head pushes against cervix
receptor - stretch receptors
control center - pituitary gland
effector - oxytocin released causing uterus to contract more
forcefully
output - baby head pushes on cervix more