Homeostasis And Feedback Loops

Front 1

Define Homeostasis

Back 1

Homeostasis is the maintenance of a constant internal environment of a cell or organism despite fluctuations in the external environment.

Front 2

Which feedback loop opposes or resists a change in the body's internal conditions?

Back 2

Negative Feedback Loop

Front 3

Which of the following is a positive feedback loop:

a) Blood temperature falls too low

b) Protein digestion

c) Water balance

d) Blood sugar concentration

Back 3

b) Protein digestion

Front 4

Fill in the blank:

If the blood temperature rises too high it is sensed by the ______________ of the brain

Back 4

Hypothalamus

Front 5

Fill in the blank:

Homeostasis is maintained primarily by the __________ feedback loop.

Back 5

Negative

Front 6

What happens in a positive feedback loop?

Back 6

The positive feedback loop increases or enhances a change in body's internal conditions. The body senses a change and activates mechanisms that accelerate or increase that change.

Front 7

Give an example of a positive feedback loop.

Back 7

Any of the following:

- Blood clotting

- Child birth

- Protein digestion

Front 8

What are two ways that the body responds to low blood temperature and how do they help to return the body to homeostasis?

Back 8

1. Arteries near skin constrict so warm blood is retained deeper in the body and less heat is lost on the surface.

2. The brain activates shivering. Each muscle tremor releases heat energy and helps to warm the body.

Front 9

True of False:

Many feedback loops are regulated by the nervous system and others by hormones of the endocrine system.

Back 9

True

Front 10

How is child birth a positive feedback loop?

Back 10

The stretching of the uterus triggers the secretion of the hormone oxytocin, which stimulates contractions of the uterus and speeds up labor.

As the body is responding by increasing or enhancing the body's internal conditions so it is a positive feedback loop.

Front 11

Fill in the blank:

Homeostasis is a state of ________________ achieved between opposing actions of adjustment of a cell/body condition

Back 11

equalibrium

Front 12

Which of the following is not something that occurs in the body when blood temperature is too high:

a) hypothalamus senses change in blood temperature

b) hypothalamus signals other nerve centres to send signals to blood vessels of the skin

c) blood vessels constrict

d) brain activates sweating

Back 12

c) blood vessels constrict

This is done when blood temperature is too low so that warm blood is retained deeper in the body and less heat is lost on the surface.