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Biology 224 > Homeostasis > Flashcards

Flashcards in Homeostasis Deck (22):
1

True or False: all animals regulate at least one physiological variable.

True, more complex animals regulate more variables and require coordination through various homeostasis mechanisms.

2

What is a tissue?

A stable association of differentiated cells that have similar structure and function. All tissues are made up of one type of cell.

3

What are epithelial tissues?

For protection, secretion, and absorption.

4

What are connective tissues?

For structural support.

5

What are muscle tissues?

For movement.

6

What are nervous tissues?

For communication, coordination, and control.

7

Define Organ.

A body structure that integrates different tissues and carries out a specific function(s). Usually composed of the four major tissue types.

8

What is an organ system?

A composition of multiple organs that carry our a major bodily function.

9

True or False: Physiological regulation usually involves just one organ system.

False, it usually involves many and can involve every organ system in the body.

10

What does Homeostasis do?

Regulate the internal body environment at or near a stable level using homeostatic mechanisms.

11

What is the use of a set point?

Homeostasis regulates a physiological variable relative to a set point, which may include negative feedback, positive feedback, or feed-forward regulation.

12

What is Negative Feedback?

The most important regulator, it returns a variable back towards its set point by minimizing the difference between the actual level and the set point.

13

Body temperature regulation in endothermic animals is an example of what?

Negative Feedback. Sensor: thermoreceptors in the skin. Integrator: hypothalamus. Effectors: skeletal muscles.

14

What does the brain do when it receives signals that the body is too hot?

Gives off heat by causing blood vessels to dilate [increasing surface area for heat exchange] or sweating.

15

What does the brain do when it receives signals that the body is too cold?

Conserves heat by causing blood vessels to constrict [reducing surface area for heat exchange] or shivering.

16

What is Positive Feedback?

Moves variable away from the set point by amplifying the difference between the actual level and the set point. Usually works in association with the negative feedback mechanism.

17

What is Feed-foward?

When future needs are anticipated, physiology is adjusted in advance. Often involves learning and complex behaviours.

18

What is an Endotherm?

A warm blooded animal that uses the heat produced by their metabolism to maintain body temperature.

19

What is an Ectotherm?

A cold blooded animal that must find other sources to use for heat, not the heat produced by their metabolism.

20

What is a Homeotherm?

An animal that maintains a steady body temperature throughout their life history.

21

What is a Heterotherm?

An animal that allows their body temperature to change throughout their life history.

22

What is Thermogenesis?

A process by which animals generate heat in their body.