Homeostasis Glossary Maintain keep up Constant the same

Homeostasis

Glossary • Maintain – keep up. • Constant – the same. • Internal – inside the body. • Environment – surroundings of the body.

What is Homeostasis? • Homeostasis - the ability of the body of an organism or cell to maintain stable internal conditions even when the outside environment changes continuously.

Homeostatic control involves 3 components • Receptor – sensor, responds to changes and sends information to • Control center – determines the set point, the point at which the variable is to be maintained. • Effector – output, sends the response to the stimulus.

For example

Video Time • http: //www. mhhe. com/biosci/bio_animations/ MH 11%20 Homeostasis_Web/index. html

Video: Eye Pupil Reflex • https: //www. youtube. com/watch? v=Yj 5 -c. Jg. VX 3 c

Homeostasis is maintained through 2 mechanisms: 1) Negative Feedback - (most common) 2) Positive Feedback

Homework • Answer all 10 problems • State whether positive or negative and why

What is the difference between positive feedback and negative feedback mechanisms?

i Insulin Binds to glucose And transports it Into the cells

What is Diabetes? Why does a high concentration of glucose in the bloodstream cause excessive urination and thirst?

What is a system? • System – a group of bodily organs that function together to maintain homeostasis and thus, the survival of the organism.

Biological Levels of Organization

Organelles • Small cellular structures that perform metabolic functions for the cell.

Cell • Most basic unit of all living things

Tissue • A group of similar cells that performs a specific function.

Organ • Formed of two or more tissues and carries out a specific function.

Organ Systems • A group of organs that work together to perform a vital body function • E. g. , the nervous system.

Systems Can’t Work Alone

Video • https: //www. youtube. com/watch? v=ZRFykdf 4 k. Dc