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/MH11%20Homeostasis_Web/index.html

Video: Eye Pupil Reflex https://www.youtube.com/watch?v=Yj5-cJgVX3c

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=ZRFykdf4kDc