6 - 1 Human Physiology

Question 1

Homeostasis

Answer 1

Tendency towards a relatively stable state or equilibrium (balance).

Question 2

Examples of Homeostasis

Answer 2

• Body Temperature 98.6°F

- Blood has a neutral pH = 7

Question 3

Electrochemical signals

Answer 3

Quick messages transferred by the nervous system.

Question 4

Negative Feedback Mechanisms

Answer 4

Long term responses often carried out by hormones.

Question 5

Lock and Key

Answer 5

Controls transmission of messages based on a shape configuration at the cellular level.

Question 6

Negative Feedback Mechanisms #2

Answer 6

Any change from the normal range of function is opposed or resisted.

Question 7

Examples of Negative Feedback Mechanisms

Answer 7

• Blood pressure
• Temperature
• Respiration rate
• Blood glucose levels

Question 8

Lock and Key Model

Answer 8

Molecules have a shape that only fits specific receptors.

Question 9

Example of Lock and Key Model

Answer 9

Square peg only fits into square hole, star peg only fits into star hole.

Question 10

Enzymes

Answer 10

Chemical proteins in the body that assist or speed up chemical reactions (catalyst).

Question 11

Communication

Answer 11

• Cells communicate with one another by releasing chemicals.
• These chemicals bind to receptors on the surface of other cells.
• The chemicals may be delivered to nearby cells or cells across the body (using the blood stream).
• When the lock and key is formed, the message has been sent.

Question 12

Determining “Self” from Invaders

Answer 12

• Your body’s immune (defense) system needs to be able to determine what is “self” and what is an invader.
• It uses the lock and key method to determine invaders from itself.

Question 13

Using Lock and Key Model in Therapies

Answer 13

Scientists create drugs that mimic (look like) messenger molecules.

• These messenger molecules may activate the response.
• Or the molecule may fit, but not perfectly, so the hole is blocked and the message CANNOT be sent.