Lecture 2 (Survival Needs, Homeostasis, Feedback Systems)

Question 1

What are the 5 survival needs?

Answer 1

Nutrients
Oxygen
Water
Normal body temperature
Appropriate atmospheric pressure

Question 2

Why are nutrients a survival need?

Answer 2

Chemicals for energy and cell building. (Carbohydrates, fats, proteins, minerals, vitamins)

Question 3

Why is oxygen a survival need?

Answer 3

Essential for energy release (ATP Production)

Question 4

Why is Water a survival need?

Answer 4

• Most abundant molecule in body
• Environment of chemical reactions
• Fluid base for secretions and excretions

Question 5

What’s the normal body temperature and why is it important to maintain it?

Answer 5

37° C, affects rate of chemical reactions

Question 6

Why is an appropriate atmospheric pressure important?

Answer 6

For adequate breathing and gas exchange in lungs

Question 7

Why is homeostasis necessary in the human body?

Answer 7

Homeostasis ensures the body’s internal environment remains constant despite changes inside and outside the body. (ex: body temperature, glucose levels)

Question 8

Which two systems control the homeostatic mechanisms of the body?

Answer 8

Nervous system (fast)
Endocrine system (slower)

Question 9

What’s a stimulus?

Answer 9

Any disruption that causes a change in a controlled condition.

Question 10

General definition of a feedback system

Answer 10

A feedback system involves a controlled condition
in the body that is continually monitored → evaluated → changed →remonitored → reevaluated

Question 11

What are the 3 components of a Feedback System? Explain each of them

Answer 11

• Receptor: Body structure that monitors changes in
  controlled condition and sends information (input) to
  control centre
  *Control Center: Brain, sets the range of values within which controlled condition should be maintained
• Evaluates input from receptors
• Generates output commands (nerve or chemical signals)
• Effector:
• Body structure that receives output from control center
• Produces a response that changes the controlled
  condition
• Nearly all organs or tissue can be effectors

Question 12

What does a negative feedback system do? Give an example

Answer 12

Reverses a change in a
controlled condition
(brings it back to
normal). Ex: Regulation of blood pressure

Question 13

What does a Positive Feedback system do? Give an example

Answer 13

A positive feedback system strengthens a change in a controlled condition. Positive feedback is designed to push levels out of normal ranges. Ex: blood clotting, child birth

Question 14

What’s the difference between a disorder and a disease?

Answer 14

Disorder: Abnormality of structure/function

Disease: Specific illness characterized by signs and symptoms

Question 15

What’s the difference between a symptom and a sign?

Answer 15

Symptom: Subjective change not observable from outside a person (ex: pain, headache, nausea)

Sign: Observable or measurable change (ex: fever, swelling)