homeostasis and response

Question 1

What is Homeostasis?

Answer 1

The maintenance of internal conditions within the body.

Question 2

What does homeostasis control?

Answer 2

Blood glucose concentration
Temperature
Water levels

Question 3

Which control systems are used for homeostasis?

Answer 3

Nervous system
Endocrine system

Question 4

What does the human nervous system consist of?

Answer 4

Central nervous system - Brain and spinal cord
Peripheral nervous system - nerve cells that carry info to or from the CNS.

Question 5

What is the purpose of homeostasis?

Answer 5

Maintains optimal conditions for enzyme actions and cell functions.

Question 6

What do all control systems contain?
What do they do?

Answer 6

Receptor cells - Cells which recognise and respond to stimuli, stimuli is something that sets off the reaction in the nervous system: light, heat, temp - these changes are detected by receptors.
Coordination centre - Receives and processes info from the receptors around the body.
Effectors - Bring about responses which restore optimum levels of such as core body temperature and glucose levels. Effectors include muscles and glands, responses could be muscle contraction or hormone release.

Question 7

What are nerve cells called?

Answer 7

Neurons

Question 8

What are neurons?

Answer 8

Carry electrical impulses from one place to another.
Bundle of neurons are called a nerve.

Question 9

What are the main types of neurons?

Answer 9

Sensory, relay, motor neurons

Question 10

Name 2 features the 3 types of neurons have in common and their purpose?

Answer 10

An axon - Long fibre which is insulated by a fatty sheath, they are long so they can carry messages up and down the body.
Dendrons - Tiny branches which branch further as dendrites. - Receive incoming impulses from other neurons.

Question 11

How is info from receptors passed along?

Answer 11

Along neurons as electrical impulses.

Question 12

What is the order of response?

Answer 12

Stimulus - Receptor - coordinator - effector - response

Question 13

What is a receptor?

Answer 13

Specialised cell that detects change in the environment (stimulus)?

Question 14

What is an effector?

Answer 14

Muscles or glands that produce a specific response to the receptor?
Contracting muscle
Gland releasing hormone into the blood

Question 15

What is a reflex action?

Answer 15

Automatic and rapid response to the stimulus?

Question 16

What is the general sequence for a reflex action?

Answer 16

Stimulus - Receptor - Sensory neurone - Relay neurone - Motor neurone - Effector - Response

Question 17

What is a reflex arc?

Answer 17

Pathway of information from a sensory to motor neurone.

Question 18

What is the pathway of response if we touch something hot?

Answer 18

1. Receptor - detects the stimulus (touching something hot)
2. Sensory neurone - sends electrical impulses to the relay neurone and connect sensory to motor neurone.
3. Motor neurone - Sends electrical impulses to an effector.
4. Effector - Produces a response (muscles contract to move hand away)