Multicellular Organisms: Control & Communication

Question 1

What are the components of the nervous system?

Answer 1

The brain, spinal chord and neurons.

Question 2

What are the two components of the CNS?

Answer 2

The brain and spinal chord.

Question 3

What are the 3 main parts of the brain?

Answer 3

• Cerebrum - big part
• Cerebellum - little squidy looking bit
• Medulla - tube looking bit

Question 4

What is the function of the cerebrum?

Answer 4

Controls memory, personality and reasoning.

Question 5

What is the function of the cerebellum?

Answer 5

Controls balance and coordination of movement.

Question 6

What is the function of the medulla?

Answer 6

Controls breathing and heart rate.

Question 7

What are the 3 types of neuron?

Answer 7

• Sensory Neuron
• Inter Neuron
• Motor Neuron

Question 8

What is the function of the sensory neuron?

Answer 8

To carry impulses from receptors located in the sense organs to the inter neuron in the CNS.

Question 9

What is the function of the inter neuron?

Answer 9

To carry impulses from the sensory neuron to the motor neuron. Operates in the CNS.

Question 10

What is the function of the motor neuron?

Answer 10

To carry impulses from the inter neuron in the CNS to the effectors (muscles/glands) which bring about a response.

Question 11

What type of message is passed through the nervous system?

Answer 11

Electrical impulse

Question 12

What is a receptor?

Answer 12

Cells located in the sense organs which detect stimuli and convert them into electrical impulses.

Question 13

What is an effector? Give 2 examples

Answer 13

Effectors are the things which respond to stimuli. Muscles and glands are examples of these.

Question 14

What is a synapse?

Answer 14

The gap between neurons.

Question 15

How are impulses passed along the synapse?

Answer 15

Chemicals diffuse across the gap.

Question 16

How are impulses transferred in a reflex arc?

Answer 16

• Sensory receptors in the skin are detected by heat.
• Impulse passes along the sensory neuron.
• Impulse crosses the synapse chemically.
• Impulse passes along the inter neuron in the CNS.
• Impulse crosses the synapse chemically.
• Muscle contracts (responds.)

Question 17

What glands release hormones?

Answer 17

Endocrine glands.

Question 18

How do hormones move around the body?

Answer 18

Through the bloodstream

Question 19

Why are only target tissues/organs affected by specific hormones?

Answer 19

Target tissues/organs have specific receptors on their cell membrane. Each hormone ONLY fits the receptors of their target cell.

Question 20

What is the role of the pancreas in blood glucose regulation?

Answer 20

The pancreas is the endocrine gland. When blood glucose levels are high, receptor cells on it detect it and release insulin. When blood glucose levels are low, receptor cells detect it and release glucagon.

Question 21

What is the role of the liver in blood glucose regulation?

Answer 21

When glucagon reaches the liver, liver cells convert glycogen into glucose to increase glucose levels. When insulin reaches the liver, the liver is stimulated and it takes up glucose and converts it into glycogen.

Question 22

What is the role of glucagon in blood glucose regulation?

Answer 22

It is released by the pancreas when blood glucose levels are low. It travels through the bloodstream to the liver where it causes liver cells to convert glycogen into glucose to increase blood glucose levels.

Question 23

What is the role of insulin in blood glucose regulation?

Answer 23

It is released by the pancreas when blood glucose levels are high. It travels through the bloodstream to the liver where it stimulates the liver and causes it to take up and convert glucose into glycogen.

Question 24

What is the role of glycogen in blood glucose regulation?

Answer 24

Storage carbohydrate for glucose.