The Nervous and Endocrine Systems

Question 1

What is the nervous system?

Answer 1

the network of nerve cells and fibers that transmits nerve impulses between parts of the body.

Question 2

What is the central nervous system?

Answer 2

brain and spinal cord
-The centre of nervous activity and processes information.

Question 3

How does the nervous system split?

Answer 3

peripheral splits into somatic and autonomic. Autnomic splits into sympathetic and parasympathetic.

Question 4

What is the peripheral nervous system?

Answer 4

the sensory and motor neurons that connect the central nervous system to the rest of the body

Question 5

What does the somatic nervous system do?

Answer 5

controls voluntary movements and reflexes.

Question 6

What does the autonomic nervous system do?

Answer 6

Governs vital functions in the body such as breathing, heart rate, digestion, sexual arousal and stress responses.

Question 7

What is the parasympathetic nervous system?

Answer 7

rest and digest
-heart rate/blood pressure decrease.
-Digestion increases.
-Pupils constrict.
-Contracts bladder.

Question 8

What is the sympathetic nervous system?

Answer 8

fight or flight
-Pupils dilate.
-inhibits digestion.
-increases heart and breathing rate.
-relaxes bladder.

Question 9

What are reflex actions?

Answer 9

Automatic and rapid actions that do not involve the conscious parts of the brain. They protect us from harm.
-Controlled by somatic nervous system.

Question 10

What happens after a reflex?

Answer 10

Information sent to brain after, so we can learn from mistakes.

Question 11

Examples of a reflex arc?

Answer 11

A bee stings finger
Stimulation of the pain receptor
Impulses travel along the sensory neurone
Impulses travel along a relay neurone
Travel along a motor neurone
The muscles react with a contraction

Question 12

What is a neuron?

Answer 12

nerve cell

Question 13

Properties of a sensory neuron?

Answer 13

-Cell body is separate from axon.
-Carries impulses from the receptors to the CNS.

Question 14

Properties of a motor neuron?

Answer 14

-Short dendrites and long axons.
-carries impulses from CNS to effectors.

Question 15

Properties of a relay neuron?

Answer 15

-No myelin sheath and a shorter axon.
-Carries impulses from sensory to motor.

Question 16

What is a dendrite?

Answer 16

a short branched extension of a nerve cell, along which impulses received from other cells at synapses are transmitted to the cell body.Wh

Question 17

What is an axon?

Answer 17

long fiber that carries impulses away from the cell body

Question 18

What is the myelin shealth?

Answer 18

Insulates the axon to prevent transmission anywhere else.

Question 19

What are the nodes on ranvir?

Answer 19

gaps in the myelin sheath, which force the impulse to ‘jump’ which speeds up transmission.

Question 20

What are terminal buttons?

Answer 20

The branched end of the axon that contains neurotransmitters.

Question 21

How does electrical transmission across synapses occur?

Answer 21

-The impulse arrives at the terminal buttons of the presynaptic neuron.
-Vesicles containing neurotransmitters move towards the presynaptic membrane.
-Vesicles fuse with the synaptic membrane, releasing neurotransmitters into the synaptic cleft.
-They diffuse across the cleft and bind to receptors in the postsynaptic neuron.
-Depending on excitation/inhibitory activity, it increases/decreases the likelihood the impulse will continue.
-Neurotransmitters released back into the synaptic cleft where they are recycled and reabsorbed.

Question 22

How does electrical transmission occur?

Answer 22

-When a neuron is in resting state, the inside of the cell is more negatively charged than the outside.
-When the neuron is activated, it becomes positively charged which causes action potential, creating the impulse.

Question 23

What is excitation?

Answer 23

When a neurotransmitter, such as adrenaline, increases the positive charge of the postsynaptic neuron. This increases the likelihood that the neuron will fire and pass on the electrical impulse.

Question 24

What is inhibition?

Answer 24

When a neurotransmitter, such as serotonin, makes the charge of the postsynaptic neuron more negative. This decreases the likelihood that the neuron will fire and pass on the electrical impulse.

Question 25

What is summation?

Answer 25

the process of adding up postsynaptic potentials and responding to their net effect

Question 26

What is the endocrine system?

Answer 26

serves to control body functions. Gland in the endocrine system secrete hormones that travel through the blood to organs throughout the body.

Question 27

What does the adrenal cortex secrete?

Answer 27

cortisol which controls the suppression of the immune system and release of fats and glucose for energy in the fight or flight response.

Question 28

What is the hypothalamus?

Answer 28

Connected to the pituitary gland and stimulates the release of hormones.

Question 29

What is the pituitary gland?

Answer 29

The master gland, it is attached to the hypothalamus. The anterior releases ACTH which stimulates the adrenal glands to release cortisol. The posterior releases Oxycontin.

Question 30

What does the thyroid gland do?

Answer 30

Produces thyroxine which is involved in regulating metabolism.W

Question 31

What does the adrenal medulla secrete?

Answer 31

adrenaline and noradrenaline

Question 32

What do the testes do?

Answer 32

testosterone for male sexual characteristics and muscle/bone mass.

Question 33

What do the ovaries produce?

Answer 33

oestrogen and progesterone which control female sexual characteristics and menstrual cycle.

Question 34

What does the pineal gland secrete?

Answer 34

melatonin which regulates sleep-wake cycle

Question 35

What is the fight or flight response?

Answer 35

When the endocrine system and autonomic nervous system work together in response to a stressor.

Question 36

How does the fight or flight response work?

Answer 36

1) When a stressors is perceived, the hypothalamus activates the pituitary gland and the ANS triggers the sympathetic state.
2) The pituitary gland triggers the adrenal medulla to release adrenaline and nor adrenaline, which triggers changes in the body. These changes are heart rate, breathing, converting glycogen to glucose.
3)Nor adrenaline acts as a neurotransmitter.
4)After the stressors, the ANS returns to parasympathetic state and normal bodily functions happen.

Question 37

What happens in response to long term stress?

Answer 37

The fight or flight is only adapted for short term stress. Long term stress means continuous fight or flight, so the immune system is continually suppressed.