Biopsychology part 1 (yr 12)

Question 1

What is included in the central nervous system

Answer 1

controls most functions of the body and mind. It consists of two parts: the brain and the spinal cord.

The brain is the center of our thoughts, the interpreter of our external environment, and the origin of control over body movement. Like a central computer, it interprets information from our eyes (sight), ears (sound), nose (smell), tongue (taste), and skin (touch), as well as from internal organs such as the stomach.

The spinal cord is the highway for communication between the body and the brain. When the spinal cord is injured, the exchange of information between the brain and other parts of the body is disrupted.

Question 2

What is included in the peripheral nervous system

Answer 2

The peripheral system allows the brain and spinal cord (CNS) to receive and send information to muscles and glands of the body, which allows us to react to stimuli in our environment. The nerves that make up the peripheral nervous system are actually the axons or bundles of axons from nerve cells or neurons.

Question 3

Role of the spinal cord

Answer 3

It is an extension of the brain. It transports messages to and from the brain to the peripheral nervous system. It is also responsible for reflexes.

Question 4

The structure of the nervous system

Answer 4

Nervous system
NS splits into the CNS and PNS.
CNS splits into the spine and the brain, while the PNS splits into somatic and autonomic.
Autonomic splits into sympathetic and parasympathetic.

Question 5

Nervous system

Answer 5

This is a specialised between of cells in the human body and is our primary internal communication system. It has two main functions:

• To collect, process and respond to information in the environment.
• To co-ordinate the working of different organs and cells in the body.

It is divided into two subsystems: the CNS and the PNS.

Question 6

Endocrine system

Answer 6

One of the body’s major information systems that instructs glands to release hormones directly into the bloodstream. These hormones are carried towards target organs in the body.

Question 7

Gland

Answer 7

An organ in the body that synthesises substances such as hormones

Question 8

Hormones

Answer 8

Chemical substances that circulate in the bloodstream and only affect target organs. They are produced in large quantities but disappear quickly. Their effects are very powerful.

Question 9

Fight or flight response

Answer 9

The way an animal responds when stressed. The body becomes physiologically aroused in readiness to fight an aggressor or, in some cases, flee.

Question 10

Adrenaline

Answer 10

A hormone produced by the adrenal glands which is part of the human body’s immediate stress response system. Adrenaline has a strong effect on the cells of the cardiovascular system - stimulating the heart rate, contracting blood vessels and dilating air passages.

Question 11

Biological changes associated with the sympathetic response

Answer 11

Increases heart rate
Increases breathing rate
Dilates pupils
Inhibits digestion 
Inhibits saliva production 
Contracts rectum

Question 12

Biological changes associated with the parasympathetic response

Answer 12

Decreases heart rate 
Decreases breathing rate
Constricts pupils
Stimulates digestion 
Stimulates saliva production 
Relaxes rectum

Question 13

Somatic nervous system

Answer 13

Transmits information from raptor cells in the sense organs to the central nervous system. It also receives information from the CNS that directs muscles to act.

Question 14

Autonomic nervous system

Answer 14

Transmits information to and from the internal bodily organs. It is ‘autonomic’ as the system operates involuntarily (it is automatic). It has two main divisions: the sympathetic and parasympathetic nervous system.

Question 15

The endocrine system : gland and hormones

Answer 15

The endocrine system works alongside the NS to control vital functions in the body. The endocrine system acts much more slowly than the NS but has very widespread and powerful effects. There are various glands that are used with the endocrine system such as the thyroid gland, pituitary gland, testes (males), ovaries (female), adrenal gland, pancreas. These glands produce hormones that are secreted into the bloodstream and affect any cell in the body that has receptor for that particular hormone.

Question 16

How does the Endocrine and autonomic nervous system working together in fight or flight

Answer 16

Often the endocrine system and the autonomic nervous system work in parallel with one another, for instance during a stressful event. When a stressor is perceived, the first thing that happens is a part of the brain called the hypothalamus triggers activity in the sympathetic branch of the autonomic nervous system. The ANS changes from its normal resting state (parasympathetic state) to the physiologically aroused (sympathetic state). The stress hormone adrenaline is released from the adrenal medulla (a part of the adrenal gland) into the bloodstream. Adrenaline triggers psychological changes in the body which creates the physiological arousal necessary for the fight or flight response. All of this happens in an instant as soon as a threat is detected. Your body goes through the sympathetic response when in fight or flight. Once the threat has passed, the parasympathetic nervous system returns the body to its resting state. The parasympathetic branch of the ANS works in opposition to the sympathetic nervous system and helps to relax the body after the fight or flight response.

Question 17

Name the main glands used in the fight or flight response

Answer 17

Hypothalamus 
Pituitary gland
Thyroid
Parathyroid 
Adrenal gland 
Pancreas
Ovaries (females)
Testes (male).

Question 18

The functions of testes

Answer 18

This gland produces the hormone testosterone which causes the development of male characteristics such as growth of facial hair, deepening of the voice and the growth spurt that take place during puberty. The production of testosterone is controlled by the hypothalamus and pituitary gland.

Question 19

Functions of ovaries

Answer 19

The two ovaries are part of the female reproductive system and are responsible for the production of eggs and for the hormones oestrogen and progesterone.

Question 20

Functions of the pituitary gland

Answer 20

The ‘master gland’, whose primary function is to influence the release of hormones from other glands. Because of this, this gland regulates many of the body’s functions. This gland is controlled by the hypothalamus.

Question 21

Function of the adrenal gland

Answer 21

The two adrenal glands sit on top of the kidneys and each adrenal gland is made up of two distinct parts, the outer part of each gland is called the adrenal cortex and the inner part is called the adrenal medulla. The main distinction between the them is that the hormones released by the cortex are necessary for life, this released by the adrenal medulla are not.

Question 22

Functions of the adrenal cortex

Answer 22

Produces cortisol which regulates or supports a variety of important bodily functions including cardiovascular and anti-inflammatory functions. The production of cortisol is increased in response to stress. If the cortisol level is low, the individual may end up having low blood pressure, poor immune function and an inability to deal with stress.
The cortex also produces aldosterone which is responsible for maintaining blood volume and blood pressure.

Question 23

Functions of the adrenal medulla

Answer 23

Releases adrenalin and noradrenaline, these are hormones that prepare the body for fight or flight. Adrenaline helps the body to respond to stressful situations, for example by increasing heart rate and blood flow to the muscles and brain and helping with conversation of glycogen to glucose to provide energy.
Noradrenaline constricts the blood vessels, causing blood to increase.

Question 24

What does the hypothalamus do

Answer 24

The hypothalamus is a collection of specialised cells that serve as the central relay system between the nervous and endocrine systems. It translates signals from the brain into hormones.

Question 25

Sensory neurons

Answer 25

These are found in receptors such as the eyes, ears, tongue and skin and carry nerve impulses to the spinal cord and brain. When these nerve impulses reach the brain they are translated into ‘sensations’, such as vision, hearing, taste, and touch. However, not all sensory neuron impulses reach the brain, as some stop at the spinal cord, allowing for quick reflex actions.

Question 26

Relay neurons

Answer 26

These Are found in the brain between sensory input neurons and motor output/response neurons, allowing them to communicate.

Question 27

Motor neurons

Answer 27

These are found in the central nervous system and control muscle movements. When motor neurons are stimulated they release neurotransmitters that bind to receptors on muscles to trigger a response, which leads to movements.

Question 28

What is synaptic transmission

Answer 28

This Is the process by which one neuron communicates with another. Information is passed down the axon of the neuron as an electrical impulse known as action potential. Once it reaches the end of the axon, it crosses the synaptic gap between he presynaptic neuron and post-synaptic neuron. When the electrical impulse (action potential) reaches the synaptic vesicles in the axon terminal they release their neurotransmitters, which cross the synaptic gap and bind to receptor sites on the post-synaptic cell, thereby completing the process of synaptic transmission.

Question 29

Excitation

Answer 29

If an excitatory neurotransmitter like noradrenaline binds to the post-synaptic receptors it will cause an electrical charge in the cell membrane which results in an excitatory post-synaptic potential, making the post-synaptic cell more likely to fire.

Question 30

Inhabitation

Answer 30

If an inhibitory neurotransmitter like GABA binds to the post-synaptic receptors it will result in an inhibitory post-synaptic potential, which makes the post synaptic cell less likely to fire