Biopsychology

Question 1

The nervous system

Answer 1

Central nervous system and Peripheral nervous system

Question 2

Central nervous system

Answer 2

The brain is the centre of all conscious awareness.
The spinal cord is an extension of the brain. It is responsible for reflex actions.
It passes messages to and from the brain and connects nerves to the PNS.

Question 3

Peripheral nervous system

Answer 3

Transmits messages, via neurons, to and from the CNS.
Further sub-divided:

• AUTONOMIC NERVOUS SYSTEM - governs vital functions in the body such as breathing, heart rate, digestion, sexual arousal and stress responses.
• SOMATIC NERVOUS SYSTEM - controls muscle movement and recieves information from sensory receptors.

Question 4

The endocrine system

Answer 4

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

Question 5

Hypothalamus

Answer 5

Produces oxytocin and ADH.

Controls weight, hunger and body temperature.

Question 6

Pituitary

Answer 6

The ‘master’ gland, controls the endocrine system.

Question 7

Thyroid

Answer 7

Produces thyroxine.

Increases heart rate and the metabolic rate. This affects growth rates.

Question 8

Parathyroid

Answer 8

Produces parathyroid hormone.

Helps control calcium levels.

Question 9

Adrenals

Answer 9

Produces adrenalin.

Triggers fight or flight response.

Question 10

Pancreas

Answer 10

Produces insulin.

Controls blood sugar levels and helps the digestive system.

Question 11

Ovaries

Answer 11

Produces oestrogen.

Prepares the body for pregnancies.

Question 12

Testes

Answer 12

Produces testosterone.

Increases aggression levels and increases hair growth.

Question 13

Sensory neuron

Answer 13

Carries messages from the PNS to the CNS.

Long dendrites and short axons.

Question 14

Relay neuron

Answer 14

Connect the sensory neurons to the motor or other relay neurons.
Short dendrites and short axons.

Question 15

Motor neuron

Answer 15

Connects CNS to effectors such as muscles and glands.

Short dendrites and long axons.

Question 16

Structure of a neuron

Answer 16

Dendrites
Cell body
Nucleus
Myelin sheath
Axon
Axon terminal

Question 17

Synaptic transmission

Answer 17

The process by which neighbouring neurons communicate with each other by sending chemical messages across the synapse that separates them.

Question 18

What happens during synaptic transmission?

Answer 18

The message arrives at the neuron as a chemical message, that turns into an electrical impulse when it reaches the dendrite. It travels through the axon as an electrical impulse and when it reaches the axon terminal it changes into a chemical neurotransmitter, so it can diffuse across the synapse, into the dendrites of the next neuron.

Question 19

Excitation

Answer 19

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 20

Inhibition

Answer 20

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

Question 21

Fight or Flight

Answer 21

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

The endocrine system and the Autonomic nervous system often work in parallel with each other, e.g. in a stressful situation.
When a stressor is perceived (e.g. thinking about an upcoming exam) the Hypothalamus triggers activity in the sympathetic branch of the autonomic nervous system. The ANS changes form its normal resting state (the parasympathetic state) to the physiologically aroused, sympathetic state.
Adrenaline is released from the adrenal medulla into the bloodstream. Adrenaline triggers psychological changes in the body e.g. increased heart rate, which creates the psychological arousal necessary for the flight or fight response.
All of this happens in an instant as soon as the threat is detected and is an autonomic reaction in the body. These changes explain why stress, panic or even excitement is often experienced as a ‘sick’ feeling.
Once the threat has passed, the parasympathetic nervous system returns the body to its resting state.