The Nervous System and the Endocrinne System (Biopsychology)

Question 1

The Human Nervous System

Answer 1

Provides the biological basis of psychological experience.

Can be further divided into the Peripheral and Central Nervous systems.

Question 2

The Central Nervous System

Answer 2

Central Nervous System:
• controls our bodily functions and psychological processes

Can be further divided into the Brain and Spinal Cord

Question 3

Peripheral Nervous System

Answer 3

• transmits messages via millions of neurones (nerve cells), to and from the central nervous system

Can be further divided into the Somatic and Autonomic Nervous systems.

Question 4

Somatic Nervous System

Answer 4

• This is the part of the PNS that is responsible for carrying sensory and motor information to and from the spinal cord
  • Is made up of 12 pairs of cranial nerves from the brain, 31 pairs of spinal nerves from the spinal cord and all of their branches

• conscious

Question 5

Autonomic Nervous System

Answer 5

• transfers information to and from internal organs to maintain life governing vital functions in the body such as breathing, heart rate, digestion, sexual arousal and stress responses
• (fight or flight)
• unconscious processes necessary for life

Can be further divided into the Parasympathetic and Sympathetic Nervous systems.

Question 6

The Brain

Answer 6

• main job is to ensure that life and psychological processing is maintained
• many parts of the brain, some of which are concerned with vital functioning and others which are involved in processes such as problem solving and higher order thinking
• the centre of all conscious awareness. The brain’s outer layer, the cerebral cortex, is highly developed in humans and is what distinguishes our higher mental functions
• the brain is divided into two hemispheres

Question 7

The Spinal Cord

Answer 7

• Facilitates the transferal of messages to and from the brain to the PNS
• Also responsible for reflex actions
• is an extension of the brain

Question 8

Sympathetic Nervous System

Answer 8

• anxiety and fear are important for survival because they ac as a mechanism to protect the body against stress and danger
• the sympathetic nervous system controls what has been called the “fight or flight” phenomenon because of its control over the necessary bodily changes needed when we are faced with a situation where we may need to defend ourselves or escape
• slows digestion, inhibits saliva production, increases heat rate, stimulates glucose production, stimulates urination (relaxes the bladder), dilates pupils, dilates bronchi

Question 9

The Endocrine System

Answer 9

One of the body’s major information systems that instructs glands to release hormones directly into the bloodstream

Question 10

Gland

Answer 10

an organ in the body that synthesises substances such as hormones

Question 11

Homeostasis

Answer 11

the maintenance of a constant internal environment within the body

Question 12

Hormones

Answer 12

Chemical substances that circulate in the bloodstream their effects on behaviour can be very powerful.

They affect target cell with receptors for specific hormones.

Question 13

Pineal Gland

Answer 13

Produces and secretes the hormone melatonin which regulates biological rhythms such as sleep and wake cycles.

Located in the brain

Question 14

Adrenal Glands

Answer 14

Adrenal glands release adrenaline directly into the bloodstream which prepares the body for fight or flight by constricting blood vessels to the stomach.
This inhibits digestion and increases your heart rate.

Women produce testosterone here.

Is stimulated by ACTH to secrete cortisol.

Is located above the kidneys.

The outer part is called the adrenal cortex (which secretes cortisol to control metabolism of glucose) and the inner part is call the adrenal medulla (which secretes adrenalin and noradrenalin)

Question 15

Pituitary Gland

Answer 15

Located in the brain and is called the master gland, Controls the release-of hormones from all the other endocrine glands. Also known as the master gland.

Located in the brain, below the hypothalamus (which controls it).

Consists of the anterior and posterior lobes.

The anterior releases ACTH in response to stress, stimulating the adrenal gland.

The posterior releases oxytocin, which is important for childbirth.

Question 16

Testes

Answer 16

This facilitates the release of the male hormone- testosterone

Testosterone affects aggression, facial hair, sex drive, muscle mass.

Question 17

Ovaries

Answer 17

this facilitates the release of the female hormones- oestrogen and progesterone

produces eggs

Question 18

(Evaluations of endocrine system) Gender differences

Answer 18

(beta-bias)

• Taylor et al 2000 found that men usually react to stress with a ‘fight or flight’ response but women may show a ‘tend and befriend’ response
• Oxytocin (a hormone secreted in both men and women) is a response to stress has been shown to make people less anxious and more sociable
• However, male hormones reduce the effects of oxytocin but female hormones oestrogen amplifies it
• Therefore, men re more vulnerable to the adverse health effects of stress and more likely to develop stress related disorders (hypertension and CHD)
• In contrast, women are more likely to ‘tend and befriend’ and this may protect women from stress and this may explain hy women live on average 7.5 years longer than men

Question 19

(Evaluations of endocrine system) Reductionist

Answer 19

• a person’s response depends on a number of different factors. These include the types of stressor involved, and the way the person interprets (cognitively) the threat. This suggests that this approach may present an oversimplified explanation.

Question 20

Sensory Neurone

Answer 20

Function:
Unipolar- only transmits messages in one direction

Carries messages from the PNS to the brain and spinal cord (CNS)

Length of Fibres:
Long dendrites and short axons

Question 21

Relay (interconnecting) neurone

Answer 21

Function:
Multipolar neurones- send and receive messages

Transfers messages from sensory neurones to other interconnecting neurones or motor neurones

Length of fibres:
Short dendrites and short or long axons

Question 22

Motor Neurone

Answer 22

Function:
Multipolar neurones- send and receive messages

Carries messages from the CNS to effectors such as muscles and glands

Length of fibres:
Short dendrites and long axons

Question 23

Structure of a Motor Neurone

Answer 23

(refer to diagram)

Cell body: includes a nucleus

Nucleus: the control centre of a cell which contains the chromosomal DNA

Dendrite: receives the nerve impulse or signal from adjacent neurones

Axon: where the electrical signals pass along

Myelin Sheath: insulates/protects the axon from external influences that might effect the transmission of the nerve impulse down the axon

Nodes of ranvier: speed up the transmission of the impulse by forcing it to jump

Terminal buttons: send signals to the adjacent cell

Question 24

process of synaptic transmission 1

Answer 24

1. nerve impulse travels down an axon
2. nerve impulse reaches synaptic terminal
3. this triggers the release of neurotransmitters
4. the neurotransmitters are fired into the synaptic gap

Question 25

process of synaptic transmission 2

Answer 25

5. neurotransmitter binds with receptors on the dendrite of the adjacent neurone 6. if successfully transmitted the neurotransmitter is taken up by the post-synaptic neurone 7. the message will continue to be passed in this way via electrical impulses

Question 26

The Reflex arc

Answer 26

a stimulus is detected by sense organs in the peripheral nervous system, which conveys a message along a sensory neurone. The message reaches the nervous system where connects with a relay neurone. This transfers the message to a motor neurone. This then carries the message to an effector such as a muscle, which causes the muscle to contract.

Question 27

Action potential

Answer 27

Occurs when a neurone sends information down an axon, away from the cell body. The action potential is an explosion of electrical activity, meaning that some event (a stimulus) causes the resting potential to move forward.

Question 28

Resting and Activating states

Answer 28

Resting: the inside is negatively charged compared to the outside Activating: the inside is positively charged causing action potential

Question 29

Refer to diagram of synaptic transmission

Question 30

Reuptake of neurotransmitters

Answer 30

the reabsorption of a neurotransmitter by a neurotransmitter transporter located along the plasma membrane of an axon terminal, broken down by enzymes

Question 31

Excitatory and inhibitory Neurotransmitters

Answer 31

Neurotransmitters can be either excitatory or inhibitory -excitation only: acetylcholine (ACh), adrenaline -inhibitory only: serotonin, GABA

Question 32

Excitatory and Inhibitory synaptic connections

Answer 32

synaptic connections can be excitatory or inhibitory- the difference lies in the action of the neurotransmitter at the postsynaptic receptor Excitatory- they make it more likely the next neurone will fire Inhibitory- they make it less likely the next neurone will fire

Question 33

Effects of excitatory and inhibitory neurotransmitters

Answer 33

If the neurotransmitter is excitatory then the pos synaptic neurone is more likely to fire an impulse as the neurotransmitter increases the positive charge (once the positive charge reaches the threshold, depolarisation occurs and the post synaptic neurone fires) If the neurotransmitter is inhibitory then the post synaptic neurone is less likely to fire an impulse as it increases the negative charge (the neurotransmitter needs to keep the charge below threshold so that depolarisation does not occur and thus the post synaptic neurone will not fire)

Question 34

Summation

Answer 34

the process that determines whether/how frequently the neurone will fire- by the combined effects of excitatory and inhibitory signals. The excitatory and inhibitory influences are summed, if the net effect on the post synaptic neurone is inhibitory, the neurone will be less likely to fire and if the net effect is excitatory, the neurone will be more likely to fire

Question 35

Parasympathetic Nervous System

Answer 35

Rest and Digest, maintains and conserves body energy and functions Increases digestion, increases saliva production, decreases heart rate