Biopsychology

Question 1

NEURONS AND SYNAPTIC TRANSMISSION: Structure and Function of Neurons
Name the 3 types of neurons

Answer 1

Sensory
Relay
Motor

Question 2

NEURONS AND SYNAPTIC TRANSMISSION: Structure and Function of Neurons
Outline the structure of a neuron

(need 8 key parts of a neuron)

Answer 2

-vary in size: from >1mm to 1m
- CELL BODY (soma) includes a NUCLEUS, which contains genetic material of the branch
- branchlike structures called DENDRITES protrude from cell body, which carry nerve impulses towards cell body
- AXON carries impulses away from cell body down the neuron
- axon covered in fatty layer of MYELIN SHEATH which protects axon and speeds up electrical transmission of impulse
- if myelin sheath was continuous, it would slow electrical transmission, thus the myelin sheath is segmented by gaps called NODES OF RANVIER (speed up electrical transmission by forcing impulse to ‘jump’ across gaps along axon)
- TERMINAL BUTTONS at end of axon which communicate with the next neuron in the chain across a gap known as the SYNAPSE

Question 3

NEURONS AND SYNAPTIC TRANSMISSION: Structure and Function of Neurons
Where is each type of neuron located in the body?

Answer 3

MOTOR NEURONS
- cell bodies may be in CNS, but they have long axons which form part of the PNS

SENSORY NEURONS
- located outside of CNS, in the PNS clusters known as ganglia

RELAY NEURONS
- make up 97% of all neurons
- most are found within brain and visual system

Question 4

NEURONS AND SYNAPTIC TRANSMISSION: Structure and Function of Neurons
Explain the concept of electrical transmission/the firing of a neuron

Answer 4

• when a neuron is in resting state, the inside of the cell is negatively charged compared to the outside
• when a neuron is activated by a stimulus, the inside of the cell becomes positively charged for a split second, causing an action potential to occur
• this creates an electrical impulse that travels down the axon towards the end of the neuron

Question 5

NEURONS AND SYNAPTIC TRANSMISSION: Synaptic Transmission
How does the transmission of signals within the neuron differ from between neurons?

Answer 5

signals are transmitted electrically within neurons, and chemically between neurons (across the synapse)

Question 6

NEURONS AND SYNAPTIC TRANSMISSION: Synaptic Transmission
Explain the process of synaptic transmission (10 steps)

Answer 6

1) electrical impulse reaches pre-synaptic terminal
2) triggers release of neurotransmitter from vesicle (tiny sacs)
3) neurotransmitter diffuses across the synapse
4) neurotransmitter is taken up by postsynaptic receptor site on the dendrite of the postsynaptic neuron
5) here, chemical message is converted back to an electrical impulse and travels down the axon for the process to begin again

Question 7

NEURONS AND SYNAPTIC TRANSMISSION: Synaptic Transmission
Explain the the process of summation

Answer 7

• neurotransmitters have either an excitatory or an inhibitory effect on the neighbouring neuron
• serotonin causes inhibition in the receiving neuron => neuron becomes more negatively charged => less likely to fire
• adrenaline causes excitation in postsynaptic neuron => more positively charged => more likely to fire
• summation: action potential of postsynaptic neuron is only tiggered is the sum of signals at any one time are excitatory

Question 8

THE NERVOUS SYSTEM
What are the 2 main functions of the nervous system?

Answer 8

1) to collect, process and respond to info in environment
2) to coordinate the working of different organs and cells in the body

Question 9

THE NERVOUS SYSTEM
Outline the Central Nervous System (CNS) division of the nervous system

Answer 9

BRAIN:
- centre of all conscious awareness
- outer layer is cerebral cortex (3mm thick) covers brain like an orange peel (only found in mammals)
- highly developed in humans (only a few living creatures don’t have a brain
- 2 hemispheres, 4 lobes

SPINAL CORD:
- extension of the brain
- passes messages to and from brain, connects nerves to PNS
- responsible for reflex actions

Question 10

THE NERVOUS SYSTEM
Outline the Peripheral Nervous System (PNS) division of the nervous system

Answer 10

PNS transmits messages via millions of neurons to and from CNS

AUTONOMIC NERVOUS SYSTEM (ANS)
- governs vital functions (breathing, heat rate, digestion, sexual arousal, stress responses
- SYMPATHETIC NERVOUS SYSTEM: fight or flight response
- PARASYMPATHETIC NERVOUS SYSTEM: rest and digest response

SOMATIC NERVOUS SYSTEM (SNS):
- governs muscle movement and receives info from sensory receptors

Question 11

THE ENDOCRINE SYSTEM
Name 3 glands, the hormone they secrete, and the function of these hormones

Answer 11

Thyroid gland: thyroxine, increases heart rate and metabolic rate
Pituitary gland (master gland): controls release of hormones from all the other glands in the body
Adrenal gland: adrenaline, creates physiological arousal to prepare body for fight or flight

Question 12

THE ENDOCRINE SYSTEM
Outline 3 differences between the endocrine system and the nervous system

Answer 12

nervous system produces quicker responses
endocrine system produces more widespread effects
endocrine system has longer-lasting effects

Question 13

THE ENDOCRINE SYSTEM
Outline how the ANS and the endocrine system work together for the fight or flight response (6 steps)

Answer 13

1) stressor detected
2) hypothalamus activates pituitary
3) pituitary stimulates ANS to switch from parasympathetic (resting state) to sympathetic (physiologically aroused state)
4) adrenaline released into bloodstream from adrenal medulla
5) adrenaline triggers physiological changes which create the physiological arousal necessary for flight or flight response
(all of this is instant and automatic)
6) once threat has passed, parasympathetic branch starts to work antagonistically to gradually oppose the sympathetic branch (rest and digest response)

Question 14

THE ENDOCRINE SYSTEM
Outline 6 changes that occur in the body in the sympathetic state

Answer 14

increases heart rate
increases breathing rate
dilates pupils
inhibits digestion
inhibits saliva production
contracts rectum

Question 15

THE ENDOCRINE SYSTEM
Outline 6 changes that occur in the body in the parasympathetic state

Answer 15

decreases heart rate, decreases breathing rate
constricts pupils
stimulates digestion
stimulates saliva production
relaxes rectum

Question 16

LOCALISATION OF FUNCTION
Outline the localisation vs holistic theory

Answer 16

holistic theory: all parts of the brain are involved in the processing of thought and action
then Paul Broca and Karl Wernicke discovered that specific areas of the brain were associated with particular physical and psychological functions
they then argued for the localisation of function theory: different parts of the brain perform different tasks and are involved with different parts of the body (and therefore if a certain area of the brain becomes damaged, the function associated with that area is affected also)

Question 17

LOCALISATION OF FUNCTION
Where in the brain(/from what perspective) do the following terms describe?

Anterior
Posterior
Dorsal
Ventral
Lateral
Medial

Answer 17

Anterior: front
Posterior: back
Dorsal: top
Ventral: bottom
Lateral: side view
Medial: if the brain was split in half, this is the view you’d see

Question 18

LOCALISATION OF FUNCTION
Fill in the gaps:

The __________ is divided into __ hemispheres.
Some of our ___________ and ________________ functions are controlled or ordained by a particular hemisphere - this is called _________________.
The ______ hemisphere is responsible for the right side of our body.
The ______ hemisphere is responsible for the left side of our body.
The cortex of both hemispheres is divided into 4 ______: _______________ , _______________ , _______________ and _______________.

Answer 18

The CEREBRUM is divided into 4 hemispheres.
Some of our PHYSICAL and PSYCHOLOGICAL functions are controlled or ordained by a particular hemisphere - this is called LATERALISATION.
The LEFT hemisphere is responsible for the right side of our body.
The RIGHT hemisphere is responsible for the left side of our body.
The cortex of both hemispheres is divided into 4 LOBES: FRONTAL LOBE, PARIETAL LOBE, OCCIPITAL LOBE and TEMPORAL LOBE.

Question 19

LOCALISATION OF FUNCTION
Motor cortex:
Where is it? Is it in one or both hemispheres? What is its function? What will the consequence be if this area is damaged?

Answer 19

MOTOR CORTEX
Location: back of frontal lobe, both hemispheres
Function: controls voluntary movement on opposite side of the body
Consequence of damage: loss of control over fine movements

Question 20

LOCALISATION OF FUNCTION
Somatosensory cortex:
Where is it? Is it in one or both hemispheres? What structure separates it from the motor cortex? What is its function?

Answer 20

SOMATOSENSORY CORTEX
Location: front of parietal lobe, both hemispheres (separated from motor cortex by central sulcus)
Function: processes sensory info (touch, heat, pressure) (5 senses). the amount of somatosensory area devoted to a particular body part denotes its sensitivity, e.g. receptors for our face and hands occupy over 1/2 the somatosensory area)

Question 21

LOCALISATION OF FUNCTION
Visual area:
Where is it? Is it in one or both hemispheres? What is its function? What will the consequence be if this area is damaged?

Answer 21

VISUAL AREA
Location: occipital lobe, both hemispheres
Function: each eye sends info from the right visual field to the left visual cortex and info from the left visual field to the right visual cortex
Consequence of damage: damage to right hemisphere can produce blindness in part of the left visual field for both eyes (or vise versa)

Question 22

LOCALISATION OF FUNCTION
Auditory area:
Where is it? Is it in one or both hemispheres? What is its function? What will the consequence be if this area is damaged?

Answer 22

AUDITORY AREA
Location: temporal lobe, both hemispheres
Function: analysis of speech-based info
Consequence of damage: potential hearing loss; the more extensive the damage, the more extensive the loss

Question 23

LOCALISATION OF FUNCTION
Broca’s area:
Where is it? Is it in one or both hemispheres? What is its function? What will the consequence be if this area is damaged?

Answer 23

BROCA’S AREA
Location: back of frontal lobe, ONLY LEFT HEMISPHERE
Function: speech production
Consequence of damage: Broca’s aphasia (slow, laborious and non-fluent speech)

Question 24

LOCALISATION OF FUNCTION
Wernicke’s area:
Where is it? Is it in one or both hemispheres? What is its function? What will the consequence be if this area is damaged?

Answer 24

WERNICKE’S AREA
Location: temporal lobe, ONLY LEFT HEMISPHERE
Function: language comprehension/understanding language
Consequence of damage: Wernicke’s aphasia (fluent but meaningless speech)

Question 25

LOCALISATION OF FUNCTION
Evaluate localisation of function