Lecture 2 brain and behaviour

Question 1

What is the difference between the central and peripheral nervous systerms

Answer 1

CNS: the brain and spinal cord. Which are the main decision making centres
PNS: sensory and motor nerves which transmit nerve impulses to and from the CNS. Including: 31 pairs of spinal nerves and 12 pairs of cranial nerves.

Question 2

What is the difference between the somatic and autonomic parts of the PNS

Answer 2

Autonomic: carries signals from internal organs to the CNS. Made up of smooth cardiac muscle. This is non- voluntary and regulates the activities of the respiratory, digestive and urogenital systems.

Somatic: Carries signals between the CNS and the body and skeletal muscles. Voluntary movement where signals are sent from the brain to the correct part of the body/ muscle.

Question 3

What can the autonomic nervous system be split into and explanations

Answer 3

1- Sympathetic nervous system: active during high stress levels. Increasing energy use, heart rate and dilates pupils
2- Parasympathetic: conserving of energy. when resting or digesting. constricts pupils.

Question 4

3 parts of the brain and the general functions

Answer 4

1) cerebrum: made of left and right hemispheres which control opposite side of body. Controls cognition, learning behaviours and emotions. Cerebral hemispheres are connected by nerve fibres called the corpus callosum

2) cerebellum: Controls motor function and procedural learning and all the same non- motor functions as the cerebrum.

3) Brain stem: divided into midbrain, pons and medulla. This controls life support function eg reflexes breathing, heart rate and blood pressure. and consciousness.

Question 5

What are the 2 types of cells in the nervous system and explain

Answer 5

1) 86 billion neurons which control sensory and motor activities
2) Glial cells: 1:1 with neurons and provide structural support

Question 6

What are the 5 parts of a neuron

Answer 6

1) cell body
2) nucleus: containing chromosomes and DNA
3) Dendrites which recieve connections from other neurons.
4) axon: transmits nerve impulses from the cell body to the terminals.
5) axon terminals: make contact with other neurons at synapses.

Question 7

What is grey and white matter

Answer 7

Grey is on the outside and white is the inside made of nerve fibre

Question 8

How do neural circuits work

Answer 8

stretch detector detects impact of an object
generates an impulse and nerve fibre
Transmitted to spinal cord
Sensory nerve synapses on motor nerve
leg moves.

Question 9

What are the 4 lobes of the cerebral hemispheres

Answer 9

1) frontal
2) parietal
3) temporal
4) occipital

Question 10

What are sulci (2 examples) and gyri

Answer 10

The sulcus creases inwards (eg central and lateral sulcus)
The gyrus folds out wards

Question 11

What are the 4 sub- cortical brain structures?

Answer 11

Thalamus. hypothalamus, basal ganglia and amygdala

Question 12

Explain the Thalamus

Answer 12

Majority of neural pathways must pass through a thalamic relay to reach the cerebral cortex

Question 13

Explain the hypothalamus

Answer 13

Used for homeostasis and the maintenance of the internal environment (controlling of endocrine and autonomic systems). And biological parameters. And influences behaviour by creating drive states.

Question 14

Explain the Basal Ganglia

Answer 14

Functions through connections in closed loops. These loops arise from the cortex to the BG then return via the thalamic relay to the same part of the cortex. As dopamine increases, loops become more active.

Question 15

What are the 3 main sets of loops in the Basal Ganglia

Answer 15

Voluntary movement
Cognition and memory
Reward based learning .

Question 16

Explain the Amygdala

Answer 16

Sensitive to stimuli which evoke fear or anxiety. Patients with no functional Amygdala experience no fear or panic.

Question 17

What can harm to the Broca’s area cause

Answer 17

Speaking difficulties or loss of ability to speak

Question 18

Explain the frontal lobe

Answer 18

The largest lobe responsible for voluntary movement, cognition, and social behaviour. And speech and language production/

Phineas Gage: had an injury in his prefrontal cortex which makes up 2/3 of the frontal lobe. This caused a drastic change in his behaviour.

Question 19

Explain the Parietal lobe

Answer 19

Contains somatic sensation, proprioception (sense of body location and movement), visuospatial awareness (of personal space and where objects are in relation to self). And reading, writing and arithmetic in the dominant Parietal lobe. (left usually)

In right Parietal lobe damage can cause patients to not pay attention to half of the world or left side of their body.

Question 20

Temporal lobe

Answer 20

Responsible for hearing (primary auditory cortex). Speech and language comprehension (Wernicke’s areas), Spatial navigation and episodic memory (hippocampus) Object recognition

Also found in the Temporal lobe

Hippocampus: Retrieval of episodic memory this degenerates in Alzheimer’s
Fusiform gyrus: Damage in the right can lead to face blindness. Right is used for reading.

Question 21

Explain the Occipital lobe

Answer 21

The smallest lobe. Responsible for vision (contains primary visual cortex and visual association cortex)
Contains 2 pathways

1) Dorsal stream (localisation- where)
2) Ventral stream (identification- what)

Question 22

Explain the Limbic lobe

Answer 22

Memory, emotion and sense of smell.