Overview of the nervous system

Question 1

What are the features of the axon and describe these features

Answer 1

Axons conduct nerve impulses.

Axon hillock - Tapers away from soma to form initial segment

Axon ‘proper’ - Branching to form axon collaterals (and recurrent collaterals)

Axon terminal - Site at which axon comes into contact with other neurons at a synapse

Question 2

How are axon terminals different to the axon proper

Answer 2

Cytoplasm - Microtubules do not extend into terminals from proper.

Axon terminal contains synaptic vesicles available for neuron to neuron communication. Rich in proteins and mitochondria, higher energy needs

Question 3

What is myelin

Answer 3

Membranous sheath that wraps around and insulates axon

Question 4

What are nodes of Ranvier

Answer 4

Gaps within the myelin sheath - Enriched in voltage-gated Na+ ion channels

Question 5

What are dendritic spines

Answer 5

Sacs of membrane protruding from dendrites to receive synaptic input

They come in sizes and types (e.g. cups, mushrooms) sensitive to type and amount of synaptic activity

Question 6

What are the two parts of the human nervous system

Answer 6

CNS - Brain and spinal cord

PNS - Autonomic, somatic nervous systems

Question 7

What is the somatic nervous system

Answer 7

Component of peripheral nervous system that innervates the skin, joints and skeletal muscle

Helps movement

Question 8

What is the autonomic nervous system

Answer 8

Sympathetic and parasympathetic divisions - Innervation to cardiovascular system, internal organs and smooth muscle

Heart rate, bp, breathing, digestion

Question 9

What physical features are present in the cerebrum of the brain

Answer 9

Bumps called gyri
Grooves called sulci
Deep grooves called fissures

Question 10

What are the postcentral and precentral gyrus responsible for and what are they separated by

Answer 10

Postcentral - Somatic sensation e.g. touch
Precentral - Voluntary movement

Separated by central sulcus

Question 11

What does the superior temporal gyrus do and what is it separated by

Answer 11

Audition
Separated by lateral fissure

Question 12

What is the frontal lobe responsible for

Answer 12

Voluntayr movement, behaviour

Attention, planning, decision making, motivation, emotional regulation

Question 13

What is the temporal lobe responsible for

Answer 13

Auditory processing and interpretation, memory

Question 14

What is the parietal lobe responsible for

Answer 14

Sensory processing and interpretation
Proprioception (I.e. equilibrium and balance of the body)

Question 15

What is the occipital lobe responsible for

Answer 15

Visual processing and interpretation (Distance, depth perception, colour, object and face recognition)

Question 16

Where is the hippocampus and what is its function

Answer 16

Embedded within the temporal lobe
Learning, memory formation and retrieval
REgulation of hypothalamus-pituitary-adrenal axis

Question 17

What happens if there is hippocampal dysfunction

Answer 17

Anterograde amnesia - Unable to create new memories

Retrograde amnesia - Generally unable to recall past memories

Question 18

What is the basal ganglia

Answer 18

Large and functionally diverse set of neural structures embedded deep within the cerebral hemispheres

Caudate, putamen globus pallidus

Question 19

Describe basal ganglia functions

Answer 19

Regulation of movement

Question 20

What happens with basal ganglia dysfunction

Answer 20

GABAergic neurons - Huntington’s disease

Dopaminergic neurons - Parkinson’s disease

Question 21

What is the diencephalon

Answer 21

Between cerebrum and midbrain, consist of thalamus and hypothalamus

Question 21

What is the diencephalon

Answer 21

Between cerebrum and midbrain, consist of thalamus and hypothalamus

Question 22

Describe thalamic function

Answer 22

Thalamus contain lots of nuclei. Some nuclei relay between sensory and motor systems and the cerebral cortex.

Some nuclei regulate arousal and pain, mood, motivation and cognition

Question 23

What is synaesthesia

Answer 23

Blending of information streams - Some people can ‘hear colour’ or ‘feel sounds’

Question 24

Describe hypothalamic function

Answer 24

Smaller collection of nuclei Some nuclei involved in homeostatic, reproductive and other diverse functions (fight/flight)

Question 25

What happens in hypothalamic dysfunction

Answer 25

Hypothyroidism - Underproduction and release of thyroid Hyperthyroidism - Excessive

Question 26

What is the brainstem

Answer 26

Between diencephalon and spinal cord, comprises midbrain, pons and medulla oblongata

Question 27

What does the midbrain do

Answer 27

Control of eye movements, auditory and visual processing

Question 28

What do the pons do

Answer 28

Relay of motor information from cerebral hemispheres to medulla, spinal cord and cerebellum

Question 29

What does the medulla oblongata do

Answer 29

Cardiovascular and respiratory homeostasis Reflexive actions including vomiting swallowing coughing and sneezing

Question 30

What is 'brainstem dead'

Answer 30

Unable to regain consciousness or breath without life support There is a loss of blood circulation to all brainstem regions

Question 31

Describe locked-in syndrome

Answer 31

When you are awake and conscious but have no means of producing speech, limb or facial movements Involves loss of blood circulation to pons

Question 32

What is the function of the cerebellum

Answer 32

Detects differences in 'motor error' between intended and actual movement. Helps the motor cortex to produce precise and co-ordinated movement

Question 33

How are seal and other animal cerebellums similar to human's

Answer 33

Cerebellum utilised in synchronisation of movement with musical rhythm. (e.g. seals doing tricks)

Question 34

Name the vertebrae of the spinal cord and their location

Answer 34

Cervical vertebrae - Neck, C1-C7 Thoracic vertebrae - Ribs, T1-T12 Lumbar vertebrae - Lower back, L1-L5 Sacral vertebrae - Pelvic area, S1-S5

Question 35

What is a dorsal root

Answer 35

Bundle of sensory neuron axons that carry sensory information into the spinal cord

Question 36

What is a ventral root

Answer 36

Bundle of motor neuron axons that carry information away from the spinal cord to striated muscle

Question 37

What is grey and white matter

Answer 37

Grey - Neuronal cell bodies divided into horns White - axon bundles divided into columns.

Question 38

Describe spinal cord function

Answer 38

Motor neurons innervate skeletal muscle allowing for movement. Also contains motor tracts that carry information for motor movement down from the brain. Spinal cord also receives sensory information from the periphery of body and contains pathways by which sensory information is transmitted to the brain.

Question 39

Describe tetraplegia

Answer 39

Full or partial loss of sensation and movement in all four limbs and torso (damage in cervical area)

Question 40

Describe paraplegia

Answer 40

Full or partial loss of sensation and movement in both legs and torso Caused by damage in the thoracic, lumbar or sacral areas

Question 41

What is the meninges and describe its function

Answer 41

3 membrane layers covering the brain and spinal cord - Dura mater, arachnoid membrane and pia mater Protection, passage of CSF, and support of cerebral and spinal blood vessels.

Question 42

What is the ventricular system and describe its function

Answer 42

Comprises of CSF-filled spaces - Lateral ventricles, third ventricle, fourth ventricle Protection of the brain, transport of nutrients and waste, regulation of buoyancy (through CSF)

Question 43

What is the vasculatory system and describe its function

Answer 43

Two pairs of arteries suppliyng blood to the brain - Internal carotid and vertebral Anterior circulation - Carotid arteries, supplies forebrain Posterior circulation - Vertebral arteries, supplying brainstem, cerebellum and upper spinal cord They deliver oxygen, remove CO2 and transport nutrients and waste