overview of the nervous system

Question 1

What does the human nervous system consist of?

Answer 1

It is comprised of the cns (central nervous system) and the pns (peripheral nervous system).

Question 2

What does the cns consist of?

Answer 2

the brain and the spinal cord

Question 3

What does the pns consist of?

Answer 3

the autonomic nervous system (parasympathetic and sympathetic ) and the somatic nervous system

Question 4

Sympathetic branch

Answer 4

fight or flight

• increased heart rate, blood pressure
• decreased digestive processes

Question 5

parasympathetic branch

Answer 5

rest and digest
decreased heart rate, blood pressure
increase digestive processes

Question 6

What are the major brain regions?

Answer 6

1. forebrain (cerebrum and diencephalon)
2. brainstem (midbrain, pons and medulla oblongata)
3. cerebellum

Question 7

Cerebrum

Answer 7

largest part of the forebrain- comprises the cerebral cortex and several subcortical structures.

1. cerebral cortex
   - frontal lobe
   - temporal lobe
   - parietal lobe
   - occipital lobe
2. Subcortical structures
   - hippocampus
   - basal ganglia

Question 8

Structure of the cerebrum

Answer 8

has a convoluted surface containing ‘bumps’ - gyri.
‘grooves’- sulci
if the grooves are ‘deep’ - fissures

Question 9

List the roles of the frontal lobe

Answer 9

• control of voluntary movement
• control of behaviour.
• attention, planning and decision making
• motivation and emotional regulation

’ home of our personality’

Question 10

List the roles of the parietal lobe

Answer 10

• sensory processing and interpretation e.g. touch

- proprioception (i.e equilibrium and balance of the body)

Question 11

List the roles of the temporal lobe

Answer 11

• auditory processing and interpretation e.g. speech

- memory e.g. formation of long term memories

Question 12

List the roles of the occipital lobe

Answer 12

• visual processing and interpretation (e.g. distance and depth perception, colour, object and face recognition)

Question 13

Subcortical structures: hippocampus

Hippocampus function

Answer 13

• learning
• memory formation and retrieval
• regulation of hypothalamus- pituitary adrenal axis.

Question 14

What happens if there are dysfunctions within the hippocampus?

Answer 14

Clive wearing - contracted a virus that caused damage to his hippocampus.

• anterograde amnesia ( unable to create new memories)
• retrograde amnesia ( unable to recall past memories)

Question 15

Subcortical structures: basal ganglia

Functions of the basal ganglia

Answer 15

• involved in regulating movement (initiation and maintenance of movement , inhibit antagonist movements)

Question 16

Basal ganglia dysfunction

Answer 16

no GABAergic neurons

no dopaminergic neurons

Question 17

The DIENCEPHALON

Answer 17

division of the forebrain situated between the cerebrum and the midbrain.
It comprises of the thalamus and the hypothalamus.

Question 18

The thalamus

Answer 18

Large part of the nuclei located in the dorsal part of the diencephalon.

Question 19

What are the thalamus functions?

Answer 19

• relay between sensory and motor systems and the cerebral cortex.
• regulate arousal and pain, mood, motivation and cognitive functions

Question 20

what is synaesthesia?

Answer 20

it is a blending of information streams

• hearing colour
• feeling sounds

Question 21

Diencephalon : hypothalamus

Hypothalamus function?

Answer 21

• smaller collection of nuclei with various functions
• homeostatic, reproductive and other diverse functions (e.g. fight or flight response)
• ‘fight or flight’ response involves the hypothalamus pituitary adrenal axis - cortisol and adrenaline release

Question 22

Hypothalamus dysfunction?

Answer 22

it plays a role in a number of conditions:

• hypothyroidism
• hyperthyroidism

Question 23

Brainstem is the portion of the brain that lies between the diencephalon and the spinal cord- comprises of the midbrain, pons and medulla oblongata. What are the functions of each?

Answer 23

Midbrain functions
- include the control of eye movements, auditory and visual processing
Pons functions
- relay of motor information from cerebral hemispheres to the medulla, spinal cord and the cerebellum
Medulla oblongata
- cardiovascular (e.g. blood pressure) and respiratory homeostasis
- reflexive actions including vomiting, swallowing, coughing and sneezing,

Question 24

What does it mean by “brainstem dead”

Answer 24

• unable to regain consciousness or breathe without the support of an artificial life support machine.
• loss of blood circulation to all brainstem regions

Question 25

What does it mean by "locked in syndrome"?

Answer 25

- awake and conscious but no means of producing speech, limb or facial movements - loss of blood circulation to pons.

Question 26

What is the function of the cerebellum?

Answer 26

- the cerebellum does not initiate movement but detects differences in motor error between an intended movement and the actual movement. - aids the motor cortex to produce a precise, coordinated movement.

Question 27

Is the function of the cerebellum conserved?

Answer 27

- it has been shown that e.g. the cerebellum is important in synchronisation of movement with musical rhythm. - this may be widespread in the animal kingdom.

Question 28

What is the structure of the spinal cord?

Answer 28

- cervical vertebrae- located in the neck and are named c1-c7 - thoracic vertebrae- attached to the ribs and are named t1-t12 - lumbar vertebrae- located in the lower back and are numbered l1-l5 - sacral vertebrae- located within the pelvic area and are numbered s1-s5

Question 29

What is the structure of a spinal cord segment?

Answer 29

a spinal nerve passes into the vertebral notch and splits into 2 roots. - dorsal root - a bundle of sensory neuron axons that carry sensory info. into the spinal cord - ventral root- a bundle of motor neuron axons that carry info. away from the spinal cord to the striated muscle. A transverse section of the spinal cord also reveals: - grey matter: comprised of neuronal cell bodies - divided into 'horns' - white matter: comprised of axon bundles - divided into 'columns'

Question 30

What is the function of the spinal cord?

Answer 30

- spinal cord contains motor neurons that innervate skeletal muscle and allow for movement as well as motor tracts that carry information for motor movement down from the brain. - spinal cord also receives sensory information (e.g. touch, pressure, temperature) from the periphery of our bodies and contains pathways by which that sensory information is transmitted to the brain.

Question 31

Spinal cord injury

Answer 31

tetraplegia- refers to the full or partial loss of sensation and movement in all 4 limbs and torso. CAUSED BY DAMAGE IN THE CERVICAL C1-C7 AREA Paraplegia - refers to the full or partial loss of sensation and movement in both legs (and torso depending on the location of the lesion) CAUSED BY DAMAGE IN THE THORACIC, LUMBAR OR SACRAL AREA.

Question 32

Protection and support in the brain

Answer 32

1. meninges 2, ventricular system 3. vasculature system

Question 33

The meninges (3 membranous layers that cover the brain and the spinal cord) What does it comprise of and what is its function?

Answer 33

the meninges comprises of: - dura mater -arachnoid membrane - pia mater The function of the meninges is: - primary function is in the protection of the brain and the spinal cord - passage of cerebrospinal fluid- ventricular system - support of cerebral and spinal blood vessels - vasculature system

Question 34

The ventricular system of the brain ( a series of interconnected, cerebrospinal fluid filled spaces that lie at the core of the forebrain and the brain stem) What does it consist of and what is its function?

Answer 34

the ventricular system consists of: - lateral ventricles - third ventricles - fourth ventricle The functions of the ventricular systems are: - protection of the brain (e.g. cushion for physical shocks) - transport (e.g. nutrients, waste products) - other functions include the regulation of the buoyancy

Question 35

Vasculature of the brain ( 2 pairs of arteries supply blood to the brain: internal carotid arteries and the vertebral arteries) structure and function?

Answer 35

- anterior circulation - derived from the internal carotid arteries- supplies the forebrain (cerebrum and diencephalon) - posterior circulation- derived from the vertebral arteries - supplies the brainstem, cerebellum and the upper spinal cord. Function of the vasculature system: - delivery of oxygen - removal of carbon dioxide - transport (e.g. nutrients, waste products.)