Neurophysiology - Basics

Question 1

What are the connective tissue layers that local anaesthetics must diffuse through to exert its effects

Answer 1

1. Epineureum (surrounding multiple peripheral nerve)
2. Perineurium (surrounding each fascicle or bundle of nerve fibres)
3. Endoneurium (surrounding a single nerve fibre)

Question 2

Describe the morphological calssification of neurons

Answer 2

COMMON
Bipolar: cell body between dendrites and axon
Pseudounipolar: Axon interrupted by a cell body
Multipolar: Dendrites insert directly into cell body
Pyramidal: Triangular cell body, single axon, many dendrites

UNCOMMON
Unipolar (may be found in the cochlear) –> single axon projects from a cell body
Anaxonic - dendrites and axons are indistinguishable

Question 3

Where on the neuron are action potentials generated?

Answer 3

At the axon hilock - junction between cell body and axon

Question 4

What is the structural classification of the brain

Answer 4

TELENCEPHALON (CEREBRUM)

• Cerebral hemispheres
• Basal ganglia
• Limbic System

DIENCEPHALON (THALAMUS)

• Thalamus
• Hypothalamus
• Subthalamus
• Metathalamus

MESENCEPHALON (MIDBRAIN)

• Connects diencephalon to rhombencephalon and cerebellum
• 3rd/4th CN nuclei and the red nucleus

RHOMBOENCEPHALON
- Pons
- Medulla Oblongata
(Cerebellum)

Question 5

What is the corpus callosum

Answer 5

Thick bundle of myelinated nerve axons that connect the left and right cerebral hemispheres

Question 6

Name and describe the function of the cerebral hemispheres

Answer 6

FRONTAL
- reasoning, planning, language, complex social and sexual behaviour

PARIETAL
- Sensory integration, dominant lobe (left 97% population) : maths, order numbers, non-dominant lobe: spatial awareness

TEMPORAL

• hearing, language, moemory
• Wernicke’s area (receptive language) between temporal and frontal lobes.

OCCIPITAL
- interpretation of visual stimuli

Question 7

What percentage of the population have a dominant left cerebral hemisphere

Answer 7

97%

Question 8

What are the functions of the hypothalamus

Answer 8

1. Regulates ANS
2. Links nervous system to endocrine system via control of pituitary gland secretion
3. Appetite and satiety
4. Osmolarity
5. Thermoregulation
6. Circadian rhythms

Question 9

What is the function of the lateral and medial geniculate nuclei and where are these found in the brain

Answer 9

They are in the metathalamus

Lateral relays visual information from the optic nerve to the primary visual cortex (occipital lobe)

Medial geniculate nucleus relays auditory information to the primary auditory cortex

Question 10

Which sensory information does not pass through the thalamus

Answer 10

Olfactory