Mod 4-Obj3: The brain stem (3 major regions)

Question 1

The brainstem

Answer 1

Includes the midbrain (mesencephalon), pons and medulla oblongata

Question 2

The midbrain

Answer 2

Also known as the mesencephalon

• Contains various nuclei
• Connection point for cranial nerves CN III and IV-involved in eye movements

Question 3

Nuclei of the midbrain: Visual and auditory reflex centres

Answer 3

1. ) Visual and auditory reflex centres
   - Centres that co-ordinate head and eye movements
   - reflexive responses to sound

Question 4

3 Nuclei of the midbrain

Answer 4

1. ) Visual and auditory reflex centres

2. ) Substantia nigra

Question 5

Nuclei of the midbrain: Substantia nigra

Answer 5

Contains neurons that produce dopamine, which control the cerebral basal nuclei
-degenerates in Parkinson’s disease

Question 6

The pons

Answer 6

Pons means ‘bride’

-Connection point for cranial nerves CN VI-VIII

Question 7

The pons contains fibre tracts that…

Answer 7

• relay sensory information from the thalamus to the cerebellum
• Relay information between the motor cortex and the cerebellum

Question 8

The pons contains various somatic and visceral motor nuclei concerned with…

Answer 8

Sleep
Hearing
Equilibrium 
Taste
Eye movement
Facial expression and sensation 
Respiratory rhythms 
Swallowing
Bladder control and posture

Question 9

The medulla oblongata

Answer 9

Inferior portion of the brainstem, blends into the spinal cord at the foramen magnum-3cm long
-Connection point for cranial nerves CN VIII-XII

Question 10

The medulla oblongata…Relay sensory information

Answer 10

Relays sensory information between different brain areas

• To the thalamus and other portions of the brain stem
• To the cerebellum (muscle stretch and joint positions) via the pons

Question 11

The medulla oblangata…Conduction pathway

Answer 11

Conduction pathways between brain and the spinal cord

e.g.) ascending and descending tracts

Question 12

The medulla oblongata…Autonomic reflex centre

Answer 12

Autonomic reflex centres: motor nuclei, regulated by the hypothalamas, which regulate visceral function

• Cardiovascular centre
• Cardiac centre: Controls force and rate of heart contraction
• Vasomotor centre: Adjust blood vessel diameter
• Respiratory centre
• Controls rate and depth of breathing
• centres regulating visceral functions: vomiting, hiccuping, swallowing, salivating, coughing….