Brainstem Region

Question 1

Main parts of the human central nervous system

Answer 1

1. Prosencephalon - Forebrain
2. Mesencephalon - Midbrain
3. Phombencephalon - Hindbrain
4. Spinal cord

Question 2

Answer 2

• Dura Mater:
• Periosteal layer
• Meningeal later

Question 3

Answer 3

Arachnoid mater

Question 4

Answer 4

Pia mater

Question 5

Main Components of Brainstem:

Four functional groupings:

Answer 5

1. Cranial nerve nuclei and related structures =
2. Long tracts =
3. Cerebellar circuits (lesion can cause wide based ataxic gait) =
4. Reticular formation and related structures =

• Consciousness
• Autonomic functions

Question 6

Longitudinal Sections of the Brainstem:

Brainstem is divided longitudinally into two sections:

Answer 6

1. Basilar (anterior) - descending tracts = located anteriorly and contains predominantly motor system structures:

• Descending axons from the cerebral cortex: corticospinal, corticobrainstem, corticopontine, corticoreticular tracts
• Motor nuclei: substantia nigra, pontine nuclei, inferior olive

2. Tegmentum (posterior)= located posteriorly

• Sensory nuclei and ascending sensory tracts
• Cranial nerve nuclei
• The medial longitudinal fasciculus (MLF): tract that coordinates eye and head movements
• The reticular formation (adjusts the general level of neural activity in the CNS)
• Midbrain has an additional longitudinal section, posterior to the tegmentum, called the tectum

Question 7

Tectum in midbrain includes structures involved in?

Answer 7

Tectum in midbrain includes structures involved in reflexive control of intrinsic and extrinsic eye muscles and in movements of the head:

• Pretectal area (pupillary and consensual reflex will be discussed later)
• Superior and inferior colliculi

Question 8

Cranial Nerves in:

• Forebrain
• Midbrain
• Pons
• Medulla

Answer 8

• Forebrain = 1, 2
• Midbrain = 3, 4
• Pons = 5,6,7,8
• Medulla = 9,10,11,12

Question 9

Cranial Nerve?

Answer 9

CN 2: Optic Nerve

Question 10

Cranial Nerve?

Answer 10

CN 3: Oculomotor Nerve

Question 11

Cranial Nerve?

Answer 11

CN 4: Trochlear Nerve

Question 12

Cranial Nerve?

Question 13

Cranial Nerve?

Question 14

Cranial Nerve?

Question 15

Cranial Nerve?

Question 16

Cranial Nerve?

Question 17

Cranial Nerve?

Question 18

Cranial Nerve?

Question 19

Cranial Nerve?