Singh 5: The Brainstem

Question 1

What are the three major divisions of the brainstem?

From rostral to caudal?

Answer 1

From rostral to caudal:

Midbrain (derived from mesencephalon)

Pons (together with cerebellum = metenceph)

Medulla (myelonocephalon)

Question 2

The Edinger Westphal Nucleus (cranial Nerve 3) is associated with which part of the brainstem?

Answer 2

MIDBRAIN

Question 3

Which cranial nerves are associated with the midbrain?

Answer 3

Cranial nerves 3 and 4

Question 4

Midbrain Anatomy:

What is the tectum

What is the tegmentum

What is the cerebral penducles

Answer 4

MIDBRAIN:
Tectum: dorsal cover, called corpora quadrigemina (aka superior and inferior colliculus… four bumps)

Tegmentum: ventral cover, houses the RAAS

Cerebral penducles: superhighway of fibers

Question 5

MIDBRAIN ANATOMY:

Substantia nigra

Red nuclei

Answer 5

MIDBRAIN:

Substantia nigra: motor movement, Parkinson;s disease, pigmented

Red nuclei: communication between cerebellum and cerebrum

Question 6

Explain some functions of the midbrain:

Answer 6

Functions of the Midbrain:

Integration of neurological signals

Eye movement and pupil dilation (CN 3)

Regulation of motor function (substantia nigra)

Modulates tone and posture (red nucleus communication cerebrum to cerebellum)

Hearing : inferior colliculus is hearing

Regulates sleep and arousal states (RAAS)

Question 7

The Reticulatar Activating System is within the _______ section of the brainstem and is important in what?

Answer 7

RAAS: part of the midbrain

Important in arousal, alertness, attention, sleep phases

Question 8

PONS:

Ventral surface reveals what?

Dorsal surface reveals what?

If you pull back the cerebellum, you’d see the?

Answer 8

PONS:

Ventral surface reveals cranial nerves 5-8

Dorsal surface (between pons and cerebellum)

If you pull back cerebellum, you’d expose the 4th ventricle

Question 9

Explain the following peduncles within the pons:

Superior cerebellar peducle

Middle cerebella peduncle

Inferior cerebellar peduncle

Answer 9

PONS:

Superior cerebellar peduncle: carries fibers from cerebellum to midbrain and thalamus

Middle cerebellar peduncle: carries fibers to cerebellum

Inferior cerebellar peduncle: carries bi-directional fibers connecting cerebellum and spinal cord

Question 10

PONS Functions:

Cranial Nerve ______ functions

• Coordination of
• Arousal and Consiousness
• Which pathways cross through the pons?

Answer 10

Pons Functions:

Cranial Nerve 5-8 functions

Coordination of movement (pontine nuclei)

Arousal and conciousness (part of RAAS)

Pathways that go through the pons:

Corticospinal (fine motor control)

Spinothalamic (pain and temp)

DCML (proprioception)

Question 11

Explain what is important about the communication between the pons and the cerebellum?

Answer 11

Communication between pons and cerebellum:

Motor inputs from cortex

Visual inputs from visual cortex

Proprioceptive info from spinal cord

Coordination of movement is super important

Question 12

Medulla Oblongata:

Anatomy:

Dorsal vs ventral?

Cranial nerves ?

Answer 12

Medulla Oblongata:

Dorsal: gracile tract and cuneate tract

Ventral: pyramids that connect the spinal cord, pons, and cerebral cortex

Cranial Nerves 9-12

Question 13

The ________ tract crosses at the decussation of the pyramids, aka the CAUDAL section of the medulla

Answer 13

The corticospinal tract crosses at the CAUDAL section of the MEDULLA (called the pyramids)

Question 14

List some functions of the medulla oblongata

Answer 14

Medulla Oblongata Functions:
Regulation of a lot of Autonomic Functions

Functions associated with CN 9-12

HR

Blood flow in conjunction with nucleus tractusu solitarius (NTS)

Respiration

Digestion

Swallowing

Vomiting

Question 15

What are the bumps on the dorsal side of the midbrain?

Answer 15

Bumps on the dorsal side of the midbrain:

called the corpra qaudrigemina

Superior and inferior colliculi

superior colliculi: vision

inferior colliculi: hearing