Singh 5: The Brainstem Flashcards
What are the three major divisions of the brainstem?
From rostral to caudal?
From rostral to caudal:
Midbrain (derived from mesencephalon)
Pons (together with cerebellum = metenceph)
Medulla (myelonocephalon)
The Edinger Westphal Nucleus (cranial Nerve 3) is associated with which part of the brainstem?
MIDBRAIN
Which cranial nerves are associated with the midbrain?
Cranial nerves 3 and 4
Midbrain Anatomy:
What is the tectum
What is the tegmentum
What is the cerebral penducles
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
MIDBRAIN ANATOMY:
Substantia nigra
Red nuclei
MIDBRAIN:
Substantia nigra: motor movement, Parkinson;s disease, pigmented
Red nuclei: communication between cerebellum and cerebrum
Explain some functions of the midbrain:
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)
The Reticulatar Activating System is within the _______ section of the brainstem and is important in what?
RAAS: part of the midbrain
Important in arousal, alertness, attention, sleep phases
PONS:
Ventral surface reveals what?
Dorsal surface reveals what?
If you pull back the cerebellum, you’d see the?
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
Explain the following peduncles within the pons:
Superior cerebellar peducle
Middle cerebella peduncle
Inferior cerebellar peduncle
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
PONS Functions:
Cranial Nerve ______ functions
- Coordination of
- Arousal and Consiousness
- Which pathways cross through the pons?
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)
Explain what is important about the communication between the pons and the cerebellum?
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
Medulla Oblongata:
Anatomy:
Dorsal vs ventral?
Cranial nerves ?
Medulla Oblongata:
Dorsal: gracile tract and cuneate tract
Ventral: pyramids that connect the spinal cord, pons, and cerebral cortex
Cranial Nerves 9-12
The ________ tract crosses at the decussation of the pyramids, aka the CAUDAL section of the medulla
The corticospinal tract crosses at the CAUDAL section of the MEDULLA (called the pyramids)
List some functions of the medulla oblongata
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
What are the bumps on the dorsal side of the midbrain?
Bumps on the dorsal side of the midbrain:
called the corpra qaudrigemina
Superior and inferior colliculi
superior colliculi: vision
inferior colliculi: hearing
