Gross Brain Flashcards
What are the parts of the PNS?
Cranial Nerves
Spinal Nerves
What are parts of the CNS?
Brain
Spinal Cord
What are the divisions of the central nervous sytem?
Prosencephalon
Mesencephalon
Rhomencephalon
Spinal Cord
What is the Proencephalon?
Forebrain
Includes the Telencephalon (cerebral cortex) and diencephalon
What is the Mesencephalon?
It includes the midbrain
What is the Rhombencephalon?
Hindbrain
It includes the Metencephalon (pons) and Myelencephalon (medulla)
What is included in the Brain stem?
Midbrain
Pons
Medulla Oblongata
Whata re the four parts of the adult brain?
Brain Stem
Cerebellum
Diencephalon
Cortex
What are the boundaries of the Medulla Oblongata?
- Caudal - decussationof the pyramids
gradual transition from spinal cord
extends below foramen magnum
- Rostral - pontomedullary junction
What are the functions of the medulla oblongata?
- Cardia center: Force and rate of heartbeat
- Respiratory center: controls rhythm and rate of breathing
Stroke and/or trauma to the medulla oblongata leads to what?
DEATH
What are the parts of the medulla oblongata?
Ventrally
Olive - inferior olivary complex: motor learning
Pyramids - corticospinal tract
decussation of pyramids - background information
Dorsal
Cuneate (outer) and Gracile (two inner)
(tubercle is the bulkier superior portion of the two and the fasciculus is the lower smoother half)
Obex and median sulcus
What are the 4 cranial nerves the originate from the Medulla Oblongata?
CN: IX, X, XI* (originate from dorsal to the olive)
and CN: XII (originate from the medulla, between the pyramids and inferior olive)
What are the 3 nerves that originate from the pontomedullary junction?
CN: VI, VII, and VIII
What is the purpose of the Pons?
Relay Signals between Cerebral cortex and Cerebellum
What nerves comes from the pons?
CN: V
Originates from the middle cerebellar peucle
What are the parts of the pons?
Middle cerebellar peduncle
Connects pons to the cerebellum
The fourth ventricle is found dorsal to what?
Dorsal to the medulla and pons and it sepreates the medullapons from the cerebellum.
What is creative about the formation of the 4th ventricle?
The fourth ventricle is formed because the presence of the cerebellum causes the roof plate to split and the canal enlarges to become the 4th ventricle over the pons and medulla
*the general embryonic origin of sensory and motor nucleu seen in the spinal cord is maintained
What are the parts of the midbrain?
Dorsally,
Corpora Quadrigemina
Superior colliculus (visual/oculomotor reflexes)
inferior colliculus (auditory relay center)
What nerve exits the brain immediately caudal to the inferior colliculus?
Trochlear Nerve
CN: IV (originates from the dorsum of the midbrain)
What are the pars of the midbrain?
Cerebral peduncle (corticospinal tract)
You can also see CN: IV (laterally) and III (medially)
What is the cerebral aqueduct?
It is the continuation of teh 4th ventricle that is behind the midbrain (tranverses the midbrain)
Where is the tectum located?
The tectum, which also stands for roof, is found dorsal to the cerebral aqueduct.
When you are looking at a cross section of the midbrain midbrain what can you see?
What is A and B?
A = Tegmentum
B = Basilar pons
This is an image of what?
Cerebellum
What is the cerebellum
coordinates and smooths movements
maintains equilibrium
maintains posture
What are the parts of the diencephalon?
Thalamus
hypothalamus
epithalamus
What is the thalamus?
Sensory(exceot olfaction)/motor/limbic relay center for information en route to the cortex
Specific thalmic nuclei project to specific areas of the cortex
What are the two specific thalmic nuclei?
Medial geniculate nucleus - auditory relay nucleus
Lateral geniculate nucleus - visual relay nucleus
What is the only nerve that originates from the diencephalon?
Optic nerve
CN II
This nerve is not a true nerve? Why
CN II is not a true nerve. It is a tract of the CNS
- The retina develops as a diverticulum of the forebrain (optic vesicle)
- Axons of CN II are surrounded by glia, not Schwann cells
- CN II is surrounded by meninges