22 - Brain Flashcards
What makes up the CNS?
Brain
Spinal cord
What makes up the PNS?
Cranial nerves
Spinal nerves
What makes up the ANS?
Sympathetic
Parasympathetic
Formation of nervous system occurs during the embryonic stage from the end of _______ week to the end of ________ week.
Second
Eighth
Superior (anterior or cranial) neuropore closes by day ______.
27
Inferior (posterior or caudal) neuropore closes by day ______.
30
The tripartite brain consists of what?
Prosencephalon
Mesencephalon
Rhombencephalon
The tripartite brain then divides into the pentapartite brain. The prosencephalon becomes _________ and _________; mesencephalon; and rhombencephalon becomes _________ and _________.
Telencephalon (most anterior)
Diencephalon
Metencephalon
Myelencephalon
The prosencephalon is not divided into ______ and ______ plates like rest of neural tube.
Alar
Basal
There are two pairs of evaginations from the prosencephalon which are…
Telencephalic vesicles
Optic vesicles
Telencephalic vesicles become what?
Cerebral hemispheres
Optic vesicles become what?
Retinas of the eye
Associate with diencephalon
Subphylum craniata (newer term for subphylum vertebrata) has two subgroups, which are…
Hagfishes (craniates without vertebrae)
Vertebrates (craniates with vertebrae)
The cranial end of the neural tube of all craniates is characterized by three primary brain vesicles, which are…
Prosencephalon
Mesencephalon
Rhombencephalon
The prosencephalon is the future…
Forebrain
The mesencephalon is the future…
Midbrain
The rhombencephalon is the future…
Hindbrain
The cranial end of the neural tube of all craniates is characterized by three primary brain vesicles. The differentiation of these vesicles occurs through localized thickenings of lateral walls and floor, and _________.
Evaginations
What is the major derivative of the myelencephalon that becomes continuous with the spinal cord?
Medulla oblongata
In this fish, the myelencephalon ism ore developed than other areas of the brain. Large neurons run the length of the tail, thought to be involved in swimming. (Myelencephalon is well developed in all the rest of the vertebrates).
Agnathans
Gray matter in the mesencephalon is organized into discrete _______ interspersed among myelinated (white) fiber tracts.
Nuclei
Gray matter in the spinal cord is continuous and is located more centrally and surrounded by myelinated fiber _______.
Tracts
This type of fish have vagal lobes associated with myelencephalon. The site of sensory nucleus (nucleus solitarius) in alar plate which may cause an enormous bulge on either side of the brainstem. May be associated with sense of taste.
Teleosts
In these, vagal lobes disappear from myelencephalon.
Amphibians
In these, the myelencephalon is well-developed.
Mammals
What are the components of the brainstem?
Medulla
Pons
Midbrain
In general, the ________ is made up of a mixture of long fiber pathways, 10 of 12 cranial nerves that enter and leave, well-organized nuclei, and a network of cells which forms the ________ reticular formation.
Brainstem
Brainstem
In the brainstem, most of the nuclei are related directly to…
Cranial nerve functions
Motor control pathways
List the descending tracts in the medulla.
Corticospinal Spinal tract V Medial longitudinal fasciculus Tectospinal Rubrospinal
List the ascending tracts of the medulla.
Medial lemniscus Spinothalamic tract Spinoreticular tract Spinocerebellar tract Cuneocerebellar tract
There are two additional components of the medulla that are not ascending or descending tracts. What are they?
Cranial nerve nuclei VIII-XII
Inferior cerebellar peduncles
The medullary pyramids (anterior) are the location of what?
Lateral corticospinal tracts
85 percent of corticospinal fibers decussate in the inferior border of the ________.
Medulla
After corticospinal fibers decussate at the inferior border of the medulla, the fibers then enter the…
Lateral columns of spinal cord
The lateral corticospinal tracts help with initiating and modulating _________.
Movement
In the medullary olives (anterior), the inferior olivary nuclei receive input from most motor areas of the brain and spinal cord. What are the functions of this?
Balance
Coordination
Sound impulse modulation
Axons of the medullary olives project to the contralateral cerebellar hemisphere via the ________ ________. These axons signal the cerebellum when a movement deviates form the planned movement.
Olivocerebellar tract