Neuroanatomy Flashcards
What is the function of the CNS and its components
- integration and command center
- brain and spinal cord
What is the function of the PNS and its components
- carries messages to and from the CNS
- paired spinal and cranial nerves
What are the two functional nervous systems
Somatic nervous system and autonomic nervous system
Name the neuroglia in the CNS
Astrocytes, Microglia, Ependymal cells, Oligodendrocytes
Name the neuroglia in the PNS
satellite cells and schwann cells
What is the function of an astrocyte
- repairs damage in the CNS and is the most abundant
What is the function of microglial cells
defensive cells of the CNS
What is the function of oligodendrocytes
form myelin sheaths around nerve fibers in the CNS
What is the function of satellite cells
acts as protective cushions and supplies nutrients in the PNS
What is the function of schwann cells
form myelin and surround neurons in the PNS (act as oligodendrocytes but for the PNS)
What are clusters of cell bodies called in the CNS and PNS
CNS = nuclei
PNS = ganglia
What are bundles of processes (axons & dendrites) called in the CNS and PNS
CNS = tracts
PNS = nerves
What is the receptive region of a neuron called
dendrites (conveys electrical signals toward the cell body)
What is the function of an axon
conduction region of a neuron, transmits impulses away from the cell body
Where are neurotransmitters released from?
knoblike axon terminals (boutons)
What is the function of myelin sheath
protect and electrically insulate the axon as well as increase the speed of impulse transmission
White matter is ________ whereas gray matter is _______
white matter is myelinated whereas gray matter is unmyelinated
Describe multipolar neurons
1 axon and several dendrites
- most abundant
- motor neurons and interneurons
Describe bipolar neurons
1 axon and 1 dendrite
- retinal neurons
- rare
Name the 3 meninges from superficial to deep
dura mater
arachnoid mater
pia mater
Describe unipolar neurons
single short process that has 2 branches
-peripheral process is more distal and associated with a sensory receptor
-central process is the branch entering the CNS
Name the layers of the dura mater
Periosteal - adherent to the skull
Meningeal - deep to the periosteal layer and forms the falx
What is in the longitudinal fissure attached to the crista galli
falx ceribri
what goes along the vermis of the cerebellum
falx cerebelli
what is the horizontal dural fold over the cerebellum and in the transverse fissure
tentorium cerebelli
What runs between the falx cerebri
superior sagittal sinus
which of these is epidural and which of these is subdural
right = subdural
left = epidural
Describe the arachnoid mater
-middle layer with web-like extensions and protruding arachnoid villi that permit CSF reabsorption
-subarachnoid space contains blood vessels and CSF
Describe the pia mater
delicate vascularized connective tissue that clings tightly to the brain
Name the 4 regions of the adult brain
cerebral hemispheres (R and L)
diencephalon
cerebellum
brain stem (midbrain, pons, medulla)
Describe the spinal cord
- extends from foramen magnum to the intervertebral disc of L1 and L2
- central cavity, edges made of gray matter with white matter core
What are ventricles lined with
ependymal cells
Describe where the 4 ventricles are located
- 2 C shaped ventricles in the L and R cerebral hemispheres
- 3rd ventricle in the diencephalon
- 4th ventricle in the hindbrain dorsal to the pons
What connects the L and R ventricles to the 3rd ventricle
the interventricular foramen of monro
What connects the 3rd ventricle to the 4th ventricle
cerebral aqueduct aka aqueduct of silvus
What connects the 4th ventricle to the subarachnoid space
the lateral aperture of luschka and the median aperture of magendie
What connects the 4th ventricle to the spinal cord
the central canal
what is the function of CSF
gives buoyancy, protection, and nourishment to the CNS as well as carrying chemical signals
What is the function of the choroid plexuses
produces CSF at a constant rate
What is the blood brain barrier made of and what does it do
continuous endothelium of capillary walls, basal lamina, feet of astrocytes
-maintains stable environment for brain and separates some bloodborne substances
What does the BBB allow to pass through
fat soluble substances like alcohol, nicotine, and anesthetics
Where is there a lack of blood brain barrier
vomiting center and the hypothalamus - where it is necessary to monitor the chemical composition of the blood
Name the 5 lobes of the cerebral hemispheres
frontal, parietal, temporal, occipital, insula
What separates the precentral gyrus of the frontal lobe and the postcentral gyrus of the parietal lobe
the central sulcus
what separates the L and R hemispheres
the longitudinal fissure
what separates the cerebrum and the cerebellum
transverse cerebral fissure
what divides the temporal lobe from the frontal and parietal lobes
Slyvian/lateral fissure
What do association fibers do
connect adjacent gyri, do not cross the midline
What do commissural fibers do
connect wide areas of the cerebral cortex of the two hemispheres across the midline
What do homotopical and heterotpical comissural fibers do
homotopical connects identical areas, heterotopical connects different areas
what are the 4 areas of the corpus callosum
Rostrum (orbital surface)
Genu (medial/lateral frontal lobes)
Trunk (wide areas of cerebral cortex)
Splenium (occipital lobes)
what do projection fibers do
connect the cerebral cortex with sub-cortical gray matter of the basal ganglia, thalamus, and nuclei of the brain stem and spinal cord
What is the major group of projection fibers connecting the rest of the body to the primary motor cortex
the pyramidal/corticospinal tract
Describe the travel of the pyramidal/corticospinal tract from top down
primary motor cortex
corona radiata
internal capsule
midbrain
pons
medulla
spinal cord
What are the parts of the internal capsule
What are the arterial suppliers of blood to the brain
pair of internal carotid arteries
pair of vertebral arteries
what do the arterial pairs form
circle of willis
What are the 3 parts of blood supply in the brain
Name the 3 regions of the brain stem
midbrain, pons, medulla oblongata
How many cranial nerves are associated with the brain stem?
10 of 12
The nuclei of which cranial nerves are located in the midbrain?
Oculomotor (3), Trochlear, (4)
What are the 2 parts of the diencephalon?
thalamus, hypothalamus
Where are cerebral peduncles located
midbrain (ventral)
where is the substantia nigra located
midbrain (ventral)
Where is the corpora quadrigemina located
midbrain (posterior)
where are the superior and inferior colliculi located and what do they do?
Midbrain (posterior)
superior: visual reflex center
inferior: auditory relay center
What cranial nerves have their nuclei in the posterior midbrain?
oculomotor and trochlear
Why are the substantia nigra named the way they are and what is their degeneration associated with?
because they are melanin pigmented and if degenerated = Parkinson’s
What do the fibers of the pons do?
connect higher brain centers and the spinal cord via the pyramidal tract, and relays impulses between motor cortex and cerebellum
What cranial nerve origins are located in the pons?
trigeminal (5), Abducens (6), Facial (7)
At what level does the medulla oblongata join the spinal cord?
level of the foramen magnum
What are the 2 major landmarks of the medulla oblongata?
pyramids and olives
What are the pyramids of the medulla oblongata
2 ventral longitudinal ridges formed by pyramidal tracts
what are the olives of the medulla oblongata
inferior olivary nuclei that relay sensory info from muscles and joints to cerebellum
What cranial nerves are associated with the medulla oblongata
8, 9, 10, 11, 12
What center regulates breathing
pons and medulla
what center regulates vestibular nuclear comples
medulla oblongata
What does the vestibular nuclear complex do
mediates responses that maintain equilibrium
Where are autonomic reflex centers located
medulla oblongata
where is the cardiovascular center located and what does it do
medulla oblongata
- cardiac center adjusts force and rate of heart contraction
- vasomotor center adjusts blood vessel diameter for BP regulation
Where is the respiratory center located
medulla oblongata
- controls respiratory rhythm, rate, depth in conjunction with pontine centers
What does the cerebellum do
subconsciously provides precise timing and appropriate patterns of skeletal muscle contraction
Describe the anatomy of the cerebellum
2 hemispheres with 3 lobes each, connected by vermis
- transverse gyri = folia
- treelike pattern of white matter - arbor vitae
Name the cerebellar nuclei later to medial
dentate, emboliform, globose, fastigii
Describe the 3 cerebellar peduncles
paired ipsilateral fibers
- superior peduncles connect cerebellum to midbrain
- middle peduncles connect pons to cerebellum
- inferior peduncles connect medulla to cerebellum
what does the cerebellar vermis of the homunculus control
the axial and proximal musculature of the limbs
what does the intermediate part of the cerebellar homunculus control
distal musculature
what does the lateral part of the cerebellar homunculus control
involved in motor planning
what does the flocculonodular lobe of the cerebellar homunculus control
balance, eye movement
What is the blood supply of the cerebellum
superior cerebellar artery (SCA)
anterior inferior cerebellar artery (AICA)
posterior inferior cerebellar artery (PICA)
What are the 2 branches of the basilar artery that supply the cerebellum
SCA and AICA
what is the largest branch of the vertebral artery that supplies the cerebellum
PICA
Describe lateral medullary syndrome aka PICA syndrome aka Wallenberg syndrome
- most common cerebellar stroke
- PICA embolus/ischemia
- pain or temporary loss of contralateral trunk, extremity control and ipsilateral face: dysphagia, slurred speech, vertigo, nystagmus, ataxia, horner’s syndrome