Gross Brain Lecture Flashcards
proximal vs distal
Proximal=closer
Distal=away
Caudal vs rostral
Caudal=towards tail
Rostral=towards head
Lateral Fissure
1) AKA sylvian fissure
2) Separates the frontal and parietal cortices from the temporal cortex
Operculum
1) Regions of cerebrum bordering the lateral fissure
2) Ex: frontal, parietal, or temporal operculum
Corpus Callosum
1) Myelinated axons that connect cerebral hemispheres
2) White matter
Grey Matter
Regions of the CNS containing a high density of neuron cell bodies
White Matter
Regions of the CNS containing a high density of myelinated fiber tracts(axons)
Thalamus
1) Bilateral Subcoritcal structure
2) relay of information to and from cerebral cortex; except olfaction goes to cerebral cortex first then thalamus
- sexual behavior
- feeding
- hormonal output of pituitary gland
- body temp regulation
3) Aka diencephalon
Cerebellum
- location
- function
1) Suprasegmental structure-superior and dorsal (away from) to brainstem
2) Coordination
Choroid Plexus
1) Produces CSF
2) located:
- Body and inferior horn of lateral ventricles
- 3rd ventricle
- 4th ventricle
Ventricular System: CSF Flow
Lady Monro’s Third Child Forced Magendie & Lushka to Say Ass & Shit
1) Lateral Ventricles
2) Interventricular foramen (Foramen of Monro)
3) Third Ventricle
4) Cerebral Aqueduct
5) Fourth Ventricle
6) Median Aperature (Foramen of Magendie)
or Lateral APerature (Foramen of Lushka)
7) Subarachnoid space
8) Arachnoid Granulations/Villus
9) Superior Sagittal Sinus
Where is the 3rd ventricle located?
1) on the Midline of the brain, between the thalamus and hypothalamus
2) continuous with cerebral aqueduct
Median and Lateral Aperatures
1) Median Aperature (foramen of Magendie) -not bilateral 2) Lateral Aperature (Foramen of Lushka) -bilateral 3) open into subarachnoid space -bathe the outer surface of brain and Spinal cord with CSF
Where is the 4th ventricle located?
1) Between the pons/medulla and the cerebellum
What are the 3 routes that CSF flows from the fourth ventricle?
1) Median Aperature
- not bilateral
- Foramen of Magendie
2) Lateral Aperature
- bilateral
- Foramen of Lushka
3) Central canal of medulla and spinal cord
- not open/patent
Trigon area of Lateral Ventricle
1) b/w posterior and inferior horn
2) Calcified glomus
3) Common for adults
Arachnoid Villus
1) Aka arachnoid Granulations
2) protrude into SSS (dural sinus)
3) site of absorption of CSF into systemic circulation (SSS)
Stenosis
Squeezing/making aperture smaller
-impeding flow
Dura Mater
1)outermost and thickest
2) fused with internal periosteum and doesn’t follow contour of brain
3) 2 layers
meningeal layer-inner layer
-fold of this layer form septa that divide cranial cavity
-falx cerebri, tentorium cerebelli, falx cerebelli, diaphgrama sella
periosteal/endosteal layer-outer later
- stops at foramen magnum and fuses with occipital bone
- *layers not easily seperable except venous sinus
Arachnoid membrane
1) lines the dura mater
2) doesn’t follow the contour of the Brain
Subarachnoid Space
1) Contains major arteries and veins that supply the CNS
Pia Matter
1) vascularized, areolar membrane
2) extends enter every sulcus and fissure of brain
3) Very thin and transparent
Relationship of neurons/axons
Direct relationship between:
- diameter of axon
- thickness of myelin sheath
- distance between nodes of the myeline sheath (nodes of Ranvier)
- conduction velocity of nerve fiber
Large diameter axons vs thin diameter axons
1) large diameter axons
- thick myelin sheaths
- longer internal distances (nodes of ranvier)
- EXHIBIT faster conduction velocities
2) Thin diameter axons
- thin myelin sheaths
- shorter internodal distances
- slower conduction velocities
3) Smallest axons
- no mylein
- slowest conduction velocities
Cell types of Nervous System
Neurons and glial cells
Neurons
1) Basic structural and functional unit of the nervous system
2) Consists of a:
- cellbody (soma or perikaryon)-gray matter
- dendrites-processes off of cell body
- axons- single process to other areas (white matter(
Myelin
insulting lipoprotein
Areflexia
lack of reflex
Hyporeflexia
weakened reflex
Hyperreflexia
excessively active reflex
-indicative of neurologic disorder
Medulla Oblongata
1) aka medulla
2) consists of:
- neurons that perform functions associated with the medulla
- asscending (sensory) and descending (motor) tracts
Forebrain composed of:
1) Cerebral hemisphere
2) basal nuclei
3) Thalamus
What is the location of the thalamus?
1) rostral to midbrain
2) Surrounded by cerebral hemisphere
Cerebral Cortex
1) layer of cell bodies
2) .5 cm thick
Subcortical White matter
1) 2nd layer of cerebral hemisphere
2) basal nuclei
- motor function
Afferent
conduction of signal toward a structure
-incoming piece of info
efferent
conduction away from structure
-sending info
Medial
toward or at the midline
Lateral
away fro midline
Cerebral hemisphere:
- posterior/doral
- santerior/ventral
- rostral
- caudal
1) Posteior/dorsal
- toward the top of the brain
2) Anterior/ventral
- base of the brain
3) Rostral
- toward frontal pole
4) Caudal
- toward occipital pole
Sympotom vs signs
1) Symptom
- deviation from normal that is stated by patient
- subjective indicator
2) Sign
- deviation from normal that is stated by physician
- objective indicator
Multiple Sclerosis
1) Demyelinating disease
2) Oligodendrocytes and their myelin segments degenerate
- replaced by astrocytic plaque
3) Loss of myelin result in an interruption of propagation of action potentials down these axons
Compression injury
1) Axonotmesis
- crushed peripheral nerve
Transection injury
1) Neurotmesis
- severed peripheral nerve
Traumatic neuroma
1) Phantom pain in people with ampuateed limbs
- neuroma developed in amputated limb
Norepinephrine
1) NT
- regulation of the sympathetic division of autonomic nervous system
- in peripheral nervous system binds to a- and B-adrenergic receptors
What is the greatest source of norepinephrine in the mammalian CNS?
Locus Ceruleus
Reserpine
1) plant alkaloid
- inhibits dopamine and norepinephrine
2) Irreversibly inactivates the monoamine-H+ transporter
- tranports dopamine in synaptic vesicle-> norepinephrine
3) Earliest therapeutic agents for treatment of hypertensive cardiovascular disease
4) Causes noradrenergic neurons:
- innervate arteriolar smooth muscle to produce less NE=vasoconstriction -overall reduction in BP
- reduced ability to stimulate noradrenergic cardiac neurons which cOuld increase heart rate->lower cardiacs output
5) cause early onset of parinksons symptoms
6) worse clinical depression
7) Rarely used today to treat hypertension