Exam 4 Flashcards
Rostral
Up and to the front
Caudal/caudad
Back and down
Sagittal plane
a cut from anterior to posterior (between the eyes)
Coronal plane
a cut from right lateral to left lateral (ear to ear)
Horizontal plane
Separates top and bottom
Oblique plane
An angled plane
Telencephalon
- Most advanced part of CNS
- Outer most part of brain (cerebral)
- Where we think, process, and remember
Diencephalon
- Inner part of brain
- contains hypothalamus (major regulator of sensing what is going on in body)
Brian steam location:
and 3 sections:
Under diencephalon
Midbrain (superior)
Pons
Medulla oblongata (Inferior)
Spinal cord decent ____ of the way down the spinal canal.
2/3
Sulcus/sulci
“grooves” or depressions on surface of brain
Gyrus/gyri
“lump” on surface of brain
Fissure
“really deep grooves”
4 main lobes of the brain:
- Frontal
- Parietal
- Occipital
- Temporal
Temporal lobe
Inferior to temporolateral fissure.
Processes hearing.
Frontal lobe
Superior to temporolateral fissure.
Anterior to central sulcus.
Thinking, personality, motor cortex
Parietal lobe
aka Somatosensory cortex Posterior to central sulcus. Superior to occipital lobe. Primary sensory area. All peripheral sensory information comes here.
Occipital lobe
aka vision cortex.
Back of brain.
Post central gyrus
Lump immediately posterior to central sulcus.
Sensory cortex.
Pre-central gyrus
Lump immediately anterior to central sulcus.
Primary motor cortex (controls skeletal muscle).
Premotor cortex
Lump immediately anterior to pre-central gyrus.
Thinking and planning of motor event.
White matter
Sending message part.
Myelinated axons.
More energy efficient than grey matter.
Gray matter
Decision-making part.
Lots of cell bodies and dendrites.
Some axons.
Requires more energy than white matter.
What % of O2 and glucose delivered to the brain is used by grey matter?
75%
Cingular gyrus
Just above corpus callosum. Involved with pain, emotions, limbic system (feelings)
Corpus callosum
cross talk between right and left side of the brain. White matter.
Broca’s Area
Function: word formation
Location: frontal lobe
Wernicke’s Area
Function: language comprehension and intelligence
Location: temporal lobe
Limbic system
has to do with emotions. Includes cingular gyrus and some parts of temporal lobe.
Sensory signals in spinal cord:
Ascending pathways
Motor signals in spinal cord:
Descending pathways
Anterior median fissure
Wide deep groove in front of spinal cord
Posterior median sulcus
Deep groove but not very wide. located in back of spinal cord.
Anterior white commissure
Small path of white matter that allows signals to get from one side of spinal cord to another, however most stay on the side they are sent or received from.
Lamina X
Small path of grey matter that allows signal in spinal cord to cross from one side to the other
Dorsal horns of spinal cord
Grey matter that protrudes into white matter posterior. Sensory input
Ventral horns of spinal cord
grey matter that protrudes into white matter anterior. Motor output
Rootlets
Small bundles of neurons that are going into the back and coming out the front of spinal cord. They all join together to create spinal nerves
Posterior VS anterior rootlets
Posterior rootlets have spinal ganglia and deal with sensory transmission.
Anterior rootlets do not have ganglia (bc the cell bodies are in the spinal cord) and they deal with motor transmission.
Ganglia
collection of cell bodies outside CNS (usually like-minded)
The peripheral nervous system starts..
..where rootlets come together to create spinal nerves.
Cranial meninge layers: (superior to inferior)
- Dura mater
- Arachnoid mater
- Space for CSF and vessels
- Pia mater
CSF function and properties:
- provides energy and pH buffer
- carries away waste
- shouldn’t contain any RBCs
- may contain a few WBCs
Concentration of ions in CSF:
[K+] 40% lower than blood [Cl-] 30% higher than blood [Na+] about the same as blood [glucose] 60mg/dL [HCO3-]
How long will it take for someone to lose consciousness if their blood flow to the brain were completely cut off?
5-15seconds
pH of CSF:
pH 7.31
Normal CSF pressure (ICP):
8-12mmHg
Normal quantity of CSF:
150mL
Normal CSF production rate:
500mL/day
Type of glial cells that produce CSF:
Ependymal cells
Locations of ependymal cells:
-Primarily in ventricles.
Choroid plexus
A tissue made up of a bunch of ependymal cells.
Location of Choroid Plexus:
- Lateral ventricles (largest producer of CSF)
- 3rd/4th ventricles
Arachnoid granulations
Where CSF is removed and enters the venous system.
Vessel where arachnoid granulations are located:
Superior Sagittal Sinus
Foramen Magnum
Hole at the base of the skull where the spinal cord descends into the spinal column.
Interventricular foramen (Foramen of Monroe)
Connects and allows CSF drainage from lateral ventricles to 3rd ventricle.
Cerebral Aquaeduct (Foramen of Silvius)
Connects and allows CSF drainage from 3rd ventricle to 4th ventricle.
Lateral aperture
Extends out laterally from both sides of the 4th ventricle and allows CSF to drain out laterally and around anterior of brain stem.
Median aperture
Allows CSF to flow out the back of the 4th ventricle and circulate around the cerebellum.
Central Canal
A canal that runs from 4th ventricle down the length of the spinal cord where CSF flows down.
Cerebellomedullary cistern (aka cisterna magna)
area that holds a lot of CSF under cerebellum and behind brain stem
Venous blood flow through brain:
Superior and Inferior sagittal sinuses –> sinus confluence –> transverse sinuses –> sigmoid sinuses –> jugular veins.
Falx Cerebri
Ridged connective tissue that divides the left and right cerebral cortex.
Tentorium cerebelli
Ridged connective tissue that separates occipital lobe and cerebellum.
Internal carotid artery
Feeds brain.
Main feed arteries into the circle of willis
External carotid artery
Feeds side of face and back of head.
Vertebral arteries
Branch off at more lateral and distal point than the carotids. They are carried up through the C-spine and through the foramen magnum.
Circle of Willis
Circle of arteries in the brain
Basilar artery
is on the anterior surface of the brain stem and feeds the posterior of the C of W. It’s created by the joining of the 2 vertebral arteries.
Anterior cerebral artery
One of the main output arteries of the circle of willis.
Feeds anterior part of cerebral cortex.
Middle cerebral artery
One of the main output arteries of the circle of willis. Larger than anterior cerebral artery because it feeds more tissue.
Posterior cerebral artery
One of main output arteries of the circle of willis. Provides bulk of blood flow to posterior portions of the brain.
Posterior communicating artery
connects posterior cerebral artery with middle cerebral/internal carotid artery.
Anterior communicating artery
connects right and left anterior cerebral arteries.
3 cerebellar arteries:
- Superior cerebellar artery
- Anteroinferior cerebellar artery
- Posteroinferior cerebellar artery
Epidural Hematoma
Bleed outside of dura mater.
Usually from crush injury or fx skull.
Common in MVAs.
Subdural hematoma
Too much fluid/bleeding between dura and arachnoid layers.
Subarachnoid hematoma
Bleeding in arachnoid space.
Very difficult to fix because clot becomes one with neural tissue.
Upper limit autoregulation (ULA)
The point at which brain blood vessels can’t constrict any further, as a response to high BP
lower limit autoregulation (LLA)
The point at which brain blood vessels can’t relax any further, as a response to low BP.
If we can’t auto regulate profusion in the brain we risk…
over perfusion with high BP and under perfusion with low BP.
Over perfusion of brain can cause..
increases in ICP.
Auto-regulation is important in the brain as well as the…
spinal cord and kidneys.
Normal volume of cerebral blood flow:
750-900ml/min
If we have a drop in pCO2 of 4mmHg, what precent drop do we have in brain blood flow?
20%
An increase in metabolism of the brain results in an increase CO2 level which will cause the brain blood vessels to….
relax (increase ICP).
A decrease in metabolism of the brain results in a decrease CO2 level which will cause the brain blood vessels to…
constrict (decrease ICP).
How many Cervical vertebrae are there?
7
How many Thoracic vertebrae are there?
12 (same number of ribs)
How many Lumbar vertebrae are there?
5
How many Sacral vertebrae are there?
In adults, 1 sacral made of 5 fused sacral vertebrae (fused by age 18)
How many coccygeal vertebrae are there?
In adults, 2 coccygeal vertebrae (started with 4, then 3 fused together)