CNS Anatomy Flashcards
CNS vs. PNS
CNS - brain and spinal cord
PNS - all the nerves that go from CNS to take impulses out to create effects and fibers that bring info back
EXCEPTION: optic nerve and retina and olfactory nerve are considered part of the CNS - described as outpatchings of the brain
weight of brain vs. energy consumption
brain is only 2% of body weight but uses 20% of the blood circulation
-body expends a lot of energy keeping the brain viable
size of brain in infant
young brain lacks insulation that adult brain does since it is still developing and much bigger proportional to the body
legal definition of death
brain death - analysis of brain waves is considered for death
color of brain during surgery
pink tissue perfused with a lot of blood vessels
arteries supply blood and veins take it away
what does brain do during surgery?
beating like the heart since the blood is coursing through and around the brain and the heart beating is changing pressure of cerebrospinal fluid (CSF)
variability in brain size
we all have different head and skull sizes and brain fills in
features of brain
similar to fingerprints and faces where there are consistent structures that may look different
gyri
folds in brain that increase the surface area for the gray matter
sulci
-gaps/valleys in-between the gryi
-vessels pass through these to go from one part of the brain to another
fissure vs sulcus
fissure - open to another part of the brain
sulcus - has a dead end…insert probe and you would hit brain matter
sylvian fissure/lateral sulcus
-labelled differently depending on where it is identified
-in one part is considered a sulcus but in another it is considered a fissure
-it is the division between frontal and temporal
-need to go through this to get to the midbrain or brainstem
cerebrum
-whole brain
-divided into lobes that are paired except for occipital lobe
-frontal - problem solving, word production, behavioral control and emotion
-temporal (2 lobes that run into fossa behind eye) - memory and emotion plus word understanding
-occipital - vision
sphenoid wing
corresponds with sylvian fissure and forms sulcus
cerebellum
-little brain
-coordination of movement and allows us to choreograph complex movements
Ex. DOES NOT fire skeletal muscles to walk/dance but coordinates movement
motor strip
-anterior to central fissure in the temporal lobe
-controls fine motor movements
somatosensory strip
-controls sensory feeling in fingers and toes
-posterior to central sulcus and located in temporal lobe
homunculus (little man)
-components of the motor and somatosensory strips
-motor strip has a lot of fibers to control fingers and face
-looking at coronal slice of brain
sagittal fissure
separates the brain
ventricles
parts of brain that are filled with cerebrospinal fluid (CSF)
brainstem
consists of the pons, medulla oblongata, and midbrain
-nerves, tracts, and dendrites are passing through the midbrain and medulla oblongata
midbrain
gives rise to two important nerves:
-ocular motor (CN 3)
-trochlear nerves (CN 4)
-forms the top of the brainstem
pons
controls three nerves:
-trigeminal nerve (CN 5), which transmits sensory info to the skin, sinuses, and mucous membranes in the face
-abducens nerve (CN 6) that controls the lateral movement of the eye
-facial nerve
-tracts run throughout the pons and midbrain
-connection between the right and left cerebellum
medulla oblongata
gives rise to three nerves:
-vestibular cochlear nerve (CN 8), which controls balance and hearing
-glossopharygneal (CN 9) for movement of the tongue
-vagus nerve (CN 10) which is called the vagabond since it sits very high up then branches down and helps with homeostasis —> works with the digestive and respiratory systems plus the heart
-accessory nerve (CN 11), located in the neck and helps with motor innervation to the muscles of the neck and upper back
-hypoglossal nerve (CN 12) and controls the innervation of the tongue
diencephalon
-upper portion of the brainstem
-forms the conduit between the brainstem, body, and brain
-contains pineal gland, thalamus, and hypothalamus
cerebral aquaduct
-narrow-like tube structure that connects the third ventricle to the fourth ventricle of the brain
-allows cerebrospinal fluid to flow between these ventricles
pineal gland
tiny endocrine gland in the middle of your brain that helps regulate your body’s circadian rhythm
clinical correlate: Andre the Giant
-neoplasm surrounding his pituitary gland, which caused giantism
-anesthesiologists would use his alcohol consumption to gauge how much sedative to give him for medical procedures
sella turcia (turkish saddle)
the pituitary gland sits here
corpus collusum
-bridge between left and right brains with tracts of white matter
-connections between the hemispheres are mixing through it
-helps left and right brains communicate