Brain - Quiz 6

Parts are: medulla, pons, midbrain

Transmission (sends signals)
Vital reflexes
     - breathing, blood pressure
Other reflexes
     - swallow, vomit, cough, sneeze, hiccup
Visual and auditory (in midbrain)
     - superior colliculus: used for EYES and head motion to a stimulus
     - inferior colliculus: used for EARS and head motion to a stimulus

corpora quadrigemina  aka the four colliculi—two inferior, two superior.  (They are respectively named the inferior and superior colliculus).  The corpora quadrigemina are reflex centers involving vision and hearing

It is made up of thalamus, hypothalamus, and pineal.
It appears at the upper end of the brain stem, situated between the cerebrum and the brain stem.

it is a sensory relay system.
Signals received from the body.  Signals sent to cerebrum.

gray matter

regulates body temperature, hunger, thirst

chunks of gray matter

Surface:
sulcuses & gyruses (grooves and bumps), fissures are DEEP sulcuses AND 4 lobes (frontal, parietal, occipital, & temporal).
Structure:
gray matter (cortex & basal ganglia)
6 layers arranged in columns

Longitudinal (splits R & L hemispheres of brain)
Central (splits frontal and parietal lobes)
Lateral/Sylvian (splits the top and temporal lobes)
Transverse splits cerebrum from the brainstem

precentral (located in frontal lobe, before central fissure)
&
postcentral (located in parietal lobe, after central fissure)

gray and white.
Gray matter - cortex (shell around the brain) AND basal ganglia (aka a group of nuclei of varied origin in the brain that acts as a cohesive functional unit)
Gray matter is arranged in cortex as 6 layers arranged in columns
White matter- corpus callosum

counciousness

balance and posture
smooth, coordinated skeletal movements

cushions, it helps protect the brain.
it is filtered blood (it is also made from blood).  main difference between CSF and plasma is protein.  Protein is common in plasma but not in the CSF

blood --> choroid plexus --> lateral ventricles --> foramina of Monro --> 3rd ventricle --> Aqueduct of Sylvius --> 4th ventricle --> subarachnoid space --> arachnoid villi -- dural sinus

CSF gets in the subarachnoid space via the 4th ventricle

*carotid and vertebrals

a rotary of blood vessels in the brain

Circle of Willis is the joining area of several arteries at the bottom (inferior) side of the brain. At the Circle of Willis, the internal carotid arteries branch into smaller arteries that supply oxygenated blood to over 80% of the cerebrum.

SUGAR (glucose) and OXYGEN
Both of these are essential.  
ALSO needs to be able to REMOVE Carbon Dioxide to function properly

are venous channels found between layers of dura mater in the brain.[1] They receive blood from internal and external veins of the brain, receivecerebrospinal fluid (CSF) from the subarachnoid space, and ultimately empty into the internal jugular vein.

is a separation of the circulating blood from the brain extracellular fluid (BECF) in thecentral nervous system (CNS). It occurs along all capillaries and consists of tight junctions around the capillaries that do not exist in normal circulation

oxygen
glucose
carbon dioxide
water

what CAN'T penetrate? --> proteins

2 seconds w/o blood flow = loss of consciousness

blood starts to solidify, hence why we do CPR.

But at this point brain starts to die.

12 pairs

1 = OLFACTORY NERVE
found- underneath frontal lobe of cerebrum (nose area)
function - responsible for sense of smell

II = Optic Nerve
found- main line that leaves from eyes (forms optic chiasma when it crosses)
function- sense of sight

III = Oculomotor
found- connects eye fibers to the midbrain
function - moves the eye around and helps focus 
EYE has 6 muscles that move it around.  1-4 are located here.

IV = Trochlear
found- also connects eye fibers to pons/midbrain
function - also assists in eye movement
eye muscle 5 (out of the 6) is located here

V = Trigeminal (aka 3 twins)
found -spread over the face
function -Sensory nerve of the face, also controls chewing muscles

VI = Abducens
found- also connects eye fibers to pons/midbrain
function- eye movement (has NOTHING to do with actual vision, just movement).  It is the 6th eye muscle (out of 6)

VII = Facial
found -emerges from the brainstem between the pons and the medulla
function -controls/moves muscles of facial expression

VIII = Vestibulocochlear (aka auditory nerve)
found -emerges from the pontomedullary junction and exits the inner skull via the internal acoustic meatus (or internal auditory meatus) in the temporal bone.
function - hearing and balance

IX = Glossopharyngeal
found - nerve to the throat  [exits the brainstem out from the sides of the upper medulla, just rostral (closer to the nose) to the vagus nerve]
function - Used for swallowing

X = Vagus
found - starts in medulla and it extends down below the head, to the neck, chest and abdomen, where it contributes to the innervation of the viscera. 
function - part of parasympathetic system

(parasympathetic system is responsible for stimulation of "rest-and-digest" or "feed and breed", part of autonomic n. system, is unconscious)

XI = Accessory 
found -in the neck
function -controls the neck muscles that move your head

XII = Hypoglossal

found -"under the tongue"
function -it moves the tongue, also senses pain.  *IT has NOTHING to do with taste, not connected to tastebuds

Facial (VI)  --> front half of tongue
Glossophryngeal (IX) --> back half of tongue
Vagus (X) --> throat