The brain Flashcards
4 major regions of the brain
- Cerebrum
- Diencephalon
- Brain Stem
- Cerebellum
where does the consciousness reside
cerebral hemispheres
gyri
superficial folds
sulci
depressions between gyri (folds)
5 regions of the brain after 5 weeks of develpment and what they later become
- Telencephalon - cerebrum
- Diencephalon - diencephalon
- Mesencephalon - mescencephalon
- Metencephalon - cerebellum and pons
- Myelencephalon - medula oblongata
Gray matter (cerebral cortex)
consists of mostly neuron cell boddies, glial cells and mylanated axons
located outside in brain and inside in spinal cord
White matter (cerebral medulla)
axons that are mylanated
Located inside in brain and outside in spinal cord
3 meninges that protect the brain
dura mater
arachnoid mater
pia mater
dura mater
outermost of the three meninges. It not only is found on the outside of the CNS, but also contributes to several inward partitions (septa) that separate parts of the brain
2 layers of the dura mater
superficial periosteal layer
deep meningeal layer
dural sinuses
periosteal layer and meningeal layer separate to form blood filled spaces. These sinuses eventually transport the blood to the internal jugular veins
this space exists between the cranium and the dura mater
epidural space
arachnoid mater
next layer under the dura mater
gets its name from its spidery legs, around which CSF flows
subarachnoid space
space in between the arachnoid mater and the pia mater
pia mater
innermost of the cranial meninges. It tightly adheres to the brain and follows every contour of the brain surface
4 dura septa
- falx cerebri
- tentorium cerebelli
- Falx cerebelli
- diaphragm sellae
falx cerebri
runs along the longitudinal fissure between the left and right cerebral hemispheres. Connects on crista gali and tentorium cerebelli
runs over the top of the cerebellum and is an enfolding of the dura matter
tentorium cerebelli
tentorial incisure/ notch
small opening just posterior to sella turcica
falx cerebelli
slightly partitions the cerebellum into left and right hemispheres
diaphragm sellae
forms a roof over the sella turcica of the sphenoid bone
where are the 4 ventricles of the brain found
1 and 2 in the cerebrum, 3 in the diencephalon and 4 in the brainstem
what is the fourth ventricle associated with
choroid plexus
helps with boyancy, protection and environmental stability
Circulates in the hollow ventricles of the brain, the central canal of the spinal cord, and the subarachnoid space
cerebrospinal fluid
formed by the ependymal cells that line the ventricles and by nearby blood vessels
choroid plexi
how does CSF drain
via the arachnoid villi
major complication of congenital toxoplasmosis and is usually associated with substantial cerebral damage
hydrocephalus
astrocytes
envelop the brain capillaries and reduce capillary permeability. This helps create the blood-brain barrier
where is the blood brain barrier missing
choroid plexi, hypothalamus and the pineal gland
cerebrum
derived from the embryonic forebrain and manages our higher brain function:
Conscious thought processes, intellectual function
Memory storage and processing
Conscious and sub conscious regulation of skeletal muscle contractions
longitudinal fissure
divides cerebrum into left and right poritons
Frontal lobe function
personality
decision making
motor functions
Parietal lobe function
Sensory integration
Temporal lobe function
hearing and smell
Occipital lobe function
Visual Processing
Insula function
memories
taste
Coup-contrecoup
usually occurs from sudden deceleration. Brain hits front of head and bounces back and hits the back causing brain injury on both sides
what does the diencephalon include
epithalamus
thalamus
hypothalamus
epithalamus
melatonin
sleep/wake cycle
thalamus
principal and final relay point for all sensory information except for the sense of smell(processed in cerebral cortex)
hypothalamus
influences heart rate, blood pressure, digestive activites, respiration. It also controls body temp, influences emotional responses, hunger, thirst and circadian rhythms
what is the brainstem composed of
midbrain (mesencephalon)
pons
medulla oblongata
functions of mid brain
visual and auditory reflexes and contributes to control of posture and movemnet
acts to relay impulses and contributes, along with the medulla oblongata, to the control of breathing
pons
medulla oblongata
acts as sensory relay for several cranial nerves, relays information to the thalamus, as a cardiac center to help control the heart, as a vasomotor center to control diameter of blood vessels, control breathing, center for sneezing, coughing, swallowing and vomiting
why doe the left side of your brain control your right side and viceversa
this occurs because the nerve fibers from the brain to the spinal cord cross over to opposite sides at the level of the medula oblongata
arbor vitae
white matter located inside cerebellum
cerebellar cortex
gray matter located on the outside of cerebellum
what separates the cerebrum and the cerebellum
a dural septum called the tentorium cerebelli
functions of the cerebellum
coordinates muscle contractions. maintains posture and balance and coordinates smooth, athletic motions
ataxia
uncoordinated, jerky movements
reticular formation
gets you our of subconscious state
can go into coma and maybe not wake up if damage occurs here
limbic system
exerts important influence upon the endocrine and autonomic motor systems. It is important in memory formation, fear, happiness and sadness
can occur whenever there is increased pressure in the brain; bleeding, tumors, infection etc
Rostrocaudal brain deterioration
transtentorial herniation of cerebrum
cerebrum swells and tries to move out the tentorial incisure
this will occur as the cerebrum pushes down on the midbrain
decorticate posturing
this occurs if thrombus (clot) blocks blood flow to the brain
Can occur when a weakened wall of a blood vessel ruptures and cuts off blood supply to a portion of the brain
stroke
