spch 311 outline 9

3; 2

the brain weighs approximately ? pounds and compromises about ?% of your body weight

large

the brain is ___ in comparison to your body size

humans have superior cognitive skills over other creatures

the current research is showing that the total number of neurons in our brain is the reason that...

cerebral cortex

the surface of the brain is called the ___ ___

neuronal cell bodies

what is the cerebral cortex made of?

white matter that consists of the neuronal axons, white because it is covered in myelin

underneath the cerebral cortex is the ...

add another layer of protection for our brain

what do the meninges do?

scalp, skull, dura mater, arachnoid mater, subarachnoid space, and pia meter

going from the outside of your head in, what are the structures?

filled with blood vessels and CSF

what is the subarachnoid space filled with?

innermost layer adhering to the gyri and sulci

what is the pia mater?

pia mater and subarachnoid space

blood vessels that run on the surface of the brain are located on top of the __ __ and in. the __ __

the capillary walls, into the extracellular space of the adjacent tissues, but not in the brain

in most parts of the body, almost all molecules can pass through...

cells of the capillaries and the cells surround the capillaries

how is the blood brain barrier formed?

pathogens, including most bacteria and viruses from leaving the blood stream and entering the brain

what does the blood brain barrier prevent?

drugs; hallucinogens

blood brain barrier limits or eliminates the effects of what on the brain? and what is the exception?

not fully developed, so that is why their brains are so susceptible for drugs and alcohol

in fetuses, the blood brain barrier is....

circumventricular organs

the bodies way around the blood brain barrier is in the ___ __

CNS, vascular system, and the endocrine system creating an alternative route for neuropeptides and hormons

CVOs link the....

20

the brain consumes approximately __% of the oxygen in the body

- oxygen nourishes the brain

- without oxygen, the brain will die

- only a few mins without blood flow to the brain can contribute or result in brain damage

explain the impact of oxygen

the brain has a rich blood of supply

due to the great need of oxygen, ....

internal carotid arteries and vertebral arteries

what are the 2 ways that oxygen enters the brain?

bring oxygenated blood from the heart to the brain

function of artiers

carry deoxygenated blood from the brain back to the heart

function of veins

acts as a waste disposal system carrying both deoxygenated blood from the brain and old or used CSF from the ventricular system

- dumpos both of these products into the internal jugular veins where it returns to the hearts

what does the venous system do?

blood pressure is lower than in the arterial system

why do fewer strokes occur in the venous system?

longitudinal, central, and lateral

what are the 3 prominent fissures?

runs from the front to the back, and seperates the 2 hemispheres

explain the longitudinal fissure

aka the fissure of rolando; separates the frontal lobe of the parietal lobe

explain the central fissure

aka the sylvian fissure; separates parietal lobe from the temporal lobe

explain the lateral fissure

gyri and sulci

all healthy brains need to have ___ and ___

condition that results in a smooth brain

what is argyria or lissencephaly?

causes severe motor, intellectual, and psychological disability

- most die before the age of 10

what happens because of a smooth brain?

it has been discovered that these layers differed in thickness and in the proportions of the neuronal types they contain

although the cerebral cortex is always composed of several layers of neurons,......

korbenian broadmann; assigned a number to each distinct part of the cerebral cortex and some of those designations are importaant for SLPs to know

the differences of the neurons were described by who and what did he do?

frontal, parietal, temporal, and occipital

4 lobes of the brain

lies at the front of the brain above the eyes; the posterior border of the love is the central fissure

location of frontal lobe

reasoning, planning, and voluntary motor movement

function of parietal lobe

lies just posterior to the central fissure, and superior to the lateral fissure

location of parietal lobe

sensory perception and sensory interpretations

function of parietal lobe

lies inferior to the parietal lobe

location of temporal lobe

some memory is housed here, also processing and understanding of auditory information, otherwise known as auditory comprehension

function of temporal lobe

lies posterior to the parietal and temporal lobes; makes up the very back of the brain

location of occipital lobe

visual processing

function of occipital lobe

85

-left: language

- right: extra linguistic features such as intonation and stress

for approximately __% of the population... explain the functions of left and right hemispheres

account for efficiency with which external info is analyzed, synthesized, and transferred from one place to another and adequate responses are formulated and executes promptly with left, right, or both limbs

explain the intra and interhemispheric conditions

data processed, decisions made, activities undertaken, and actions performed

these interconnecting fibers keep all brain areas informed of __ __, __ __, and ___ __ and ___ __

- travel vertically to connect the cortex with the brainstem and spinal cord structures

- fibers between the cortical surface and the thalamus create the coronal radiata and taper/narrow into internal capsule

explain projection fibers

corticothalamic and thalamic fibers

what do the anterior limbs contain?

thalamic nuclei with the frontal cortex and limbic singulet gyrus

what does the anterior limb connect?

corticopontine fibers that monitor frontal projections

the anterior limb contains ___ __ that do what?

site for corticobulbar fibers that descend to innervate the cranial nerve nuclei to and play an important role in motor speech processes

what is the genu?

much larger and is known to contain the corticospinal fibers that project to the spinal motor neurons

what is the posterior limb?

- motor

- broadly originate from motor cortex and terminate in the spinal cord

- specifically originate from the precentral gyrus and descend through the coronal radiata into internal capsule and the ped pedunculi in the midbrain

explain corticospinal fibers

pyramid in the medulla, before crossing midline, and entering the spinal cord

what do the corticospinal fibers form?

motor cortex and originate in brainstem

where do the corticobulbar fibers originat e from?

collect cutaneous (skin) and proprioceptive sensation from the skin and joints to project to the CNS

explain sensory projection fibers

enter the spinal cord, ascend through brain stem, and internal capsule and then gets to corona radiata, and projects to the primary sensory cortex in parietal lobe

where do the sensory projection fibers enter ...

- most numerous of the 3 types and are confined within each hemisphere

- making an association to the lobes within the same hemisphere

what are association fibers?

- provide efficient bidirectional channels for communication among the cortical areas within each hemisphere

- important for refined and integrated behavioral responses

function of association fibers

lesions in pathways an result in disconnections between areas within a hemisphere

pathology of association fibers

U shaped fibers that bend around a sulcus and connect 2 adjacent gyri

what are short association fibers?

superior longitudinal fasciculus, inferior longitudinal fasciculus, cingulum, and uncinate fasciculus

what are the 4 long fibers?

frontal lobe to occipital lobe

superior longitudanal connects the ___ __ to the __ __

arcuate fasciculus ; temporal lobe

many fibers from parietal lobe curve around as the __ __ and project to the __ __

- communication link among the lobes

- connects the wernicke's area (temporal lobe) to broca's area (frontal lobe)

- significant to the normal acquisition of language functions

why is the arcuate fasciculus important?

connects the temporal with occipital lobe

explain inferior longitudinal fasciculus

C shaped association fiber lined beneath the singlet gyrus and above the corpus callosum

what are cingulum?

medial, frontal, and parietal cortices with temporal cortex

what does the cingulum connect?

travels parallel to the inferior longitudinal fasciculus and connects orbital frontal gyri to the rostral region in temporal lobe

explain uncinate fasciculus

300-400 million fibers, connecting all the corresponding cortical areas in both hemispheres; bridges the 2 hemispheres together

what does the corpus callosum contain?

memory traces, experiences, and unique learning abilities

the fibers of the corpus callosum allows each hemisphere to access __ __, __, and __ __ __ of the contralateral hemispheres

split brain where the hemispheres act independently of one another

- severs corpus callosum

the commissurotomy produces the ...

sever the corpus callosum

if someone has epileptic seizures and you __ __ __ __, it can reduce amount of seizures

second fiber bundle which originates from the ventral temporal lobe, and connects the amygdaloid complexes and both olfactory systems

what are anterior commissure?