evaluating shape and texture of objects being touched. understanding speech and formulating words to express thoughts and emotions
forms posterior region of each hemisphere
what are the functions of the temporal lobe?
hearing and smell. storage of hearing and smell. understanding speech
what is an important anatomic feature of the frontal lobe?
what are the functions of the frontal lobe?
(higher intellectual functions)voluntary motor
where does the frontal lobe end?
ends posteriorly at a deep groove called central sulcus
what is the inferior border of the frontal lobe?
lies deep to frontal bone. forms anterior part of the cerebral hemisphere
what is an important anatomical feature of the parietal lobe?
lies internal to parietal bone. forms superoposterior part of each cerebral hemisphere. terminates anteriorly at central sulcus. posteriorly at a relatively indistinct parieto-occipital sulcus and laterally at a lateral sulcus
what are the 5 lobes of each cerebral hemisphere?
what is each cerebral hemisphere divided into?
5 anatomically and functionally distinct lobes
what is the corpus callosum?
connects the hemispheres. provides main communications link btwn cerebral hemispheres
what are the 2 halves of the cerebrum?
left and right cerebral hemispheres
what are the paired cerebral hemispheres separated by?
deep longitudinal fissure that extends along the midsagittal plane.
what does the cerebrum enable us to do?
where is the cerebrum formed from?
what does the cerebrum contain?
large number of neurons which are needed for the complex analytical and integrative functions performed by the cerebral hemispheres
what do astrocytes act as?
"gatekeepers" permit materials to pass to the neurons after leaving the capillaries
what can diffuse across the endothelial plasma membranes and onto the interstitial fluid of the CNS to reach brain neurons?
only lipidsouble compounds
where is the blood brain barrier reduced or missing?
3 locations in CNS: choroid plexus
what is the cerebrum?
the location of conscious thought processes and the origin of all complex intellectual functions
what are the 4 cranial dural septa?
what is the falx cerebri?
largest of the 4 dural septa. sickle shaped vertical fold of dura mater (located in midsagittal plane) projects into longitudinal fissure btwn left and right cerebral hemispheres
what are the 2 dural venous sinuses w/in the falx cerebri?
superior sagittal sinus and inferior sagittal sinus
what contributes to the blood brain barrier?
both the capillary endothelial cells and the astrocyte perivascular feet
what do tight junctions btwn adjacent endothelial cells do?
reduce capillary permeability and prevent materials from diffusing across the cappilary wall
lies inferior to lateral sulcus and underlies temporal bone.
what is the tentorium cerebelli?
(1 of cranial dural septa) horizontally oriented fold of dura mater that seprates occipital and temporal lobes of the cerebrum from the cerebellum
what is the gap on the anterior surface of the tentorium cerebelli?
or opening called tentorial notch (or tentorial incisure) to allow for the passage of the brainstem
what does the blood brain barrier do?
strictly regulates what substances can enter the interstitial fluid of the brain. keeps neurons in brain from being exposed to drugs
what is nervous tissue protected by?
blood brain barrier (bbb)
what is CSF formed by?
the choroid plexus in each ventricle.
what is the choroid plexus composed of?
a layer of ependymal cells and the capillaries that lie w/in the pia mater.
what is CSF produced by?
secretion of fluid from the ependymal cells that originates from the blood plasma
CSF transports nutrients and chemicals to brain and removes waste products from brain. protects nervous tissue from chemical fluctuations that would disrupt neuron function.
CSF provides liquid cushion to protect delicate neural structures from sudden movements. helps slow movements of brain if skull move suddenly and forcefully
what are the functions of cerebrospinal fluid?
brain floats in CSF
whats do all the ventricles contain?
cerebrospinal fluid (CSF)
what is cerebrospinal fluid?
what are the 4 ventricles in the brain?
2 lateral ventricles (in cerebrum
what is the cerebral aqueduct?
passes through the mesencephalon and connects the 3rd ventricle w/the tetrahedron shaped 4th ventricle.
where is the 4th ventricle located?
btwn the pons and the cerebellum.
what does the 4th ventricle merge with?
the slender central canal in the spinal cord
what are ventricles?
cavities or expansions w/in the brain that are derived from the lumen of the embryonic neural tube. are continous w/one another as well as with the central canal of the spinal cord
what is the small opening w/in the diaphragma sellae?
what is the diaphragma sellae?
smallest of dural septa
what can the dura mater and bones of skull may be separated by?
potenetial epidural space
what does the epidural space contain?
arteries and veins that nourish the meninges and bones of cranium
what is the falx cerebelli?
(1 of cranial dural septa)sickle shaped vertical partition that divides the left and right cerebellar hemispheres
what are dural venous sinuses?
do not have valves to regulate venous blood flow. large veins drain blood from brain and transport blood to internal jugular veins that help drain blood circulation to the head
what is the dura mater composed of?
w/in the cranium 2 fibrous layers: meningeal layer and periosteal layer (forms the periosteum on the internal surface of the cranial bones)
what is the dura mater?
what is btwn the arachnoid and the overlying dura mater?
potential space called subdural space. becomes actual space if blood or fluid accumulates there
what do the arachnoid trabeculae do?
extend through the subarachnoid space from the arachnoid to the underlying pia mater.
what is the arachnoid composed of?
delicate web of collagen and elastic fibers arachnoid trabeculae.
what is the arachnoid?
from deep to superficial
what is the cranial meninges?
what is the pia mater?
innermost of the cranial menings. a thin layer of delicate areolar connective tissue
what do some parts of the cranial menings form?
some of the veins that drain blood from the brain
what are the cranial meninges?
3 connective tissue layers that separate the soft tissue of the brain from the bones of the cranium
What is the brain protected by?
what happens w/in the masses of white matter?
the brain contains discrete internal clusters of gray matter called cerebral nuclei (oval
what is the external layer of gray matter called?
what happens during brain development?
an outer superficial region of gray matter forms from migrating peripheral neurons
what are the functions of the occipital lobe?
processing incoming visual information and storing visual memories
where does the white matter derive its color from?
from the myelin in myelinated axons
what does the gray matter do?
houses motor neuron and interneuron cell bodies
what are the 2 distinct areas w.in the brain and spinal cord?
gray matter and white matter
when do the gyri and sulci develop?
in the late fetal period
what happens as the future brain develops?
its surfaces becomes folded
what does the telencephalon do during the embryonic and fetal periods?
the telencephalon grows rapidly and envelops the diencephalon
where does the myelencephalon arise from and what does it eventually form?
arises from the rhombencephalon and forms the medulla oblongata
where does the metencephalon arise from and what does it eventually form?
arises from the rhombencephalon and forms the pons and cerebellum
what does the mesencephaon do?
the only primary vesicle that does not form a new secondary vesicle
where does the diencephalon arise from and what does it eventually form?
arises from the prosencephalon and forms the thalamus
where does the telencephalon arise from and what does it eventually form?
arises from the prosencephalon and forms the cerebrum
what are the 5 secondary brain vesicles?
by the 5th week of development
what do the 3 primary vesicles develop into?
what is the hindbrain called?
what is the midbrain called?
what is the forebrain called?
what do the 3 primary brain vesicles give rise to?
all the different regions of the adult brain.
In the human embryo
where does the brain form from?
what happens by the late 4th week of development?
the growth has formed 3 primary brain vesicles
what is the term posterior synonymous with?
caudal (toward the tail)
what is the term anterior synonymous with?
rostral (toward the nose)
how many cranial nerves is the brain associated with?
12 pairs of cranial nerves
what does the outer surface of an adult brain exhibit?
folds called gyri and shallow depressions btwn those folds called sulci
How is each cerebral hemisphere divided into?
may be further divided into 5 functional areas called lobes
what is the cerebrum divided into?
into left and right halves: cerebral hemispheres
what are the 4 major regions of the brain?
small lobe deep to lateral sulcus. lack of accessibility prevents aggressive studies of its function but involved w/memory and interpretation of taste
what are the 3 categories of functional areas?
where is the primary motor cortex located?
somatic motor area
what do the neurons of the primary motor cortex do?
control voluntary skeletal muscle activity. axons of these neurons project contralaterally (opposite side) to the brainstem and spinal cord
what do the left and right primary motor cortex control?
left primary motor cortex controls the right side voluntary muscles
what can the innervation of the primary motor cortex be diagrammed as?
innervation of the primary motor cortex to various bodyparts can be diagrammed as a motor homunculus on the precentral gyrus
where is the motor speech area located?
what is the motor speech area responsible for?
controlling muscular movements neccessary for vocalization
where is the frontal eye lid located?
on superior surface of the middle frontal gyrus
what does the frontal eye lid control?
control and regulate eye movements needed for reading and coordinating binocular vision
where is the primary somatosensory cortex housed?
w/in the postcentral gyrus of the pariteal lobes.
what do the neurons of the primary somatosensory cortex do?
receive general somatic sensory information from touch
what is the sensroy homunculus?
may be traced on the postcentral gyrus surface
what is the primary visual cortex responsible for?
located on occiptal lobe
what is the primary auditory cortex responsible for?
located in temporal lobe
what is the primary gustatory cortex responsible f
what is the primary olfactory cortex responsible for?
located in temporal lobe
what are association areas?
integrate new sensory inputs w/memories of past experiences.
what is the premotor cortex?
somatic motor association area
what is the somatosensory association area?
located in parietal lobe and lies posterior to primary somatosensory cortex. interprets sensory information. responsible for integratng and interpreting sensations to determine texture
what is the auditory association area?
located w/in temporal lobe
what is the visual association area?
located in occipital lobe
what are 2 functional brain regions?
Wernicke area and gnostic area
what is the Wernicke area?
(functional brain region) located only w/in left hemisphere
what is the gnostic area?
common integrative area
what are high order processing areas?
other association areas. process incoming information from several different associtation areas
what is central white matter composed of?
lies deep to gray matter of cerebral cortex. composed of myelinated axons.
what are the 3 tracts?
what are association tracts?
connect different regions of the cerebral cortex w/in the same hemisphere.
what are commissural tracts?
extend btwn the cerebral hemispheres through axonal bridges called commissures.
what are projection tracts?
link the cerebral cortex to the posterior brain regions and the spinal cord.
what are cerebral nuclei?
what are the components of the cerebral nuclei?
what does the caudate nucleus produce?
when person walks
what does the amygdaloid body do?
participates in the expression of emotions
what does the putamen do?
controlling muscular movement at the subconscious level
what does the globus pallidus do?
both excites and inhibits the activites of the thalamus to contro and adjust muscle tone