76 terms

Cross Sectional Anatomy Unit 3

Aka- convolutions
complicated arrangements or folds that make up the surface of the brain
Aka- Fissures
grooves that seperate Gyri; many have specific names for identification
Interhemispheric fissure
Aka- longitudinal fissure
deep grove separating 2 cerebral hemispheres; divides brain into right and left halves
Interhemispheric fissure contains:
falx cerebri and superior sagittal sinus
Sylvian fissure
Aka- Lateral fissure
separates the frontal and parietal lobes of the brain from the temporal lobe
Fissure of Rolando
Aka- Central Fissure
separates the frontal and parietal lobes of the cerebrum and is a landmark separating the 2 of the major gyri on the surface fo the brain
Pre-central Gyrus is located
anterior to central fissure and posterior to the post-central gyrus
Brain is partitioned into several large divisions including:
cerebrum, the cerebellum, the brainstem, and diencephalon
(each portion can be further divided and defined according to anatomical landmarks)
largest portion of the brain and is divided into right and left hemispheres and smaller divisions called lobes
Frontal lobe of cerebrum
most anterior aspect of each cerebral hemisphere, lying just deep to the frontal bone
Parietal lobe of cerebrum
middle division of right and left cerebral hemisphere lying beneath each parietal bone
Occipital lobe of cerebrum
most posterior region of the right and left cerebral hemispheres
Temporal lobe of cerebrum
lies under each temporal bone; this portion of the brain is bound superiorly by the Silvian fissure (aka lateral fissure)
Aka- Island of Reil
is the central division of each cerebral hemisphere; structure is deep to the temporal lobe w/in each cerebral hemisphere; insula includes portions of the frontal, temporal, and parietal lobes
Corpus Callosum
a dense collection of nerve fibers connection the right and left cerebral hemispheres
Gray matter
nuron bodies
White matter
myelinated axons that contain pathways to transmit info from and to cortex
Cerebral cortex
outer most portion of the cerebrum, composed of gray matter, approximately 3-5 cm thick.
Corpus callosum
densest localized portion of white matter
largest part of the hindbrain, positioned just below the tentorium
conects medially the right and left heisphere of cerebellum
superior, middle, and inferior; used by cerebellum to communicate w/ the other parts of the brain
Cerebellar peduncles
connects brain stem and cerebellum
Conduit b/w cerebral cortex, cerebellum, and spinal cord and origin for 10 of 12 cranial nerves
Medulla oblongata
most inferior part of brainstem and hindbrain; continues as the spinal cord below the foramen magnum
part of brainstem that is the prominent bulge b/w midbrain and medulla oblongata; has semi-spherical shape
part of brainstem superior to pons at the junction of the middle and posterior cranial fossa
Cerebral aqueduct
transverses the midbrain
portion of the forebrain composed primarily of the thalamus, hypothalamus, epithalamus, and pituitary gland
large nucleus in the medial part of each cerebral hemisphere, forming part of the lateral wall of the 3rd ventricle
inferior to thalamus and connects to the posterior lobe of the pituitory gland by way of the infundibulum
Penial Gland
most significant feature of the epithalamus; an endocrine structure positioned at the roof of the midbrain, often calcified
Pituitary gland
endocrine gland, sometimes called "master gland" or "hypophysis"; positioned in the sella turcia of the sphenoid; composed of an anterior and posterior lobes
anterior lobe of pituitary gland
posterior lobe of pituitary gland
connects pituitory to hypothalmus
Ventricular system
series of four cavities and several passages w/in the brain all filled w/ csf
Lateral Ventricles
largest cavities of the ventricular system; each can be separated into specific regions
Regions of Lateral Ventricles
anterior horn, body, posterior horn, inferior horn, and triangular area (aka trigone)
Thrid ventricle
narrow cavity located b/w the right and left halves of the thalmus
Fourth ventricle
diamond shaped space b/w cerebellum and medulla oblongata and pons of the brainstem
Foramen of Monro
interventricular foramen allows for communication b/w the lateral ventricles and 3rd ventricle
Cerebral aqueduct
Aka- Sylvian aqueduct
passageway connecting the 3rd and 4th ventricles
Foramen of Luschka
pair of apertures in the 4th ventricle connectiong the ventricular system w/ the Subarachnoid space
Foramen of Magendie
largest opening in the 4th ventricle allow CSF into central canal of spinal cord and basilar cisterns
Subarachnoid space
a narrow fluid-filled space circulating CSF in and around the brain
Basal Cisterns
widened areas in the subarachnoid space
Choroid plexus
located on the floor of the lateral ventricles, network of capillaries produced the CSF that satisfies the nutritional needs fo the brain and spinal cord
surrourd and protect brain; 3 layers are the dura mater, arachnoid membrane, and pia mater
Dura mater
tough outermost membrane of the brain and spinal cord, is a fibrous membrane attached to the inner table of the skull
Falx Cerebri
section of dura mater which folds into the longitudional fissure of the brain; separates the two hemispheres.
Falx Cerebelli
fold of dura mater that forms a vertical partition b/w 2 hemispheres of the cerebellum
Tentorium cerebelli
tent-shaped fold fo the dura mater located in the transverse cerebral fissure
Diaphragma Sellae
horizontal, circular fold which covers the sella turcica; region of dura mater serves to separates the pituitary gland f/ the hypothalamus and optic chiasm; infundibulum of pituitary gland also passes through
Epidural Space
area outside of the dura mater
Sub-dural space
space below the dura mater
Arachnoid layer
middle meninx covering the brain and spinal cord; a fibrous membrane attached to the inside of dura mater. Strands of the arachnoid cross the subarachnoid space to reach the pia mater
Pia Mater
the innermost membrane of the brain and spinal cord; highly vascular membrane is attached to the surface of the brain
unique vascular system - circle of willis
Arteries forming the circle of willis
internal carotid arteries, posterior cerebral arteries, anterior cerebral arteries, posterior communicating arteries, anterior communicationg arteries, and basilar artery
3 arteries that supply blood to cricle of willis
two internal carotids and basilary arteries
Basilary artery
formed by union of 2 vertebral arteries near the level of the Foramen Magnum- supplies blood to the posterior portion of the brain.
Internal carotid arteries
branches of the common carotid arteries, supply blood to the anterior, medial, and lateral regions of the brain
Communicationg Arteries
circulate blood b/w the major vessels that supply blood to the brain; posterior communicating arteries join the posterior cerebral arteries w/ the internal carotid arteries
Anterior cerebral arteries
brances off the internal carotid arteries and supply blood to the anterior and middle regions of the brain
Anterior communicating artery
joins the anterior cerebral arteries
Posterior communicating arteries
join the posterior cerebral arteries and branches off the internal carotid
Middle cerebral artery
branch from the internal carotid artery and supply blood to lateral aspect of brain
Venous Drainage of the brain
accomplished by several major venous pathways, all ultimately drain into internal jugular veins
Superior Sagittal Sinus
a venous cavity (aka vein) b/w the 2 dural layers of the falx cerebri along its attachment to the inner table of the skull; continues as the transverse sinus (vein)
Inferior sagittal sinus
much smaller than the superior sagittal sinus, this vein runs posteriorly along the free edge of the falx cerebri
Transverse sinus
venous space in the tentorium cerebelli along its attachment to the occipital bone
Straight sinus
Venous cavity formed by the junction of the inferior sagittal sinus and the great cerebral vein located along the attachment of the falx cerebri to tentorium cerebelli
Confluence of the sinuses
poster junction of the superior Sagittal, Straight, and Transverse Sinuses; where Sagittal sinus b/c transverse sinus
Path of venous flow in brain
Superior Sagital b/c transverse sinus b/c sigmoid sinus, which b/c internal jugular vein
Sigmoid sinus
continuation of the transverse sinus towards the jugular foramen dumping into jugular vein