Cerebrum Flashcards
location of cerebrum
- anterior and middle cranial fossae of the skull
- whole concavity of the vault of the skull
forms the central core
diencephalon
forms the cerebral hemispheres
telencephalon
extends posteriorly to the point where the third ventricle becomes continuous with the cerebral aqueduct and anteriorly as far as the interventricular foramina
diencephalon
superior surface of the diencephalon is concealed by the
fornix
thick bundle of fibers that originates in the hippocampus of the temporal lobe and arches posteriorly over the thalamus to join the mammillary body
fornix
- actual superior wall of the diencephalon is formed by the ___
- This consists of a layer of ependyma, which is continuous with the rest of the ependymal lining of the third ventricle.
roof of the third ventricle.
vascular fold of pia mater
tela choroidea
- vascular processes
- project downward from the midline into the cavity of the third ventricle
choroid plexuses
consists of nerve fibers that connect the cerebral cortex with other parts of the brainstem and spinal cord
lateral surface
formed in its superior part by the medial surface of the thalamus and in its inferior part by the hypothalamus
medial surface
Medial surface are separated from one another by a shallow sulcus
hypothalamic sulcus
A bundle of nerve fibers, which are afferent fibers to the habenular nucleus, forms a ridge along the superior margin of the medial surface of the diencephalon and is called
stria medullarus thalami
diencephalon can be divided into four major parts
- thalamus
- subthalamus
- epithalamus
- hhypothalamus
- large ovoid mass of gray matter that forms the major part of the diencephalon
- serves as a cell station to all the main sensory systems (except the olfactory pathway)
thalamus
location of thalamus
each side of the third ventricle
of the thalamus is narrow and rounded and forms the posterior boundary of the interventricular foramen
anterior end
- The posterior end of the thalamus is expanded to form the
- overhangs the superior colliculus and the superior brachium
pulvinar
forms a small elevation on the under aspect of the lateral portion of the pulvinar.
lateral geniculate body
covered medially by the tela choroidea and the fornix, and laterally, it is covered by ependyma and forms part
of the floor of the lateral ventricle;
superior surface
The medial surface of the thalamus forms the superior part of the lateral wall of the third ventricle and is usually connected to the opposite thalamus by a band of gray matter, the
interthalamic connection
The lateral surface of the thalamus is separated from the lentiform nucleus by the very important band of white matter called the
internal capsule
location of subthalamus
between the thalamus and the tegmentum of the midbrain
- shape of a biconvex lens
- important connections with the corpus striatum
- involved in the control of muscle activity
subthalamic nucleus
contains many important tracts that pass up from the tegmentum to the thalamic nuclei; the cranial ends of the medial, spinal, and trigeminal lemnisci are examples
subthalamus
location of habenular nucleus
medial to the posterior surface of the thalamus
believed to be a center for integration of olfactory, visceral, and somatic afferent pathways
hebenular nucleus
- small, conical structure that is attached by the pineal stalk to the diencephalon
- lies posterior to the midbrain
- possesses no nerve cells
pineal gland
superior part of the base of the stalk contains the
habenular commissure
inferior part of the base of the stalk contains the
posterior commissure
Two types of cells are found in the gland
pinealocytes & glial cells
Concretions of calcified material called ___ progressively accumulate within the pineal gland with age
brain sand
- important endocrine gland capable of influencing the activities of the pituitary gland, the islets of Langerhans of the pancreas, the parathyroids, the adrenal cortex and the adrenal medulla, and the gonads
- The gland has been found to be most active during darkness
pineal gland functions
- present in high concentrations within the pineal gland
- plays an important role in the regulation of reproductive function
melatonin
- extends from the region of the optic chiasma to the caudal border of the mammillary bodies
- lies below the hypothalamic sulcus on the lateral wall of the third ventricle
hypothalamus
Physiologically, nearly all the activities in the body are influenced by the
hypothalamus
- controls and integrates the functions of the autonomic nervous system and the endocrine systems and plays a vital role in maintaining body homeostasis
- regulation of body temperature, body fluids, drives to eat and drink, sexual behavior, and emotion
hypothalamus
Anterior to the hypothalamus is an area that extends forward from the optic chiasma to the lamina terminalis and the anterior commissure
pre optic area
location of thalamus
superior to the hypothalamus, and the subthalamic region lies inferolaterally to the hypothalamus
flattened bundle of nerve fibers situated at the junction of the anterior wall and floor of the third ventricle
optic chiasma
convex mass of gray matter, as seen from the inferior surface
tuber cinereum
hollow and becomes continuous with the posterior lobe of the hypophysis cerebri
infundibulum
raised part of the tuber cinereum to which is attached the infundibulum
median eminence
The median eminence, the infundibulum, and the posterior lobe (pars nervosa) of the hypophysis cerebri together form the
neurohypophysis
two small hemispherical bodies situated side by side posterior to the tuber cinereum
mammillary bodies
slitlike cleft between the two thalami
third ventricle
formed by a thin sheet of gray matter, the lamina terminalis, across which runs the anterior commissure
anterior wall
formed by the opening into the cerebral aqueduct
posterior wall
formed by the medial surface of the thalamus superiorly and the hypothalamus inferiorly
lateral wall
The lateral wall is limited superiorly by the
stria medullaris thalami
The lateral walls are joined by the
interthalamic connection
formed by a layer of ependyma that is continuous with the lining of the ventricle
superior wall or roof
largest part of the brain
cerebral hemisphere
deep midline sagittal fissure
longitudinal cerebral fissure
fissure contains the sickle-shaped fold of dura mater ___ and the anterior cerebral arteries.
falx cerebri
- great commissure
- connects the hemispheres across the midline
corpus callosum
increase the surface area of the cerebral cortex maximally
folds or gyri
gyri are separated from each other by
sulci or fissure
___ and ___ boundaries used for the division of the cerebral hemisphere into frontal, parietal, temporal, and occipital lobes
parieto-occipital sulci & calcarine sulci
only sulcus of any length on this surface of the hemisphere that indents the superomedial border and lies between two parallel gyri
central sulcus
- deep cleft found mainly on the inferior and lateral surfaces of the cerebral hemisphere.
- It consists of a short stem that divides into three rami.
lateral sulcus
- begins on the superior medial margin of the hemisphere about 2 in (5 cm) anterior to the occipital pole
- passes downward and anteriorly on the medial surface to meet the calcarine sulcus
parieto-occipital sulcus
- found on the medial surface of the hemisphere
- commences under the posterior end of the corpus callosum and arches upward and backward to reach the occipital pole, where it stops
calcarine sulcus
occupies the area anterior to the central sulcus and superior to the lateral sulcus
frontal lobe