Unit 4 Lab 1: The Cerebrum

Calcarine Sulcus (Fissure)

Located in the occipital lobe. It runs roughly perpendicular to the parieto-occipital sulcus and contains the primary visual cortex. Primary reception area for visual information

Caudate nucleus

"Caudate" Part of the basal ganglia. Located medially next to the lateral ventricle. It is larger anteriorly and smaller posteriorly. It is C-shaped, and a small part of it can be observed next to the inferior horn of the lateral ventricle.

Anterior Cerebral Arteries

A branch of the internal carotid artery. Travels anteromedially to the median longitudinal fissure. (look at other picture)

Tentorium Cerebeli

A dural reflection (inward extension of the dura mater) that separates the cerebrum from the cerebellum

Falx Cerebri

A dural reflection (inward extension of the dura mater) that separates the right and left hemispheres

Cerebellum

A large structure of the hindbrain that controls fine motor skills. "Little brain"

Frontal Lobe

A region of the cerebral cortex that has specialized areas for movement, abstract thinking, planning, memory, and judgement

Occipital Lobe

A region of the cerebral cortex that processes visual information

Third Ventricle

A thin midline space that separates the left and right thalami. Notice in the right image that the third ventricle appears to have a hole in the middle of it. This is created by a midline thalamic structure called the massa intermedia, or interthalamic adhesion, which connects the two thalami and passes through the third ventricle.

Arachnoid Granulations

Aggregations of tiny white granules near the superior midline of the brain. They function to return cerebrospinal fluid from the subarachnoid space (between this arachnoid mater layer and the pia mater layer of meninges) to the blood. Fingerlike structure that projects from the subarachnoid space of the meninges into blood-filled dural sinuses and reabsorbs cerebrospinal fluid.

The Circle of Willis

Blood supply to the brain. The brain is supplied by two sets of arterial trunks: the vertebral arteries and the internal carotid arteries. Allows blood to flow across the midline of the brain in the event of an arterial occlusion. Provides more than one pathway for blood to reach the brain.

Middle Cerebral Arteries

Branch of the internal carotid artery. Dives deep within the lateral fissure

Flow of CSF

CSF can be produced by the choroid plexus in all of the cerebral ventricles but the longest possible pathway of CSF flow begins in the lateral ventricle: Lateral Ventricle to Interventricular Foramen (of Monro) to Third Ventricle to Cerebral Aqueduct to Fourth Ventricle to Escape via apertures or via the central canal

Interventricular Foramen (of Monro)

Connects each lateral ventricle to the third ventricle.

Anterior Communicating Artery

Connects the two anterior cerebral arteries just before they enter the median longitudinal fissure. This can be an artery connecting them or the two anterior cerebral arteries can appear to just "touch" each other and then split again. Connects anterior cerebral arteries

Cerebral Hemispheres

Contain the brain regions involved in our higher cognitive functions, including language, learning, memory, and personality. The right and left halves of the cerebrum.

Dural Reflections

In a few places the dura mater folds and dives into spaces between parts of the brain, these are called the dural reflections. Inward extentions of the dura mater

Inferior Temporal Gyrus

Inferior to the middle temporal gyrus and is essential for visual object recognition.

Middle Temporal Gyrus

Inferior to the superior temporal gyrus and is involved in object recognition.

Basal Ganglia

Involved in the control of voluntary motor function. It's structures are located in the deep portion of the cerebrum surrounding the ventricles and they are separated by a white matter structure called the internal capsule.

Cerebrum

Largest part of the brain. Area of the brain responsible for all voluntary activities of the body. Largest part of brain, associated with higher order functioning including control of voluntary behaviour, e.g. Thinking, planning, perceiving, understanding language.

Fourth Ventricle

Lies between the pons and the cerebellum. This ventricle narrows rostrally into the cerebral aqueduct, which connects it with the third ventricle. It also narrows caudally and then transitions into the central canal of the medulla and spinal cord. From the fourth ventricle CSF can escape via apertures or via the central canal.

Insula

Located deep within the Sylvain fissure. Its functions are not well understood but it is thought to play a role in taste. (Difficult to see on full brain specimens) Isolated

Amygdala

Located in the anterior portion of the medial temporal lobe. It is involved in behavior and giving emotional meaning to sensory input and memory. Aggression and fear

Hypothalamus

Located just anterior and inferior to the thalamus. Responsible for many functions including endocrine control, species preserving behaviors (hunger, thirst), and circadian rhythm. A neural structure lying below the thalamus; directs eating, drinking, body temperature; helps govern the endocrine system via the pituitary gland, and is linked to emotion

Anterior Commissure

Located just anterior to the thalamus. It interconnects parts of the frontal and temporal lobes of the two hemispheres. Connects the anterior parts of the cerebral cortex. Involved in contralateral communication.

Cerebral Cortex

Makes up the surface of the cerebral hemispheres and it is a layer of gray matter. This surface is thrown into many folds forming sulci and gyri. The intricate fabric of interconnected neural cells covering the cerebral hemispheres; the body's ultimate control and information-processing center.

Marginal Ramus

Marginal ramus of the cingulate sulcus. In the anterior parietal lobe, the cingulate sulcus turns upward to reach the dorsal surface of the brain. This posterior vertical portion is called the marginal ramus of the cingulate gyrus.

Central Sulcus

Marks the boundary between the frontal and parietal lobes. Hits a dead end before the temporal lobe. To identify it, observe the corpus callosum and the cingulate gyrus above it. The sulcus dorsal to the gyrus is the cingulate sulcus. Follow the cingulate sulcus up dorsally (superior) as it comes to a stop near the dorsal aspect of the brain surface. Move rostrally one sulcus and that is the central sulcus. Separates frontal lobe from parietal lobe

Pons

Middle portion of the brainstem. A brain structure that relays information from the cerebellum to the rest of the brain

Midbrain

Most dorsal portion of the brainstem. A small part of the brain above the pons that integrates sensory information and relays it upward.

Lateral Ventricles

On a mid-sagittally sectioned brain you can see the lateral ventricle is the open space in the middle of the hemisphere. Has 4 parts: 1) Anterior Horn - anterior portion located in the frontal lobe. Separated from each other by a thin bilaminar membrane called the Septum Pellucidum 2) Body - Thin, middle portion 3) Posterior Horn - Most posterior portion, located in the parietal and occipital lobes 4) Inferior Horn - Portion that extends inferiorly and anteriorly into the temporal lobe Ventricles located in each cerebral hemisphere.

Putamen

Part of the basal ganglia. Located just lateral to the internal capsule The putamen is lateral and slightly superior to the smaller globus pallidus.

Globus Pallidus

Part of the basal ganglia. Located just lateral to the internal capsule. Has two parts

Temporal Lobe

Part of the brain that processes auditory and olfactory information. Associated with emotion, language, and memory formation. An area on each hemisphere of the cerebral cortex near the temples that is the primary receiving area for auditory information Contains 3 gyri running parallel to the lateral (Sylvian) fissure.

Parietal Lobe

Part of the brain that processes tactile information, contains the somatosensory cortex. A region of the cerebral cortex whose functions include processing information about touch.

Medulla Oblongata

Part of the brainstem that controls vital life-sustaining functions such as heartbeat, breathing, blood pressure, and digestion. Most interior (caudal) portion of the brainstem.

Pre central Gyrus

Part of the frontal lobe just anterior to the central sulcus. This is the location for the Primary Motor Cortex, where all voluntary motor signals are initiated. The pre central sulcus is anterior to the pre central gyrus. Primary motor area

Post central gyrus

Part of the parietal lobe just posterior to the central sulcus. This is the Primary Somatosensory Cortex, which processes incoming general sensory information. The post central sulcus is just posterior to the post central gyrus. primary somatosensory cortex

Hippocampus

Posterior to the amygdala in the medial temporal lobe. Essential for storing new memories and it is often atrophied in alzheimer's patients. Swirly appearance in the cross sections.

Thalamus

Right above the midbrain (brainstem). Located deep in the brain (cannot be seen on full brain specimens). This is the relay center of the brain. Many pathways have a synapse here. A structure in the forebrain through which all sensory information (except smell) must pass to get to the cerebral cortex.

Superior Temporal Gyrus

Runs inferior to the lateral (Sylvian) fissure and contains auditor association areas. Primary auditory cortex

Internal Capsule

Separates the caudate from the globus pallidus and putamen. Carries fibers to and from the cerebral cortex, including the fibers of the corticospinal tract. (Look at globus pallidus picture)

Parieto-Occipital Sulcus

Separates the parietal lobe from the occipital lobe.

Median longitudinal fissure

Separates the right and left cerebral hemispheres

Caudal

Structures closer to the tip of the spinal cord AKA toward the back (posterior) of the head (caudal = tail) Posterior Towards the tail

Cingulate Sulcus

Superficial to the cingulate gyrus Separates the frontal & parietal lobes from cingulate gyrus

Cingulate Gyrus

Superior to the corpus callosum. This extends from the frontal lobe through the parietal lobe. It is part of the limbic system and is involved in emotional regulation and pain regulation. It also plays a role in understanding the consequences of behaviors and avoiding negative consequences in the future. Directly above Corpus Callosum, pain/emotions processed

Posterior Cerebral Arteries

The basilar artery splits on the ventral surface of the pons to give off right and left posterior cerebral arteries. (look at a different picture)

Lateral (Sylvain) Fissure

The boundary between the frontal and temporal lobes.

Ventricles

The brain contains several ventricles (open spaces) in brain that contain cerebro spinal fluid. Makes the brain buoyant (float). All the ventricles contain choroid plexus, which produces CSF within the ventricles.

Sulcus (singular) Sulci (plural)

The folds of the brain diving in away from the visible surface of the brain. Increases the surface area of the cortex to make more room for neurons involved in higher cognitive functions.

Cerebral Aqueduct

The fourth ventricle narrows rostrally into the cerebral aqueduct, which connects it with the third ventricle. Connects the third and fourth ventricles

Pia Mater

The innermost dural membrane. It cannot be seen with gross examination of the brain, but it is covering the surface of the brain tissue, including within the sulci and gyri. thin, delicate inner membrane of the meninges

Corpus Callosum

The largest white matter pathway connecting the right and left hemispheres of the brain. The large band of neural fibers connecting the two brain hemispheres and carrying messages between them.

Genu

The most anterior portion of the corpus callosum. (Genu=bend)

Rostral

The most frontal portion of the brain (rostrum = nose) Anterior Towards the nose

Splenium

The most posterior portion of the corpus callosum. Region of corpus callosum that connects occipital regions of the two hemispheres and thus carries mostly visual information

Gyrus (singular) Gyri (plural)

The portion of the cortex that are exposed and visible. Increases the surface area of the cortex to make more room for neurons involved in higher cognitive functions. "Puffs" in the cerebral cortex.

Superior Sagital Sinus

The superior portion of the falx cerebri. This is a dural venous sinus that drains blood from the brain. It is also the place where cerebro spinal fluid travels through the arachnoid granulations (villi) to return to systemic blood flow.

The Meninges

The three connective tissue membranes that cover the brain: dura mater, arachnoid mater, and pia mater. The brain and spinal cord are surrounded by several layers of specialized tissue and cerebrospinal fluid (it acts like a cushion). The meninges protect the brain by anchoring it to the skull and preventing excessive movement.

Vertebral Arteries

The two vertebral arteries fuse along the brainstem to form the single basilar artery. (Better picture on Circle of Willis card)

Internal Carotid Arteries

They travel through the skull and have been cut so it looks as if their lumen is facing towards you. (Look at picture on Circle of Willis card) Divides into two branches: the anterior cerebral artery and middle cerebral artery.

Dura Mater

Thick, outermost layer of the meninges surrounding and protecting the brain and spinal cord. The dura mater follows the contours of the inner surface of the skull and does not dive into the sulci of the brain.

Posterior Communicating Artery

Thin arteries that connect the posterior cerebral and internal carotid arteries

Arachnoid Mater

This is the middle layer of the meninges and it is a delicate, transparent membrane. The arachnoid mater does not follow the contours of the sulci and gyri; rather it follows the form of the overlying dura. Weblike middle layer of the three meninges.

Brainstem

Three parts: the midbrain, the pons, and the medulla oblongata. The oldest part and central core of the brain, beginning where the spinal cord swells as it enters the skull; the brainstem is responsible for automatic survival functions.

Dorsal

Toward the back With respect to the brainstem and spinal cord, dorsal=posterior. With respect to the cerebrum plane, dorsal = superior

Ventral

Toward the belly With respect to the brainstem and spinal cord, ventral=anterior. With respect to the cerebrum plane, ventral=inferior