Lab 3: Gross And Internal CNS III

Question 1

Lateral Fissue

Answer 1

A deep groove that separates the temporal lobe from the frontal and parietal lobes

Question 2

Central Sulcus

Answer 2

A relatively unbroken vertical sulcus that separates the frontal and parietal lobes

Question 3

Corpus Callosum

Answer 3

The major cortical commissure

Question 4

Central Sulcus (medial view of cerebral cortex)

Answer 4

It’s superior end forms a small notch that makes the boundary between the frontal and parietal lobes

Question 5

Cingulate Sulcus

Answer 5

Encircles the corpus callosum and ends posteriorly as 2 vertical branches that surround the central sulcus; anterior (paracentral sulcus) and posterior (marginal sulcus)

Question 6

Parietooccipital Sulcus

Answer 6

Posterior angled sulcus that separates parietal and occipital lobes

Question 7

Calcarine Sulcus

Answer 7

Horizontal sulcus within the occipital cortex; it’s walls contain the primary visual cortex

Question 8

Insular Lobe (insula)

Answer 8

Deep lobe on the lateral surface. Gently spread margins of lateral fissure to observe. Contains short vertical gyri

Question 9

Basal Surface of Forebrain

Answer 9

Examine the frontal lobe that rests on the roof of the orbit

Temporal lobe that’s lateral to the floor of the hypothalamus (contains the mammillary bodies)

Occipital gyri: posterior pole

Question 10

Frontal Lobe Gyri

Answer 10

Precentral gyrus: vertical gyrus immediately anterior to the central sulcus. Contains most of the primary motor cortex that sends voluntary movement to the opposite side of the body above the knee

Anterior to this: there are 3 named gyri that are relatively horizontal
Subdivide these into: Superior frontal gyrus
Middle frontal gyrus (looks like 2 gyri)- contain areas for thinking and decision making
Inferior frontal gyrus

Question 11

Inferior frontal gyrus

Answer 11

Subdivided into orbital (anterior)
Triangular (middle)
Opercular (posterior)

Question 12

Broca’s Area

Answer 12

Usually in the left hemisphere (language dominant)

Triangular and opercular parts

Involved with selection of words for voluntary speech

Question 13

Paracentral lobule

Answer 13

Surrounds the central sulcus on the medial view of the cerebral cortex (u-shaped). In between paracentral and marginal sulcus

Contains:
Anterior paracentral lobule that contains primary motor cortex for leg/foot (frontal lobe)
Posterior paracentral lobule that contains somatosensory cortex for leg/foot (parietal lobe)

Question 14

Orbital frontal cortex

Answer 14

Basal surface of the cerebral cortex

Component of the limbic or emotional system

Question 15

postcentral gyrus (parietal lobe)

Answer 15

Contains primary somatosensory cortex which receives impulses from receptors on the opposite side of the body above the knee

Question 16

Superior parietal lobule and Inferior parietal lobule

Answer 16

Areas involved with memory storage of internal and environmental spatial info

3-D CNS info

Question 17

Temporal Lobe Gyrus

Answer 17

Superior Temporal Gyrus: upper lateral gyrus

Middle Temporal Gyrus: intermediate lateral gyrus separated from the superior Temporal Gyrus by a superior temporal sulcus

Inferior Temporal Gyrus: lower gyrus that borders the basal surface

Question 18

Transverse Temporal Gyri

Answer 18

2-3 gyri that extend horizontally inward from the superior Temporal gyrus to the depths of the lateral fissure

Contain primary auditory cortex for perception of sound stimuli

Continuous with the superior Temporal gyrus

Question 19

Planum Temporale

Answer 19

Posterior to the transverse temporal gyri

Upper surface of the superior Temporal gyrus

Continuous with cortex of the inferior parietal lobule

High level sensory processing

Question 20

Wernicke’s Area (receptive speech)

Answer 20

Language dominant hemisphere (usually the left)

Planum Temporale and adjacent areas of the inferior parietal lobule

Processing for the comprehension of spoken, written or sign language

Question 21

Parahippocampal gyrus

Answer 21

Medial gyrus of the basal surface of the temporal lobe

Question 22

Uncus

Answer 22

Medial fold of the rostrum end of the parahippocampal gyrus

Clinically: during increased intracranial pressures above the tentorium cerebellum, it can herniated through the opening formed by the free edge of the tentorium and compress structures of the midbrain

Question 23

Gyri of Insula

Answer 23

Lateral surface, deep in the lateral fissure

Function in taste, visceral sensation and possibly paths linked to addiction

Question 24

Lateral Occipital Lobe Gyri

Answer 24

A small number of broken gyri at the posterior pole

Question 25

Occipital Lobe (medial view)

Answer 25

Cortex posterior to the parietal-occipital sulcus

Question 26

Cuneus (these are gyri)

Answer 26

Upper occipital cortex on the medial side

Question 27

Calcarine Fissure

Answer 27

Separates the cuneus above from lingual gyrus below

Question 28

Lingual Gyrus

Answer 28

Below calcarine fissure Extending to posterior pole

Question 29

Limbic Lobe

Answer 29

Concerned with emotional tone and memory | Encircles the corpus callosum q

Question 30

Cingulate gyrus (limbic lobe)

Answer 30

Encircling most of the corpus callosum

Question 31

Parahippocampal gyrus and uncus

Answer 31

Difficult to see except on the basal surface

Question 32

Medial view of the Corpus Callosum and its components

Answer 32

It's a major cortical commissure that includes: rostrum-thinned anteroventral area Genu-anterior bending part Body-large intermediate part Splenium-caudal part

Question 33

Lamina Terminalis

Answer 33

Vertical membrane that descends from the rostrum of the corpus callosum. It was the roster all end of the medial forebrain during development

Question 34

Anterior Commissure

Answer 34

Posterior to the lamina terminalis; connects parts of left and right Temporal lobe

Question 35

Septum Pellucidum

Answer 35

Midline membrane that separates the lateral ventricles

Question 36

Diencephalon

Answer 36

This part of the forebrain surrounds the third ventricle and is deep to the cerebral hemispheres. It has several components including the thalamus, hypothalamus and pineal gland

Question 37

Hypothalamic Sulcus

Answer 37

Groove along the wall of the third ventricle that marks the boundary between the thalamus (above) and hypothalamus (below)

Question 38

Thalamus

Answer 38

Superior to hypothalamic sulcus

Question 39

Massa intermedia or interthalamic adhesion

Answer 39

Thalamic nuclei that variably fuse in the midline

Question 40

Hypothalamus

Answer 40

Below hypothalamic sulcus

Question 41

Optic Chiasm

Answer 41

Crossing of optic nerve fibers

Question 42

Falx Cerebri and Tentorium Cerebelli

Answer 42

Supportive partitions between parts of the brain

Question 43

Internal Capsule

Answer 43

Boomerang-shaped sheet of white matter that is seen on an axial slice of the forebrain

Question 44

Subcortical nuclei called Basal ganglia

Answer 44

Seen on axial slice of the forebrain

Question 45

Longitudinal cerebral fissure and lateral fissure

Answer 45

External landmarks on an axial slice of the forebrain

Question 46

Subdivisions of Telencephalon on an Axial Scan

Answer 46

Cortex White matter including subcortical white matter: core of white matter in each cortical gyrus that consists of fibers traveling to and from its cortical neurons And Deep white matter: located deep to the subcortical area; contains many tracts traveling in different directions Internal capsule: boomerang-shaped bundle of axons that connect the cerebral cortex and lower CNS areas; has subdivisions three of which are landmarks that can be seen together ONLY IN THE HORIZONTAL PLANE

Question 47

Three parts of internal capsule

Answer 47

Can only bee seen together in the HORIZONTAL PLANE Anterior limb: located between 2 subcortical nuclei or basal ganglion Genu (bend): lateral to the interventricular foramen (part of ventricular system that connects the lateral and third ventricle) Posterior limb: area between the thalamus medially and a subcortical nucleus called the lentiform nucleus laterally

Question 48

Subcortical Nuclei or Basal Ganglion on an Axial Image

Answer 48

Include several individual nuclei, including the caudate nucleus (anterior) and a group of nuclei described collectively as the lentiform nucleus; involved in movement planning

Question 49

Coronal Section of the Forebrain (structures seen)

Answer 49

Thalamus (diencephalon) Telencephalon: that includes: Cortex: peripheral sheet of gray matter Subcortical white matter: finger-like white matter projections that consist of axons bringing info to and from cortical neurons Deep White Matter: mass of bundles of fibers passing in different directions Posterior Limb of internal capsule: bundle of fibers traveling between the thalamus and the lentiform nucleus en route to the cortex or lower structures Subcortical nuclei (basal ganglion): including the lentiform nucleus (putamen and globus pallidus) that are located lateral to the internal capsule Also can see: longitudinal and lateral fissures, cerebral peduncles of the midbrain and the base of the pons