L12 Limbic System

Question 1

Anatomically, the limbic structures include the:

Answer 1

A. Gyri: Subcallosal, the cingulate, and the parahippocampal gyri,
B. The hippocampal formation
C. The amygdaloid nucleus
D. The mammillary bodies, and the anterior thalamic nucleus.

Question 2

-connecting pathways of limbic system.

Answer 2

alveus
fimbria
Fornix
mammillothalamic tract
stria terminalis

Question 3

The hippocampal formation consists of:

Answer 3

1. The hippocampus,
2. The dentate gyrus, and
3. The parahippocampal gyrus.

Question 4

curved elevation of gray matter that extends throughout the entire length of the floor of the inferior
horn of the lateral ventricle:

Answer 4

HIPPOCAMPUS

Question 5

anterior end of hippocampus expanded to form:

Answer 5

pes hippocampus.

Question 6

thin layer of white matter covered hippocampus on its superior or ventricular surface called:

Answer 6

the alveus

((It’s nerve fibers originate in hippocampal cortex))

Question 7

• Fibers of alveus medially form ………….
• The fimbria continuous with the …… of the fornix.
• The hippocampus terminates ………….of the corpus callosum.

Answer 7

-fimbria
-crus
-posteriorly beneath the splenium

Question 8

narrow, notched band of gray matter that lies between the fimbria of the hippocampus
and the parahippocampal gyrus is:

Answer 8

dentate gyrus

Question 9

-dentate gyrus Anteriorly, continued into

Answer 9

uncus

Question 10

-dentate gyrus Posteriorly, accompanies the fimbria almost to the splenium of the corpus callosum and becomes continuous with :

Answer 10

indusium griseum.

Question 11

-thin, vestigial layer of gray matter that covers the (superior surface) of the
corpus callosum:

Answer 11

indusium griseum

Question 12

-superior surface of the indusium griseum are two slender bundles of
white fibers on each side called the

Answer 12

medial and lateral longitudinal striae.

Question 13

Lies between the hippocampal fissure and the collateral sulcus?

Answer 13

PARAHIPOCAMPAL GYRUS

It Continuous with the hippocampus along the (medial edge ) of the temporal lobe.

Question 14

-Site of AMYGDALOID NUCLEUS

Answer 14

partly anterior and partly superior to the tip of the inferior horn of the lateral ventricle.

((fused with the tip of the tail of caudate ,which has passed anteriorly in the roof of the inferior horn LV))

Question 15

-The stria terminalis emerges from

Answer 15

posterior aspect of Amygdaloid nucleus

Question 16

amygdaloid nucleus consists of a complex of nuclei which are

Answer 16

1- larger basolateral group
2- smaller corticomedial group.

Question 17

Fimbria leaves the posterior end of the hippocampus as :

Answer 17

the crus of the fornix.

Question 18

crus of fornix from each side curves ……….. and ………. beneath the splenium of the corpus callosum and around the posterior surface of the thalamus.

Answer 18

posteriorly and superiorly

Question 19

….is applied closely to the undersurface of the corpus callosum.

Answer 19

Body of fornix

Question 20

crura connected by transverse fibers called the ….

Answer 20

commissure of the fornix .

Question 21

• Anteriorly, the body of the fornix is connected to the undersurface of the corpus callosum by :

Answer 21

the septum pellucidum.

Question 22

• Inferiorly, the body of the fornix is related to…..

Answer 22

the tela choroidea and the ependymal roof of the 3rd ventricle

Question 23

The body of the fornix splits anteriorly into two anterior columns of the fornix, each of which curves anteriorly and inferiorly over the:

Answer 23

interventricular foramen (foramen of Monro).

Question 24

• Each column of fornix disappears into the:

Answer 24

lateral wall of the (third ventricle) to reach the mammillary body .

Question 25

MAMMILLOTHALAMIC TRACT

connections between the mammillary body and :

Answer 25

the anterior nuclear group of the thalamus.

Question 26

-STRIA TERMINALIS runs as a bundle of nerve fibers posteriorly in the roof of the (inferior horn of the lateral ventricle ) on the medial side of the tail of the caudate nucleus follows the curve of the caudate nucleus and comes to lie in the :

Answer 26

floor of the body of the lateral ventricle.

Question 27

AFFERENT CONNECTIONS HIPPOCAMPUS

Answer 27

Six groups
1-Fibers in cingulate gyrus.
2-Fibers in septal nuclei
3-Fibers arising from one hippocampus pass across the midline to the opposite hippocampus in the commissure of the fornix.
4. indusium griseum
5. entorhinal area or olfactory-associated cortex.
6. dentate and parahippocampalgyri.

Question 28

EFFERENT CONNECTIONS HIPPOCAMPUS

Answer 28

The fibers within the fornix are distributed to:

Fibers pass posterior to the anterior commissure to
1-enter the mammillary body, where they end in the medial nucleus*
2. end in the anterior nuclei of the thalamus
3. enter the tegmentum of the midbrain.
‎( هذول كلهم بادين بنفس المكان يعني الجملة اللي فوق هي البدايه )

4. Fibers join the stria medullaris thalami to reach the habenular nuclei
5. Fibers pass anterior to the anterior commissure to end in the
   - septal nuclei
   -the lateral preoptic area
   - anterior part of the hypothalamus.