Neuroanatomy Lab (Week 5) Flashcards Preview

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Flashcards in Neuroanatomy Lab (Week 5) Deck (30):
1


Lateral fissure (sulcus)


Runs between temporal lobe and frontal/parietal lobes

2


Central sulcus


Separates frontal lobe from parietal lobe

Generally separates primary motor cortex (precentral gyrus) from primary somatosensory cortex (postcentral gyrus)

3


Paracentral lobule

 

Continuation of primary motor and primary somatosensory cortex onto medial surface of hemisphere

(lower limbs)

4


Calcarine fissure


Primary visual cortex is on either side of calcarine fissure

5


Parieto-occipital sulcus


Separates parietal and occipital lobes

6


What can be seen on ventral aspect of hemisphere?


Olfactory bulb

Olfactory tract

Medial and lateral olfactory striae

Anterior perforated substance (between medial and lateral olfactory striae)

Orbital gyri

Uncus of temporal lobe

7


Uncal herniation


Uncus on medial aspect of temporal lobe herniates through tentorial notch and compresses structures of the brainstem

8


Lenticulostriate arteries


Proximal regions of middle cerebral artery give off branches (lenticulostriate arteries) that penetrate brain in the region of anterior perforated substance

Supply basal ganglia and middle part of internal capsule (including genu)

Rupture or occlusion of these terminal arteries is a common cause of stroke

9


What artery supplies small anteromedioventral territory of head of caudate and putamen in many cases?


Anterior cerebral artery

10


Insular cortex


Deep within lateral fissure

Covered by frontal operculum, parietal operculum and temporal operculum

Branches of middle cerebral artery are in this region

Basal ganglia is deep to insular cortex

11


Transverse temporal gyri


On upper surface of temporal operculum (near lower part of postcentral gyrus)

Primary auditory cortex

12

Optic (visual) radiations

Lateral geniculate nucleus of the thalamus (near posterior region of thalamus) sends out tough fibers that loop forward then outward then backward to fan out in occipital lobe and terminate in calcarine cortex

Most anterior group of fibers is called Meyer's loop (responsible for upper visual field); note Meyer's loop is in temporal lobe!

13


Lateral structure of the temporal lobe


Entorhinal cortex

Hippocampus

Amygdala

14


Limbic cortex


C-shaped region of cortex made up of cingulate gyrus and parahippocampal gyrus

Info from cingulate cortex reaches parahippocampal gyrus through cingulum

15


Collateral sulcus (fissure)


Under (ventral) parahippocampal gyrus??

16


What is at the rostral end of the parahippocampal gyrus?


Uncus

17


Entorhinal cortex


On surface of uncus and on rostral region of parahippocampal gyrus

Sometimes can see small elevations on surface created by clusters of cells within outer layers of entorhinal cortex

18


Fornix


C-shaped pathway that interconnects medial regions of forebrain (septal nuclei and hypothalamus) to laterally located temporal lobe (hippocampus)

Floor of lateral ventricle and roof of 3rd ventricle??

Curves downward caudal to anterior commissure and continues to mammillary body

Small part passes further rostrally (pre-commissural part of fornix) to connect with septal region

19


Stria terminalis


C-shaped structure that interconnects amygdala and septal region of forebrain

Small diameter, between caudate and thalamus

Major efferent pathway of the amygdala

20


Pes (foot) of the hippocampus

Largest part of hippocampus at rostral end

Marked by several indentations that resemble toes

21


Alveus


Thin layer of white matter than covers hippocampus

Formed by axons of neurons in subiculum and some hippocampal pyramidal cells

As axons leave pyramidal cells they bend abruptly to become parallel to the surface formin alveus, and then continue longitudinally in the fimbria

22


Fimbria


Axons leave pyramidal cells and form alveus then form fimbria

Fimbria grows as hippocampus progressively diminishes in size posteriorly and becomes fornix

23


Where does the parahippocampal gyrus end?

Hippocampal fissure?

24


What can you see if you open the hippocampal fissure?


Teeth of the dentate gyrus

Maybe the fornix

25


Where is the amygdala?


Complex of nuclei within the uncus

26


What is located on the medial surface of the uncus?


Primary olfactory cortex

27


What does the anterior commissure connect?


Temporal lobes

Some oflactory nuclei

28


Connections/direction of mammillary --> fornix --> hippocampus


Info goes both ways!

Mammillary bodies --> fornix --> hippocampus

Hippocampus --> fornix --> mammillary bodies

ALSO: septal region (in front of anterior commissure) --> fornix --> hippocampus (this would be using ACh)

AND: hippocampus --> fornix --> septal region

Fornix is bidirectional!

29


What does the uncus cover?


Amygdala and most anterior part of hippocampus

30


Rostral to caudal, what we see


Most rostrally we see amygdala

More caudal see most anterior part of hippocampus (pes!)

Most caudal see normal hippocampus (where we see our normal circuitry)

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