Telencephalon (Cerebrum) Flashcards
1
Q
Telencephalon
A
- large part of the brain containing the cerebral cortex (of the two cerebral hemispheres)
- as well as several subcortical structures, including the hippocampus, basal ganglia, and olfactory bulb
- the cerebrum is the uppermost region of the central nervous system
2
Q
Where does the telencephalon develop from?
A
The prosencephalon or forebrain is the embryonic structure from which the cerebrum develops prenatally
3
Q
Telencephalic white matter - projection fibers
A
- projection fibers consist of efferent and afferent fibers uniting the cortex with the lower/other parts of the brain and with the spinal cord
e. g. Corona radiata - white matter sheet of both ascending and descending axons carries most of the neural traffic from and to the cerebral cortex - The corona radiata is associated with the corticopontine tract, the corticobulbar tract, and the corticospinal tract.
4
Q
Telencephalic white matter - commissural fibers
A
- or transverse fibers
- axons that connect the two hemispheres of the brain
5
Q
Corpus Callosum
A
- It is the largest white matter structure in the human brain
- wide, thick nerve tract, consisting of a flat bundle of commissural fibers
- beneath the cerebral cortex in the brain
- only found in placental mammals
- It spans part of the longitudinal fissure, connecting the left and right cerebral hemispheres, enabling communication between them
- four main parts; individual nerve tracts that connect different parts of the hemispheres. These are the rostrum, the genu, the trunk or body, and the splenium
6
Q
Relations of Corpus Callosum
A
- fibers radiate in the white matter and pass to the various parts of the cerebral cortex
- those curving forward from the genu into the frontal lobes - forceps minor
- those curving backward from the splenium into the occipital lobes - forceps major (also forceps posterior)
tapetum - main body of fibers between these two parts
7
Q
Commissura anterior
A
- commissural fiber, pars anterior/post.
- white matter tract (a bundle of axons) connecting the two temporal lobes of the cerebral hemispheres across the midline
- placed in front of the columns of the fornix
- The great majority of fibers connecting the two hemispheres travel through the corpus callosum, which is over 10 times larger
- key role in pain sensation, more specifically sharp, acute pain, contains decussating fibers from olfactory tracts
8
Q
Commissura fornicis
A
- commissural fiber
- a C-shaped bundle of nerve fibers in the brain that acts as the major output tract of the hippocampus
- also carries some afferent fibres to the hippocampus from structures in the diencephalon and basal forebrain
- The fornix is part of the limbic system
9
Q
Commissura posterior
A
- left and right parts of tectum and tegmentum of midbrain
- important in the bilateral pupillary light reflex.
10
Q
Association fibers
A
- axons that connect cortical areas within the same cerebral hemisphere
- short fibers - Many of the short association fibers (also called arcuate or “U”-fibers) lie immediately beneath the gray substance of the cortex of the hemispheres, and connect together adjacent gyri.
- Some pass from one wall of the sulcus to the other
11
Q
Long association fibers
A
- The long association fibers connect the more widely separated gyri and are grouped into bundles
12
Q
Fasciculus longitudinalis superior
A
- ass. f.
- frontal lobe to occipital lobe
- ass. f.
13
Q
Fasciculus longitudinalis inferior
A
- ass. f.
occipital to temporal lobe
14
Q
Cingulum
A
- ass. f.
- cingulate gyrus to entorhinal cortex
- ass. f.
15
Q
Fasciculus uncinatus
A
4.
- ass. f.
frontal lobe to temporal lobe
16
Q
Speech areas
A
17
Q
Lateralisation of functions
A