Neuroanatomy Practical 3 Flashcards
Lateral view of cerebral hemisphere (frontal pole on the right)
What structure is hidden between the temporal and parietal lobes? What fissure/sulcus is it located in?
Insula: portion of the cerebral cortex folded deep within the lateral sulcus (the fissure separating the temporal lobe from the parietal and frontal lobes) within each hemisphere of the mammalian brain.
Function of insula (N.B. part of lobe been removed in photo)
processes information associated with hearing and equilibrium
What is being pointed to? (lobes have been removed)
Insula
Which foramina connect each lateral ventricle to the 3rd ventricle?
Interventricular foramen / foramen of Monro
Where does the 3rd ventricle sit?
The diencephalon encloses the third ventricle (thalamus either side)
Which structure sits either side of the 3rd ventricle?
Thalamus
Which structure is being pointed to? Function?
The interthalamic adhesion (also known as the intermediate mass or middle commissure) is a flattened band of tissue that connects both parts of the thalamus at their medial surfaces
Which foramen connects the 3rd and 4th ventricle?
Cerebral aqueduct
Which structures sit anterior and posterior to the 4th ventricle?
Pons anteriorly and cerebellum posteriorly
What is the 4th ventricle continuous with?
The central canal of the medulla and spinal cord
Where does CSF escape into subarachnoid space?
From 4th ventricle via foramen of Lushka (x2) laterally and foramen of Magendie (x1) medially/posteriorly
What brain region contains the cerebral aqueduct?
Midbrain
View of dorsal aspect of 4th ventricle behind pons
This is the hippocampus (one on right and one on left). Where does it sit? Function?
Sits in temporal lobe –> memory
Describe shape of hippocampus
Sends fibre bundle (fornix) with characteristic C-shape as it arches over the thalamus to end up in the hypothalamu
What is the fornix?
The fornix is a C-shaped bundle of nerve fibers in the brain that acts as the major output tract of the hippocampus. The fornix also carries some afferent fibers to the hippocampus from structures in the diencephalon and basal forebrain. The fornix is part of the limbic system.
Describe location of hippocampus and fornix
- Sits inferior to inferior horn of lateral ventricle in the temporal lobe
- Fornix sits medial to lateral ventricles and arches over thalamus to end in the hypothalamus
What does the fornix connect to?
Mamillary bodies of hypothalamus
What is found lateral to the thalamus?
Fibres of internal capsule
What does the internal capsule contain?
Ascending (sensory) and descending (motor) fibres
What is the internal capsule found medial to?
Lentiform nucleus
What composes the lentiform nucleus?
- Putamen (laterally)
- Globus pallidus (medially)
View of caudate nucleus
- C-shaped exterior of caudate nucleus; head, body and tail
- Lentiform nucleus in middle
The caudate nucleus and the putamen share some connections. What are these called?
Cellular bridges
Together, the caudate nucleus and lentiform nucelus form what structure?
Corpus striatum
What interrupts the cellular bridges?
Some fibres of internal capsule
What is found superior to fornix (between lateral ventricles)?
Corpus callosum –> major cerebral commissure
What is being pointed to?
The amygdala is one of two almond-shaped clusters of nuclei located deep and medially within the temporal lobes of the brain’s cerebrum (anterior to hippocampus)
Where is the primary visual cortex located?
Posterior pole of occipital lobe
Where is the primary auditory cortex located?
Superior temporal gyrus
What is Broca’s area?
a region in the frontal lobe of the dominant hemisphere, usually the left, of the brain with functions linked to speech production located in the ingerior frontal gyrus
What is the calcarine sulcus?
Subdivides the occipital lobe superiorly and inferiorly
Fornix drawn in blue
Which 2ary brain vesicle do the mamillary bodies belong to?
Diencephalon
Which 2ary brain vesicle does the thalamus belong to?
Diencephalon
Which 2ary brain vesicle does the caudate nucleus belong to?
Telencephalon
Which 2ary brain vesicle does the corpus callosum belong to?
Telencephalon
A patient exhibits a variety of behavioural and language problems such as a failure to inhibit responses that are socially inappropriate. Such an individual is most likely to suffer from dementia involving the:
a) parieto-occipital region
b) prefrontal cortex
c) inferior temporal cortex
d) corpus callosum
Prefrontal cortex; planning complex cognitive behavior, personality expression, decision making, and moderating social behaviour
A 79 year old woman is admitted to ER after she was found unconscious in her apartment. After she regained consciousness, a neurological examination indicated that she suffered a stroke with paralysis of the right arm and leg as well as loss of speech.
The loss of speech in this patient was due mainly to damage of the:
a) superior frontal cortex
b) inferior temporal gyrus
c) inferior frontal gyrus
d) superior temporal gyrus
Loss of speech; damage to inferior frontal gyrus (Broca’s area found here)
A 35 year old man suffered a stroke that did not cause paralysis. However, he discovered that he was unable to perform complex learned movements.
The region of the cerebral cortex most likely affected by the stroke was the:
a) precentral gyrus
b) postcentral gyrus
c) premotor cortex
d) prefrontal cortex
Premotor cortex; an area of the motor cortex lying within the frontal lobe of the brain just anterior to the primary motor cortex.
What is this sulcus? What is found anterior and posterior?
Central sulcus;
- anterior is frontal lobe and precentral gyrus
- posterior is parietal lobe and postcentral gyrus