2 - Brain anatomy and Cortical localisation Flashcards
Where is the brainstem located?
Beneath the cerebrum and in front of the cerebellum
What are the 3 parts of the brain stem?
- The midbrain
- The pons
- The medulla
What are the 2 paired structures coming out the midbrain called?
Cerebral peduncle
of midbrain
Describe the Cerebral peduncle
(of midbrain)?
White matter fibres travel here
These fibres attach our midbrain to the rest of the brain
What is found on the medulla?
Bulges
What is the innermost bulge in the medulla called?
The pyramids
What is the outermost bulge in the medulla called?
The olives
How many cranial nerves arise from the brain stem?
10
Which cranial nerves arise from the brain stem?
III- Occulomotor IV- Trochlear V- Trigeminal VI- Abducens VII- Facial VIII - Vestibulocochlear IX - Glossopharyngeal X - Vagus XII - Hypoglossal XI – Accessory
Where does the oculomotor nerve arise from?
The Cerebral peduncle in the midbrain
Ventral
Where does the trigeminal nerve arise from?
Emerges from the middle of the pons
Ventral
Where does the Abducens nerve emerge from?
The junction between the pons and the medulla
At the midline
(Ventral)
Where does the Facial nerve emerge from?
The junction between the pons and the medulla
Lateral to the midline
(Ventral)
Where does the Vestibulocochlear nerve emerge from?
The junction between the pons and the medulla
Lateral to the 7th
(Ventral)
Where does the Glossopharyngeal nerve emerge from?
At the medulla just inferior to 8th cranial nerve
Ventral
Where does the Vagus nerve emerge from?
At the medulla just inferior to 9th cranial nerve
Ventral
Where does the Hypoglossal nerve emerge from?
At the medulla between the junction of the pyramids and the olives
(Ventral)
Where does the accessory nerve emerge from?
At the medulla just inferior to 10th cranial nerve
Ventral
Which cranial nerves do not emerge from the brainstem
I- Olfactory nerve
II- optic
Where does the trochlear nerve emerge from?
Dorsal side of the brain stem below the inferior colliculi
What are the bumps visible on the dorsal side of the midbrain?
Colliculi
How many Colliculi are found on the dorsal side of the midbrain?
4 (2 pa
2 superior
2 inferior
Which of the 10 cranial nerves emerging from the brainstem is different to the rest and why?
The trochlear nerve as it emerges from the dorsal side of the brain
The space between the pons and the cerebellum is filled with what?
Fluid
What happens if we remove the cerebellum?
We are left is the floor of the fluid space
What is found at the top of the medulla?
The open medulla which is the space where fluid is
What is space lateral to the open medulla called?
The closed medulla
What are cranial nerves I and II
Extensions of the cerebrum
Where does the olfactory nerve emerge from
Synapses with the olfactory bulb which is an extension of the telencephalon
What is the olfactory nerve an extension of?
The telencephalon
How does information travel along the olfactory nerve?
- Electrical impulse travels through the olfactory nerve
- Synapses with the olfactory bulb
- Then passes through the olfactory tract
- Impulse is Brough to the cortex which processes the information
Where does the optic nerve emerge from?
Develops as an extension of the diencephalon
What is the diencephalon?
The inner brain
How many divisions are there of the diencephalon?
There are 4 division
What are the 4 divisions of the diencephalon
- Thalamus
- Hypothalamus
- Epithalamus
- Subthalamus
Where is the diencephalon found?
Sits on top of the brainstem connecting it to the central hemisphere
Describe the thalamus segment of the diencephalon
Made up of several nuclei
It is all grey matter
They relay stations between parts of the CNS
Kind of like the receptionist of the diencephalon
Where is the thalamus located in the diencephalon
In the centre
What does the thalamus do in the brain?
Receives info from the spinal cord and the brain and sends that information to the different corresponding parts of the brain
Describe the hypothalamus
Made up of several nuclei
Completely grey matter
Where is the hypothalamus found?
Below the thalamus
What is the function is the hypothalamus
Regulates neuroendocrine and autonomic functions
Where is the Subthalamus found?
Found below and lateral to the thalamus
What is the function of the sub thalamus?
It is involved in motor control
In which view is the sub thalamus not visible?
The midsagittal view
Where is the epithalamus found?
Upon (above) the thalamus
Describe the epithalamus
It includes the pineal gland
Describe the pineal gland
Secretes melatonin which regulates sleep an wake cycles
What are folds in the brain called?
Gyri (sing= gyrus)
What are grooves in the brain called?
Sulci (Sing= sulcus)
What are specific sulk in the brain used to do?
They are used to divide the cerebral hemisphere into lobes
What is the groove right in the centre called?
The central sulcus
Why is the central sulcus important?
It separates the frontal and parietal lobe
Why is the lateral sulcus important?
It separates the frontal lobe from the temporal lobe
Which grooves can be found in the temporal lobe?
The superior and inferior temporal sulci
What is the groove right at the back of the brain called?
The parieto-occipital sulcus
Which 6 sulci must we be aware of?
- Central sulcus
- Lateral sulcus
- Inferior temporal sulcus
- Superior temporal sulcus
- Parieto-occipital sulcus
- Calcarine sulcus
- The cingulate sulcus
Why is the parieto-occipital sulcus important?
It separates our parietal and occipital lobes
Which sulcus is found at the caudal end of the medial surface of the brain?
The calcarine sulcus
Why is the calcarine sulcus important?
It is involved in the visual pathway
What is the function os the corpus callosum?
Bind of white matter fibres that attaches the left hemisphere to the right hemisphere
What is the function of the frontal lobe?
It is the motor cortex
It regulates emotions, behaviour and personality
What is the function of the parietal lobe?
It is the sensory cortex
It is important fro spacial awareness
It is important for understanding language
What is the function of the temporal lobe?
It is the auditory cortex
It is responsible fro regulating emotions
What is the function of the occipital lobe?
It is the visual cortex