Topography of the Brain Flashcards
What is the three parts of the brain stem
Medulla
Pons
Midbrain
What is the three functions of the brain stem
Vital centres for autonomic behaviours
Pathways for fibre tracts - so reach cerebral hemispheres
Brainstem nuclei - involved with 10or 12 cranial nerves
What two cranial nerves is the brainstem not involved with and where do they emerge
CN I
CN II
Emerge from the cerebrum
What is the only cranial nerve to originate posteriorly from the brain stem
CN IV originates posteriorly from the midbrain
What does the medulla continue as
continues as spinal cord at the foramen magnum of cranium
What is the two projection on either side of the midline at the front of the medulla
Pyramid
What is contained in the pyramid of the medulla
Tract of motor fibres
What is it called when the pyramid fibres cross at the lower part of the medulla
Decussation of the pyramid
What is the rounded oval prominence on the surface of the medulla oblongata in the brain
Olive
What is contained in the olive
Inferior Olivary nucleus
Superior Olivary nucleus
What does the inferior olivary nucleus aid
Cerebellar motor learning and function
What does the superior olivary nucleus aid
Perception of sound
What cranial nerve emerge from the anterior surface of the medulla
Cranial nerves: CN IX, X, XI, XII
How does the medulla connect to the cerebellum
By the inferior cerebellar peduncle
What is medial lemniscus and where is it found
a large ascending bundle of heavily myelinated axons of sensory that decussate in the brainstem (pons and medulla)
What is present in the grey matter of the medulla
Cranial nerve nuclei
Inferior olivary nucleus
Nuclei of reticular formation*
Sensory nuclei
What is the position of the 4th ventricle in the brain stem
The 4th ventricle cavity has the medulla and pons sitting anteriorly and the cerebrum posteriorly
What connects the pons to the cerebellum
The middle cerebellar peduncle
What are the cranial nerves that emerge from the pons medulla junctions
CN VI, VII, VIII
What is an additional cranial nerve that emerges from the pons
CN V
What ventricular cavity is present in the midbrain
The cerebral aqueduct
What connects the midbrain to the cerebellum
The superior cerebellar peduncle
What connects the midbrain to the cerebrum
Cerebral peduncles
Where is the cerebral peduncle located
Anterior, infront of the thalamus and down into the midbrain
What is the name of the 2 pea size bodies locates posterior to the midbrain
Superior colliculus
Inferior colliculus
What is superior colliculi involved in
Visual reflex
What is inferior colliculi involved in
auditory reflex
What two nerves originate from the midbrain
CN III
CNIV
What is the name of the black line in the section of the midbrain
substantia nigra
Where is the red nucleus and what is its function
red nucleus is a structure in the rostral midbrain involved in motor coordination
Where is the nucleus for the CN III and IV
Periaqueductal grey matter
What surround thePeriaqueductal grey matter
White matter embedded with nucleii
What is present in the grey matter of the pons
Cranial nerve nucleus
Pontine nuclei - part of pons involved in motor function
Nuclei of reticular formation
What is present in the white matter of the pons and medulla
Middle cerebellar peduncle /Inferior cerebellar peduncle
Medial leminiscus (sensory)
Pyramidal tract (motor)
What separates let and right hemispheres of the cerebellum
Vermis
How many peduncles connect the cerebellum to the brainstem
3
What is present in the grey matter of the cerebellum
Cortex on surface
Deep nuclei
What is present in the white matter of the cerebellum
Arbor vitae
Cerebellar peduncles
What is present in each hemisphere os the cerebellum
Anterior, posterior and flocculonodular lobe
What is present on the surface of the cerebellum
Sulci and folia
What is the overall function of the cerebellum
Posture maintenance
Fine tuning motor activity
Where is the 3 places information for the cerebellum originate
Pyramidal tracts
Ipsilateral (same side) proprioceptors from periphery (sensory receptors in the muscle_
Vestibular nucllei in the ear (balance and posture)
How does the cerebellum overall mange to control balance and co-ordination
By Calculating the best way to coordinate force, direction, extent of muscle contraction to maintain posture prevent overshoot and ensure smooth coordinated muscle contraction
How is the calculated information sent back to the cerebral cortex
Via the superior cerebellar peduncle in an afferent fibre, to midbrain then cerebral peduncle on midbrain to cerebral hemisphere
How do you test for abnormalities in the cerebellum
Finger – nose test
Knee-heel test
Walking in a straight line
Define ataxia
neurological sign consisting of lack of voluntary coordination of muscle movements that includes gait abnormality
Where is the diencephalon located
Deep within the cerebral hemisphere around the third ventricle
What does the diencephalon develop from
diencephalic vesicle (part of forebrain vesicle)
What is the diencephalon composed of
Thalamus, Hypothalamus (and pituitary),
Epithalamus (pineal gland).
What is the overall function of the epithalamus
Connect the limbic system to other parts of the brain
What gland is located in the epithalamus
the pineal gland
What is the function of the pineal gland
produces melatonin, which helps maintain circadian rhythm (sleepwalk cycle) and regulate reproductive hormones.
What makes up the majority of the diencephalon
The thalamus
What is mainly contained in the thalamus
Contains groups of nucleii - anterior, medial and lateral group.
What is the main function of the thalamus
sensory relay station
What group of nuclei in the thalamus are involved in processing sensory information
lateral
What separates thalamus and hypothalamus
Hypothalamic sulcus
What is the functions of the hypothalamus
main visceral control centre & is essential for overall homeostasis.
How does the hypothalamus link the Visceral/nervous system to the endocrine system
Via the pituitary gland
What is the 6 homeostric roles of the hypothalamus
Autonomic Control Centre Body temperature regulation Regulation of food intake Regulation of water balance & thirst Regulation of sleep-wake cycle Control of endocrine system functioning
What does the hypothalamus connect to
The pituitary stalk
How does the cerebellum receive info from the pyramidal tracts
Via the cerebellar peduncles
If herniation of the cerebrum occurs through the foramen magnum what herniates first
The tonsils part of the posterior lobe