Lab 2: Brain Flashcards
What is the forebrain made up of?
Superficial part of the hemispheres
Basal ganglia
Diencephalon
What is the superficial part of the hemispheres made up of in a medial view??
Cortex, corpus callosum, parieto-occipital sulcus, calcarine sulcus, primary visual cortex
What is the cortex?
Grey matter thrown into ridges gyri and folds sulci.
What is the corpus callosum?
A white matter tract carrying information between the hemispheres.
Where is the primary visual cortex centred?
On the calcarine sulcus.
What is the diencephalon made up of in a medial view?
Thalamus, hypothalamus, pituitary gland, third ventricle
What is the function of the thalamus?
Relays almost all sensory input to the cortex.
What are the functions of the hypothalamus?
Controls internal body functions, and the autonomic nervous system.
What is the pituitary gland? What is it controlled by?
A gland attached to the hypothalamus and controlled by it.
Which gland is always torn off when the brain is removed from the skull?
Pituitary gland
What is the third ventricle? What is it’s appearance?
The ventricle of the diencephalon.
A slight depression overlying the thalamus.
What is the midbrain made up of in a medial view?
Superior and inferior colliculi, cerebral aqueduct, cerebral peduncles.
What do the superior and inferior colliculi form the roof of?
What are the roles of the colliculi?
The roof of the midbrain.
Have a minor role in controlling eye movements, and movements related to auditory stimuli.
What is the cerebral aqueduct?
A narrow passage linking the 3rd and 4th ventricles, about as thick as a matchstick.
What are the cerebral peduncles? What do they make up the floor of?
Thick white-matter tracts making up the floor of the midbrain.
What do the cerebral peduncles carry information between?
They carry information between the cerebral cortex and the spinal cord (corticospinal fibres) and between the cortex and the pons (corticopontine).
What is the hindbrain made up of in a medial view?
Cerebellum, pons, medulla, fourth ventricle
What is the cerebellum?
A motor centre which co-ordinates movements.
What does the pons carry/contain?
Carries corticospinal fibres, and also contains nuclei of cranial nerves.
What does the medulla carry?
Corticospinal fibres e.g. the pyramids, cranial nerve nuclei and grey matter controlling breathing and the heart.
What are the ventricles of the brain?
CSF-filled cavities
What are the 4 major parts of the brain?
Brain stem, cerebellum, diencephalon, cerebrum
What does the brain stem consist of?
Medulla oblongata, pons, and midbrain
Where is the diencephalon situated with relation to the brain stem?
It is superior to the brain stem
What is the largest part of the brain?
Cerebrum
What is the Exner’s area for?
Controls hand movements for writing
What is the function of Broca’s speech area?
Controls larynx and tongue for speech
What is the function of Wernicke’s speech area?
Main processing centre for spoken language
What are the functions of the supramarginal and angular gyri?
Interprets visual symbols as written words.
What is the superficial part of the hemispheres made up of in a coronal section?
Cerebral cortex, corpus callosum, lateral ventricles
What doe the folding of cortex into gyri and sulci allow?
It triples the available area of the cortex.
Which structure of the brain is sometimes cut twice in one coronal slice because of its arc-shape?
Corpus callosum
In a coronal section, what are the basal ganglia made up of?
Caudate nucleus, putamen, globus pallidus
What are the functions of the basal ganglia?
Motor centres which initiate and terminate gross body movements and control muscle tone.
In a coronal section, what is the diencephalon made up of?
Thalamus, hypothalamus, third ventricle, internal capsule
What is the internal capsule?
The great white matter tract which carries all information to and from the cortex.
In a coronal section, what does the midbrain consist of?
Superior and inferior colliculi, cerebral aqueduct, cerebral peduncles, substantia nigra
What is the function of the substantia nigra?
Functions as part of the basal ganglia controlling unconscious body movements.
What is the hindbrain made up of in a coronal slice?
Pons, cerebellum, fourth ventricle
What are the three types of cranial meninges?
1) dura mater
2) arachnoid mater
3) pia mater
What separates the two hemispheres?
Falx cerebri
What separates the two hemispheres of the cerebellum?
Falx cerebelli
What separates the cerebrum from the cerebellum?
Tentorium cerebelli
What is cerebrospinal fluid?
A clear, colourless liquid composed primarily of water.
How does blood flow to the brain?
Mainly via the internal carotid and vertebral arteries.
What does the blood-brain barrier consist mainly of?
Tight junctions that seal together the endothelial cells of brain blood capillaries and a thick basement membrane that surrounds the capillaries.
How many lateral ventricles are there in each hemisphere?
One
What is the shape of the third ventricle?
Narrow slitlike cavity along the midline superior to the hypothalamus and between the right and left halves of the thalamus.
Where does the fourth ventricle lie?
Between the brain stem and cerebellum
What are the three basic functions of the CSF?
1) Mechanical protection
2) Homeostatic function
3) Circulation
What is the blood-cerebrospinal fluid barrier formed by?
Tight junctions of ependymal cells.
What is meant by contralateral control?
One side of the brain controles the opposite side of the body
What is meant by saggital and parasaggital section?
Saggital: straight down the middle
Parasaggital: To the side of the centre so misses structures
What is the anterior and posterior region of the primary visual cortex responsible for?
A: Peripheral vision
P: Central vision
During a collision with the back of the head, what is affected?
Central vision
What is the function of a mammillary body?
Olfactory (smell) reflexes
What link does the pituitary provide?
Neural-hormonal link
What is the purpose of the thalamus?
Switchboard which distinguishes between conscious and subconscious awareness/reaction. It may send information to the cortex (conscious) or basal ganglia in the cerebellum (unconscious reflexes).
What surrounds the intermediate mass and the left and right side of the thalamus?
Cerebrospinal fluid
State what the superior and inferior colliculi control.
Sight and sound reflexes
What are the cerebral peduncles?
White matter tracts that are projection fibres
What are the functions of the cerebellum?
Controls muscle tone
Balabc
Intention vs achievement
Suggests adjustments
What area is first affected by alcohol?
Cerebellum
What exhibits ipsilateral (same side) control?
Cerebellum
What does the pons control?
Communication between hemispheres of the cerebellum
What does the medulla contain?
White matter tracts
What are the five components of hearing and speaking?
Primary auditory cortex Wernicke's area Broca's area Primary motor cortex (face) Primary auditory area
What are the five general components of either hearing and speaking or reading and writing?
1) Receive input
2) Understand meaning
3) Plan response
4) Conduct response
5) Feedback evaluation
What are the 4 main primary areas?
Primary motor cortex
Primary somatosensory cortex
Primary visual cortex
Primary auditory cortex
What does the PMC control?
Voluntary muscle movement
What specific region of the PVC controls central vision?
The pole
What does the PAX receive information about? How is it organised?
Auditory information: pitch, tone, rhythm
Tonotopic organisation. Recognises high pitch in some areas and low pitch in other areas.
Do the four primary areas have any function in integrating information?
NO
What are the four main secondary/association areas? What are the functions of each?
Exner’s area: plans movements in writing
Broca’s speech area: pans movements in speaking
Supramarginal and angular gyri: understanding reading and writing and giving meaning to written symbols.
Wernicke’s area: understanding speech and giving meaning to sound
Where is Exner’s area found?
In the premotor cortex, just before the part of the PMC associated with the hand.
What lies in the cortex? What makes up the white matter tracts?
Cell bodies of neurones. Send axons (white matter) which makes up white matter tracts.
What are the three types of white matter tract?
1) Commissural fibres/tract
2) Projection fibres
3) Association fibres
What function do commissural fibres have?
Transfers information between hemispheres.
What function do projection fibres have?
Transfers information from the top of the brain to the bottom
What function do association fibres have?
Transfers information within the same hemisphere. e.g. between gyri.
What does the head of the caudate nucleus run along?
The walls of the lateral ventricle
What type of structure is the cerebellum?
Posterior structure
