Week 1 - A - Neuroanatomy 1 - Paul Felts - mainly C.N.S Flashcards
What can the nervous system be divided into?
The central and peripheral nervous system (and the autonomic nervous system)
What forms the peripheral nervous system and what forms the central nervous system?
PNS - 12 cranial nerves and the 31 pairs of spinal nerves and their branches CNS - consists of the brain and spinal cord
What does the CNS begin as in the early stages of development - approx week 4?
Begins as the neural tube
At week 4, there are three primary besicles in the nueral tube, what are these primary vesicles known as? (forebrain, midbrain, hindbrain)
Prosencephalon (forebrain) Mesencephalon (midbrain) Rhombencephalon (hindbrain)
The primary vesicles then form secondary vesicles by week 6-8 of development, what are the secondary vesicles known as?
Prosencephalon becomes - telencephalon and the diencephalon The mesenchephalon remains as the mesenchephalon The rhombencephalon becomes the metencephalon and the myelencephalon
What do the telencephalon and the diencephalon give rise to?
Telenchephalon - gives rise to the left and right cerebral hemispheres Diencephalon gives rise to thalalmus + hypothalamus
What do the mesencehphalon, metencephalon and myelencephalon give rise to?
Mesencephelon - midbrain Metencephalon - pons and cerebellum Myelencephalon - medulla oblonglata
Name the three primary vesicles What they divide into to become the secondary vesicles and The major derivatives from the secondary vesicles
Prosencephalon - Telencephalon: left and right cerebral hemispheres Diencephalon: thalamus + hypothalamus Mesenchephalon - Mesencephalon: Midbrain Rhombencephalon - Metencephalon: Pons and cerebellum Myelencephalon: medulla oblongata
What forms the brainstem?
The combination of the midbrain pons and medulla
Name the secondary vesicles which give rise to the derivatives of the mature brain - start with the outlined brain and work towards the spinal cord
Telencephalon - rise to the cerebral hemispheres Diencephalon - thalamus + hypothalamus Mesencephalon - gives rise to the midbrain Metencephalon - pons and cerebellum Myelencephalon - medulla oblongata
Neurones and glial cells are the two principle cells of the central nervous system What are the four parts of a typical neurone?
Have the dendrites, cell body, axon and nerve endings
What is the function of the dendrites and axons?
The dendrites are branched propagations from the cell body that recieve information from other neurons and carry it to the cell body Axons carry messages away from the cell body to the other neurons, muscles or glands
What are the 4 types of glial cell in the CNS?
Astrocytes Oligodendrocytes Microglia Ependymal cells
What are the functions of the 4 types of glial cell?
Astrocytes - role in maintaining the blood brain barrier and environmental homeostasis Oligodendrocytes - produce myelin in the central nervous system Microglia - main immune surveillance cells and antigen presenting cell (APC) Ependymal cells - Ciliated cuboidal/columnar epithelium that line the ventricles
Oligodendrocytes produce myelin in the CNS, what produces myelin in the PNS? What is the function of myelin?
Schwann cells produce myelin the PNS The function of myelin is to increase the speed of nerve impulses
Throughout the brain, there are ‘bumps and valleys’ (indentations) What are these bumps and valleys properly known as?
Gyrus - bumps and sulcus - valley (indentation) (there are also fissures which are very deep indentations)
What is the functions of the gyri and sulci in the brain?
They increase the surface are of the brain increasing the amount of cerebral cortex able to fit in the skull
Which slice separates into right and left and which separates into front and back?
Coronal - front and back (anterior and posterior) Sagittal - right and left
What is the generalization for the arrangement of grey matter and white matter in the brain?
Generally grey matter on the outside with white matter on the inside - however there is a central cavity of grey matter in the brain
What do they grey and white matter in the brain contain?
The white matter contains mainly axons and their support cells The grey matter contains huge numbers of neuron cell bodies
What is the difference in arrangement of matter in the spinal cord compared to brain?
Brain White matter inside Grey matter outside with central cavity of grey matter also Spinal cord White matter outside Grey matter inside in a ‘H’ like fashion White matter - aons Grey matter- cell bodies
The grey matter in the spinal cord is arranged in horns What is the white matter arranged in?
The white matter is arranged in columns, anterior, posterior and lateral The columns are also known as funiculus - ie dorsal column = dorsal funiculus
Why can the white matter columns also be known as fascicles?
This is because the columns are groups of bundled axons which are also known as fascicles
What is the main sulcus in the brain that separates the frontal and parietal lobe?
This is the central sulcus
Where does the primary motor and primary somatosensory sit in relation to the central sulcus?
The primary motor area sits anterior to the central sulcus in the precentral gyrus The primary somatosensory area sits posterior to the central sulcus in the postcentral gyrus
What is the deep groove in the brain that separates the right and left hemispheres? What allows communication between right and left hemispheres?
The deep groove is known as the longitudinal fissure The corpus callasoum allows communication between the right and left hemispheres
What is the white matter situated in the inferomedial aspect of both hemispheres of the brain known as?
This would be the internal capsule - nerve signals are transmitted through this space in the axons
A small lentil like shaped structure of gray matter is situated in the brain lateral to the internal capsule, what is this known as? It is important in movement control
This is the lentiform nucleus
Just superior to the corpus callosum on a saggital slice of the brain is what gyrus?
This would be the cingulate gyris - above this structure is the cingulate sulcus
What is the cingulate gyrus involved in?
It is involved in emotion formation and processing/memory
What is the sulcus in the occipital lobe where the primary visual cortex is located known as?
This is known as the calcarine sulcus
What is the function of the pineal gland? What joins the right and left thalami?
The primary function of the pineal gland is to produce melatonin. This modulates duirnal rhythm The two thalami are joined by the interthalamic adhesion although there is no transmission here
What are the borders of the frontal lobe?
The frontal love has the central sulcus as its posterior border with a line drawn to reach the corpus callosum and The lateral sulcus as its lateral border from the temporal lobe
What are the borders of the parietal lobe of the brain?
The central sulcus anteriorly The parieto-occipital sulcus posteriorly with a line connecting this to the preoccipital notch (produced by a notch from temporal bone) Bordered laterally by a line from the lateral sulcus
What are the borders of the occipital lobe?
It lies posterior to the line made by joining the parieto-occipital sulcus to the preoccipital notch
Finally what are the boundaries of the temporal lobe?
The lateral sulcus supreriorly with a line drawn backwards extending from this and a line drawn from the parieto-occipital sulcus to the preoccipital notch posteriorly
What are the five lobes of the brain?
Frontal lobe Parietal lobe (x2) Occipital lobe Temporal lobe (x2) and the Insular lobe (x2)
Where is the insular lobe normally found and what does it play an important role in?
The insula is hidden from view in the lateral fissure and has an important role to play in the patient’s experience of pain and tatse
What is another name for the lateral sulcus?
The sylvian fissure
What are the three layers of the meninges? they protect the brain and spinal cord
Dura mater Arachnoid mater Pia mater - only a couple of cells thick
Where is CSF (cerebrospinal fluid) produced and what is the flow of CSF?
Produced in the choroid plexuses of the ventricles Flow from lateral ventricles down through the interventricular foramen into the 3rd ventricle Then down the cerebral aqueduct (sylvian aqueduct) into the 4th ventricle CSF then exits into the subarachnoid space via lateral apertures and into the central canal of the spinal cord via lateral apertures Once in the subarachnoid space it escapes into the superior saggital sinus via arachnoid granulations
Where does the dural venous sinuses drain into?
Drains into the internal jugular vein
Which two ventricles are midline structures? What lobes are the four horns of the lateral ventricles situated in?
The third and fourth ventricles Lateral ventricles Anterior horn - frontal lobe Body - parietal love Posterior horn - occipital lobe Inferior horn - temporal lobe
What is the nervous system that spans from the oesophagus to the rectum known as?
The enteric nervous system
Which arteries supply the different regions of brain?
Blue - anterior cerebral artery - basically most of frontal lobe / parietal lobe Red - middle cerebral artery - temporal lobe / parietal lobe Green - posterior cerebral artery - mainly occipital lobe
Which arteries form the circle of willis?
- Anterior cerebral arteries (x2)
- Anterior communicating artery
- internal carotid arteries (x2)
- Posterior communicating artery (x2)
- Posterior cerebral artery (x2)
- The basilar artery (right + left vertebral arteries)
The middle cerebral artery is a branch of the internal carotid artery
