Anatomy of The Brain and Cranium Flashcards
what does the CNS consist of?
brain
spinal cord
what does the PNS consist of?
12 pairs of cranial nerves
31 pairs of spinal nerves
autonomic nerves
what does the neural tube develop from?
three swellings > five swellings
what are the five swellings of the neural tube?
telencephalon (cerebral hemispheres) diencephalon (thalamus, hypothalamus) mesencephalon (midbrain) metencephalon (pons, cerebellum) myelencephalon (medulla oblongata)
two types of cells in the nerve system
- neurons
2. glial cells
role of neurons
transmit impulses to other neurons and effector cells
most common type of neuron
multipolar (many dendrites and one axon)
role of the axon/ axon hillock
take information away
what modality are unipolar neurons?
sensory
four types of glial cells in the CNS
astrocytes
oligodendrocytes
microglia
ependymal cells
role of astrocytes
support
BBB
environmental homeostasis
role of oligodendrocytes
produce myelin in CNS
what produces myelin in the PNS?
Schwann cells
what is the microglia
macrophages
what are the ependymal cells?
ciliated cuboidal/ columnar epithelium that line ventricles
appearance of the brain
gyri and sulci (deep is fissure)
white matter at the centre, except thalamus
where is the central sulcus?
separates frontal and parietal lobes
where is the longitudinal cerebral fissure?
separates the two cerebral hemispheres
what is in the calcarine sulcus?
visual cortex
name of a collection of nerve cell bodies in the CNS?
nucleus
name of collection of nerve cell bodies in the PNS?
ganglion
is the dura adherent to the skull?
yes
what innervates the dura
CNV
two layers of the dura
- periosteal
2. meningeal
what does the dura fold to form?
septa including diaphragm sellae, tentorium cerebelli and falx cerebri
where does venous drainage of the brain happen?
passage between dural layers called dural venous sinuses from cerebral veins and confluences at internal occipital protuberance and drains into IJV at jugular foramen
examples of venous sinuses
superior sagittal
inferior sagittal
cavernous sinus
where is arterial supply to the brain found? (circle of Willis)
sub-arachnoid space so is bathed in CSF
layers of the scalp
Skin Connective tissue (arteries of the scalp found here) Aponeurosis Loose connective tissue Pericranium
what type of joints are the sutures in the skull?
fibrous joints
what is the pterion?
H-shape on the lateral aspect of the skull formed between frontal, parietal, temporal and sphenoid bones
thinnest part of the skull
middle meningeal artery is deep to this
three major cerebral arteries that supply the brain
anterior cerebral artery
middle cerebral artery
posterior cerebral artery
what arteries make up the Circle of Willis?
right and left anterior cerebral arteries
left and right anterior communicating arteries
right and left ICA
left and right middle cerebral artery
left and right posterior communicating arteries
left and right posterior cerebral artery
basilar artery (from right and left vertebral arteries)
role of corpus callosum
allows communication between two sides of the brain
what is at the precentral gyrus?
motor cortex
what is in the postcentral gyrus?
somatosensory cortex
where is the lateral fissure?
above temporal lobe
which part of the basal ganglia is also in the midbrain?
substantia nigra
what is the clivus?
portion of the skull anterior to the foramen magnum
how does the ICA enter the cranium?
foramen lacerum > carotid canal
what are arachnoid granulations made of?
arachnoid mater
what supplies blood the the meninges
middle meningeal artery
how do the vertebral arteries reach the cranium/ circle of willis?
via foramina of the cervical vertebrae
