the brain Flashcards
what are the most prominent features of the brain grossly?
the large cerebral hemispheres
the highly folded surface of the cerebellum
what lies between the 2 cerebral hemispheres?
the longitudinal fissure
how do the two cerebral hemispheres communicate w/ each other?
via the corpus callosum
what vessels lie on the superior surface of the corpus callosum?
the anterior cerebral arteries
what part of the brain is supplied by the anterior cerebral arteries?
the frontal and parietal lobes
where does the lateral fissure lie?
on the lateral surface of the brain between the temporal lobe and the frontal and parietal lobes
what vessel is contained w/in the lateral fissure?
the middle cerebral artery
where does the central sulcus run from / to?
from the longitudinal fissure to the lateral fissure
what is the function of the central sulcus?
separate the frontal lobes from the parietal lobes
where does the motor cortex lie in relation to the central sulcus?
the motor cortex lies anterior to the central sulcus
where does the sensory cortex lie in relation to the central sulcus?
the sensory cortex lies posterior to the central sulcus
what are the ‘lumps’ of the brain called?
gyri (singular gyrus)
what are the folds on the brain called?
sulci (singular sulcus)
where does the visual cortex lie?
in the occipital lobe
what is the diencephalon?
the thalamus, hypothalamus and epithalamus / pineal gland
what is the brainstem?
the pons and medulla
how do varying parts of the brain communicate w/ each other?
via white mater tracts
where do the basal ganglia lie?
deep in the brain mostly surrounded by the insula except for the substantial nigra which lies in the midbrain
where can the substantia nigra be seen?
a small black line crossing the tissue of the midbrain
what is the function of the basal ganglia?
regulate initiation and termination of body movements
also involved w/ memory, planning and emotional response via the limbic system
what is the internal capsule?
a white fibre pathway that separates the globes palladus and putamen from the caudate nucleus
what is usually found in the lateral ventricles?
the choroid plexus
what is the function of the choroid plexus?
production of CSF
what is the function of the hypothalamus?
role in autonomic regulation of the body
links the nervous system to the endocrine system via its communicate w/ the pituitary gland
what are the superior and inferior colliculi?
small lumps of tissue that are part of pathways assoc w/ the visual and auditory systems
which cranial nerves arise from the midbrain?
CN3 - oculomotor
CN4 - trochlear
what part of the brain do most cranial nerves arise from?
the brainstem (pons and medulla)
where does the pituitary gland lie?
it sits under a small piece of dura covering the sella turcica
how does the pituitary gland communicate w/ the rest of the brain?
via a tiny stalk called the pituitary stalk
what is the function of the pituitary gland?
releases growth hormone
releases FSH and LH in women
where does the blood supply to the brain come from?
the internal carotid arteries and the vertebral arteries
how is the circle of willis formed?
the internal carotid arteries and the vertebral arteries anastamose w/ each other to form the circle of willis
explain the course of the vertebral arteries
they ascend the neck through the transverse processes of the transverse foramen of the cervical vertebrae and joint close to the foramen magnum to form the basilar artery
explain the course of the internal carotid artery
the internal carotid artery is a terminal branch of the common carotid artery that passes into the carotid canal (one on each side) and through the cavernous venous sinus
explain the meninges
the meninges are protective layers that cover the brain and spinal cord
there are three layers of meninges:
- dura mater - outermost tough connective tissue sheet
- arachnoid mater - midle layer ‘spiderweb’ connective tissue
- pia mater - innermost layer stuck to the surface of the neural tissue
what is the falx cerebri?
a dural fold that lies between the cerebral hemispheres
what does the fall cerebri carry?
the inferior sagittal dural venous sinus
what is the tentorium cerebelli?
a dural fold covering the cerebellum
which 3 arteries provide the meninges w/ blood supply?
anterior ethmoid artery
middle meningeal artery
posterior meningeal artery
where does the anterior ethmoid artery arise from?
from the ethmoid branches of the internal carotid artery
where does the anterior ethmoid artery supply?
the dura of the anterior fossa
where does the middle meningeal artery arise from?
the maxillary artery
explain the course of the middle meningeal artery
it passes through the foramen spinosum to supply the dura w/ blood
which artery is the main supply to the dura?
the middle meningeal artery
where does the posterior meningeal artery arise from?
the occipital artery
where does the posterior meningeal artery supply?
the dura of the posterior fossa
explain the nerve supply to the meninges
the nerve supply is mainly from the trigeminal nerve
what are the dural venous sinuses?
they act as large vein related to the meninges and wall of the skull
describe venous drainage of the brain
the dural venous sinuses drain blood from the brain and channel it into the internal jugular vein
what is the confluence of sinuses?
an area of the brain which collect blood from the dural venous sinuses and passes it to the transverse and sigmoid sinuses and from here blood from the brain drains into the internal jugular vein
how is CSF made?
in the choroid plexus by specialised cells called ependymal cells
where are the lateral ventricles located?
in each of the cerebral hemispheres
where is the third ventricle located?
between the two parts of the thalamus
where is the fourth ventricle located?
related to the cerebellum and brainstem
how does CSF move between the ventricles and the spinal cord?
through small foramina and the cerebral aqueduct
how is CSF recycled?
through arachnoid villii (granulations) into the dural venous sinuses
