Intro to NS Flashcards
5 things in the spinal cord
- sensory axons to carry sensory info to the brain
- cell bodies of motor neurons
- preganglionic sympathetic and parasympathetic neurons
- interneurons
- ascending and descending fiber tracts
What are the three parts of the brain?
brainstem, cerebellum, forebrain
What are the parts of the brain stem?
medulla, pons, midbrain
What does the brain stem do?
receive sensory input from head and neck sensory systems
provides motor control to head and neck muscles
autonomic control to head, neck, and visceral organs
coordinates vital functions (consciousness, respiration, circ, tone, eye)
What does the cerebellum do?
smooths and coordinates motor activity
What are the components of the forebrain?
diencephalon: thalamus and hypothalamus
telencephalon: olfactory system, limbic system, basal ganglia, neocortex
What are the meningial layers? How are they grouped?
leptomeningies:
- pia: innermost layer that adheres to brain surface and follows convolutions
- arachnoid: trabeculated and stretches across sulci. CSF in subarachnoid space
pachymeninges:
3. Dura: adherent to the skull. venous sinuses located between the two layers
Describe the anterior circulation to the brain. What does it supply?
Internal carotid system: internal carotid arteries divide into the anterior and middle cerebral arteries.
supplies the fronatl lobes, parietal lobes, superior temporal lobes, and basal ganglia.
Describe the posterior circulation to the brain?
2 vertebral arteries unite to form the basilar artery. Basilar artery branches to form the posterior cerebral arteries.
Supplies the brain stem, cerebellum, diencephelon, occipital lobes, inferior temportal lobes.
superior cerebellar artery and the anterior inferior cereberllar arteries come off the basilar artery
posterior inferior cerebellar arteries come off the verebral arteries to supply to brain stem.
What is the circle of Willis?
communication btw the anterior and posterior circulations at the base of the brain with anterior and posterior communicating arteries. may provide some collateral circ for the brain
What is the venous drainage of the brain?
blood drains into the superficial and deep cerebral veins
internal jugular veins, basilar veins, and the Great Vein of Galen drain into the venous sinuses. Venous sinuses drain to the internal jugular veins
What are the major venous sinuses?
superior and inferior sagittal sinuses, straight sinuses, transverse sinuses, and sigmoid sinuses
What is CSF?
ultrafiltrate of plasma that is a cushion that protects the brain from the skull, and may be a communication channel for neurotransmitters.
What secretes CSF>
choroid plexus from all 4 ventricles
Describe the flow of CSF.
flows from lateral ventricles through foramina of monro to third ventricle through the cerebral aqueduct into the 4th ventricle and through the foramina of luschka (lateral) and magendie (middle) into the subarachnoid space. then abosrbed into the venous sinuses by arachnoid granulations.
