24. Arachnoid granulations: This is where the CSF produced in the choroid plexuses of the ventricles and which has circulated into the subarachnoid space is reabsorbed. Longitudinal fissure
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31. Basal (or cerebral) Nuclei Misnomer: basal ganglia Gray matter internal to the cerebral cortex, below floor of lateral ventricles. Function: modulate motor output from the cerebral cortex. Subconscious control of skeletal muscle tone and coordination of learned movement patterns. Parkinson's disease is caused by the loss of at least 80% of the dopaminergic neurons in basal nuclei and substantia nigra (resting tremor) Fig 15.11
32. Diencephalon Epithalamus Pineal gland - produces melatonin, sets diurnal cycles Thalamus (~12 nuclei) Hypothalamus Just superior to optic chiasma Infundibulum - connects to pituitary gland Some functions: Control of autonomic nervous system Coordination of nervous and endocrine systems Secretion of hormones - ADH and oxytocin
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34. Metencephalon: Cerebellum Hemispheres and lobes Cortex -gray surface with folia - fine ridges and sulci - grooves between the ridges Purkinje cells , axons of which become arbor vitae (white matter) in center Regulation of posture and balance
45. Glossopharyngeal (CN IX) C: mixed O: sensory from posterior 1/3 of tongue / motor from medulla oblongata D: medulla / muscles for swallowing, parotid gland
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48. Spinal Cord and Spinal Nerves Explain spinal cord anatomy, including gray and white matter and meninges (give the general functions of this organ). Discuss the structure and functions of the spinal nerves and plexuses. Describe the structural components of reflexes.
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50. 1. Cervical Enlargement Gray matter expanded to incorporate more sensory input from limbs and more cell bodies for motor control of limbs
51. Spinal Meninges 3) Pia mater 2) Arachnoid 1) Dura mater Three membranes surround all of CNS 1) Dura mater - "tough mother", strong 2) Arachnoid meninx - spidery looking, carries blood vessels, etc. Subarachnoid space 3) Pia mater - "delicate mother", adheres tightly to surface of spinal cord
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53. Lumbar Puncture (= Spinal Tap) For clinical examination of CSF or administration of radiopaque dyes, drugs and sometimes anesthetics However: mostly “epidurals” for anesthetics L3 L4
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55. Peripheral Nerves Definition: bundles of axons. AKA tracts in CNS Organization – coverings: Epineurium wraps entire nerve Perineurium wraps fascicles of tracts Endoneurium wraps individual axons
56. Anatomy of a Peripheral nerve Function: sensory - afferent motor - efferent mixed - contains axons of both
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59. 4 Principal Plexuses Braids of ventral rami of cervical, thoracic, lumbar or sacral spinal nerves Cervical Plexus Phrenic nerve - innervates diaphragm
62. Autonomic Division of NS Compare and contrast the structures of the sympathetic and the parasympathetic divisions, including functions and neurotransmitters. Show the levels of integration in the ANS, and compare these with the SNS. www.freelivedoctor.com
Buoyancy : brain weight in air: about 1.4 kg – in CSF about 50 g (= 97% lighter) because it is only a little denser than the CSF. Protects brain from crushing itself. Arachnoid granulations only appear at about 3 years of age. Infants are therefore especially sensitive to alterations or hyperactivity of the choroid plexuses.l
Alcohol, nicotine and anesthetics can diffuse through BBB. Blood borne toxins (urea, food toxins, bacterial toxins) cannot get through. Recent discovery: During prolonged emotional stress the tight junctions of the BBB are opened.
In 90-95% of people left side has more control over language, math and logic. Right side is more involved withy visual-spatial skills, intuition, emotion, artistic and musical skill.
Substantia nigra is in mesencephalon
Thalamus = 80% of diencephalon. Gateway (relay station) to the cerebral cortex not just for sensory input but for all info. Processing and editing also takes place. About 12 nuclei Hypothalamus also about 12 nuclei. Main visceral control center of the body
Scm = sternocleido mastoid muscle
31 pairs of spinal nerves – designated as are vertebrae a. 8 cervical b. 12 thoracic c. 5 lumbar d. 5 sacral
Plexus - plexuses
do NOT require cerebral processing but can be modified by cerebral control
General functions 1. excitatory of digestive organs 2. depresses heart rate and blood pressure 3. constricts pupils of eyes 4. sexual arousal 5. slows breathing 6. constricts urinary bladder