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Download Nervous system Cranial meninges
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Nervous system Central - brain and spinal cord Peripheral - spinal nerves, motor and sensory nerves Cranial meninges Dura mater Arachnoid Pia mater Scalp Skull Arachnoid mater Subarachnoid space of brain Brain 1 Neurocoel and ventricles CNS develops from anterior DHNC, which has neurocoel Ventricles Right lateral ventricle Left lateral ventricle Third ventricle Fourth ventricle 2 Cerebral spinal fluid provides almost neutral balance for brain (it “floats”) cushions and nourishes brain p.476 Cerebral spinal fluid CSF produced from blood plasma at choroid plexus tissue that lines ventricles. It is resorbed back to blood at venous sinus Hydrocephalus 3 Gray matter vs. white matter Cerebrum Cerebrum is divided into two hemispheres, and cerebral cortex is outer gray matter Hemispheres connected via corpus callosum corpus callosum Gyri (bumps) and Sulci (grooves) along surface of cortex define areas of cerebrum Cerebrum layers 4 Four lobes of cerebrum Frontal Parietal Temporal Occipital Somatosensory cortex Senses conscious body senses including: pain, hot/cold and proprioception (position) Motor cortex Produces muscle movements in body, but does not plan them Primary motor cortex Somatosensory cortex Frontal lobe Central sulcus Parietal lobe 5 Thalamus Thalamus is at the top of the brain stem and many conscious sensory signals synapse there before travelling to cerebral cortex Midbrain Near the thalamus are the superior and inferior colliculi that specifically direct visual and auditory input to cortex 6 Hypothalamus and pituitary Hypothalamus controls release of endocrine hormone from pituitary Pineal Pineal secretes melatonin at night to maintain circadian rhythm within body Pineal is red Internal ‘clock’ is green Blue arrows signify melatonin release Cerebellum and brain stem Cerebellum maintains balance, muscle tone and stores ‘muscle memory’ for skilled activities Medulla- Controls basic functions: breathing, heart rate, digestion, etc. Medulla 7 Spinal nerves Spinal nerves Dermatome A dermatome is a portion of dermis that is innervated by the same spinal nerve – they are metameric 8 Motor Cranial nerves Sensory Mixed Branchiomeric nerves Nerves 5, 7, 9, 10 – all are mixed 5 – Trigeminal - Mandibular arch 7 – Facial - Hyoid arch 9 – Glossopharyngeal – Pharynx, tongue 10 – Vagus – Pharynx, tongue, viscera Tracing the wiring of your ears Tensor tympani Inserts on malleus Innervated by trigeminal (5) Stapedius Inserts on stapes Innervated by facial (7) Muscles help dampen ear bone movement to protect cochlea from loud sounds, diminish ‘head’ sounds 9
