![]() adrenal glands, sweat glands, liver, blood vessels, and hair follicles work through this system exclusively (not parasympathetic) Parasympathetic Nervous System - the part of the ANS that facilitates relaxation and replenishment ("rest and digest") ganglia near spinal cord, form tightly-knit chain, activity tightly coordinated 2 parts (sympathetic and parasympathetic always active, activity is complimentary) Sympathetic Nervous System - the part of the ANS that produces the "fight or flight" response cranial: sensory (visual, auditory, taste, smell, tactile for face, and some organ feedback) and motor (eye movement, facial expression, chew and swallow, speech, neck muscles, some organs) Autonomic Nervous System - the part of the PNS that is responsible for assessing and maintaining the body's internal environment spinal: sensory (body's surface, skeletal muscle feedback) and motor (skeletal muscles) 31 pairs spinal nerves and 12 cranial nerves Weaker in medulla (lets some toxins past - vomiting) Somatic Nervous System - part of the PNS that is responsible for body's interaction with the external environment Active transport for others (glucose) (energetic, protein-mediated) Passive transport: small, uncharged (O2, CO2), and fat-soluble molecules protects brain from infection (brain lacks body's immune system and cellular regeneration) neural functioning depends on regulation of chemistry of intra- and extra-cellular fluids helps cushion and support (float) jellylike brain, protect spinal cord, and provide a reservoir of hormones and nutrition Blood-Brain Barrier -semi-permeable barrier, controls what chemicals enter brain, created by closing gaps between capillaries' endothelial cells drawn into subarachnoid space of meninges and central canal of spine Brain is under 2% body weight but uses 20% of body's continuous blood supply Cerebral Spinal Fluid -fluid, produced by ventricles, found within spinal cord and in covering around CNS Hydrocephalus (water on brain):flow from ventricles blocked, may be surgically drained Blood Vessels -Complex web of arteries (incoming) and veins (outgoing) that feed (glucose) and cleanse brain CSF drain into subarachnoid space of meninges and central canal of spine 2 lateral and 3rd ventricles in forebrain, cerebral aqueduct in midbrain, 4th ventricle in hindbrain Meningitis: inflammation of meninges Ventricles - four hollow chambers (plus aqueducts) in brain that produce the cerebral spinal fluid that feeds, cleans, and cushions brain Pia Mater (pious mother): pliant inner layer, conforms to brain and spine surface, includes blood vessels Arachnoid Mater (spider mother): spiderweb-like layer (subarachnoid space filled with CSF) Dura Mater (tough mother): thick outer layer immediately under the bone Note: for sense organs and muscles in the head, cranial nerves of PNS serve this function Grey Matter area of the spinal cord (center) consisting of soma and dendrites, including inter-neurons White Matter area of the spinal cord consisting of myelinated axons, ascending and descending tracks to/from brain, surrounded by grey matter Central Canal tube through core of spinal cord containing fluid (cerebral spinal fluid) Meninges - three-layered protective covering that surrounds CNS Sensory in via dorsal root, motor out via ventral root Hippocampus ("seahorse") Part of limbic system, involved in memory formation and spatial mapping Amygdala ("almond") Part of limbic system (at end of hippocampus), involved in anger/fear and recognizing emotions in others Cingulate Gyrus Part of limbic system, "re-entrant" layer (just under cortex) between cortex and lower systems, for +/- evaluation Cerebral Cortex ("bark") Outermost forebrain structure, 6 layered, highly convoluted (gyri/bulges and sucli/folds)Ĥ lobes, central sulcus divides parietal from frontal, lateral sulcus divides frontal from temporal Bell-Magendie Law Governs directions of info flow in/out of the spinal cord
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