Nervous System Anaphy MX Reviewer PDF

Nervous System - Divided into 2 Parts - Central - Brain and spinal cord - Group of neurons in CNS = Nucleus (except for basal ganglia) - Peripheral - All nervous tissue outside CNS - Group of neurons in PN...

Nervous System - Divided into 2 Parts - Central - Brain and spinal cord - Group of neurons in CNS = Nucleus (except for basal ganglia) - Peripheral - All nervous tissue outside CNS - Group of neurons in PNS = Ganglia / ganglion - Kinds of NS under PNS - Somatic - Voluntary - Autonomic - Sympathetic (fight or flight) - HR up - BP up - Digestion down - Parasympathetic - HR down - BP down - Digestion up - - Classification based on stimuli - Afferent - Send action potential or stimuli from outside environment to the brain - Efferent - Action potential from brain to target organ  - Both somatic and autonomic - Parts of neuron - Dendrite - Receives signals from axon terminals - Cell body (soma) - Cell membrane - Nucleus - Axon - Transmits electrical signal - Myelin sheath - Insulates portions of axon - Protects and increases rate of transmission of signal - Made of Schwann Cells in the PNS - Made of Oligodendrocytes in the CNS - Node of ranvier - Portions of the axon not insulated by the myelin sheath - Electric signals jump from node to node - Axon terminal - End of the axon, receives the electrical signal and transfers neurotransmitters to dendrites through the synapse (gap between axon terminal and dendrite) - Secretes acetylcholines or catecholamines (epinephrine, norepinephrine, dopamine) - Preganglionic neurons only secrete acetylcholines to ganglionic neurons - Postganglionic adrenergic neurons secrete catecholamines that are received by adrenergic receptors in target organs - Otherwise, postganglionic neurons also secrete acetylcholine to target organ that are received by muscarinic receptors (g-protein coupled receptors) - Blood brain barrier - Shields brain from toxic substances - Filter harmful compounds from brain to bloodstream - Supply brain tissue with nutrients - Composed of - Endothelial cells - Core structural component - Pericytes - Embedded in basement membrane - Astrocytes - star-shaped glial cells help to protect and repair nervous tissue - Capillary basement membrane - This acellular component separates the cellular components of the BBB - Brain - Cerebrum - Largest part of the brain - White and gray matter - White matter due to myelin sheath concentration - Inner layer - Gray matter due to cell body concentration - Outermost  - Cerebral cortex - Lobes - Frontal - Movement and executive function - Parietal - Sensory info - Locates where we are - Guides movement in 3D - Temporal - Hearing - Smell - Memory - Visual recognition of faces and languages - Surrounds and communicates with hippocampus - Send info from short term to long term memory - Occipital - Vision - Other parts - Internal capsule - Highway that allows information to flow through neurons to and from cerebral cortex - Basal ganglia / Basal nuclei - Located within the internal capsule - Divided into - Pallidum - Striatum - Caudate nucleus and putamen - Inhibits undesired movement - Corpus callosum - Connects the left and right hemisphere of the brain - Diencephalon - Thalamus - Processes sensory info from body and send them to cerebral cortex - Sends motor info from cerebral cortex to body - Hypothalamus - Regulate body temp - Sleep / wake cycle (circadian rhythm) - Eating / drinking - Regulates release of endocrine hormones - Pituitary gland - Anterior / posterior - Produces and secretes hormones - Cerebellum - Coordinate movement, precision, balance - Fine tune motor activity to muscle memory - Brainstem - Midbrain - Vision - Hearing  - Motor control - sleep/wake cycle - Consciousness - Pons - Facial expressions / sensation - Body equilibrium / posture - Medulla - Blood pressure - Breathing - Swallowing - Coughing - Vomiting - Digestion - Where 90% of corticospinal tract fibers cross over to the opposite side of the brainstem (crossing of action potential to opposite side is called decussation) - Spinal cord - Gray matter is in the innermost part while the white matter is the outer layer - Anterior or ventral horn - Butterfly shape - Receives info from motor cortex sends to skeletal muscle to voluntary movement - Efferent - Posterior horn of the spinal cord - Afferent - Lateral horns - Sympathetic - PNS fibers - Carries info to and from CNS - Parts - Ganglion - Made up of neuron cell bodies - Cranial nerve ganglia in cranial nerves - Dorsal root ganglia in the spinal cord - Nerves - Made up of axons Reflexes ○ Fast involuntary response ○ Does not reach the brain ○ Travels from sensors > afferent fibers > dorsal horn of spinal cord > ventral horn > efferent fibers > target muscle - Meninges - Protective layers of the brain - Dura mater - outermost - Arachnoid mater - Subarachnoid space - Contains the Cerebro-spinal fluid - Cushions the brain and spinal cord with nutrients - Pia mater - Cranial nerves - 12 pairs - Exit skull through different foramina - Mainly innervate the head and neck - 3 group - Sensory - Motor - Mixed - OOOTTAFVGVAH - 1. Olfactory - Smell - 2. Optic - Sight - 3. Oculomotor - Movement of the eyes - 4. Trochlear - Ability of the eye to move superior oblique - 5. Trigeminal - Ophthalmic nerve - Mandibular nerve - Maxillary nerve - 6. Abducens - Lateral eye movement - 7. Facial - Sensory: anterior third of the tongue (sweet and salty) - Motor: movement of the cheeks - 8. Vestibulocochlear - Vestibular nerve - Balance - Romberg test - Cochlear nerve - Hearing - 9. Glossopharyngeal - Motor - Muscle of the throat, swallowing and movement of the pharynx - Sensory - Posterior third of the tongue (bitter and sour) - 10. Vagus - Motor - Swallowing - Speech - Decrease HR - Decrease BP - Decreases RR - Largest cranial nerve, reaches the stomach - 11. Accessory - Neck and shoulders - trapezius - 12. Hypoglossal  - Movement of the tongue - SSMMBMBSBBMM - Simon says many money but my brother says bad business makes money - SO4LR6-3 1975 128 - Spinal nerves - 31 pairs - 8 pairs cervical - 12 pairs thoracic - 5 pairs lumbar - 5 pairs sacral - 1 coccygeal