Neuro Exam 1 Study Guide.pdf

Lecture 1 – Neuroscience 1) Describe the basic functions and classifications of the nervous system a. Sensory receptor à sensory input à integration in brain and spinal cord à motor output à effector b. Functions i. Processing information ii. Sensation (perception) à physical and chemical stimuli fr...

Lecture 1 – Neuroscience 1) Describe the basic functions and classifications of the nervous system a. Sensory receptor à sensory input à integration in brain and spinal cord à motor output à effector b. Functions i. Processing information ii. Sensation (perception) à physical and chemical stimuli from environment received by specialized receptors and converted to electrical signal iii. Integration à nervous system processes information (electrical signal) iv. Motor function à effectors produce response or effector c. Classifications i. Basic function à signal perception, internal signal transduction, signal release ii. Sphere of activity à somatic and autonomic nervous system iii. Location of body parts (topography) à CNS and PNS iv. Direction of signal transmission à afferent (sensory) and efferent (motor) v. Macroscopic structure of CNS à nerve cell bodies from gray matter and myelinated axons from white matter 2) Describe the topographic organization of the nervous system a. CNS à housed in protective bony cavities à cranium and vertebral canal i. Brain (encephalon) and spinal cord ii. Telencephalon à largest and most complex part of CNS 1. Highest level of integration b. PNS à connects CNS to peripheral targets i. Nerves and ganglia ii. Nerves arising from spinal cord leave their bony canal through intervertebral foramina and are distributed to target organ iii. Spinal nerves are formed in foramina by union of dorsal (posterior) roots and ventral (anterior) roots iv. Small spinal ganglion in intervertebral foramen appears as a slight swelling of dorsal v. In limbs, ventral rami of spinal nerves come together to form plexuses vi. Plexuses give rise to peripheral nerves that supply the limbs 1. Brachial à arms 2. Lumbosacral à legs c. Somatic nervous system i. Somatic sensation and somatomotor function ii. External environment d. Autonomic/Visceral nervous system i. Visceral sensation and visceromotor function ii. Internal environment 3) Review the locations of grey and white matter in CNS and PNS a. Grey matter à collection of nerve cell bodies b. White matter à axons with glial sheath (myelin) CNS PNS Grey matter Cortex and nucleus ganglion - brain à outside - spinal cord à inside White matter Pathway nerve - brain à inside - spinal cord à outside 4) Review major structures of epidural space a. Dura i. Closest to cranium ii. Cranial dura à attached to bone iii. Spinal dura à NOT attached to bone iv. Epidural space à space between vertebral bone and underlying spinal dura b. Arachnoid i. Linking dura and pia mater c. Pia mater i. Closest to brain and very thin d. Meningitis (lecture 7) i. Infection in one of the maters 5) Review the function of cauda equina a. Bundle of lumbar and sacral nerve roots that extend from L2 to their respective exit point b. Also known as horse tail Lecture 2 – Physiology of Neurons 1) Review major structures of neurons a. Dendrites, cell body and nucleus, axon b. Node of Ranvier and myelin sheaths c. Axon hillock à where AP triggered d. Nissl bodies à rough ER 2) Review classification of neurons a. Based on function i. Sensory neuron 1. Functional polarity theory à information flow in one direction 2. From dendrites and cell body (input or receiver part) to axon (output or effector part) ii. Motor neuron 1. Directly innervate effector cells (usually muscle or gland cells) 2. Receive inputs from sensory neurons iii. Interneuron 1. Commonly found in spinal cord 2. Transmits signal between sensory and motor neurons b. Based on branches that originate from cell body i. Bipolar à cell body in middle 1. Inner ear, retina, olfactory, sensory organs ii. Pseudounipolar à cell body hanging 1. D.R.G. and some cranial nerves (CN V) iii. Multipolar à many dendrites in cell body with long axon 1. Motor cortex and cerebellum 2. Three types à motor neuron of spinal cord, pyramidal cell of hippocampus and Purkinje cell of cerebellum 3) Review myelin function in CNS and PNS (why do nerves have myelin) a. Myelin insulates the axons electrically à significantly boosts nerve conduction velocity à AP jumps from one node of Ranvier to next b. CNS à almost all axons myelinated i. Oligodendrocytes c. PNS à myelinated in regions where fast reaction speeds are needed i. Schwann cells 4) Review retrograde and anterograde transport (major proteins and function) a. Neuronal cytoskeleton i. Important for transport, maintaining shape/structure, and compartmentalizing cell Mechanism Material transported Fast anterograde Kinesin à movement Mitochondrial vesicles down axon toward synapse Fast retrograde Dynein à movement away Degraded vesicular from synaptic terminal membrane, absorbed back toward cell body exogenous material Slow anterograde n/a Cytoskeletal elements, soluble proteins, actin Lecture 3 – Membrane Potentials and Action Potentials 1) Terminology a. Depolarization à process of making membrane potential less negative b. Hyperpolarization à process of making membrane potential more negative c. Threshold potential à membrane potential at which occurrence of AP inevitable d. Overshoot à portion of AP where membrane potential is positive e. Refractory period à period during which another normal AP can’t be elicited in an excitable cell 2) Review step-by-step of the action potential (channels, ions, depolarization, hyperpolarization) a. Resting potential à Na out, K in b. Depolarization à Na in