Nervous System (1/4) Flashcards
Spinal Nerves
Thirty one pair of mixed nerves arise from the spinal cord and supply all parts of the body except the head
They are named according to their point of ______
___ Cervical (______)
___ Thoracic (______)
___ Lumbar (______)
___ Sacral (______)
___ Coccygeal (___)
Issue
8; C1-C8
12; T1-T12
5; L1-L5
5; S1-S5
1; C0
Nerve Plexuses
All ventral rami except T2-T12 form interlacing nerve networks called ______
Each muscle receives a nerve supply from more than one ______ ______
Damage to one spinal segment ______ completely _______ a muscle
Plexuses
Spinal Nerve
Cannot, Paralyze
Brachial Plexus
Formed by ______ and ____ (C4 and T2 may also contribute)
Brachial plexus gives rise to the nerves that innervate the _____ ______
C5-C8, T1
Upper Limb
Brachial Plexus
There are four major branches of this plexus
______ - Five ventral rami (______)
______ - Upper, middle, and lower, which form divisions
______ - Anterior and posterior serve the front and back of the limb
______ - Lateral, medical, and posterior fiber bundles
______
Roots; C5-T1
Trunks
Divisions
Cords
Branches
Brachial Nerves: Plexus
______ ______: second most common postop peripheral neuropathy
______: innervates the deltoid and teres minor
_______: sends fibers to coracobrachialis, biceps brachii, and brachialis (______ at elbow)
______: branches to most of the flexor muscles of forearm and opponens pollicis (______ of forearm, ______ of wrist, ______ of thumb, ______ of lateral three fingers)
Brachial Plexus
Axillary
Musculocutaneous; Flexion
Median, Prontation, Flexion, Opposition, Flexion
Brachial Nerves: Plexus
______: supplies the flexor carpi ulnaris and half of the flexor digitorum profundus (_____ of wrist, ______ of fingers, ______ of medial two fingers)
______: supplies ALL extensors of arm and forearm muscles (______ at elbow, ______ of forearm, ______ of wrist and fingers)
________ ______: can be blocked to reduce pain from tourniquet inflation during IV regional neural anesthesia
Ulnar, Flexion, Adduction, Flexion
Radial, Extension, Supination, Extension
Intercostobrachial Nerve
Neuron
Basic ______ ______ of CNS; around _____ billions of neurons
Responsible for _______ and _______ of nerve impulses
________ cells: produce myelin sheath which wraps around axon, providing insulation
_____ of ______: gaps in myelin sheath
_________ are synthesized in the _____ _____ and transported to synaptic knobs
Building Block, 100
Integration, Transmission
Schwann
Node of Ranvier
Neurotransmitters
Neuron
Neurons follow an ______ or _____ law in regard to action potentials
_______ _______: node to node jumping of depolarization
______ results slow or blocked conduction, such as seen with ______ ______ (nerve impulse conduction disorder)
All, Nothing
Saltatory Conduction
Demyelination, Multiple Sclerosis
Neurons
_______ neuron: short axon process arising from one side of the cell body, and a short dendritic process arising from the opposite site. Ex: ______ ______ neurons, including those found in the ____, _____, and ____
_______ neuron: has single large extension from its cell body. They are found in lower ______, but never in ______
________ neuron: present in _____ ______ ganglia
Bipolar, Special senses
Eyes, Ears, Nose
Unipolar, Invertebrae, Humans
Pseudounipolar, Dorsal Root
Neurons
_______ neuron: comprised of one axon and multiple dendritic processes; they are the most common type of neuron in the ______ and ______ ______
Other types of neurons include _______, ______, and ________
Multipolar
Brain, Spinal Cord
Sensory, Motor, Interneuron
Depolarization
Makes the cell membrane potential less ______ due to movement of positively charged ____ ions into the cell ( increased _______)
Negative, Na+
Excitability
Repolarization
The change that occurs after depolarization that returns membrane potential back to its ______ ______. Repolarization results from the movement of positively charged ____ ions out of the cells
Resting Potential
K+
Hyperpolarization
Makes the membrane potential more _______ due to movement of negatively charged ____ ions into the cell (reduced ______)
Negative, Cl, Excitability
Inward Current
The flow of _______ charge into the cell. Inward current ______ the membrane potential
Positive, Depolarizes
Outward Current
The flow of ______ charge out of the cell. Outward current ______ the membrane potential
Positive, Hyperpolarizes
Action Potential
Property of _____ cells (nerve and muscle) tha consists of a rapid _______ followed by ______ of the membrane potential
Excitable, Depolarization
Repolarization
Threshold
The membrane potential at which an action potential is _______
At threshold potential, net ______ current becomes larger than net ______ current
The resulting depolarization becomes self sustaining and gives rise to ______ of action potential
If net inward current is less than net outward current, no _____ _____ will occur
Inevitable
Inward, Outward
Upstroke
Action Potential
Resting Membrane Potential
Measured potential difference across the cell membrane (____ to ____ mV)
At rest, the nerve membrane is far more ______ to K+ than to ____
Leaky ___ channels are responsible for resting membrane potential
The ______ pump maintains resting membrane potential
-70 to -90 mV
Permeable, Na+
K+
Na+/K+
Action Potential
Action potential, or “______ ______” is a property of excitable cells that consists of a rapid depolarization (interior becomes less _______) followed by repolarization of membrane potential
Upstoke: Inward ___ movement; _______ blocks these voltage sensitive Na+ channels
Downstroke: Outward ___ movement; Outward flow of K+ _______ the membrane potential
Both ions flow by ______ _______
Nerve Impulse
Negative
Na+, Lidocaine
K+, Hyperpolarizes
Simple Diffusion