Vana 102 Chapter 7.2- The Nervous System
Cards (63)
- The control center allowing the body to react to the environment. Stores, integrates and initiates all appropriate response to information it receives. Organized into a communication network.
- Conducts sensory information from the periphery to the CNS. Sensory info travels in ascending tracts from spinal cord (“lower”) to the brain (“higher”).
- Sensory fibers in the spinal cord travel toward the brain.
- Consists of motor nerves that conduct from higher to lower levels of the CNS and from the CNS to the periphery.
- Extend from the brain down descending tracts in the cord to synapse on lower motor neurons (LMN).
- Bundles of upper motor neuron fibers that move caudally in the spinal cord.
- Extend away from the spinal cord and brain to the muscles and glands of the body.
- Allows diseases to differentially affect separate parts of the nerve cell.
- Are different for different sets of neurons, disease processes can selectively affect specific sets of neurons.
- Proliferate after brain damage, forming a scar (gliosis). This can be detrimental, mechanically placing stress on the surrounding brain tissue, causing irritation of adjacent tissue, and/or a possible epileptic focus.
- A specialized site of apposition where information passes from one nerve cell to another cell.
- An electrical event that travels down an axon.
- The neuron that is transferring info to the postsynaptic cell.
- The terminal end of the presynaptic nerve that is in apposition with the post synaptic cell; contains the synaptic vesicles.
- Membrane-bound organelles containing neurotransmitters located in the synaptic button.
- a chemical substance within the synaptic vesicle that mediates info transfer betweennerve cells and other cells at synapses; different sets of neurons.
- The neuron, muscle or gland receiving info from the presynaptic cell.
- The synaptic connection between a neuron and muscular tissue where electrical impulses pass from the neuron to the muscle cell; this can result in the contraction of the muscle.
- Nerve action potential propagates down the axon to reach the synaptic knob; causes the synaptic vesicles to release their neurotransmitters into the synaptic cleft; the neurotransmitters diffuse across the cleft to bind to receptors on the postsynaptic membrane; if the postsynaptic cell is a nerve, it can initiate or inhibit another nerve action potential in the postsynaptic nerve.
- Integral protein inserted in the membrane of the postsynaptic cell; function to bind with a neurotransmitter, resulting in a change in the membrane of the post synaptic cell.
- A zoonotic importance, causing hydrophobia (fear of water, as in drinking) due to paralysis of the pharynx (IX and X). With pharyngeal paralysis, salivation or choke first
- Before general anesthesia allowed animals to be put down and recovered safely, nerve blocks of the head were commonly used.
- The median and musculocutaneous nerve appear as one nerve in the brachium, except for the musculocutaneous muscular branches. The two nerves are separate in the carnvores.
- A condition seen in horses due to injury of the suprascapular nerve. This result in rapid atrophy of the supraspinatus and infraspinatus muscles which produces prominent scapular spine. Before atrophy, the shoulder is unstable and slips laterally , appearing to be dislocated.
- Does not extend past the carpus as it does in other domestic species. Median, the ulnar and the median cutaneous antebrachial (a branch of the musculocutaneous) –are the three nerves passing the carpus in the horse
- Bifurcates into the medial and lateral branches proximal to the carpus.
- Is a direct continuation of the median nerve in the cannon region.
- Bifurcates just proximally to the carpus into dorsal and palmar branches.
- Wraps around the cannon bone and descends on the dorsolateral side of the cannon region to the fetlock.
- Joins with the lateral branch of the median nerve to form the lateral palmar nerve.
- Travel down either side of the flexor tendons. At the level of the fetlock they give off a dorsal branch and continue as the palmar digital nerves.
- Pass distally on the palmar aspect of the digit to innervate the heel region of the foot. They form a triad along with the digital vein and the digital artery on each side. These triads are arranged vein, artery, nerve (VAN) from dorsal to palmar/plantar.
- Passes distally to innervate the toe region of the foot.
- Carries fibers from the medial palmar nerve (median nerve fibers) to the lateral palmar nerve (ulnar and median nerve).
- Travel together for a small segment past the fetlock. This is important when trying to block one without getting the other.
- Arises at the carpus from the lateral palmar nerve then dives deep and travels in close association to the metacarpal bones below the suspensory ligament.
- Are extensions of the deep ulnar nerve. They course distally in between the splint bones and the cannon bone. At the buttons of the splints they become superficial and continue to the fetlock joints.
- Is a cutaneous continuation of the musculocutaneous nerve. It extends distally to the fetlock.