Small Animal Anatomy Physiology Portion

List the basic organs and describe the basic functions of the nervous system

Basic Organs: Brain, spinal cord, and nerves

Basic Functions of the Nervous System: Homeostasis, perceives sensory modalities, transmits information to the CNS, processes the information and then transmits the appropriate response to the muscle and gland cells via efferent neurons

Describe cell body, cell process, grey matter, white matter, nucleus, ganglion, nerve fiber, tract and nerve

Cell Body: Gray glossy, where nucleus and major organelles are located, form the grey matter of the CNS

Nuclei: Collections of cell bodies within the CNS

Ganglia: Collections of cell bodies outside the CNS

Cell Process: Cytoplasmic extensions of the neuron that allow electrical impulses to be conducted over very long distances, white glossy

Tracts: Nerve fibers within the CNS

Nerves: Nerve fibers outside of the CNS

List an example of a ganglion where synapses occur. List an example of a ganglion where synapses do not occur.

List and describe the anatomic divisions of the central nervous system. List the functional divisions of the nervous system and describe each division. Describe where the constituent neurons for each division are typically found.

1. Efferent

   1. General Somatic Efferent (GSE) - Multipolar neurons, located within the grey matter of the brain and spinal cord, distributed to the voluntary skeletal muscles of the body, most cranial nerves and all spinal nerves

   2. General Visceral Efficient (GVE) - Multipolar neurons, located within the grey area of the brain and spinal cord, distributed to involuntary muscles of organs and cardiac muscle, some cranial nerves and spinal nerves, functional component of the autonomic nervous system

   3. General Somatic Afferent (GSA) - Transmits stimuli from the animal’s external environment, receptors near the surface of the body, responsible for touch, temperature and nociception, pseudopolar and found within all spinal nerves and few cranial nerves

   4. Special Somatic Afferent (SSA) - Associated with special senses, transmits information associated with vision and hearing, bipolar neurons

   5. General Visceral Afferent (GVA) - Transmits sensory organs of blood vessel and visceral organs

   6. Special Visceral Afferent (SVA) - Information associated with special senses, smell and taste, bipolar neurons found within CNN I and VII and IX

   7. GP and SP - Carries information associated with detecting position of the head, neck, trunk and limbs

Distinguish UMN from LMN

UMN descend down the cord and synapse onto the lower motor neurons. They can either be excitatory or inhibitory. Their axons travel caudally through the brain stem, down the white matter of the spinal cord. They are totally confined with the CNS. LMN’s are mainly inhibitory, are outside of the CNS and are outside of the CNS.

Describe the Autonomic Nervous System

GVE and GVA functional components of the nervous system

-Not under voluntary control

-initiates the fight or flight response

Differentiate the following criteria regarding the division of the ANS into parasympathetic and sympathetic division

1. Location of preganglionic nerves

2. Location of postganglionic nerves

3. Major postganglionic neurotransmitter substance

4. Major functional differences

1. Parasynpathetic:

   1. Maintaining everyday normal housekeeping and energy conservation

   2. GVE LMS, found in gray matter of the sacral spinal cord

   3. Commonly called the craniosacral division

2. Sympathetic

   1. Responsible for maintaining homeostasis in stressful situations, the “fight or flight” response

   2. Located within the gray matter of the thoracolumbar spinal cord, intermediolateral gray horn/column

   3. T1-L4 spinal nerves