PNS: Multiple Levels of Organization Flashcards
Central Nervous System
the brain and spinal cord
-The brain can be divided into the brainstem and cerebral hemispheres and cerebellum
Peripheral Nervous System
The neurons or parts of neurons that exist outside of the CNS and connect the CNS to other tissues of the body.
-Cranial nerves, spinal nerves, sympathetic trunk, ganglia, and peripheral nerves
Autonomic Nervous System
the visceral motor components of the PNS that control smooth muscle, cardia muscle, and glands. The ANS has a parasympathetic and sympathetic division
Parasympathetic Division of ANS
Deals with vegetative functions and mechanisms that maintain tissue health and/or build internal resources.
-Active in an animal at rest.
Sympathetic Division of the ANS
Prepares individual to deal with stressful/threatening situations.
-Defend itself or flee
Enteric Nervous System
A network of sensory, motor, and secretory neurons located within the wall of the gastrointestinal tract.
Neurons
A bundle of axons with their surrounding connective tissue and blood vessels, traveling in the PNS.
Plexus
Mingling of nerves in which axons rearrange between nerves. Plexuses may have ganglia associated with them
Ganglion
a cluster of neuron cell bodies in the PNS
Nucleus
A cluster of neuron cell bodies in the CNS
Afferent
A sensory neuron or pathway carrying information to the CNS
Efferent
A motor neuron or pathway carrying information away from the CNS to control effectors
Effector
tissue or cell that generates the response in a nervous system pathway (muscle/gland)
Somatic
refers to skin and musculoskeletal structures (muscles, bones, joints, tendons)
Visceral
internal organs, blood vessels, glandular tissue
Nervous System Function
- Communication between tissues
- Integrate and process information from the environment and the body
- Control movement and Physiological processes
Path of motor response
Sensory (afferent) info –> CNS–> Process –> Effector tissue –> Motor response
- Sensory info detected by sensory neurons
- Info travels to CNS by nerves
- Processed by interconnected neuron network
- Motor neurons generate response via peripheral nerves and neurons that release hormones into circulation
Functional tissue of the nervous system
Neurons and glial cells
CNS: grey and white matter
PNS: ganglia and nerves
Grey matter and ganglia
contain neuron cell bodies and supporting glial cells
White matter and Nerves
Contain axons, supporting glial cells
Nerves: support connective tissue
Neurons function
- Detect broad range of information from the internal and external environment
- Process that information via networks of interconnected neurons
- Communicate with other body tissues to control movement and physiological functions
Characteristics of a neuron:
Dendrites: detect and receive information
Axon: carries an electrical signal (action potential) over a distance
-Many covered with lipid myelin sheath
Axon terminal: at the end of the axon branch which forms close contacts (synapses) with other neurons/effector cells
3 categories of neurons
- Multipolar
- Pseudounipolar
- Bipolar
Functional categories of neurons
Sensory
Motor
Interneurons