EXAM 4: Nervous System Flashcards
Nervous System
The master controlling and communicating system of the body.
Neurons
Nerve cells; key to neural communication
Three Overlapping Functions of the Nervous System
Sensory input, integration, motor output
Sensory Input
Information gathered by sensory receptors used to monitor changes inside and outside the body
Integration
A process by which the nervous system integrates sensory information gathered and decides what to do with it at each moment
Motor Output
A response that is caused by muscles or glands (effectors) that is activated by the nervous system
Two Principal Parts of the Nervous System
Central Nervous System (CNS) and Peripheral Nervous System (PNS)
Central Nervous System (CNS)
the brain and spinal cord;
it occupies the dorsal cavity;
it is the integrating and control center of the nervous system;
it interprets sensory input and dictates motor output based on reflexes, current conditions, and past experience.
Peripheral Nervous System (PNS)
Part of the nervous system outside CNS;
cranial nerves, spinal nerves and ganglia;
mainly consists of bundled fibers (axons) that extend from the brain and the spinal cord and ganglia (neuron cell bodies)
Cranial Nerves
Carry impulses to and from the brain
Spinal Nerves
Carry impulses to and from the spinal cord
Sensory Division
Afferent division;
Nerve fibers (axons) that convey impulses to the central nervous system from sensory receptors located throughout the body
Two Different Types of Fibers of Afferent Nervous System
Somatic nerve fibers and visceral nerve fibers
Somatic Nerve Fibers
Convey impulses from the skin, skeletal muscles, and joints
Visceral Nervous System
Transmit impulses from visceral organs that occupy the ventral body cavity
Motor Division
Efferent division of the PNS that transmits impulses from the CNS to effector organs (muscles and glands);
muscles contract and glands secrete
Two Subdivisions of the Motor Division
Somatic nervous system and Autonomic Nervous system
Somatic Nervous System
Somatic nerve fibers that conduct impulses from the CNS to skeletal muscles;
Voluntary nervous system
Autonomic Nervous System
Visceral nerve fibers that regulate the activity of smooth muscles, cardiac muscles and glands;
Involuntary nervous system
Sympathetic Division of Autonomic Nervous System
mobilizes body systems during activity
Parasympathetic Division of Autonomic Nervous System
Promotes house-keeping functions during rest;
Conserves energy
Neroglia
Glial cells that associate closely with neurons;
there are six types;
outnumber neurons in CNS
6 Types of Neuroglia
CNS: astrocytes, microglial cells, oligodendrocytes, ependymal cells
PNS: satellite cells and Schwann cells (neurilemma)
Schwann Cells
neurilemma