X A&P - Chp 9 - nervous system, spinal cord, spinal nerves Flashcards
Action Potential
Electric current that spreads along membrane of neuron
Central NS comprised of
Brain and spinal cord
Peripheral NS comprised of
Cranial and spinal nerves
Dendrite
Fiber that carries impulses towards cell body
Axon
Fiber that carries impulse away from cell body
Afferent
- Sensory type
- Carries impulses towards CNS
- An outside thing Affected me. Afferent
Efferent
- Motor type
- Caries impulses away from CNS to muscle/gland
Efferent
- Motor type
- Caries impulses away from CNS
- The message from brain effected the outside
(Functional divisions)
Somatic nervous system
- Voluntary
- Skeletal muscles
Parts of Autonomic NS
- Sympathetic
- Parasympathetic
Sympathetic
- Fight or flight
- originate in spinal cord in thoracic and lumbar region (thoracolumbar)
Sympathetic
- Fight or flight
- originate in spinal cord in thoracic and lumbar region (thoracolumbar)
Somatic Nervous System
voluntary, conscious will (Skeletal Muscles)
Biofeedback
training to consciously control involuntary functions, i.e. blood pressure, heart rate
Effector
Any tissue or organ that carries out a nervous system command (muscles, glands)
Structural Division of Nervous System
- Central Nervous System (Brain, Spinal Cord)
- Peripheral Nervous System (Cranial, Spinal Nerves)
Nodes
small spaces on axon between Myelin Sheath
(Anatomic Division)
Peripheral Nervous System
- Somatic (voluntary, conscious will)
- Autonomic aka Visceral Nervous System (involuntary)
Autonomic Nervous System (visceral nervous system)
- Involuntary
- Smooth muscle, cardiac muscle, glands
- Found in soft body organs, viscera
Myelinated coated Fibers color
White, in white matter of of brain and spinal cord
Structure of Neurons
- Dendrites (receptors, conduct impulses TO cell body)
- Axons (conduct impulses AWAY from cell body, to another neuron, muscle, nerve)
Color of un-myelinated fibers
grey, grey matter
Myelin Sheath (see pic)
- insulates and protects fiber. Formed by Schwann cells, wrap around axon.
- When sheath is complete, remaining small spaces remain, Nodes.
Nerve
a fiber bundle within the PNS
interneurons (central and/or association nuerons)
relay info within CNS
Myelin Sheath (see pic)
-insulates and protects fiber. Formed by Schwann cells, wrap around axon.
Tract
a fiber bundle within the CNS
Endoneurium
coating around an individual nerve fiber
Perinuerium
coating around a fascicle
Fibers contained in a nerve
sensory, motor or a combo of both
Epineurium
coating around the entire nerve
Sensory neurons (afferent neurons)
- conduct impulses TO spinal cord.
- If you touch something it AFFECTS you
Sensory nerves (afferent)
cranial nerves containing only sensory fibers sending messages to the brain
Motor nerves
cranial nerves conducting messages AWAY from the brain
Mixed nerves
most of the cranial nerves and ALL spinal nerves and
Astrocytes
stem cells, regeneration of nervous tissue
Resting State (of nerve impluse)
inside negaticve, outside positive (polarized)
motor neurons (efferent neurons)
-conduct impulses to muscle/glands (effectors). reflex to -withdraw when you are touching something sharp/hot
Depolarization
Na+ flows inside and K+ flow out making inside more positive and outside negative