Nervous Flashcards
• branch of
medicine that
specializes in
diagnosing &
treating
nervous system
disorders
NEUROLOGY
• the means of communication
of the nervous system
NERVE IMPULSE
• or “action potential “ or
“electrical signal“
NERVE IMPULSE
FUNCTIONS of the
Nervous System
• Sensory receptor
monitors stimuli or changes in
the body’s internal & external
environment
sends its gathered information
or input to the brain & spinal
cord
SENSORY FUNCTION
• the analysis & interpretation of
sensory input & making decisions
consciously or unconsciously
INTEGRATION
FUNCTIONS of the
Nervous System
• may produce any of the ff.:
✓ immediate response
✓ information stored as
memory
✓ ignoring of the input
INTEGRATION
•major
organs for
processing
sensory input
& initiating
responses
BRAIN AND SPINAL CORD
•specific areas in
the brain &
spinal cord w/c
process particular
inputs
CONTROL CENTERS
FUNCTIONS of the
Nervous System
• sending of commands or motor
outputs to activate effector organs:
✓ voluntary or conscious control:
skeletal muscles
✓ involuntary or unconscious
control: smooth & cardiac
muscles, glands
MOTOR FUNCTION
DIVISIONS of the Nervous
System
✓ includes the brain & spinal
cord, w/c occupies the cranial &
vertebral cavities, respectively.
CENTRAL NERVOUS SYSTEM
DIVISIONS of the Nervous
System
✓ comprise sensory receptors &
all nerves outside the CNS
✓ relays information to & from the
CNS
PERIPHERAL NERVOUS SYSTEM
DIVISIONS of the Nervous
System
2. Functional Divisions of the PNS
✓ conveys impulses to the CNS
from sensory receptors located
in various parts of the body
SENSORY OR AFFERENT DIVISION
- Functional Divisions of the PNS
a) Sensory or Afferent division
✓ associated w/ muscles, joints,
& skin
SOMATOSENSORY RECEPTORS
- Functional Divisions of the PNS
a) Sensory or Afferent division
✓ found in the ear, eye, nose, &
tongue
SPECIAL SENSE RECEPTORS
DIVISIONS of the Nervous
System
2. Functional Divisions of the PNS
a) Sensory or Afferent division
✓ found in the internal organs
AUTONOMIC/VISCERAL SENSORY RECEPTORS
DIVISIONS of the Nervous
System
2. Functional Divisions of the PNS
✓ carries impulses from the CNS to
effector organs (muscles &
glands)
✓ subdivided into (1) somatic & (2)
autonomic divisions
MOTOR OR EFFERENT DIVISION
DIVISIONS of the Nervous
System
2. Functional Divisions of the PNS
b) Motor or Efferent division
✓ regulates activities under
voluntary control
✓ initiates skeletal muscle
actions
SOMATIC NERVOUS SYSTEM
DIVISIONS of the Nervous
System
2. Functional Divisions of the PNS
b) Motor or Efferent division
✓ regulates involuntary actions
(e.g. heart rate, BP, body temp.)
✓ involves cardiac muscle, smooth
muscle & glandular tissue
AUTONOMIC NERVOUS SYSTEM (ANS)
DIVISIONS of the Nervous
System
2. Functional Divisions of the PNS
b.2. Autonomic nervous system (ANS)
✓ has two (2) subdivisions:
supports “fight-or-
•flight” responses or emergency
actions
SYMAETHETIC NERVOUS SYSTEM
DIVISIONS of the Nervous
System
2. Functional Divisions of the PNS
b) Motor or Efferent division
b.2. Autonomic nervous system (ANS)
✓ has two (2) subdivisions:
•supports “rest-and-
digest” activities
PARASYMPATHETIC NERVOUS SYSTEM
TYPES of CELLS in Nervous
Tissue
NEURON
NEUROGLIA
THE NEURON Parts
DENDRITE
CELL BODY
AXON
• or “glia “ or “glial cells”
• collective term for
supporting cells of the
nervous system
• outnumber the neurons
• found in both CNS & PNS
NEUROGLIA
• Support, protect & nourish neurons
• Divide by mitosis
• Do NOT transmit nerve impulses
CHARACTERISTICS OF
NEUROGLIA
NEUROGLIA OF THE CNS
• star-shaped cells
• most abundant glial cells of
the CNS
ASTROCYTES
NEUROGLIA OF THE CNS
• functions:
✓ hold neurons in place
✓ regulate exchange of
substances to & from CNS
neurons
ASTROCYTES
NEUROGLIA OF THE CNS
• functions:
✓ form the blood–brain
barrier to protect neurons
from harmful chemicals
ASTROCYTES
NEUROGLIA OF THE CNS
• spider-like cells
• phagocytes of CNS
• smallest & least abundant
neuroglia of the CNS
MICROGLIA
NEUROGLIA OF THE CNS
• functions:
✓ protect against
microorganisms
✓ clear away debris of dead
cells
MICROGLIA
NEUROGLIA OF THE CNS
• or “ependyma”
• ciliated cells
• line the fluid-filled cavities
of CNS (ventricles of brain
& central canal of spinal
cord)
EPENDYMAL CELLS
NEUROGLIA OF THE CNS
• function: produce
cerebrospinal fluid (CSF) &
assist in its circulation
EPENDYMAL CELLS
NEUROGLIA OF THE CNS
• cells whose branches wrap
around axons of CNS
neurons
OLIGODENDROCYTES