PHYSIOLOGY OF THE NERVOUS SYSTEM
Veterinary General Physiology
The Nervous System
sustained movement
- It provides rapid regulation over greater
3. Suppression of useless
distance patterns of movement
- It coordinates multiple organs
- Cells: Neuron, Neuroglia
thalamus 1. Relay station for all synaptic
Ultimate Function of N. S. input
- Rapidly translate sensory information into 2. Crude awareness of
action potentials (APs) which can be sensation
processed (integrated) into an adaptive 3. Some degree of
consciousness
response via activation of effector organs.
4. Role in motor control
- Whole body regulation (1 of the 2 control
systems)
hypothalamus 1. Regulation of many
homeostatic functions, such
Simple Neural Pathways: Reflex arcs
as temperature control,
thirst, urine output, and food
intake
ORGANIZATION OF THE NERVOUS 2. Important link between
SYSTEM nervous and endocrine
● Central Nervous System (CNS) systems
● Peripheral Nervous System (PNS) 3. Extensive involvement with
emotion and basic behavioral
Central Nervous System (CNS) patterns
- where most neuronal bodies are contained
- Brain
cerebellum 1. Maintenance of balance
- Spinal cord
2. Enhancement of muscle
tone
1. Brain
3. Coordination and planning of
- contains forebrain, midbrain, hindbrain
skilled voluntary muscle
activity
a. Forebrain
- receives, integrates sensory
information from nose, eyes, ears brainstem 1. Origin of majority of
- in land-dwelling vertebrates', contains (midbrain, pons, peripheral cranial nerves
the highest integrating centers medulla) 2. Cardiovascular, respiratory,
and digestive control centers
b. Midbrain
3. Regulation of muscle reflexes
- coordinates reflex responses to sight, involved with equilibrium
sounds and posture
c. Hindbrain 4. Reception and integration of
- reflex control of respiration, blood all synaptic input from spinal
circulation, other basic tasks cord; arousal and activation
- in complex vertebrates, coordination of cerebral cortex
5. Role in sleep–wake cycle
of sensory input, motor dexterity, and
possibly mental dexterity
2. Spinal Cord
- Long, slender cylinder of nerve tissue
Main components Function - Enclosed in by vertebral column
- spinal nerves are named according to the
cerebral cortex 1. Sensory perception
2. Voluntary control of muscle region of the vertebral column from which
3. Language they emerge
4. Personality traits ● Humans: C8T12L5S5Cocc1
5. Sophisticated mental events, ○ 8 cervical (neck) nerves, 12
such as thinking, memory thoracic (chest) nerves, 5
decision making, creativity, lumbar (abdominal) nerves, 5
and self-consciousness
sacral (pelvic) nerves, and 1
basal nuclei 1. Inhibition of muscle tone coccygeal (tailbone) nerve
2. Coordination of slow, ● Canine: C7T13L7S3Cd20-23
1
, PHYSIOLOGY OF THE NERVOUS SYSTEM
Veterinary General Physiology
- thick bundle of elongated nerve roots within
the lower vertebral canal is known as the
cauda equina
● Gray matter - consists of:
○ cell bodies
○ dendrites
○ glial cells
○ can be viewed as the computers of
CNS
● White matter - consists of:
○ myelinated fibers (axons)
○ white appearance is due to the lipid
(fat) of the myelin
○ viewed as wires of CNS that connects
the computers to each other
Peripheral Nervous System (CNS)
- has nerve fibers carrying information
between CNS and other parts of the body
(periphery)
- contains ganglia (cell bodies of most sensory
neurons and some non motor effector
neurons)
PNS Division:
a. Afferent
- convey signal towards CNS
➔ Sensory stimuli
➔ Visceral stimuli
b. Efferent
- convey signal from CNS
➔ Autonomic NS
➔ Somatic NS
➔ Enteric NS
- Efferent autonomic nerve pathways consist of
a two-neuron chain between the CNS and the
effector organ
EFFECTS OF THE AUTONOMIC NERVOUS SYSTEM
ON VARIOUS ORGANS
2
Veterinary General Physiology
The Nervous System
sustained movement
- It provides rapid regulation over greater
3. Suppression of useless
distance patterns of movement
- It coordinates multiple organs
- Cells: Neuron, Neuroglia
thalamus 1. Relay station for all synaptic
Ultimate Function of N. S. input
- Rapidly translate sensory information into 2. Crude awareness of
action potentials (APs) which can be sensation
processed (integrated) into an adaptive 3. Some degree of
consciousness
response via activation of effector organs.
4. Role in motor control
- Whole body regulation (1 of the 2 control
systems)
hypothalamus 1. Regulation of many
homeostatic functions, such
Simple Neural Pathways: Reflex arcs
as temperature control,
thirst, urine output, and food
intake
ORGANIZATION OF THE NERVOUS 2. Important link between
SYSTEM nervous and endocrine
● Central Nervous System (CNS) systems
● Peripheral Nervous System (PNS) 3. Extensive involvement with
emotion and basic behavioral
Central Nervous System (CNS) patterns
- where most neuronal bodies are contained
- Brain
cerebellum 1. Maintenance of balance
- Spinal cord
2. Enhancement of muscle
tone
1. Brain
3. Coordination and planning of
- contains forebrain, midbrain, hindbrain
skilled voluntary muscle
activity
a. Forebrain
- receives, integrates sensory
information from nose, eyes, ears brainstem 1. Origin of majority of
- in land-dwelling vertebrates', contains (midbrain, pons, peripheral cranial nerves
the highest integrating centers medulla) 2. Cardiovascular, respiratory,
and digestive control centers
b. Midbrain
3. Regulation of muscle reflexes
- coordinates reflex responses to sight, involved with equilibrium
sounds and posture
c. Hindbrain 4. Reception and integration of
- reflex control of respiration, blood all synaptic input from spinal
circulation, other basic tasks cord; arousal and activation
- in complex vertebrates, coordination of cerebral cortex
5. Role in sleep–wake cycle
of sensory input, motor dexterity, and
possibly mental dexterity
2. Spinal Cord
- Long, slender cylinder of nerve tissue
Main components Function - Enclosed in by vertebral column
- spinal nerves are named according to the
cerebral cortex 1. Sensory perception
2. Voluntary control of muscle region of the vertebral column from which
3. Language they emerge
4. Personality traits ● Humans: C8T12L5S5Cocc1
5. Sophisticated mental events, ○ 8 cervical (neck) nerves, 12
such as thinking, memory thoracic (chest) nerves, 5
decision making, creativity, lumbar (abdominal) nerves, 5
and self-consciousness
sacral (pelvic) nerves, and 1
basal nuclei 1. Inhibition of muscle tone coccygeal (tailbone) nerve
2. Coordination of slow, ● Canine: C7T13L7S3Cd20-23
1
, PHYSIOLOGY OF THE NERVOUS SYSTEM
Veterinary General Physiology
- thick bundle of elongated nerve roots within
the lower vertebral canal is known as the
cauda equina
● Gray matter - consists of:
○ cell bodies
○ dendrites
○ glial cells
○ can be viewed as the computers of
CNS
● White matter - consists of:
○ myelinated fibers (axons)
○ white appearance is due to the lipid
(fat) of the myelin
○ viewed as wires of CNS that connects
the computers to each other
Peripheral Nervous System (CNS)
- has nerve fibers carrying information
between CNS and other parts of the body
(periphery)
- contains ganglia (cell bodies of most sensory
neurons and some non motor effector
neurons)
PNS Division:
a. Afferent
- convey signal towards CNS
➔ Sensory stimuli
➔ Visceral stimuli
b. Efferent
- convey signal from CNS
➔ Autonomic NS
➔ Somatic NS
➔ Enteric NS
- Efferent autonomic nerve pathways consist of
a two-neuron chain between the CNS and the
effector organ
EFFECTS OF THE AUTONOMIC NERVOUS SYSTEM
ON VARIOUS ORGANS
2
