Nervous System Flashcards
What is the nervous system?
The major control system of the body.
Functions to receive and process incoming sensory information and send out motor commands to muscles and glands to direct their functions.
Central Nervous System (CNS) includes:
Brain
Spinal Cord
Peripheral Nervous System (PNS) includes:
Cranial Nerves
Spinal Nerves
The Higher Level Control (Upper Management) takes place where?
Brain
Where does the (Localized Control - Reflex activity) [Junior Management] occur?
Spinal Cord
What conducts impulses to and from higher levels?
Spinal Cord
What is divided into segments which give rise to spinal nerves (workers)?
Spinal Cord
What is a neuron?
The basic functional unit of the nervous system.
What type of neuron is number 1?
Multipolar
What type of neuron is number 2?
Bipolar
What type of neuron is number 3?
Pseudounipolar
What is the usual funcation of, number 3?
Sensory
What is the defination of a nerve?
a collection of neuronal cell processes, axons, located in the PNS external to the CNS. A nerve will also contain supporting cells (Schwann cells) and CT (endoneurium, perineurium, and epineurium)
What is the definition of a tract?
a collection of neuronal cell processes traveling within the CNS.
What is the defintion of a ganglion?
a collection of neuron cell bodies outside of the CNS
What is the defintion of a nucleus?
a collection of neuron cell bodies within the CNS.
What is number 1?
Gray Matter
(contains cell bodies)
What is number 2?
White Matter
(contains tracts)
What is number 3?
Ventral Horn
(Ventral gray column)
What is number 4?
Lateral Horn
(Lateral gray column)
(Intermediolateral gray column)
What is number 5?
Dorsal Horn
(Dorsal gray column)
What do Primary Afferent Neurons do?
Conduct sensory impulses from periphery into the CNS.
Afferent = Toward the CNS
What do Final Efferent neurons do?
Conduct motor impulses from the CNS to effector organ
aka Lower Motor Neurons (LMN)
Efferent = away from the CNS
What is this diagram for and what are number 1 and 2?
Monosynaptic Patellar Reflex
- Primary Afferent Neuron
- Final Efferent Neurons
(Lower Motor Neurons LMN)
Which diffection are Efferent neurons going?
Aways from the CNS
Which direction are the Afferent neurons going?
Toward the CNS
What are interneurons?
Relatively short neurons interposed between afferent and efferent neurons.
Where are interneurons located?
Entirely within the CNS
True or False: Interneurons can be excitatory or inhibitory?
True
Explain the withdrawal reflex:
Where are projection neurons found?
CNS
How do Projection Neurons compare to Interneurons?
Compared to interneurons, projection neurons send their axons longer distances before terminationg.
Whare a ascending projection neurons?
The cell body is in the spinal cord, most project cranially to terminate in the neuronal population in the brain
(forming an ascending tract)
What is a descending projection neurons?
The projection pathway begins in the nucleus or cortex of the brain, the axon extends caudally to terminate in the brainstem or spinal cord.
(forming the decedning tract)
Aka Upper Motor Neurons (UMN)
Connection between the Upper managment and workers
What is number 1?
Projection Neurons
(Ascending projection neurons)
What is number 2?
Interneurons
What is number 3?
Final Efferent Neurons
What is number 4?
Primary Afferent Neurons
What is the purpose of number 1?
Sends the signal to the brain (takes some time)
Classification based on direction of impulse:
- Conduct impulses toward the CNS
- Conduct impulses away from the CNS
- Afferent (sensory)
- Efferent (motor)
Classification based on region of the body supplied:
- Main body mass
- Organs / blood vessles
- Somatic
- Visceral
Description of General Somatic Efferent (GSE) Peripheral Neurons:
Multipolar neurons that supply most of the skeletal muscles of the body
A single neuron extends all the way from the CNS to the muscle fibers involved.
Description of General Visceral Efferent (GVE) Peripheral Neurons:
Multipolar neurons that supply smooth muscle, cardiac muscle, and glands
From the autonomic nervous system (ANS)
Consist of 2-neuron chain between the CNS and the effector organ
Description of General Somatic Efferent (GSE) Special Visceral Efferent (SVE) Peripheral Neurons:
Multipolar neurons that supply skeletal muscles that are derived from brachial arches (muscles or facial expression, mastication, pharyngeal, and laryngeal muscles, and some mucles of the neck and shoulders).
Like GSE neurons, a single neuron extends all the way from the CNS to the mucle fibers innervated.
Description of General Somatic Afferent (GSE) Peripheral Neurons:
Pseudounipolar neurons that carry sensory information from the somatic body systems (skin, musculoskeletal system, etc)
Cell bodies are located in the sensory ganglia
Description of General Visceral Afferent (GVA) Peripheral Neurons:
Pseudounipolar neurons that carry sensory information from the visceral body systems
Cell bodies are located in the sensory ganglia
Description of Special Somatic Afferent (SSA) Peripheral Neurons:
Bipolar neurons that carry visual and auditory information
Description of Special Visceral Afferent (SVA) Peripheral Neurons:
Bipolar and pseudounipolar neurons that carry taste and smell sensations.
What is the classification of the neuron and where does it start and end, at number 1?
General Somatic Afferent (GSA)
Carries sensory information from the somatic body systems (skin, musculoskeletal system, etc)
Dorsal gray horn of the spial column.
What is the classification of the neuron and where does it start and end, at number 2?
General Visceral Afferent (GVA)
Carries sensory information from the visceral body systems.
Dorsal gray horn of the spial column.
What is the classification of the neuron and where does it start and end, at number 3?
General Visceral Efferent (GVE)
Lateral horn of the spinal column.
Supply smooth muscle, cardiac muscle, and glands.
Consists of a 2-neuron chain between the CNS and the effector organ.
Form the autonomic nervous system (ANS)
What is the classification of the neuron and where does it start and end, at number 4?
General Somatic Efferent (GSE)
Ventral horn of the spinal column.
Supply most of the skeletal muscles of the body
A single neuron extends all the way from the CNS to the muscle fibers involved.
What is number 1?
Remember that these labels apply to both sides.
Dorsal Root
Sensory, afferent
What is number 2?
Remember that these labels apply to both sides.
Ventral Root
Motor, efferent
What is number 3?
Remember that these labels apply to both sides.
Dorsal branch
motor and sensory
What is number 4?
Remember that these labels apply to both sides.
Ventral branch
motor and sensory
What is number 5?
Remember that these labels apply to both sides.
Communicating branch
What is number 1?
General Somatic Efferents
Ventral branch of the spinal nerve
What is number 2?
General Somatic Afferents
Ventral branch of the spinal nerve
What is number 3?
General Somatic Efferents
Dorsal branch of the spinal nerve
What is number 4?
General Somatic Afferents
Dorsal branch of the spinal nerve
What is number 5?
Dorsal root ganglion
(sensory/afferent ganglion)
The spinal nerve dorsal branches go where?
Epaxial region:
The epaxial musculature and dorsal 1/3 of the body for cutaneous innervation
The spinal nerve ventral branches go where?
Hypaxial region:
The hypaxial musculature (and the limbs) as well as to the ventral 2/3 of the body for cutaneous innervation
How many cervical spinal nerves are there?
8
C1: Lateral vertebral foramen of atlas
C2-C7: in from of the respective vertebra
C8: after C7
How many Thoracic spinal nerves are there:
T1 - T13
After the respective thoracic vertebra
How many Lumbar spinal nerves are there:
L1 - L<span>7</span>
After the respective Lumbar vertebra
How many Sacral spinal nerves are there:
S1 - S3
S3 - pelvic sacral foramen