DOG exam 2: general nervous system concept Flashcards
CNS: Central Nervous System is split into 2 structures. what are those structures?
Encephalon (Brain)
Spinal cord (Medulla Spinalis)
Part of the NS that is protected by bony cavities (Cranial cavity and vertebral canal), and three layes of membranes known as meninges
CNS: Central Nervous System
Anatomical divisions of the Nervous system s
CNS (central nervous system)
PNS (peripheral nervous system)
how many pairs of cranial nerves are there
12 pairs
how many pairs of spinal nerves are there
36 pairs
PNS: Peripheral Nervous System consist of (3)
Cranial nerves (12 pairs)
Spinal nerves (36 pairs)
Nerves & trunks of autonomic nerve system (ANS)
Functional divisions of the Nervous system (2)
SNS: Somatic Nervous System
ANS: Autonomic Nervous System
Is the Somatic Nervous system
voluntary or involuntary?
skeletal or smooth?
voluntary, skeletal
Is the Autonomic Nervous system
voluntary or involuntary?
skeletal or smooth?
involuntary
visceral(smooth, heart, glands)
In the CNS many somas are called (general term)
grey matter
In the CNS specific somas are called
nucleus (bunch of somas with specific function)
or
cortex (layer of somas)
In the CNS a group of axons is called (general term)
white matter
the terms tract, funiculo, fasciculus, lemniscus, and peduncle all refer to
axons in the CNS
association, projection and comminssural are terms for
fibers in CNS related to axon in CNS
If you take a sample from the CNS and you notice a mix of somas and axons, what is it called
reticular formation
In the PNS, a group of somas are called
ganglion
In the PNS, if we have a group of axons they are called
nerves, root, trunk or branches
do you have nerves in your brain
no, they’re tract, funiculo, fasciculus, lemniscus, and peduncles
Is there a reticular formation in the PNS
NO
what 3 main layers form the embryo
Ectoderm
Mesoderm
Endoderm
in embryonic development, what layer is neural tissue, epidermis
ectoderm
in embryonic development, what layer develops into somites that differentiate into skeletal and muscle tissues, the notochord, blood vessels,
dermis, and connective tissues
Mesoderm
in embryonic development, what layer epithelium of the digestive and respiratory systems, organs associated with the digestive system, such as the liver and pancreas
Endoderm
the ____________ is formed in the ectoderm,
dorsal to the notochord of the mesoderm
neural plate
The cells in the neural plate form a ____________
neural groove
The cells in the borders of the neural groove form the ____________
neural crests
The cells of neural crests will form most of what system
Peripheral nerve system, including ganglia and spinal nerves
The rest of cells in the neural groove will close and form the _____________, including the _________ in the middle
neural tube, neural canal
The neural tube will form what system
Central nerve system, including encephalon and spinal cord.
what kind of section is this
transverse section
identify 1-3
- ectoderm
- neural canal
- neural tube
label 1 (what structure is teal)
label 2 (what is leaving)
- dorsal gray column- receive info from outside
- axons of ventral root- send info towards tissues
what is being pointed to
Encephalic vesicles
Prosencephalon (hindbrain, forebrain or midbrain)
forebrain
Mesencephalon (hindbrain, forebrain or midbrain)
midbrain
Rombencephalon (hindbrain, forebrain or midbrain)
hindbrain
label 1-3
- Prosencephalon- forebrain
- Mesencephalon- midbrain
- Rombencephalon-hindbrain
limit between Spinal cord and brainstem is known as what part of the spinal cord
Pyramidal decussation:
the Caudal end of the spinal cord is called
Medullary cone
name parts 1and 2 of the spinal cord
- Pyramidal decussation:
- Medullary cone
Place where the pyramidal fiber (upper motor neurons) cross over to the opposite side of the spinal cord
Pyramidal decussation
what is the red arrow pointing to (be specific)
Pyramidal decussation
Medullary cone, end of spinal cord is located where in the cat? dog?
Cats: Between S2 & S3
Dogs: Between L6 & L7
the segments that gives origin to the nerves
supplying the thoracic and pelvic limbs are called
intumescentiae (enlarged part of spinal cord)
Cervical intumescence are located in what vertebrae
C6–T2: thoracic limbs innervation
Lumbar intumescence are located in what vertebrae
L4–S3: pelvic limbs and pelvic viscera
innervation
these are showing the spinal cord in what cross section
transverse section
the funiculi are composed of _________________ axon fibers, of which many are grouped within bundles (fasciculi or tracts) of common origin,
destination, and function
ascending and descending
label from top to bottom
“highways”
top= Dorsal funiculus
middle= Lateral funiculus
bottom=ventral funiculus
what is being represented in blue? red?
blue= ascending axon fibers
red= descending axon fibers
what is the blue arrow pointing to? red? green?
blue: Dorsal horn
red: Lateral horn Thoracic & Lumbar segments
green: Ventral horn
what does blue represent? red?
blue: Sensory or Afferent
From the body toward CNS
red: Motor or Efferent (effect):
Toward a muscle or gland
Label 1-4 TOWARDS THE CNS
- Spinal nerve (sensory/motor)
- Spinal ganglion
- dorsal root
- dorsal horn
label 1-3 TOWARDS MUSCLE/GLAND
1.ventral horn
2. ventral root
3. spinal nerve (sensory/motor)
Afferent neurons are ____________ neurons
Pseudounipolar
label 1-3
- spinal ganglion
- spinal nerve
- intervertebral foramen
what rootlets are represented by blue? red?
blue: dorsal rootlets
red: ventral rootlets
neural canal expands to form
brain
all spinal nerves are within the intervertebral foramen except
C2
Domestic dog has ____ pairs of cervical spinal nn
8
Domestic dog has ____pairs of thoracic spinal nn
13
Domestic dog has ____pairs of lumbar spinal nn.
7
Domestic dog has ____pairs of sacral spinal nn
3
Domestic dog has ____pairs of caudal spinal nn
5
what is being pointed to
dorsal rootlets of C1
Label A-E sections of the spinal cord
A: Cervical (C1–5: neck)
B: Cervical intumescence (C6–T2: thoracic limbs)
C: Thoracolumbar (T3–L3: trunk)
D: Lumbosacral intumescence (L4–S3: pelvic limbs and pelvic viscera)
E:Caudal segments (Cd1–5: tail)
GSE neurons stands for
General
Somatic
Efferent
what does E stand for in GSE neuron
Efferent
Motor impulse to a skeletal
muscle
That will stimulate the contraction of the muscle cells
GSE neurons live in the __________
ventral horn
how many GSE neurons leave ventral horn and go to skeletal muscle
one neuron
(can have a bunch of one neuron signals)
is confined to the central nervous system (brain and spinal cord), you may think of it as a “central motor neuron”
Upper motor neuron (UMN)
has its cell body in the CNS, but the the axon is in the periphery, you may think of itas a “peripheral motor neuron”
Lower motor neuron (LMN)
Describe where the motor neuron is in 1-3
- Soma of motor neuron in ventral horn
- ventral horn
- Motor neuron in dorsal branch of
spinal nerve
Describe where the motor neuron is in 1-3
1.Motor neuron in ventral root
2. Motor neuron in spinal nerve
3. Motor neuron in ventral branch of spinal nerve
What does GSA neuron stand for
General Somatic Afferent
GSA neuron:
Receptors in skin, cornea, mucosa, hair/feather follicle, connective tissue is referred to as
Tactile and nociception
GSA neuron:
Length changes Receptors in tendons,
Ligaments, muscles, joints is referred to collectively as
Proprioception
Is Afferent towards or away from CNS
transmit sensory impulses towards CNS
A reflex comprises three parts
list them.
Sensory input
Central connection
Output
peripheral receptor- afferent neuron
what part of a reflex is this? (sensory, central connection, output)
sensory input
in the brain or spinal cord- interneuron
what part of a reflex is this? (sensory, central connection, output)
central connection
lower (peripheral) motor neuron that
connects to the muscle via a neuromuscular junction
what part of a reflex is this? (sensory, central connection, output)
output
Damage to any one of the reflex components (sensory, central connection, and output) will result in a
reduction or loss of the reflex
Gravity (arrow) stretches the extensor muscle, stimulating its contraction via the reflex arc.
The flexor muscle is inhibited
by a collateral fiber and an inhibiting interneuron
Myotatic reflex arc
Damage to UMNs reflexes will still be present; they may even be increased due to loss of ___________________
inhibitory UMN influence
Damage to LMNs results in
Reduced/lost reflexes