L3_ Introduction to the nervous system Flashcards
what’s in the central nervous system?
brain and spinal cord
what’s in the peripheral system?
all nerves outside of the spinal cord
what’s the somatic nervous system?
voluntary control of sensory and motor functions
What’s the autonomic nervous system?
involuntary control over visceral organs
myotome?
group of muscle innervated by a single spinal nerve
dermatome?
area/region of skin innervated by a single spinal nerve
What’s the basic trajectory of an information in the nervous system?
1- stimulis from the environment
2- the sensory (afferent) receives the information from the environment
3- information processing in the central nervous system
4- the motor (efferent) receives an information fro the central nervous system to coordinate an action on effector organs
Types of Sensory (2) and motor (2)
- Somatic Sensory: touch, pressure, vibration
- Visceral Sensory (autonomic): pain, nausea, hunger
- Somatic Motor: muscle contraction, joint movement
- Visceral Motor (autonomic): gland secretion, cardiac muscle contraction
What’s the trajectory of an information in the cell of the nervous system?
1- The dendrite receives the information from another dendrite
2- the information is transfered to the cell body of the neuron
3- the information is after transported by the axon (covered by myelin to increase the speed of electrical impulses) to relay the information in the form of electricity
4- the information is transfered to the synapse and will do the synapsing (passes information onto other nerves or effector organ chemically) with the dentrite of another neuron
Pathway of sensory and motor information
1- joints, skin, skeletal muscle 2- somatic sensory fibers 3- CNS 4- somatic motor fibers 5- skeletal muscle
muscle fibers are stimulated to contract by the nervous system. This stimulation or innervation of muscle fibers occurs via….
motor neurons
motor unit definition?
one motor neuron innervating multiple muscle fibers (synchronous contraction)
- targeting specific muscle fiber
What will happen if it’s a big motor unit
it will contract more muscle fibers
What will happen if it’s a smaller motor unit
it will innervate less muscle fibers
What’s the white matter?
Around the grey matter and contains the myelinated axons
What’s the grey matter?
In the middle of the spinal cord and contains bundles of cell bodies
How can you identify the dorsal root
the dorsal root has a ganglion and not the ventral root
Which information passes through the dorsal rami?
information from the :
- skin of the back
- intrinsic muscles of the back
Which information passes through the ventral rami?
informatiom from :
- everything else in the body (not the skin of the back nor the intrinsic muscle of the back)
Explain the pathway of sensory and motor information if the information given is a push on your back.
1- The information enters by the dorsal ramus
2- passes into the spinal nerve
3- into the posterior root
4- goes in the sensory side (posterior) of the spinal cord
5- synapse from the sensory side to the motor (anterior) side of the spinal cord
6- leaves the motor side of the spinal cord by the anterior root
7- passes into the spinal nerve
8- and leaves by the dorsal ramus to give a motor reponse to your back
Explain the pathway of sensory and motor information if the information given is a tap on your shoulder.
1- The information enters by the ventral ramus
2- passes into the spinal nerve
3- into the posterior root
4- goes in the sensory side (posterior) of the spinal cord
5- synapse from the sensory side to the motor (anterior) side of the spinal cord
6- leaves the motor side of the spinal cord by the anterior root
7- passes into the spinal nerve
8- and leaves by the ventral ramus to give a motor reponse to your shoulder
where does the spinal cord from the cervical spine exit?
they exit above of their corresponding vertebrae
where does the spinal cord from the thoracic and lumbar spine exit? and why?
They exit under their corresponding vertebrae
this is because in the cervical spine there is 7 vertebrae and 8 spinal nerve so C7 exits above CVII, but C8 can’t exit above CVIII because it doesn’t exits. Because of that it will exit above TI so the other spinal nerve will exit under their corresponding vertebrae
What’s the conus medullaris?
It’s the end of the spinal cord at L1/L2
