exam 4 step by step Flashcards
Ventral horn
Contains motor neurons for skeletal muscles
Doral Horn
Contains sensory neurons receiving signals from the body
Lateral Horn
Contain cell bodies of preganglionic neurons of the ANS
Gray Commissure
Connects the two sides of the spinal cords gray matter
Central cCanal
Contains CSF
White Matter
surrounds the gray matter, made of ascending and descending nerve tracts
Cauda equina
Roots of spinal nerves hanging from the lower end
Conus Medullaris
the tapered end of the spinal cord (L1-L2)
Filum Terminale
Extension of pia mater anchoring the spinal cord to the coccyx
Ascending tracts:
Spinocerebellar
Posterior Funiculus
Lateral spinothalamic
Anterior Spinothalamic
Descending Tracts
Corticospinal
Tectospinal
Rubrospinal
Reticulospinal
Vestibulospinal
Spinocerebellar is for?
Propioception to the cerebellum
Posterior funiculcus
Light touch , pressure, and proprioception
Lateral spinothalamic
Pain and temperature
Anterior spinothalamic
Crude touch and pressure
Corticospinal/pyramidal pathway starts at?
primary motor cortex (precentral gyrus)
Extrapyramidal pathway starts at
brain stem nuclei
Flaccid partalysis occurs
when there is damage to lower motor neurons
Skeletal muscle is unable to receive any stiumulation so becomes limp and without muscle tone
Spastic paralysis is?
Occurs when there is damage to primary motor cortex or upper motor neuron
There is no voluntary control but muscles can still contract reflectibley and over time become stiff and tighted with excessive muscle tone.
Somatic reflex step by step : direct reflex (monosynaptic) and what is the example
- 1st order sensory neurons deliver impulses to and synapse with lower motor neurons
- the lower motor neurons then transmit impulses out to a skeletal muscle.
Stretch reflex:
1. the elongation of muscle causes stretch receptors to generate impulses on 1st orde sensory neurons
2. 1st order sensory neuron transmit impulses to the spinal corde
3. lower motor neurons transmit the impulses back to the original elongated muscle, which responds by contracting
4. maintains myscle tone and upright.
Indirect reflex is? and what are the examples
an association neuron connects the 1st order sensory neuron with the lower motor neurons
Flexor reflex:
1. caused by extreme pain.
2. receptors on 1st order sensory neurons generate impulses that are transmitted to the spinal cord
3. 1st order snesnory neurons synapse with association enurons and
4.association neurons synapse with lower motor neurons
5.lower motor neurons terminate at and stiumlate contraction of a flexor.
Deep tendon reflex
1.cuased by extreme tension in muslce, and stiumulates a proprioceptor in its tendon
2. pathway is the same as in a flexor excpet the lower motor neurons are inhibited.
ANS is for? and where is it received by? and works with?
cardiac muscle, smooth muscle, and glands.
received by the hypothalamus, brain stem/spinal cord sent to cardiac and smooth muscles.
works with endocrine
ANS has two motor neuron pathways
- preganglionic neuron
cell body is in the lateral horns of gray matter - postganglioninc neuron
cell body in a ganglia
ANS has two divisions. and both are coordinated by?
- parasympathetic : rest
- sympathetic : fight or flight
coordinate by the hypothalamus
Parasympathetic
- fibers originate in the brain stem or sacral spinal cord
- preganglionic fibers are long
- postganglionic fibers are short
- gangli
Dorsal Root is for?
Sensory neurons
Ventral Root is for?
Motor neurons
Dorsal Horn is for?
Interneurons
Sympathetic Nervous cell bodies are found in?
Lateral horns of gray matter in throacic and upper lumbar regions (T1-L2)
Pathway axons for sympathetic Preganglionic
- exit spinal cord via the ventral root and join the spinal nerve
- white rami communicates: Axons then travel to the white rami communicants, entering the sympathetic chain ganglia
The 3 ways the preganglionic of sympathetic can move
- synapse at same level : synpase with post gagnlionic in the sympathetic chain ganglionic
- travel up or down the chain: preganglionic travels higher or lower before synapsing with post.
- pass through without synapse: pre can pass through the chain and form splanchnic nerves, traving to collateral ganglia in the abdominal cavity
- Synpase in collateral ganglia
or
- travel directly to the adrenal medulla where they stimulate the release of epinephrine (adrenaline) and norepinephrine into the blood stream .
Postganglionic in Sympathetic
Norepinephrine is released by most postganglionic
Acetylcholine is released at sweat glands and binds to muscranic receptors to regulate sweat production .
