Spinal Cord Structures
The anterior gray horn of the spinal cord contains the cell bodies of ______ neurons.
Somatic motor neurons (control skeletal muscles)
A dermatome is defined as…
An area of skin supplied by a single spinal nerve.
Reflexes you are born with, such as the withdrawal reflex, are called ______ reflexes.
Innate reflexes
The afferent division of the nervous system carries ______ information, while the efferent division carries ______ commands.
Sensory; motor
This division of the autonomic nervous system decreases heart rate.
Parasympathetic
The anterior root of a spinal nerve contains only ______.
Axon of motor neurons
Name the four major nerve plexuses of the body.
Cervical, brachial, lumbar, sacral.
Reflexes learned through repetition and practice, such as driving or playing piano, are called ______ reflexes.
Acquired reflexes
A ______ is a group of axons in the CNS, while a ______ is a group of axons in the PNS.
Tract; nerve
This division of the autonomic nervous system facilitates urination by contracting the bladder wall and relaxing the sphincter.
Parasympathetic
The layer of connective tissue that surrounds a fascicle within a peripheral nerve is the
perineurium
The _______ nerve, which controls the diaphragm, arises from the cervical plexus.
Phrenic nerve
Reflexes that control skeletal muscle contractions are called ______ reflexes, while those that regulate smooth muscle, cardiac muscle, and glands are called ______ reflexes.
Somatic reflexes; visceral reflexes.
A neural pathway includes the tract, the nerve, and the ______ that delivers information to/from the CNS.
Soma (cell body)
This division of the autonomic nervous system dilates pupils to enhance vision.
Sympathetic
Name the three layers of the spinal meninges from outermost to innermost.
Dura mater → arachnoid mater → pia mater
Which plexus supplies the upper limbs?
Brachial plexus
The Babinski sign is normal in infants but abnormal in adults. What does a positive Babinski sign indicate?
Damage to descending corticospinal tracts (upper motor neuron lesion).
The corticospinal pathway begins where in the brain?
Primary motor cortext
Compare preganglionic neurons and ganglionic (postganglionic) neurons in terms neurotransmitters for parasympathetic and sympathetic.
parasympathetic: preganglionic- ACh and ganglionic- ACh
sympathetic: preganglionic- ACh and ganglionic- norepinephrine
A patient reports numbness and loss of sensation in a specific dermatome, but motor function is still intact. The lesion is localized to the spinal cord. This damage most likely involves the ______.
Posterior Root
Name all of the nerves in the lumbosacral plexus.
Lumbar, sciatic, and pudendal.
Name the five steps of a reflex arc.
1) Receptor → 2) Sensory neuron → 3) Information Processing → 4) Motor neuron → 5) Effector.
A patient who has undergone an amputation continues to feel pain in the missing limb. This phenomenon occurs because the brain still receives signals through the ______ pathway, which transmits pain and temperature sensations.
spinothalamic pathway
Distinguish between sympathetic chain ganglia, collateral ganglia, and terminal ganglia.
Sympathetic chain ganglia: alongside vertebral column, control body wall and limbs.
Collateral ganglia: anterior to vertebral column, control abdominal/pelvic organs.
Terminal ganglia: near or within target organs, parasympathetic control.