Lab Exam 5 Flashcards
What is a Receptor?
Responds to a stimulus.
What is a sensory neuron?
Transports info to the CNS.
What is the integration center and where is it located?
It is located in the spinal cord or brainstem; where sensory info is received and transferred to the motor neurons.
What is a motor neuron?
It transports impulses away from the CNS to effectors.
What is an effector?
A muscle or gland cells that respond to the motor neurons.
What is a somatic reflex?
they activate skeletal muscle
What is a autonomic (visceral) reflex
Activate smooth muscle, cardiac muscle, or glands.
What is a Monosynaptic reflex?
They involve only two neurons and have a single synapse.
What is a polysnaptic reflex?
they involve several synapses and neurons.
What is a muscle spindle?
A special receptor found within fascicles of skeletal muscle.
What spinal nerves are tested during a biceps Reflex and what is a normal response?
C5 & C6 Contraction of biceps brachii muscle; slight elbow flexion
What spinal nerves are tested during a Triceps Reflex and what is a normal response?
C7 & C8 contraction of the triceps brachii; slight elbow extension
What spinal nerves are tested during a Patellar Reflex and what is a normal response?
L2, L3 & L4 contraction of the quadriceps femoris muscle group; slight knee extension
What spinal nerves are tested during a Ankle Jerk Reflex and what is a normal response?
S1 & S2 contraction of the gastrocnemius; slight plantar flextion
What spinal nerves are tested during a Babinski Reflex and what is a normal response?
S & S2 (and the lesser extent, L4 & L5) in an adult plantarflexion abnormal responds is extension of the great toe and abduction of the other toes.
What spinal nerves are tested during a Brachioradialis Reflex and what is a normal response?
C5 & C6 Wrist extension, supination, elbow flexion
What is a relfex?
automatic, involuntary responses to an internal or external stimulus.
What is the function of muscle spindles?
Special receptors that trigger a reflex muscle contraction that prevents over-stretching.
What are the Extrinsic Muscles of the eye?
Superior rectus, Inferior rectus, Lateral rectus, Medial rectus, Superior oblique, and Inferior oblique
Which specific branches of the NS control the radial fibers of the iris? Which control the circular fibers? What response results form stimulation of each group of muscle fibers
Sympathetic Nervous system–> dilation; parasympathetic Nervous System–>Pupil constriction.
Explain why your nose runs when you cry.
The lacrimal gland produces tears that wash across your eye and drain into the nasal cavity via the nasolacrimal sac and nasolacrimal duct.
What are the intrinsic muscle of the eye?
Iris and the ciliary muscle
Identify the muscles, its action and what nerve innervates it.
A: Superior oblique Depresses eey and turns it lateraly; Trochlear nerve IV
B: Medial rectus Moves eye medially; Oculomotor nerve III
C : Inferior oblique elevates eye and turns it laterally; oculomotor nerve III
D: inferior rectus-depresses eye and turns it medially; oculomotor nerve III
E: Lateral rectus- moves eye lateraly; Abducens nerve VI
F: Superior rectus- elevates eye and turns it laterally; oculomotor nerve III
What is this showing?
Vitreous Humor
What is this picture showing?
The retina attached at the optic disc and the tapetum lucidum (helps the cow is in the dark)
What fluid fills the anterior cavity of the eye?
aqueous humor
What is this?
If rods are activiate and the cones are inactive, which fibers of the iris muscle are contracting?
Which specific branch of the NS causes this response?
Radial fibers; sympathetic
What do you call the opening of the iris?
Pupil
Why does the vasuclar tunic of the eye contain so much black pigment?
B/C it absorbs light and prevents the relfecting and scattering w/ in the eye.
What is emmetropia?
word used to describe the refraction of light in the normal eye.
What is Myopia?
Nearsightedness. Light focuses in front of the retina. need concaved lens to correct; light rays diverge to extend focal point.
What is hyperopia?
Farsightedness; Light focus behind the retina; need convex lens which causes the light to converge.
shortening the focal point.
What is the Snellen Chart?
it is a chart used to test visual acuity.
what is presbyopia
farsightedness caused by loss of elasticity of the lens of the eye, occurring typically in middle and old age.
List in order the structures of the eye through which light passes before it strikes the optic sensory neurons.
Cornea, aqueous humor, lens, viterous humor, retina
On a bright day which type of optic sensory neuron will be stimulated?
Cones
What are the layers of the posterior eye?
from superficial to deep
sclera, choroid, & retina
How is the retina attached to the eye?
what types of cells form the retina?
it is held in place by pressure form the vitreous humor, it is only attached at the optic disc. Rods and Cones
What causes the lens to change shape?
The ciliary body
What muscles allow a person to look at an aobject to the right without moving the head or body?
Lateral rectus and medial rectus muslces.
What forms the ciliary body? what do they do?
The ciliary muscles which control the shape of the len and the Ciliary process which produces aqueous humor that fills the anterior cavity of the eye
Where are the auditory sensory receptors located?
Cochlea
Where are the balance sensory receptors located?
Semicircle canals
What changes vibrating air movement to vibrating bone movment?
Air vibrations move the typanic membrane which vibrate the aucoustic ossicles (malleus, incus, stapes)
Give the collective name for the tiny ear bones. Where are they located? List their names in order from external to internal.
Auditory ossicles; Middle ear, Malleus, incus, & stapes
Where in the skull are the middle and inner ear structures located in the temporal bone.
petrous portion of the temporal bone
What nerve transmits auditory and balance information form the ear to the brain?
Vestibulochlear nerve VIII
What feature on the vestibule does the stapes contract?
oval window
