2nd exam Flashcards
5 characteristics of aqueous humor:
Fill anterior segment of the eye, is watery, freely flowing, is drained continously and is secreted by ciliary body through Schlemm canal
4 characteristics o vitreous humor:
fills posterior segment between lens and retina, is gelatinous, stagnant and not drained as much
What region has the sharpest image?
fovea
what are the 3 pairs of muscles that control the eye?
medial and lateral recti, superior and inferior recti and superior and inferior oblique
What are the 3 nerves responsible for occulomotor reflexes?
oculomotor, trochlear and abducent
Convex lens ________ light while concave lens _____
converges, diverge
The accomodation of eye is given by contraction of _______ muscles that relax _______, increasing the _______ of the lens for near vision.
ciliary, the suspensory ligaments, curvature
Normal vision is called ________ while farsightedness is ________ and nearsightedness is ______
emmetropia, hyperopia, myopia
Glasses for myope are
concave
Cones are responsible for ____ vision and rods are for ______
day, night
Images are processed in the ______ geniculate
lateral
What are the 2 chambers in the cochlea?
scala vestibula on top and scala tympani on bottom, are connected by cochlear duct where most hearing occurs
What perceives sound?
organ of cort
Basilar fibers are shortest and thickest _________ they perceive _______ frequency sound, where membrane is ______
near the base of the cochlea, high frequency, narrowest
The thinnest basilar fibers are near ___________, they perceive _______ frequency sounds, where basilar membrane is _______
the apex of cochlea, low, widest
The primary sensory cell body for the auditory system is in
the spiral ganglion
The ______ system is the main organ responsible for equilibrium
vestibular
Vestibular system has two regions:
crista ampullaris (aka semicircular canals) and macula
The macula consists of:
utricle and saccule
Semicircular canals respond to _______ while maccula responds to _______
kinetic movement (angular acceleration and deceleration), gravitational pulland linear acceleration
Utricle is in _______ plane and senses orientation when in _______ and saccule is in ______ and senses orientation ________
horizontal, upright, vertical, when laying down
What are the 3 systems that maintain posture and equilibrium?
vestibular pathway, cerebellar and reticular systems
Which part control moderately complex reflexes?
Brainstem and cerebelum
What are the main differences between muscle spindles and golgi tendons?
Muscle spindles are spread in the muscles and sense length, are innervated by sensory and motor fibers. While golgi tendons sense tension, are scattered in tendons and are innervated only by sensory fibers
Muscle sensory information is sent to the brain via:
dorsal column medial lemniscus
How are muscle spindles and golgi tendons related?
When muscle spindles receive signals to contract by fast fibers, the tension increases and the golgi tendons inform the brain in order to prevent injury from extreme contraction
In the corticospinal tract where do the fibers cross to the opposite side?
In the medulla oblongata
What movements are controlled by the corticospinal tract?
Fine purposeful skilled movements
What is the route of fibers in extrapyramidal tract?
from motor cortex to basal ganglia or cerebellum or brainstem then spinal cord
What constitutes the brainstem?
medula, pons and midbrain
What performs motor functions of face?
brainstem
What are the unique functions of cerebellum?
pre-planning of next movements, change of one muscle movement to another, smooth progression of movements, control intensity of muscle contraction when load changes
What are the regions of the cerebellum? and their functions?
Vermis is mostly responsible for trunk, intermediate zone of hemisphere is responsible for limbs and lateral zones of the hemispheres don’t have topographic map but are involved in the planning and sequencing of complex movements
Where does the output signal from the cerebellum comes from in each region and the functions?
From vermis is fastigial nucleus (maintenance of equilibrium, control of posture), intermediate zone in interposed nuclei (coordination of reciprocal contraction of agonist and antagonist muscles in the limbs) and lateral zone begin in dentate nucleus (coordination of sequential motor activities)
What are the unique functions of the basal ganglia?
Planning and controlling of complex patterns of skilled muscle movements, control relative scale of intensity of muscle, direction of movement and sequence of multiple succesive movements
What are the regions of the basal ganglia?
caudate nucleus, putamen, globus pallidus, subthalamic nucleus and substantia nigra
Where does the motor cortex project fibers in the basal ganglia?
caudate nucleus and putamen (corpus striate) via corticostriate fibers
Where does the nerves originate in sympathetic and parasympathetic systems?
Between T1 and L2 (thoraco-lumbar) and cranial nerves of brainstem and sacral part of SC (cranio-sacral)
Where do preganglionic neurons pass through?
anterior roots (or motor roots)
How are the fibers of adrenal gland different than others?
It only has preganglionic fibers that terminate on the chromaffin cells, these synapse only on the spinal cord. it secretes adrenalin and nor-adrenalin
What is the preganglionic neurotransmitter of the sympathetic and parasympathetic systems?
Acetylcholine (cholinergic receptors)
What is the neurotransmitter of postganglionic neurons in the sympathetic system?
Mostly norepinephrine
What is the neurotransmitter of postganglionic neurons in the parasympathetic system?
acetylcholine
Where is the ganglia in the sympathetic and parasympathetic systems?
close to the spinal cord, far from spinal cord and close to the organs
What are the receptors for acetylcholine in the ganglia and in the tissue?
nicotinic receptors in ganglia and muscarinic receptors in parasympathetic neurons (but can have others)
What are cholinergic and adrenergic receptors?
receptors of acetylcholine and adrenaline (epinephrine)
What are the 4 main differences of sympathetic and parasympathetic?
sympathetic is responsible for rapid responses, nerves leave the spinal cord between L1 and T2 (thoracolumbar), ganglia is close to the spinal cord, postganglionic neurotransmitter is mostly norepinephrine. while parasympathetic is different
