Lab Questions Flashcards
what are the three types of cones
blue, green, red
what is the function of hair cells
transforms the stimulus into neural signals
list the major events in the physiology of hearing
1) auricle directs sound waves into external auditory canal
2) sound waves strike the tympanic membrane, causing it to vibrate back and forth
3) vibration travels from the tympanic membrane through the ossicles
4) the stapes moves back and forth, which pushes the membrane of the oval window in and out
5) the movement of the oval window sets up fluid pressure waves in the perilymph of the cochlea (scala vestibule)
6) pressure waves deform the walls of the scala vestibule and scala tympani which then push the vestibular membrane back and forth and increases and decreases the pressure of the endolymph inside the cochlear duct
7) the changes of the endolymph moves the basilar membrane which move the hair cells of the spiral organ against the tectorial membrane
8) the movement/bending of the hairs produces receptor potentials that produce nerve impulses in cochlear nerve fibers by the release of a neurotransmitter
3 pathways involved in blood clotting
extrinsic pathway, intrinsic pathway, common pathway
extrinsic pathway
Tissue factor (TF) aka thromboplastin leaks into blood from outside vessels and initiates the formation of prothrombinate. In the presence of Ca2+, TF begins a series of reactions that activates clotting factor X. WIth clotting factor x, it combines with factor V in the presence of Ca2+ to form active enzyme prothrombinase
intrinsic pathway
activators are either in direct contact with blood or contained within the blood. Trauma to endothelial cells causes damage to platelets, resulting in release of phospholipids by the platelets. Contact with collage fibers activates clotting factor XII which starts a series of reactions that eventually activates clotting factor X. Platelet phospholipids and Ca2+ can also participate in the activation of factor X. Once factor X is activated, it combines with factor V to form the active enzyme prothrombinase
common pathway
prothrombinase and Ca2+ catalyze the conversion of prothrombin to thrombin. Thrombin (in presence of Ca2+) converts fibrinogen to loose fibrin. Thrombin also activates factor VIII which strengthen and stabilizes the fibrin threads to a steady clot.
