OCB04-2010 Vestibular System Flashcards
What are the 3 key inputs for balance?
Vestibular system
Proprioception
Vision
Where is the vestibular system located?
In the inner ear and deep in the petrous part of the temporal bone
What are the two organs of the equilibrium?
Semi-circular canals and otolith organs
What is the inner ear also known as?
Labyrinth
What are the two components of the labyrinth?
Bony and Membraneous
What is the bony labyrinth?
A shell of bone located on the outer surface which protects the delicate organs inside
What is the membraneous labyrinth?
The inner component, running inside the bony labyrinth
It consists of a series of membraneous sacs where the organs of hearing and balance are located
What fluid fills the membraneous labyrinth?
Endolymph
What is the ionic composition of endolymph?
Most fluids in the body have a high sodium and low potassium, but endolymph has the opposite- high potassium and low sodium
Where does the endolymph drain out of?
Endolymphatic duct
What fluid is between the membraneous and bony labyrinths?
Perilymph
What is the ionic composition of perilymph?
High sodium and low potassium concentration
What is the electrical potential of endolymph?
80-90mV
Why does endolymph have a more positive electrical potential that perilymph?
Endolymph has a higher concentration of potassium compared to sodium
What does the difference between ionic confrontation of the endolymph and perilymph lead to?
A voltage difference which is important for the functioning of the system
