Vestibular System Flashcards
What is the main function of the vestibular system
- Responsible for maintaining our balance, posture and spatial orientation
what are the 3 receptor systems that the vestibular system integrates
- The eyes
- General proprioceptive(muscle, joints and tendons) and cutaneous receptors
- Vestibular receptors in the inner ear (the vestibular apparatus)
what is the inner ear made out of
- The labyrinth
- Vestibular apparatus
- Cochlear
What are the two types of fluid within the labyrinth
- endolymph
- perilymph
what is the difference between the endolymph and perilymph
Endolymph
- High in potassium low in sodium
Perilymph
- Low in potassium high in sodium
- this allows the vestibular cells to function and establish the end-cochleae potential
what is the labyrinth divide into
The labyrinth contains an auditory part and a vestibular par
What is present the vestibular part of the labyrinth
In the vestibular part, there are 3 semicircular ducts (posterior, anterior and lateral)
- these lie 90 degrees to each other
what activates the cells int he semicircular ducts
Movement of endolymph inside may activate the cells in the duct, depending on the position of the head.
what is also present in the vestibular part
there is also the utriculus and the sacculus.
What are present in the utriculus and sacculus
Present in these are small protrusions where the vestibular cells lie.
what do vestibular cells have
The vestibular cells have many cilia(stereocilia and kinocilia), which depending on movement cause hyperpolarisation or depolarisation of the cell by releasing glutamate.
What is present in the ampulla
Inside the ampulla, there is a gelatinous substance called the cupula where the cilia are embedded.
movement of the cupola….
causes movement of the cilia
what is the difference between the ampulla, utricular and saccule
In the ampulla there is cupola which embeds the cilia whereas In the utricular and saccular maculae, there are also cilia cells but they are slightly different due to the presence of otoconia (calcium crystals which provide gravitational stimulation).
what do the hair cells of the articles and saccule work together to produce
The hair cells of the utricles and saccule work together to provide a 3-dimensional representation of direction of linear force.