Posture and Balance

Question 1

Which 3 sensory modalities are important in maintaining balance and posture

Answer 1

Somatosensory system (muscle and joint proprioceptors)
Vesticular system
Visual system

Question 2

The 2 parts of the vestibular apparatus

Answer 2

Semicircular canals (anterior, posterior and lateral, linked to the amupllae)
Vestibule containing the utricle and saccule (otolith organs)

Question 3

Key features of the vestibular apparatus

Answer 3

Bony labyrinth surrounds a soft membranous labyrinth

Question 4

The vestibular branch of CnVIII is made up of what 3 nerves?

Answer 4

Utricular nerve
Saccular nerve
Ampullary nerve

Question 5

Translational motion and linear acceleration is detected by what part of the vestibular apparatus?

Answer 5

Utricle and saccule

Question 6

Rotational motion and angular acceleration is detected by what part of the vestible?

Answer 6

Semicircular canals

Question 7

Sensory detectors of the utricle and the saccule

Answer 7

Maculae

Question 8

2 main structurual features of the sensory detection of the utricle and saccule

Answer 8

Matrix of supporting cells surrounding hair cells that are innervated by utricular and sacular sensory nerve fibres
Hair cells possess tufts of cilia that penetrate into gelatinous calcium carbonate cytstals; the otolithic membrane

Question 9

What happens the innervation of the sensory herve if the stereocilia tilts to the left

Answer 9

Depolarization- increased firing of sensory nerve

Question 10

What happens the innervation of the sensory herve if the stereocilia tilts to the right

Answer 10

Hyperpolarization- decreased firing of sensory nerve

Question 11

Describe the composition of hair cells

Answer 11

Made up of many stereocilia, but only one kinocilium