Sense of equilibrium

1. Sense of Equilibrium (pg 8)

2. Sense of Equilibrium (pg 8) Allows you to balance

3. Sense of Equilibrium (pg 8) Allows you to balance Structures involved in equilibrium are located in the inner ear

4. Sense of Equilibrium (pg 8) Allows you to balance Structures involved in equilibrium are located in the inner ear 2 types: Dynamic and static

5. Static equilibrium Occurs when body is motionless or moving in a straight line

6. Static equilibrium Occurs when body is motionless or moving in a straight line The vestibule contains two saclike structures, the utricle and the saccule . Each contains a small structure called a macula

7. Static equilibrium Occurs when body is motionless or moving in a straight line The vestibule contains two saclike structures, the utricle and the saccule . Each contains a small structure called a macula The macula contains hair cells that protrude into the jelly-like otolithic membrane. A dense layer of calcium carbonite crystals, called otoliths , cover the surface of the membrane

8. Static equilibrium Occurs when body is motionless or moving in a straight line The vestibule contains two saclike structures, the utricle and the saccule . Each contains a small structure called a macula The macula contains hair cells that protrude into the jelly-like otolithic membrane. A dense layer of calcium carbonite crystals, called otoliths , cover the surface of the membrane When you tilt your head forward, gravity pulls the otoliths and membrane down, which bend the hair cells and stimulates nerve impulses

9. Dynamic equilibrium Occurs when the body is moving in a rotational or angular direction

10. Dynamic equilibrium Occurs when the body is moving in a rotational or angular direction 3 Semicircular canals, each at right angles to each other. Contain fluid called endolymph

11. Dynamic equilibrium Occurs when the body is moving in a rotational or angular direction 3 Semicircular canals, each at right angles to each other. Contain fluid called endolymph At the base of each canal is swelling called an ampulla

12. Dynamic equilibrium Occurs when the body is moving in a rotational or angular direction 3 Semicircular canals, each at right angles to each other. Contain fluid called endolymph At the base of each canal is swelling called an ampulla Ampulla contains the crista ampullaris , which consists of hair cells covered by a dome-shaped gelatinous mass called the cupula

13. Dynamic equilibrium Occurs when the body is moving in a rotational or angular direction 3 Semicircular canals, each at right angles to each other. Contain fluid called endolymph At the base of each canal is swelling called an ampulla Ampulla contains the crista ampullaris , which consists of hair cells covered by a dome-shaped gelatinous mass called the cupula When the head turns, the semicircular canals move with it, but the endolymph lags behind due to inertia. The fluid pushes against the cupula and tilts it to one side. This causes the hairs to bend, sending nerve impulses