HumanPhysiology.academy

home  

Vestibular (condensed)

 

The vestibular system can be divided into two parts:

a. the parts that detect linear acceleration (utricle and saccule); also called static movements

b. the parts that detect rotational acceleration (the three semi circular canals); also called dynamic movements.

 

A. The Utricle and the Saccule:

 

1. The Utricle and the Saccule:

The utricle and the saccule are fluid-filled spaces. They contain a macula which is oriented in the horizontal direction ( = utricle) or in the vertical direction (= saccule). These two organs therefore detect movements in the horizontal or in the vertical direction.

diagram of the saccule and the utricle

 

2. The Macula:

The macula is the sensor in these two organs. It essentially consists of a row of hair cells. The hairs are connected to a gelatinous mass called the otholithic membrane. The other side of the hair cell is connected to a nerve. This is the beginning of the vestibular nerve.

diagram of the macula

 

one hair cell

transduction in the macula

 

Vestibular condensed 2 >

HumanPhysiology.academy 2014