Did you know about Acousticolateralis system in vertebrates ?

Receptors are similar to receptors of inner ear the lateral line system and inner ear are collectively called acousticolateral system.

Lateral line organ (proprioceptors) stretch receptors:

Special mechanoreceptors in skin of fishes and aquatic amphibians .

Function

They receives deep vibrations in water and information about water current also sense thermal and chemical nature of water.

Neuromast

Each lateral line organs of these proprioreceptors are called neuromast

Location

They are located on surface of skin or grooves and canals sunk below skin.

Cells of neuromast

There are two types of cells of neuromast

1. Hair cells or receptor cells
2. Supporting cells

1. hair cells or receptors cells.

They end at sensory nerve fibers. Each hair cell bears a short stereocillia and one long kinetocillium. The cillia projects into a gelatinous Cupule that projects in fluid.

changes in fluid — — stimulation of cupule & cilia — — stimulate sensory nerve fibers

2.supporting cells:

Supporting cells surround hair cells and support them ,this system is controlled by 7,9,10 cranial nerves.

LATERAL LINE SYSTEM

Lateral line canal proper

In this system neuromast are arranged in rows or line

cyclostomes fishes, aquatic or larval amphibia — — located on skin surface in form of oral groove.

Sharks and other fishes — neuromast located on skin surface in form of open groove.

Holocephali — — groove remains open .this tube opens on surface by minute pores.

Pits organs

Present only in fishes. Individual neuromasts lying in small pits on skin. They open on surface by minute pores. pits organs don't have any special arrangement.

ELECTRORECEPTORS (AMPULLAE OF LORENZINI)

Ampullae of lorenzini

They lie deeply in skin of head ,it is found in elasmobranches, some bony fishes and amphibians .

Structure

It consists long tube which end in an ampulary sac.

Centrum

Each sac consists of 8–9 radically expanded chambers with sensory cells arranged around a central core called centrum. From each sac arises nerve fibers. Tube opens into minute pore .Ampulae was considered thermoreceptor formerly they are related to pressure changes and same function as electric receptors.

Vesicles of sari:

Present on ventral surface of body found only in electric ray (Torpedo).They are in form of close sac

Function

They function as mechanical receptors.