Anatomy & EmbryologyStudent Presentations’

Program 2011-2012

Parts of the respiratory system Parts of the respiratory system

of the of the elephantelephant

• The respiratory tract of elephants is

comprised of the conducting portion

(external nares, nasal tubes, internal

nares, pharynx, larynx and trachea)

and the respiratory portion (bronchi,

bronchioles, alveolar duct and alveolar

sac in lung). Sound is produced from

larynx. The lungs are attached to the

thoracic walls and diaphragm,

oblitherating the potential pleural

Picture or movie is here if needed

pressure to assist breathing in other mammals. The respiratory system of the elephant is quite exceptional in a

number of ways. The elephant lacks a pleural cavity. This means the lungs are directly attached to the walls of the chest cavity and to the diaphragm. Thus respiratory movements are solely dependent on chest musculature, since there is no mechanism of inflating the lungs by negative pressure in the pleural cavity as is usual in mammals. As a result of this unique physiology, the elephant would find it difficult to breathe if any restraint or pressure is placed on the movement of the chest and diaphragm, essentially over time suffocating from its own tremendous weight.

Air enters the lungs through internal nares which are located high on the forehead. The position of the nares is indicated by the plate-size circle of skin.An elephant can breathe through its mouth as well as through its trunk, so it can retain water or dust in the trunk without having to hold its breathe.

•The trunk

the trunk is a fusion of the nose and upper lip, elongated and

specialized to become the elephant's most important and

versatile appendage. The elephant's trunk is sensitive enough to

pick up a single blade of grass, yet strong enough

………………………………………………………………………………………

•……………………………………………………………………………………………

•……………………………………………………………………………………………

•……………………………………………………………………………………………

•……………………………………………………………………………………………

•……………………………………………………………………………………………

•……………………………………………………………………………………………

to rip off branshes of a tree . It is

composed of muscles, vessels, nerves,

fat and other connective tissues, and

skin. The trunk evolved from fused

muscles of nose, upper lip and cheeks.

It contains no bone or cartilage,

although cartilage is found around the

nostrils and at the base of the trunk.

The muscles are include superficial and

Picture or movie is here if needed

• internal muscles. The total number of a muscles is

approximately 150,000.. Superficial muscles run

longitudinally along the dorsal, ventral and lateral aspects of

the trunk. The internal muscles are deep to the superficial

mucles and include radial muscles and transverse muscles.

The two nostrils are separated by a membranous septum

and are connected to openings in the frontal aspect of the

cranium. The functions of the trunk include feeding,

watering, dusting, smelling, touching, communicating

…………………………………………………………………

• (Touch and sound promoter), defense and others. The trunk

of an adult Asian elephant can hold about 10 liters of water.

Lungs

However, elephants do not have pleural cavity. Rather, their

ample lungs are attached directly to the chest cavity wall

and the diaphragm.

• The lungs are divided into smaller units by a network of

thick, stretchy septa. Each of the septal units measures

approximately 10mm3. They are suspended on the septa in

……………………………………………………………………………………………

• ……………………………………………………………………………………………

• ……………………………………………………………………………………………

• ……………………………………………………………………………………………

• ……………………………………………………………………………………………

• ……………………………………………………………………………………………

• ……………………………………………………………………………………………

• ……………………………………………………………………………………………

• order to prevent the dependent alveoli

from being compressed under the

weight of the body or due to

gravitation. The nature of the septa is

such that they work to keep the intra-

pulmonary system from being crushed

due to gravitation by using tethering

forces.