Changes

[[Image:DogThorax.jpg|right|thumb|350px|''Dog Thorax, contents of Thoracic Cavity removed. ©Nottingham 2008'']]

[[Image:DogThorax.jpg|right|thumb|250px|''Dog Thorax, contents of Thoracic Cavity removed. ©Nottingham 2008'']]

==Introduction==

==Introduction==

The Diaphragm is a dome-shaped musculotendinous sheet separating the thoracic and abdominal cavities. It is convex on it's cranial surface.

The Diaphragm is a dome-shaped musculotendinous sheet separating the thoracic and abdominal cavities. It is convex on it's cranial surface. In the neutral position between full [[Anatomy and Physiology#Inspiration|inspiration]] and full [[Anatomy and Physiology#Expiration|expiration]], the most cranial part of the Diaphragm is in line with the 6th Rib.

 

In the neutral position between full [[Anatomy and Physiology#Inspiration|inspiration]] and full [[Anatomy and Physiology#Expiration|expiration]], the most cranial part of the Diaphragm is in line with the 6th Rib.

==Structure==

==Structure==

*The Muscular part of the diaphragm is peripheral, surrounding the central Tendinous area.

The Muscular part of the diaphragm is peripheral, surrounding the central Tendinous area. The muscular part has sections which arise from the xiphoid Process of the [[Ribs and Sternum - Anatomy & Physiology|Sternum]], [[Spinal Column - Anatomy & Physiology|vertebral Column]] and caudal [[Ribs and Sternum - Anatomy & Physiology|ribs]].

*The muscular part has sections which arise from the  

**Xiphoid Process of the [[Ribs and Sternum - Anatomy & Physiology|Sternum]]

**[[Spinal Column - Anatomy & Physiology|Vertebral Column]]  

**Caudal [[Ribs and Sternum - Anatomy & Physiology|Ribs]].

==Openings within the Diaphragm==

==Openings within the Diaphragm==

*The Diaphragm has three openings:

The Diaphragm has three openings: '''Aortic Hiatus''' - the most Dorsal opening, contains the Aorta, Azygous Vein and Thoracic Duct; '''Oesophageal Hiatus''' - contains the oesophagus, dorsal and ventral Vagal trunks and '''Caval Foramen''' - lies within the central tendoninous region of the diaphragm, and contains the Caudal Vena Cava. This opening does not allow movement;the diaphragm is fused with the vessel wall.

**'''Aortic Hiatus''' - the most Dorsal opening, contains the Aorta, Azygous Vein and Thoracic Duct.

**'''Oesophageal Hiatus''' - contains the oesophagus, dorsal and ventral Vagal trunks.

**'''Caval Foramen''' - lies within the central tendoninous region of the diaphragm, and contains the Caudal Vena Cava. This opening does not allow movement;the diaphragm is fused with the vessel wall.

==Function==

==Function==

During [[Anatomy and Physiology#Inspiration|Inspiration]], the diaphragm contracts to increase the volume of the thoracic cavity, decreasing it's pressure, thus drawing air in.

During [[Anatomy and Physiology#Inspiration|Inspiration]], the diaphragm contracts to increase the volume of the thoracic cavity, decreasing it's pressure, thus drawing air in. The Diaphragm relaxes for [[Anatomy and Physiology#Expiration|Expiration]].

The Diaphragm relaxes for [[Anatomy and Physiology#Expiration|Expiration]].

==Vasculature==

==Innervation==

 

The Diaphragm is supplied by the '''phrenic nerve'''.

* The Diaphragm is supplied by the Phrenic Nerve.

==Species Differences==

==Species Differences==

*Because of the shorter thorax, the diaphragm is steeper in the '''ruminant''' compared to the '''horse'''.

Because of the shorter thorax, the diaphragm is steeper in the '''ruminant''' compared to the '''horse'''. '''Avian''' species do not possess a diaphragm. Air moves in and out of their lungs via [[Avian Respiration - Anatomy & Physiology#Air Sacs|Air Sacs]].

*'''Avian''' species do not possess a diaphragm. Air moves in and out of their lungs via [[Avian Respiration - Anatomy & Physiology#Air Sacs|Air Sacs]].

==References==

==References==

*{{citation|initiallast = Dyce|initialfirst = K.M|2last = Sack|2first = W.O|finallast = Wensing|finalfirst = C.J.G|year = 2002|title = Textbook of Veterinary Anatomy|ed =3rd|city = Philadelphia|pub = Saunders}}

{{citation|initiallast = Dyce|initialfirst = K.M|2last = Sack|2first = W.O|finallast = Wensing|finalfirst = C.J.G|year = 2002|title = Textbook of Veterinary Anatomy|ed =3rd|city = Philadelphia|pub = Saunders}}

[[Category:Musculoskeletal System]][[Category:Respiratory System - Anatomy & Physiology]]

[[Category:Musculoskeletal System]][[Category:Respiratory System - Anatomy & Physiology]]

[[Category:To Do - A&P]]

[[Category:To Do - AimeeHicks]]