Changes

==Introduction==

==Introduction==

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.

The Diaphragm is a dome-shaped musculotendinous sheet separating the thoracic and abdominal cavities. It is convex on its 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.

==Structure==

==Structure==

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 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]].

==Openings within the diaphragm==

==Openings within the diaphragm==

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.

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  

:'''Caval Foramen''' - lies within the central tendinous 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. The Diaphragm relaxes for [[Anatomy and Physiology#Expiration|Expiration]].

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

==Innervation==

==Innervation==

[[Image:PhrenicNerveDog.jpg|right|thumb|250px|©RVC 2008]]

[[Image:PhrenicNerveDog.jpg|right|thumb|250px|©RVC 2008]]

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

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]].

==References==

==References==

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

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

[[Category:To Do - AP Review]]

[[Category:A&P Done]]