Changes

=== Suspensory Apparatus  ===

=== Suspensory Apparatus  ===

In species with large udders, especially in dairy cattle there is a  suspensory apparatus, which is organised into the lateral and medial laminae, which suspend the mammary gland from the ventral aspect of the trunk by their attachment to the pubic symphysis. The '''lateral lamina''' consists of collagen fibres from the fascia of the pubic symphysis and the edge of the superficial inguinal ring. The '''medial lamina''' consists of elastic fibres from the tunica flava ventral to the pubic symphysis The '''intermammary groove''' divides the left and right rows of mammae.  

In species with large udders, especially in dairy cattle, there is a  suspensory apparatus, which is organised into the lateral and medial laminae suspending the mammary gland from the ventral aspect of the trunk by their attachment to the pubic symphysis. The '''lateral lamina''' consists of collagen fibres from the fascia of the pubic symphysis and the edge of the superficial inguinal ring. The '''medial lamina''' consists of elastic fibres from the tunica flava ventral to the pubic symphysis The '''intermammary groove''' divides the left and right rows of mammae.  

== Blood Supply  ==

== Blood Supply  ==

=== Arteries  ===

=== Arteries  ===

In species with '''inguinal mammary glands''' (cow, ewe, goat, mare), the main blood supply is from the '''external pudendal artery'''. This arises indirectly from the external iliac artery via the femoral artery. The external pudendal artery passes through the inguinal canal. In species which also have '''thoracic and abdominal mammary glands''' (bitch, queen, sow) additional blood supply is derived from the '''internal thoracic artery''' and its branches -  cranial superficial epigastric arteries.  

The main blood supply to the inguinal mammary glands is from the '''external pudendal artery'''. This arises indirectly from the external iliac artery via the deep femoral artery. The external pudendal artery passes through the inguinal canal. In species which also have '''thoracic and abdominal mammary glands''' (bitch, queen, sow) additional blood supply is derived from the '''internal thoracic artery''' and its branches - cranial superficial epigastric arteries as well as from '''lateral thoracic''' and '''intercostal arteries'''.  

=== Veins  ===

=== Veins  ===

In most species'''thoracic and cranial abdominal mammary glands '''drain via '''cranial superficial epigastric veins''' into the '''internal thoracic vein'''. '''Caudal abdominal and inguinal mammary glands '''drain via '''caudal superficial epigastric veins''' into the '''external pudendal vein'''.I

In most species'''thoracic and cranial abdominal mammary glands '''drain via '''cranial superficial epigastric veins''' into the '''internal thoracic vein'''. '''Caudal abdominal and inguinal mammary glands '''drain via '''caudal superficial epigastric veins''' into the '''external pudendal vein'''.  

Additionally in cattle during the first pregnancy an anastamosis develops between cranial and caudal superficial epigastric veins forming the '''subcutaneous abdominal vein''' (milk vein). As a result some venous drainage from the bovine udder passes in a cranial direction via this vessel, which then drains deeply through the abdominal wall (milk well) into the internal thoracic vein<br>  

In cattle a venous ring is formed between the base of the udder and the abdominal wall. During the first pregnancy, an anastamosis develops between cranial and caudal superficial epigastric veins forming the '''subcutaneous abdominal vein''' (milk vein). As a result some drainage from venous ring passes in a cranial direction via this vessel, which then drains deeply through the abdominal wall (milk well) into the internal thoracic vein. Other drainage passes to the external pudendal veins or to perineal veins.<br>  

== Innervation  ==

== Innervation  ==

== Lymphatics  ==

== Lymphatics  ==

The more caudal mammary glands drain to the&nbsp; '''superficial inguinal lymph node''' and the more cranial mammary glands to the axillary lymph nodes.  

The more caudal mammary glands drain to the&nbsp; '''superficial inguinal lymph node''' and the more cranial mammary glands to the axillary or sternal lymph nodes.  

=== Lymphatic drainage in the cow  ===

=== Lymphatic drainage in the cow  ===