58. Anatomy of the udder and clinical consequences. Defence mechanisms of the udder in cattle. Flashcards
Anatomical Composition of the mammary gland?
Anatomical composition of the mammary gland
- Non common canal of the quarters
- No common blood supply
- 400L blood = 1 L milk
- Weight: 50-75kg
Structure of the teat?
Structure of the teat
- Epidermis
- Dermis
- Muscles
- Endothel
- Length – decreasing in size in lactations 1-3, then stable
- Diameter – 2-4cm
- Shape – cone or cylinder shape
Epidermis?
Epidermis
- Keratinized cells
- 4-5 times thicker than skin
- Strongly attached to dermis
- No hair follicles, sweat glands, sebaceous glands
Dermis?
Dermis
- Blood vessels and nerves
- Nerve endings in the epidermis
o Venous plexus at the base of the teat: importance in milking and suckling
Muscle layer?
Muscle layer
- Circular and longitudinal and oblique layers
- Sphincter muscle around the teat canal
o At milking the teat becomes longer (30-40%), teat canal opens and becomes shorter
o Post milking dipping importance
Endothel?
Endothel
• Strongly attaching cubic epithelial cells
o Bacterium invasion: to help WBC entrance keeping distance for them
Mammary gland defence mechanism?
Mammary gland defence mechanism
• Anatomical barriers – 1st line of defence
o Teat sphincter muscle
§ Closes 2 hours after milking
o Teat canal
o During drying off stratified epithelial cells derive a keratin plug
o Keratinized epithel of the teat cistern
- Innate immune response
- Alveolar macrophages (TNF-a, IL-1B
- Neutrophil recruitment from the bloodstream
Suspension of the mammary gland?
