1 / 63

The Mammary Gland

The Mammary Gland. The milk secreting organ Modified sweat gland Exocrine gland. MAMMARY GLANDS. thoracic. inguinal. abdominal. MAMMARY GLANDS. 4 abdominal; 15 openings / teat. MAMMARY GLANDS. 2 thoracic, 6 abdominal, ; 3-7 openings / teat. MAMMARY GLANDS.

lapis
Download Presentation

The Mammary Gland

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. The Mammary Gland • The milk secreting organ • Modified sweat gland • Exocrine gland

  2. MAMMARY GLANDS thoracic inguinal abdominal

  3. MAMMARY GLANDS • 4 abdominal; 15 openings / teat

  4. MAMMARY GLANDS • 2 thoracic, 6 abdominal, ; 3-7 openings / teat

  5. MAMMARY GLANDS • 2 thor., 6 abdom. 2 ing., ; 8-10 openings/ teat

  6. MAMMARY GLANDS • 4 thor., 2 abdom. 4 ing., ; 1 opening/ teat

  7. MAMMARY GLANDS • 2 inguinal ; 1 opening/ teat

  8. MAMMARY GLANDS • 2 inguinal ; 2 openings/ teat

  9. MAMMARY GLANDS • 4 thor., 6 abdom. 2 ing., ; 2 openings/ teat

  10. MAMMARY GLANDS • 4 inguinal ; 1 opening/ teat

  11. Anatomy of the Mammary Gland • Mammary gland - milk secreting structure including teats, duct system, lobes, lobules, and secretory tissue • Modified sweat gland • Exocrine gland • Cow • Large & in inguinal region • 4 teats/quarters = 4 separate glands • No mixing of ducts across quarters

  12. Anatomy of the Mammary Gland • Rear quartes produce approx. 60% of the milk and the fore quarters produce the remaining 40% • The size and shape of udders vary with the 1) producing ability, 2) age, and 3) genetic of the cow

  13. Anatomy of the Mammary Gland • Cow • Front & rear quarters separated by fine membrane • Left and right separated by median suspensory ligament • Supernumerary teats (some with duct and secretory system)

  14. How much support is enough? • High producing Holstein cow • Empty Udder = 25 kg. • Milk = 30 kg • 25 + 30 = 55 kg !!!

  15. Udder Support in Cow • Skin • Fine connective tissue below skin • Connective tissue attaches front quarters to abdominal wall • Lateral suspensory ligaments (LSL) • Median suspensory ligament (MSL) • The subpelvic tendon

  16. Udder Support in Cow • LSL • Sling around udder • 2 layers • Inelastic, more fibrous than MSL

  17. Lateral Suspensory Ligaments • Like a “hammock” around the udder • From the pelvis to the median suspensory ligament • Mostly fibrous tissue • Collagen • Attaches to the alveolar tissue • Provides internal framework

  18. Udder Support in Cow • MSL • Primary support • Relatively elastic • 2 layers • Broken MSL – pendulous udder

  19. Median Suspensory Ligament • Primary support of the udder • Two adjacent heavy sheets of tissue • Mostly elastic, some fibrous tissue • Attaches to the abdominal wall • Divides the udder into halves • Glands on each half are divided by sheetsof tissue © Biology of Lactation, Schmidt

  20. Udder Support in Cow • Lamella septa • Connective tissue • Runs between LSL & MSL • Divides parenchyma into lobes and lobules

  21. Duct System • Teat meatus, the small canal located in the end of each teat is .5 to 1 cm long and is the only sphincter in each gland • Seven or eight loose folds of membrane known as furstenburg rosette are located above the teat meatus • The teat cistern, the cavity within the teat hold 30 to 90 ml of milk.

  22. The Secretory Tissue • A Lobe: group of lobules • A Lobule: group of alveoli • Alveoli: cluster of alveolus • Alveolus: a single layer of epithelial cells surrounding a central lumen

  23. Blood Supply to Mammary Gland • 400 kg blood to produce 1 kg of milk • 2 major arteries • Front ½ of udder • Rear ½ of udder • 4 major veins • 2 follow same path as arteries • 2 mammary veins

  24. Nervous System • Sensory (afferent) nerves in skin and teats • Positive stimulation of teats and surrounding area initiates milk let-down reflex via oxytocin © Biology of Lactation, Schmidt

  25. Nervous System • Sympathetic (efferent) (involuntary) nerves associated with arteries in the gland • Control blood flow to the gland • Innervation of sphincters muscles in teats • Stress causes vasoconstriction decreasing milk secretion and let-down • No parasympathetic innervation • No nerves to myoepithelial cells or alveolar cells

  26. Lymph System of Mammary Gland • What is lymph & what does it do? • Supramammary lymph nodes • Lymph vessels • Factors that influence edema • Age • Diet (especially NaCl) • Exercise • Genetics

  27. Mammary Gland Development • Five phases of mammary development • Prenatal (teats & cisterns dev.) • Prepubertal (limited growth) • Postpubertal • Pregnancy (most growth) • Early lactation

  28. Mammary Gland Development • Major development occurs at puberty and during gestation • Hormones • Estrogen (growth of duct system) • Progesterone (development of alveolar tissue in combination with other hormones) • GH (growth of duct system) • Prolactin (initiation and continuity of lactation)

  29. Mammary Gland Development

More Related