The mammary gland (Duct and secretory system)

Question 1

Duct and secretory system

Answer 1

Teat :
- Streak canal
- Sphinctormuscle
- Teat cistern

Gland cistern

Duct system

Question 2

Streak canal (teat canal) positron

Answer 2

at base of teat which milk comes from

Question 3

Streak canal (teat canal) length

Answer 3

5 - 13 mm

Question 4

Streak canal (teat canal) diameter

Answer 4

0.4 - 1.6 mm diameter

Question 5

Streak canal lined by ……..

Answer 5

Cells form folds to close the canal bet. Milkings

Question 6

Streak canal Produce …

Answer 6

Lipid like sub. Is bacteriostatic so prevent bacterial penetration and mastitis

Question 7

The canal is kept closed by …

Answer 7

an involuntary circular sphincter muscle found in distal part of the canal

Question 8

Diameter of streak canal increase by …

Answer 8

aging

Question 9

….. canals less resistant to mastitis

Answer 9

Wide

Question 10

Teat sphinctor muscle

Answer 10

At the distal part of the streak canal ( last 2 mm) Involuntary circular muscle

Question 11

acts as a barrier (physical to the entry of bacteria

Answer 11

Teat sphinctor muscle

Question 12

Tightness of sphincter muscle is …. trait depend on …

Answer 12

inherited

sire selection

Question 13

Slow milkers has …. muscles , so …

Answer 13

Strong muscle so less milk and less susceptible to mastitis

Question 14

Fast milkers has …. muscles , so …

Answer 14

Weak or patent or poor muscle easy milked and give more milk but susceptible to mastitis and leakage

Question 15

Teat sphinctor muscle function

Answer 15

Constrict the opening (teat orifice) so keep the milk in the udder between milking

Question 16

Frustenburgs Rosette …… mucosal folds

Answer 16

6-10

Question 17

Frustenburgs Rosette Located in

Answer 17

internal part of streak canal , proximal part

Question 18

Frustenburgs Rosette radiate in … directions

Answer 18

All directions to teat cistern

Question 19

Frustenburgs Rosette Function

Answer 19

1. Barrier against pathogens
2. Major point for entry of leukocytes into gland
3. Contain bacteriocidal protein

Question 20

Teat cistern located ….

Answer 20

just above the streak canal

Question 21

The cavity of teat

Answer 21

Teat cistern

Question 22

Teat cistern hold …… of milk

Answer 22

10 - 50 ml

Question 23

Into which milk drains from the gland, and from which milk is removed during the milking process

Answer 23

Teat cistern

Question 24

Teat cistern contain in upper part …..

Answer 24

Accessory mammary tissue irritation overmilking of (AMT) cause infection to spread to all udder so rapid removal of teat cups

Question 25

Teat cistern wall

Answer 25

Rich in blood vessels so when using MM the high vacuum blood congestion irritation of the lining so pulsation cycle is required

Question 26

Cricoid ring

Answer 26

Annular folds Bet gland and cistern Marks the boundary bet gland and teat cistern

Question 27

Gland cistern Located ...

Answer 27

Just above the teat cistern and partially separated from it by a circular fold

Question 28

A cavity act as a reservoir of milk

Answer 28

Gland cistern

Question 29

Gland cistern hold

Answer 29

400 - 500 ml milk

Question 30

A number of large ducts branch off from the gland cistern

Answer 30

Duct system

Question 31

Function of duct system

Answer 31

1. To collect the milk from the secretory tissue 2. Store part of the milk between milkings 3. Transport it to the gland cistern

Question 32

Duct system branch and re branch into smaller and smaller ducts and finally into the ....

Answer 32

Terminal ductules that drain each alveolus

Question 33

Milk route

Answer 33

Gland cistern → 12 - 50 large collecting duct → commom duct → terminal ductule → lobule

Question 34

Alveoli

Answer 34

Microscopic structure lined with a single layer of epithelial cells Single layer of epiyhelial cell + blood capillary (network) + mypepithelial cell + fibroblast

Question 35

Alveoli function

Answer 35

Take nutrients from blood to the alveolar lumen.

Question 36

Functional unit of milk production

Answer 36

Alveoli

Question 37

Drain into terminal ductules

Answer 37

Alveoli

Question 38

Alveoli capacity

Answer 38

1 mm3

Question 39

Lobule

Answer 39

10 - 250 Alveoli

Question 40

Lobe

Answer 40

group of lobules

Question 41

Milk letdown

Answer 41

Stimuli → Afferent sensory nerve → CNS → Oxytocin → myoepithelial cell contract → lumen of alveoli → terminal ductule → common duct → large collecting duct gland cistern → teat cistern → streak canal