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ANSC exam 3 (last part before final) > Lactation > Flashcards

Flashcards in Lactation Deck (41):
1

what is the mammary gland

milk secreting structure
1. teat
2. duct system
3. lobes

2

what is the udder

complex organ made up of a series of systems

3

what are the different systems in the udder

supportive system
secretory system
duct system
blood, lymph and nerve systems

4

describe the udder of a cow

1. two separate halves
2. 4 separate mammary glands
3. it is an exocrine gland

5

When is the greatest growth of the udder and when does the growing stop

1. greatest growth between 1st and 2nd lactation
2. stops growing after 5 years of age

6

describe 4 things about the mammary gland

1. specialized skin glands
2. produce colostrum
3. present in males and females
4. number and appearance differs among species

7

what are the 2 parts of the mammary gland support system and describe them

1. Lateral Suspensory Ligament (LSL)
-extends along both sides of udder to midline
-connects to MSL
2. Medial Suspensory Ligament ( MSL)
-provides most support and elasticity
-creates 2 distinct halves between left and right

8

in what species do two glands drain to 1 teat

sows (10-14 teats)
mares (2 teats)
queens (10 teats)
bitches (8-12 teats)

9

what is a function of a teat besides excretion of milk

main barrier against infection

10

how many glands per teat in cows and ewes

1 gland per teat

11

what are the 6 parts of a mammary gland

1. streak canal
2. teat cistern
3. gland cistern
4. duct system
5. lobule
6. alveoli

12

what is the streak canal

first part of the teat
1. milk passes before expulsion
2. keratin plug will form to prevent entrance of bacteria
3. surrounded by teat sphincter muscle to prevent leaking

13

what is the teat cistern

1.storage of milk prior to suckling or milking
2. holds 100-400 mL of milk

14

what is the gland cistern

common pooling area for milk from duct system

15

what is the duct system

1. TRANSPORTS milk from lobule to gland cistern
2. consists of 1st and 2nd degree ducts
3. non secretory

16

what is the lobule

each lobule contains 150 to 220 alveoli
This is the place where milk is actually produces

17

what are alveoli and what are their 3 functions

they are the producers of milk

functions
1. remove nutrients
2. transform into milk
3. discharges into duct system

18

What makes up the alveolus

1. lumen: opening of alveolus that collects milk
2. epithelial cells: secreting cells of alveolus
3. duct: transports milk from the alveolus to the gland cistern
4. myoepithelium: muscle cells that contract in response to oxytocin
5. arterioles and venuoles: provide blood flow
-brings substrates for milk production

19

how many liters of blood must flow to the udder to make 1 liter of milk

500L

20

describe mammary gland before birth

very immature gland
duct system is initiated
non functional teats present

21

describe mammary gland at birth

glands and teats are present
streak canal
teat and gland cistern
rudimentary collecting ducts

22

describe mammary gland from birth to puberty

1.immature gland grows in size and function
2. grow at similar rate to rest of body
3. growth initiated by growth hormones release from pituitary gland

23

describe mammary gland from puberty to pregnancy

1. glands grow with each additional estrous cycle
2. sex hormones (progesterone and estrogen) produces by ovary simulate growth
3. growth is more rapid than the rest of the body

24

mammary gland during pregnacy

1. progesterone produced by placenta stimulates lobular development
2. preparation for nursing by young

25

mammary gland during lactation

1. high levels of prolactin secreted by pituitary gland time of birth
2. lobules grow substantially
3. prolactin initiates and maintains milk secretion by mammary gland

26

mammary gland during involution

1. at end of lactation or weaning the gland returns to normal state and size

27

what is colostrum

1. first milk produced
2. provide extra nutrients and immune fuction
-fat
-proteins
-nonfat solids
- immunoglobins

28

what is passive immune transfer with relation to colostrum

1. immune system develops after birth
2. contains immunoglobins or other antibodies
3. inadequate intake increases sickness and death

29

absorption of colostrum

1. only 24 hours after birth
2. gut starts to close not allowing proteins to be absorbed
*requires about 5% of body weight in colostrum

30

in the production of milk, what are the screening components of blood and what is synthesized in cellular metabolism

1. screen components
-water
-vitamins
-minerals
2. synthesis of cellular metabolism
-lactose
-proteins
-fat

31

what hormone is released for milk let down

oxytocin (stimulates myoepithelial cells of alveolus

32

how long does it take for the gland to be refilled with milk

6 hours

33

what are the main components of milk

carbs
proteins
lipids
calcium

34

describe Milk Carbs

1. lactose primary sugar
2. synthesized by epithelial cells of alveoli
3. glucose and galactose (disaccharide)
4. broken down in small intestine by enzyme lactase

35

describe milk proteins

1. casein primary protein
-80% of milk protein
2. milk serum proteins (larger than casein)
-18% proteins-whey
3. provide high levels of amino acids to consumers

36

describe casein

1. primary milk protein
2. synthesized by epithelial cells of alveoli
3. found in the form of casein micelles
4. negatively charged
5. pulls calcium of of the blood
6. essential for cheese making process

37

describe milk lipids

1. % varies by species
2. triglycerides make up more than 90% of solids
-source of fatty acids

38

what percent of milk lipids do dairy cows and seals have

1. cows milk consists of 3.5%
2. seals 50%

39

describe milk fat

1. fat content of milk influenced by diet
2. high fiber diets-more acetate- increase milk fat %
3. milk fat % receives lower emphasis than milk production
4. cows are fed to maintain adequate milk fat (3.5%)

40

minerals in milk

excellent source of calcium
estrogen important for protecting bone matrix

41

one problem with high producing cows

more calcium pulled from blood can mean milk fever