201 L12

Question 1

What are the purpose of breasts?

Answer 1

Nutrition of young

Spacing of pregnancies

Question 2

What are mammary glands?

Answer 2

Modified sweat glands

Question 3

What tissue are mammary glands derived from?

Answer 3

From tissue that is first identified in the mammary/milk crests and develop between the armpits and the groin.

Question 4

Where is abnormal breast development likely to occur?

Answer 4

Along the lines of the mammary crests.

Question 5

Derivation of the breast;

Breast development begins with the formation of ——— —– at about — weeks

The first development takes place as a ——– growth of the ———- to form the ——— breast bud

Secondary buds develop from the ——— bud.

These secondary buds will become the ———- —–, which convey the —— from the —— producing tissue inside the breast to the ——)

As ———– progresses the buds develop ——— (become canalised)

Canalisation is induced by the ——— steroids ——— and ————-.

Answer 5

Breast development begins with the formation of mammary buds at about 6 weeks

The first development takes place as a downward growth of the epidermis to form the primary breast bud

Secondary buds develop from the primary bud.

These secondary buds will become the lactiferous ducts, which convey the milk from the milk producing tissue inside the breast to the nipple

As gestation progresses the buds develop lumens (become canalised)

Canalisation is induced by the placental steroids estrogen and progesterone.

Question 6

By birth can the breasts potentially make milk?

Answer 6

Yes

Question 7

When are the breast fully developed?

Answer 7

By birth

Question 8

What is required for milk production?

Answer 8

Hormonal stimulus

Question 9

At birth some babies make a colostrum-like secretion called witch’s milk. what causes this?

Answer 9

Because the fetus has been exposed to the placental steroids and maternal hormones they are able to form this secretion.

Question 10

Name the external structure of the breast described below;

Has many different shapes

Answer 10

Body of the breast

Question 11

Name the external structure of the breast described below;

Is usually raised, cylindrical and pigmented

Answer 11

Nipple

Question 12

Name the external structure of the breast described below;

Pigmented circle of tissue that surrounds the nipple.

Answer 12

Areola

Question 13

What internal structure joins the skin at the nipple?

Answer 13

lactiferous ducts

Question 14

What external structure contains sebaceous glands which give a granular texture to the surface?

Answer 14

Areola

Question 15

What is the major component of the breast?

Answer 15

Adipose tissue of the pectoral fat pad.

Question 16

What is the function of the pectoral fat pad?

Answer 16

Give the breast its texture and shape

Question 17

What ligaments are the breasts supported by?

Answer 17

Cooper’s ligaments

Question 18

What factors effect the function of the cooper’s ligaments?

What does this result in?

Answer 18

Age
Hormones

Less support

Question 19

What do the cooper’s ligaments do?

Answer 19

Hold up the breast

Question 20

How many lobes are there in the breast and what are they made up of?

Answer 20

15-20 lobes made up of milk secreting lobules

Question 21

Each of the lobules connects to a single ——— —–.

Answer 21

Lactiferous duct

Question 22

Each of the lobules in the breast connects to a single ——— —–.

Answer 22

Lactiferous duct

Question 23

The ———– ——– runs towards the nipple and expands into a —– ——–.

The ——- —– open onto the nipple to allow ——– of the ——.

Answer 23

The lactiferous duct runs towards the nipple and expands into a lactiferous sinus (the broadening of the lactiferous duct).

Question 24

What is the function of the lactiferous sinus?

Answer 24

Additional storage of milk

Question 25

When do the breast ducts have active alveoli? What triggers their growth?

Answer 25

At puberty Estrogen and progesterone

Question 26

What is the resting, non-pregnant, non-lactating breast tissue dominated by?

Answer 26

The duct system and fat NOT THE MILK PRODUCING ALVEOLI

Question 27

What promotes the growth of alveolar buds during menstruation?

Answer 27

Estrogen and progesterone

Question 28

What effect do successive cycles of menstruation have on breast tissues?

Answer 28

Produce more milk producing tissue within the breast causing increased growth

Question 29

What is noticeable about the before menstruation?

Answer 29

There is increased volume

Question 30

During pregnancy what hormones influence breast tissue growth and what are their functions?

Answer 30

Estrogen -Breast growth Progesterone - induces side branching of ducts Prolactin - alveolar development, stimulate casein and alpha lactalbumin mRNAs Insulin and Cortisol - stimulate alveolar epithelial cell division (cells that are going to produce the milk)

Question 31

In the ------- --------- gland the alveolar structures are relatively insignificant compared to the ducts.

Answer 31

Resting mammary

Question 32

When does the breast weigh the most?

Answer 32

When it is lactating

Question 33

In theory ------- should promote milk production but --------- does not occur until after birth. This is because the steroids, particularly ---------- seem to prevent major milk production. ---------- is also a smooth muscle relaxant and prevents milk ---------.

Answer 33

In theory prolactin should promote milk production but lactation does not occur until after birth. This is because the steroids, particularly progesterone seem to prevent major milk production. Progesterone is also a smooth muscle relaxant and prevents milk ejection

Question 34

What hormone is produced in large amount in pregnancy, but falls at birth?

Answer 34

Prolactin

Question 35

Where is prolactin secreted from?

Answer 35

The anterior pituitary if the hypothalamus

Question 36

What stimulates the prolactin release from the pituitary? How do we know this?

Answer 36

Neuroendocrine reflex We know it's a neuroendocrine reflex because cutting the nerves to the nipple prevents this reflex

Question 37

What does prolactin induce?

Answer 37

The production of milk proteins.

Question 38

-------- of the infant on the nipple induces secretion of --------- by the ----- -----. The ------- and ------- of the -------- determines --------- secretion. The level of --------- determines the level of ----- produced. This means the baby is able to ------- the amount of ------- it gets.

Answer 38

Suckling of the infant on the nipple induces secretion of prolactin by the anterior pituitary. The duration and extent of the suckling determines prolactin secretion. The level of prolactin determines the level of milk produced. This means the baby is able to regulate the amount of food it gets.

Question 39

Milk ejection response (MER) ------ stimulates the synthesis and secretion of ------- by the ------ ------. ---------- induces the contraction of the ------- cells of the -------- causing ejection of the ------ into the -----. This is called the ------ ----- response.

Answer 39

Suckling stimulates the synthesis and secretion of oxytocin by the posterior pituitary. Oxytocin induces the contraction of the myoepithelial cells of the alveoli causing ejection of the milk into the ducts. This is called the let down response.

Question 40

What other stimuli can induce the release of oxytocin?

Answer 40

Stimulation of the female reproductive tract.

Question 41

Why might a lactating women have a milk let down during sex?

Answer 41

This is because the stimulation of the cervix causes the release of oxytocin, which is important in causing uterine contractions to help sperm transport. But the same hormone causes the let down response

Question 42

What are the stimuli that can induce the milk ejection response?

Answer 42

Suckling Smell of the baby crying baby

Question 43

How does lactation affect fertility?

Answer 43

Prolactin can suppress secretion of the gonadotropins, FSH and LH, particularly LH (stimulates ovulation). Therefore, lactating women often have no or irregular menstrual cycles. So lactation has a contraceptive effect - spacing out the birth of babies Not a very reliable contraceptive

Question 44

What benifits does breastfeeding have on the mother?

Answer 44

Contraceptive effect - spacing out the birth of babies There is a decreased relative risk of developing breast cancer and ovarian cancer

Question 45

What benifits does breastfeeding have on the infant?

Answer 45

Babies are protected from getting GI tract infections, asthma, childhood obesity, type 1 and 2 diabetes and sudden infant death syndrome

Question 46

If there is additional breast tissue where it is usually found?

Answer 46

Along the line of the embryonic milk ridge

Question 47

Can lactiferous ducts exit the breast at sites outside the nipple?

Answer 47

Yes