Mod 5 Gonads and other organs

Question 1

What are gonads?

Answer 1

• testes in males
• ovaries in females
• produce steroid hormone and gametes (sperm and egg)

Question 2

Order?

Answer 2

Hypothalamus –> GnRH (via Blood) –> Ant. pit (LH and FSH) –> gonads (sex hormone) –> target cells

Question 3

What is testosterone?

Answer 3

Testosterone is a male reproductive anabolic steroid.
Testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as secondary sexual characteristics such as increased muscle and bone mass, and the growth of body hair.

Question 4

What is testosterone produced by?

Answer 4

Testosterone is produced by Leydig cells in testes, located in the scrotum outside male pelvic cavity

Question 5

What is a steroid hormone?

Answer 5

A steroid hormone is a lipid-soluble hormone, which modifies gene activity

Question 6

What does testosterone target and action?

Answer 6

Testosterone is involved in spermatogenesis and descent of testes. Also, involved in growth and maturation of reproductive organs.
Targets: libido, anabolic effects (bone, Sk.M), and sebum and hair growth
Action:
Hematopoiesis: production of blood cellular components, enhances basal M.R and aggressiveness

Question 7

Testosterone note

Answer 7

testosterone is converted to another steroid to some target organs. (prostat, brain bone)

Question 8

What is the hypothalamic-pituitary-gonadal axis process in males?

Answer 8

1) Hypothalamus releases GnRH
2) The anterior pituitary secretes FSH and LH
3) FSH indirectly stimulates spermatogenesis
4) LH stimulates Leydig cells to secrete testosterone
5) testosterone acts at other sites (maturation of sex hormones, 2ndary sex characteristics, libido)
6) testosterone inhibits the release of FSH< LH and GnRH
7) inhibit released by Sertoli cell inhibits the release

Question 9

What are gonads (ovaries)

Answer 9

• located in the female pelvic cavity
• each ovary contains many ovarian follicles, each follicle consists of an egg (oocyte) surrounded by layer of cells
• follicles vary is size and development exists at any time
• 1 dominant follicle releases an oocyte from ovary
  (older) - scarred and pitted surface of ovary

Question 10

what are the hormones that the ovaries produce?

Answer 10

The ovaries produce estrogen and progesterone for female reproduction development and 2ndary sex characteristics

Question 11

Where are these females hormones produced?

Answer 11

produced by developing follicle (estrogens) and corpus luteum (estrogen and progesterone) in ovaries

Question 12

What are estrogen and progesterone?

Answer 12

estrogen and progesterone are steroid hormones, they are lipid-soluble and they modify gene activity

Question 13

What do estrogen and progesterone target?

Answer 13

• oogenesis and ovulation (estrogen)
• growth and maturation of the reproductive hormones and breasts
• established and regulate ovarian and menstrual/uterine cycles

Question 14

What are estrogen and progesterone actions?

Answer 14

estrogen and progesterone actions consist: of the production of cervical mucus, libido (estrogen), anabolic effects including bone growth, fat deposition and feminization of the pelvis
- cardioprotective (estrogen), elevates body temp. in pregnancy, it prepares the uterus and glands

Question 15

What are the steps of the establishment of the ovarian cycle?

Answer 15

• before puberty, ovaries secrete some estrogens which inhibit GnRH, after puberty the hypothalamus is less sensitive to estrogens so gonadotropin (FSH and LH) increase which promotes oogenesis

Question 16

The regulation of the ovarian cycle

Answer 16

Follicular: (d1-14): FSH and LH promote survival and growth of follicles ( to make estrogen)
Ovulation: LH surge triggers rupture of dominant follicle and oocyte release
Luteal (d14-28): ruptured follicle forms corpus luteum, making progesterone and estrogen

Question 17

What happens if there is no pregnancy?

Answer 17

the corpus luteum degenerates

Question 18

What happens if there is a pregnancy?

Answer 18

in pregnancy, the corpus luteum persists until the placenta takes over

Question 19

Ovary process summary

Answer 19

• menstrual (uterine cycle)
• cyclic changes to uterine lining in response to ovarian hormones
• coordinated with ovarian cycle (controlled by gonadotropins LH and FSH)

Question 20

what occurs in infertility and early preg. loss?

Answer 20

• a hormonal imbalance ( infertility is the inability to conceive after 12 months)
• main causes are ovulation disorders, semen abnormalities, and tubal disease

Question 21

What is anovulation?

Answer 21

A decrease in body fat, obesity, low ovary reserve), luteal phase defect- corpus luteum insufficient and a decrease in progesterone

Question 22

What is amenorrhea?

Answer 22

excessive exercise, low body fat, no periods, stress)

Question 23

What are other imbalanced

Answer 23

• hyperprolactin (excesses milk)

and there may be a decrease in sperm quantity and quality (Damage to DNA)

Question 24

What does the placenta secrete?

Answer 24

temp. endocrine organ and secretes several hormones that sustains pregnancy –> estrogen, progesterone and human chorionic gonadotropin (hCG)

Question 25

What does the adipose secrete?

Answer 25

Leptin targets the CNS neurons to promote satiety and decrease in appetite and eating.

Question 26

What does the GI tract secrete?

Answer 26

It secretes various types of peptide proteins –> target areas of digestion

Question 27

What does the heart secrete?

Answer 27

the atrial natriuretic peptide (ANP) it targets adrenal cortex to inhibit aldosterone, therefore produces a decrease in blood volume and pressure

Question 28

What do the kidneys secrete?

Answer 28

the kidneys secrete erythropoietin (EPO) targets the bone marrow for red blood cell production (renin apart of RAAS)

Question 29

What does the skeleton secrete?

Answer 29

osteocalcin, it targets the pancreas to secrete insulin and increase insulin sensitivity

Question 30

What does the skin epidermis do?

Answer 30

The skin epidermis has cholecalciferol (inactive vit. D) modified in the liver and fully activated in kidneys.