Chapter 26

Gonads

Primary sex organs that secrete sex hormones including testosterone and estrogen

Gamete

Sex cells, male (sperm) and female (ova)

Fertilization

A sperms and egg fuse to form a single cell (zygote)

Pregnancy

When zygote travels through uterine tube and implants in the uterine wall

Mentions the function of the reproductive system

To keep species alive

Name the organs of male reproductive system

Testes, scrotum, penis, epididymis, ductus deferens, accessory sex glands (seminal vesicles, prostate)

Mentions the function of the scrotum

Layers of skin that covers and protects testes. It is a connective tissue that surrounds testes.

Name the muscles in scrotum and mention their function

Cremaster muscle: in charge of the remorseful action, brings testes closer to the body when it’s cold. When it’s hot muscles relax.

Internal anatomy of testes

Seminefirous tubules, straight tubules, rete testis and efferent tubules

Pathway of sperms from seminal vesicles to the end of the urethra

Semineferous tubule, straight tubules, rete testis, efferent ductules, epididymis, ductus deferens, ampulla of ductus deferens, ejaculatory ducts and urethra (prostatic, membranous and spongy)

Cells in the testes and their functions

Spermatogenic cells: sperm forming cells

Sustentacular cells: support sperm production

Interstitial cells (Leydig): in between seminefirous tube and produces testosterone

Stages of Spermatogenesis

Starts with spermatogonium (single 2n cell, 46 chromosomes) which becomes active in male after puberty. Goes through mitosis (# of chromosomes becomes half). Is not a secondary spermatocyte (n) and goes through meiosis II. It is now spermatids (n, not mature) and then turns into 4 sperm (mature)

Characteristics of mature sperm

Head: has nucleus and DNA

Midpiece: full of mitochondria to make ATP for movement

Tail: has flagellum which helps them move

Hormonal control for testes

FSH is responsible for sperm production which goes into Semineferous tubules. LH is for the secretion of testosterone and goes to the interstitial cells

Ducts in the male reproductive system and their functions

Epididymis: group of curly tubules. Sperm stays in here until maturation

Ductus deferens: main duct that takes sperm from epididymis to ejaculatory duct to then go to urethra

Semineferous tubules: loops in the lobules of the testes where sperm is produced

Urethra

Structures in spermatic cord

Ductus deferens, blood and lymph vessels, nerves and cremaster muscle

Accessory glands in male and mention their functions

Seminal vesicles, prostate and bulbourethral glands

Seminal vesicles

Secrete 60-70% of seminal fluid

Prostate

Secretes the other 20-30% of seminal fluid. Has Prostate specific antigen (PSA) which is an enzyme that liquifies semen and helps with finding prostatic cancer

Bulbourethral glands

Make mucous for lubricación for sexual intercourse and is alkaline because the environment in the vagina is acidic so it neutralizes it

Physical characteristics of semen

Sticky whitish mixture of sperm

Histology of uterine tubes

Cilia in the uterine tube which help the movement of secondary oocyte and fertilized ovum

Major parts and erectile tissues of penis

External penis: root, body (shaft) and glans penis

Internal penis: has three erectile bodies which include 2 corpora cavernosa and corpus spongiosum

Functions of the female reproductive system

Must be able to support developing embryo and provide nourishment to growing infant

Function of ovaries

Main sex glands in female and make estrogen and progesterone

Reproductive ligaments and location

Broad ligament: large and flat, attaches ovaries, uterus and uterine tube to bony pelvis

Ovarian ligament: connects ovary to wall of uterus

Suspensory ligament: connects ovary to bony pelvis and blood vessels pass through

Stages of oogenesis in order

Before birth: have oogonium (2n) which goes through mitosis and turns into primary oocyte (2n)

Primary oocyte: starts meiosis I and stops

Primordial follicle: have the primary oocyte in the center and only as one layer

Primary follicle: still has the primary oocyte but has multiple layers

Secondary follicle: still has the primary oocyte but has pockets of fluid

Mature follicle: pockets of fluid joins and make antrum, primary oocyte gets pushed to the side. Here, the primary oocyte finishes meiosis I and turns into secondary oocyte (n = 23). The secondary oocyte states meiosis II and stops (doesnt finish)

Ovulation: release of secondary oocyte from mature follicle. The secondary oocyte has two destinies: it becomes an ovum through being fertilized by sperm and finished meiosis II. Or secondary oocyte never finds sperm, so it doesnt finish meiosis II and dies, rupturing wall of ovary

Anatomy of uterine tube and function

Uterine tubes are necessary for fertilization and is the location of fertilization

Isthmus: narrowest part

Ampulla: largest, fertilization happens here

Infundibulum: opening at the distal end of uterine tube

Fimbriae: finger like structure

Anatomy of uterus

Fundus, body, cervix, wall of uterus (endometrium, myometrium and perimetrium), ovaries and vagina

Layers of uterine wall in order

Endometrium (innermost)

Myometrium (middle)

Perimetrium (outermost)

Functions of vagina

Organ for sexual intercourse and is the passageway for giving birth and menstrual flow

Parts of vulva

Mon pubis: covers pubic symphysis

Labia majora: layers of skin, fat, and covered by hair

Labia minora: hairless, inside labia majora. Has vestibule which has two orifices, urethral and vaginal

Clitoris: erectile, anterior part of vulva and is for sexual pleasure

Parts of mammary glands

Adipose tissue: cushioning/protecting glands

Lactiferous ducts: take milk to nipple

Alveoli: make the milk and is needed for the production of milk

Nipple: milk comes out

Stages of female reproductive cycle in order

Day 1: First day of period

Phase 1: Menstrual phase (Days 1-5)

Phase 2: Proliferative Phases (Day 6 - 13)

Phase 3: Ovulation (Day 14)

Phase 4: Postovulatory/Secretory Phase (Day 15-28)

Phase 1: Menstrual phase (Days 1-5)

Destruction of endometrium

In the ovary: primordial follicles turn into primary follicle then into secondary follicle. The follicles secrete estrogen.

Phase 2: Proliferative Phase (Days 6-13)

Stratum basalis is repairing endometrium in order to prepare for pregnancy.

Secondary oocyte converts to mature follicle

Phase 3: Ovulation (Day 14)

Need LH for the LH surge which is needed for ovulation to happen. If there is no LH surge then no ovulation.

Phase 4: Postovulatory/Secretory Phase (Day 15-28)

In the uterus the endometrium thickens beacuse of progesterone

In the ovaries, remnant of mature follicle turns into corpus luteum and secretes progesterone. If pregnancy happens then the corpus luteum will continue to secrete progesterone for three months. If no pregnancy, then it will die and turn into corpus albicans

Hormone needed for ovulation

LH