Reproductive System

What is the scrotum and why is their location an essential adaptation?

The scrotum is a pouch of skin outside the body that holds the testes. Its location is an essential adaptation because it keeps the testes a few degrees cooler than normal body temperature, which is necessary for proper sperm production. If the testes were inside the body, the higher temperature would impair sperm development, reducing fertility. 

Seminiferous tubules function

Produce sperm cells

Pampiniform venous plexus function

Cools arterial blood before it enters the testes. 

Epididymis function

storing, transporting, and maturing sperm

Ductus Deferens function

sends sperm cells to ejaculatory duct.

What does the Seminal Vesicle add to semen?

It adds fructose for energy and provides nutrients for sperm.

What does the Prostate Gland add to semen?

Secretes alkaline fluid that contains citrate, a nutrient for sperm

Bulbourethral Gland function

Secretes fluid that lubricates end of penis

What does the head of a sperm do?

Contains DNA and enzymes to help penetrate oocyte

What does the tail of a sperm do?

A flagellum provides locomotion

What does the body of a sperm do?

Contains many mitochondria 

What cells produce testosterone

Interstitial 

Fallopian tube function

Where fertilization typically occurs

Uterus function

Protects and sustains embryo during pregnancy

Vagina function

Conveys uterine secretions to outside of body; receives erect penis during sexual intercourse; provides a passageway for offspring during birth process 

Ovary function

Produces oocytes and female sex hormones

Fimbriae function

Fingerlike extensions that fringe the infundibulum margin that help capture the egg after ovulation. They sweep the ovulated egg into the tube (oviduct) so it can travel toward the uterus and potentially be fertilized.

What are other names for fallopian tubes?

Uterine tubes or oviducts

Where does fertilization take place?

Fallopian tube 

What hormone causes the development of female secondary sex characteristics

Estrogen

What hormone causes ovulation?

Luteinizing hormone (LH)

What produces progesterone?

The corpus luteum in the ovaries.

What hormone levels cause menstruation?

Low levels of estrogen and progesterone trigger the shedding of the uterine lining, leading to menstruation.

The greater vestibular glands (aka Bartholin’s gland) are the homolog for what male part?

Bulbouretheral Gland 

Gametes

Sex cells (sperm or egg)

Reproductive system functions

1. Produce, transport, and maintain gametes

2. Maintaining developing zygote/fetus (female)

3. Produce sex hormones

Meiosis

Type of cell division that results in gametes

What does meiosis produce?

Four haploid daughter cells

What does Oogenesis result in?

One ova (egg) and three polar bodies that deteriorate because they lack sufficient cytoplasm and nutrients.

Testes

Primary male sex organ

At what time in utero do the testes move through the abdominal wall to scrotum

7-8 months

What is the descent of testes stimulated by?

Testosterone

Where is sperm produced?

Seminiferous Tubules

Epididymis

Site of storage of sperm cells

Vas (ductus) Deferens

Muscular tube that transports sperm from the epididymis to the ejaculatory duct.

What is semen made of

Sperm cells from testes, alkaline fluids from prostate, fructose from seminal vesicle, and lubricant from bulbourethral

Circumcision

Removal of prepuce on penis

Penis

Completely surrounds urethra

Oogenesis

the process of forming female gametes (ova) in the ovaries, starting before birth and continuing until menopause

Labia

Encloses and protects underlying organs, scrotum homolog

Clitoris

Excitatory organ, corresponds to male penis

What does progesterone do?

Prepares the uterus for implantation of zygote, thickens the lining, and promotes formation of glands and blood vessels

3 Menstrual Cycle Phases

1. Flow - endometrium sheds (menstrual)

2. Follicular - ovulation occurs (proliferate)

3. Luteal - corpus luteum forms (secretory)