Chapter 19, The Reproductive System Flashcards
What are female sex cells
Eggs, or oocytes
What are the male’s primary sex organs
The testes
Where do sperm cells and male hormones form
Testes
Where are the testes housed
In the scrotum
What is the process in which sperm cells form
Spermatogenesis
What are spermatogonia
Spermatogenic cells that are undifferentiated in the male embryo
At puberty, the spermatocytes reproduce by the process called
Meiosis
What does meiosis produce in the male
Four sperm cells with 23 chromosomes in each of their nuclei
What are the male internal accessory organs
Two epididymides, two ducts deferentia, two ejaculatory ducts, a urethra, two seminal vesicles, and the prostate gland
How long are the epididymides
6 meters long
What are tightly coiled, threadlike tubes about 6 meters long
The epididymides
What is each epididymis connected to
Ducts within the testes
Immature sperm cells reaching the epididymis are _____
Nonmotile
After the sperm cells mature in the epididymis, they have the potential to do what
Move independently and fertilize eggs
When do sperm swim
After ejaculation
What are seminal vesicles
Saclike structures that attach to the ductus deferens
What do seminal vesicles do
Secrete a slightly alkaline fluid that contains fructose that provides energy for the sperm
What does the fructose that is secreted by the seminal vesicles do
Provides energy for the sperm
What does the prostate gland secrete
A thin, milky fluid with an alkaline pH
What does the fluid that the prostate gland neutralize
The fluid containing sperm cells, which is acidic, and the acidic excretions of the vagina
What is semen
The fluid the male urethra secretes during ejaculation
What does semen consist of
Sperm cells from the testes and the fluids from the prostate gland and seminal vesicles
During sexual stimulation, what kind of impulses travel from the spinal cord
Nerve impulses
What do the nerve impulses from the spinal cord release during sexual stimulation
Nitric oxide
What does the nitric oxide that is released by the nerve impulses from the spinal cord during sexual stimulation do
Dilates the arteries leading to the penis
At the same time that the arteries leading to the penis dilate during sexual stimulation, what happens to the veins of the penis
Increased pressure on the arteries compress the veins of the penis, reducing the flow of blood away from it
When blood is prevented from flowing away from the penis during sexual stimulation, what happens
Blood accumulates in erectile tissue and the penis swells, producing an erection
What is released from the penis first
Fluid from the prostate gland
What is released after the fluid from the prostate
The sperm cells and the fluid from the seminal vesicles
What secretes the hormones that control male reproductive functions
The hypothalamus, anterior pituitary gland, and testes
What are male sex hormones
Androgens
What is the most important androgen
Testosterone
What are the causes of male infertility
The testes don’t descend into the scrotum, causing the higher temperatures of the body to kill the sperm
Sperm don’t produce tails
What are the female’s primary sex organs
Ovaries
What do the ovaries produce
Female sex cells and sex hormones
Before birth, how many oocytes are produced in the embryo
Several million
How do oocytes begin
As primordial follicles
What is oogenesis
The process of egg cell formation
Beginning at puberty, some primary oocytes are stimulated to do what
Continue meiosis
When the primary oocyte divides, _____
One of the resulting cells is a secondary oocyte, and the other is a smaller polar body
What is a secondary oocyte
A resulting cell after the primary oocyte divides
What can the large secondary oocyte do that the other polar body cannot
Be fertilized by a sperm cell
What do some of the primordial follicles do at puberty
Mature to form primary follicles
How many primary follicles may begin maturing at any time?
20
But one follicle usually outgrows the others
What do the 20 primary follicles develop into
The primary oocyte
What happens after the follicles develop into the primary oocyte
The secondary oocyte and first polar body are produced
An egg is released from the ovary in a process called what
Ovulation
What happens if the oocyte isn’t fertilized within 24 hours
It degenerates
Where does fertilization occur
In the uterine tube
What does the uterus receive and what does it do
The developing embryo and keeps it for development
What is the lower third of the uterus
Cervix
The cervix extends ____
Downward into the upper part of the vagina
What are the female external reproductive organs
The labia majora, labia minora, the clitoris, and the vestibule
What are the external sexual organs of the female collectively called
The vulva
What corresponds to the penis in males and has a similar structure
The clitoris
The same process of ____ occurs in the female as in the male
Erection
What stimulates enlargement of accessory organs
Estrogen
What may happen to elite female athletes
Sometimes, they have irregular reproductive cycles that may completely stop
If elite females have irregular reproductive females, what might this impair
Their ability to conceive
Why may elite athletes not be able to conceive
Too little body fat
Why can too little body fat inhibit an elite athlete’s ability to produce
Diminished fat reserves decreases secretion of estrogen levels
There is too little estrogen
What is the most effective birth control
Abstinence
What is the second most effective birth control
Oral contraceptives
What do oral contraceptives contain
Synthetic estrogen and progesterone
What do women need to get tested for periodically
Cervical cancer
What is used to detect the presence of abnormal cells in the cervix
A pap smear
What can women going through menopause take to replace estrogen in the body
Hormone replacement therapy
How many women will develop breast cancer at some point in their life
1 in 8
How many breast cancer cases are men
1%
What could signal breast cancer
A small area of thickened tissue, a dimple, a change in contour, or a nipple that is flattened, points in an unusual direction, or produces a discharge
How does a woman perform a monthly “breast self-exam”
Lies flat on back with arm raised behind her head and systematically feels all parts of each breast
Sometimes breast cancer gives no warning at all
What are signs that may not occur until the disease has spread beyond the breast
Fatigue and feeling ill
What is the next step after finding a lump in your breast
A physical exam
Physical exam
A health-care provider examines the breast and does a mammogram
Mammogram
An x-ray scan that can pinpoint the location and approximate extent of abnormal tissue
What can an ultrasound scan distinguish
The difference between a cyst and a tumor
Cyst
Fluid-filled sac of glandular tissue
Tumor
Solid mass
If an area of the breast is suspicious, a thin needle used to take a ____ of the tissue, whose cells will be scrutinized for cancer
Biopsy (sample)
Eighty percent of the time, a breast lump is a sign of what
Fibrocystic breast disease, which is benign
Benign
Noncancerous
Fibroadenoma
A solid mass of connective tissue
Lumpectomy
Removes a small tumor and some surrounding tissue
Simple mastectomy
Removes a breast
Modified radical mastectomy
Removes the breast and surrounding lymph nodes, but preserves the pectoral muscles
Only ____% to _____% of all breast cancers arise from an inherited tendency
5-10
What are male sex cells
Sperm
