Holes Human Anatomy and Physiology Eleventh Edition Shier

Hole’s Human Anatomy and Physiology Eleventh Edition Shier w Butler w Lewis Chapter 22 Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. 1

Male Reproductive System • Primary sex organ (gonads) • testes • Accessory sex organs: • Epididymis • Ductus deferentia – aka vas deferens • Seminal vesicles • Prostate gland • Bulbourethral gland • Scrotum • Penis 2

Testes • Suspended by spermatic cord • Within saclike structure called the scrotum posterior view • Develop in same area of kidneys but descend through inguinal canal before birth • Green box p. 850 • Cryptorchidism • Inguinal hernia • Strangulated hernia 3

Structure of the Testes • Constructed of seminiferous tubules • Seminiferous tubules lined with epithelium from which sperm is made • Interstitial cells are between seminiferous tubules and secrete male hormones • P. 851 Testicular cancer 4

Formation of Sperm Cells Spermatogonia in seminiferous tubules undergo meiosis to produce sperm 5

Spermatogenesis Through meiosis one primary spermatocyte will produce 4 sperm cells. 6

Structure of a Sperm Cell Three Regions 1. Head • Acrosome – enzymes that aid in penetration of egg • Nucleus – contains 23 chromosomes 2. Midpiece – contains mitochodria which produce energy needed for sperm to move 3. Tail – flagellum used for movement 7

Leeuwenhoek’s idea of sperm Actual Sperm 8

Epididymides • tightly coiled tubes • connected to ducts within testis • secretes substances that promote maturation of sperm cells • Immature sperm stored there until they reach maturation 9

Ductus Deferentia • Aka vas deferens • muscular tubes • about 45 cm each • extends from epididymis to ejaculatory duct which is the tube that leads into the urethra • Functions is to carry sperm from epididymis to urethra 10

Seminal Vesicles • attached to vas deferens near base of bladder • secrete alkaline fluid which regulates p. H needed for sperm • • secretes fructose which sperm use for energy • Secretes prostaglandins that cause muscular contractions within female reproductive organs • contents empty into ejaculatory duct 11

Prostate Gland • surrounds proximal portion of urethra • ducts of gland open into urethra • secretes a thin, milky, alkaline fluid • • secretion enhances mobility of sperm and sustain them by neutralizing acidic conditions both from sperm themselves and within female reproductive system • P. 858 Clinical Application: Enlarged Protate 12

Study links finger length to prostate cancer risk http: //www. msnbc. msn. com/id/40442341/ns/health-cancer/ LONDON — Men with long index fingers have a lower risk of prostate cancer, British scientists said on Wednesday, a finding that could be used to help select those who need regular screening for the disease. More likely Less likely 13

Bulbourethral Glands • Aka Cowper’s gland • inferior to the prostate gland • secrete mucus-like fluid • fluid released in response to sexual stimulation 14

Semen • Includes • sperm cells • secretions of seminal vesicles, prostate gland, and bulbourethral glands • slightly alkaline – p. H approximately 7. 5 • 120 million sperm cells per milliliter • Sperm live for weeks in testes but only about 3 days (72 hours) outside of male body 15

• Scrotum • pouch of skin and subcutaneous tissue • dartos muscle • smooth muscle in subcutaneous tissue • Helps maintain optimal temperature for sperm by moving testes closer or further away from body • medial septum divides scrotum into two chambers • each chamber houses a testis and epididymis 16

Penis • conveys urine and semen to outside of body • specialized tissue designed to become erect for insertion into the vagina 17

Penis • Consists of 3 layers of tissue • Urethra extends through • Distal end forms glans penis where urethral opening is found • Contain pairs of arteries, veins, and nerves • Circumcision – prepuce (foreskin) is removed 18

Hormonal Control of Male Reproductive Functions • hypothalamus releases gonadotropin-releasing hormone (Gn. RH) • Gn. RH stimulates the anterior pituitary to produce gonadotropins (LH and FSH) 19

LH and FSH • FSH – follical stimulating hormone stimulates spermatocytes to produce sperm • LH – luteinizing hormone stimulates interstitial cells to produce androgens (male hormones) 20

Actions of Testosterone The androgen testosterone is responsible for secondary sex characteristics. • increased growth of body hair • sometimes decreased growth of scalp hair • enlargement of larynx and thickening of vocal cords • thickening of skin • increased muscular growth • thickening and strengthening of the bones 21

Hormone Regulation • Hormone levels are regulated by a negative feedback system between the hypotalamus, anterior pituitary, and testes. • Levels increase with puberty (begins around age 10) 22

Female Reproductive System • Primary sex organ (gonads) • ovaries • Accessory sex organs: • Uterine tubes (fallopian tubes) • Uterus • Vagina 23

Ovary Attachments Ovaries and uterus are held in place by ligaments. 24

Primordial Follicles • Females are born with approximately 1 million primordial oocytes. • At puberty these begin to develop and be released one per month. 25

Oogenesis • beginning at puberty primary oocytes undergo meiosis • Results in one secondary oocyte • Unequal division of the cytoplasm results in development of polar bodies which degenerate 26

Follicle Maturation Primordial follicle Mature (Graafian) follicle • Egg matures in a fluid filled, blister-like follicle • Maturation of a follical takes about 10 -14 days. 27

Follicle Maturation Several follicles will be maturing at the same time just at different rates. 28

Ovulation • Wall of follicle ruptures releasing the oocyte. • Green box P. 870 Clomid 29

Ovulation 30

Uterine Tubes aka Fallopian Tubes • About 10 cm long • convey eggs toward the uterus • Fingerlike projections called fimbriae direct egg into tube • Lining has cilia that help move egg downward 31

Lining of Uterine Tubes 32

Uterus aka Womb • hollow muscular organ that receives the embryo that has been fertilized in the uterine tube • End of uterus that opens into vagina is called the cervix 33

Cervix • Pap Smear is a test to check the cells of the cervix for any abnormality that might lead to or indicate cervical cancer • HPV – human papilloma virus leading cause of cervical cancer 34

Uterine Wall 3 layers 1. Endometrium – mucosal layer 2. Myometrium – smooth muscle layer 3. Perimetrium – serosa layer 35

Vagina aka Birth Canal • fibromuscular tube that conveys uterine secretions, receives the penis during intercourse, and provides an open channel for offspring • Opening from outside is partially covered by hymen – a membrane 36

Hormonal Control of Female Reproductive Functions • estrogens inhibit LH and FSH during most of the reproductive cycle • Birth control pills work because they are synthetic forms of estrogen and progesterone 37

Effects of Estrogens • development of breasts and ductile system of the mammary glands • increased adipose tissue in breasts, thighs, and buttocks • increases vascularization of skin • Body hair growth is due to androgens that increase at puberty 38

Female Reproductive Cycle • Like in the male, the hypothalamus secretes Gn. RH • Gn. RH stimulates the anterior pituitary to produce LH and FSH • FSH stimulates a follicle to develop 39

Female Reproductive Cycle • The follicle produces some estrogen • LH stimulates cells within the ovary to produce estrogen precursors • As a result of increasing estrogen levels the endometrium thickens 40

Female Reproductive Cycle • A spike in hormone levels (LH and FSH) during mid-cycle will cause ovulation to occur (egg released) • The leftover follicle, corpus luteum, secretes an increased level of progesterone. 41

Female Reproductive Cycle • Progesterone causes the endometrium to become more vascular. • If pregnancy does NOT occur the corpus luteum dries up and the hormone levels drop drastically • As a result of the drop in hormone levels the endometrium is shed 42

Menopause • usually occurs in late 40 s or early 50 s • reproductive cycles stop • ovaries no longer produce as much estrogens and progesterone • some female secondary sex characteristics may disappear • may produce hot flashes and fatigue • hormone therapy may prevent effects on bone tissue 43

Mammary Glands • located in the subcutaneous tissue of the anterior thorax within the breasts • composed of lobes • estrogens stimulate breast development in females 44

Birth Control • coitus interruptus • rhythm method • mechanical barriers • condom • diaphragm • cervical cap • spermicidal foams or jellies • chemical barriers • spermicides • oral contraceptives • hormonal • injectable contraception • hormonal • intrauterine devices • surgical methods • vasectomy • tubal ligation 45

Surgical Methods of Birth Control Vasectomy Tubal ligation 46