19 - Reproductive System (HSF)

Primary Sex Organs (Gonads)

Testes (male) & Ovaries (female)

Sex Organs produce …

Gametes (sex cells)

• Sperm (male)

• Ova (female)

Sex Organs secrete …

steroid sex hormones

• androgen (male)

• estrogen and progesterone (female)

Accessory Reproductive Organs

ducts, glands, and external genitalia

What part of the Male Reproductive System produces sperm?

Testes within the scrotum

How does sperm get to the exterior?

System of Ducts

System of Ducts (Sperm to exterior)

Epididymis to ductus deferens to ejaculatory duct to urethra

Testes

Sperm-producing male gonads that lie within the scrotum

Accessory Sex Glands

Seminal Glands, Prostate, Bubalo-Urethral Glands

Scrotum

Sac of Skin that hangs outside abdominopelvic cavity.

Contains paired testes, midline divides scrotum into 2 compartments, one for each testis.

3 Degree Celsius lower than core body temp, necessary for sperm production.

2 Sets of Muscles that keeps temp same in scrotum

Dartos & Cremaster Muscles

Dartos Muscle

smooth muscle, wrinkles scrotal skin, pulls scrotum close to body.

Cremaster Muscles

bands of skeletal muscle that elevate testes

Each testis is surrounded by …

2 Tunics

Tunica Vaginalis

outer layer derived from peritoneum

Tunica Albuginea

inner layer forms fibrous capsule

Septa divide testis

site of sperm production

Testes Blood Supply

Testicular arteries arise from abdominal aorta.

Testicular veins arise from pampiniform venous plexus surrounding each artery.

Helps keep them cooler, absorbing heat from testicular arteries.

Spermatic Cord

encloses nerve fibers, blood vessels, lymphatics that supply testes

Testicular Cancer

Rare, most common cancer in men (15-35)

cryptorchidism most common risk factor.

sign: painless, solid mass in testis

90% cured by surgical removal of testis and radiation or chemo

Pensis

Male copulatory organ

External Genitalia

Scrotum and Pensis

Pensis consists of …

root and shaft that ends in glans penis

prepuce/foreskin

Prepuce

foreskin, cuff of loose skin covering glans

Circumcision

surgical removal of foreskin

Penis made up of…

spongy urethra and 3 cylindrical bodies of erectile tissue, spongy network or CT, and smooth muscle with vascular spaces.

Corpus spongiosum

surrounds urethra and expands to form glans and bulb

Corpora Cavernosa

paired dorsal erectile bodies

Erections

erectile tissue fills with blood, causing penis to enlarge and become rigid

Crura

proximal ends of corpora cavernosa surrounded by ischiocavernosus muscle; anchors penis to pubic arch

Male Perineum

Diamond-shaped region between pubic symphysis, coccyx, and ischial tuberosities.

Suspends scrotum

Contains root of penis and anus

Duct of the Epididymis

6m in length

Nonmotile sperm enters, passes through slowly (about 20 days), becomes motile.

During ejaculation, epididymis contracts, expelling sperm into ductus deferens.

Ductus Deferens

about 45 cm long

passes through inguinal canal to pelvic cavity

joins duct of seminal vesicle to form ejaculatory ducts

smooth muscle in walls propels sperm from epididymis to urethra

Vasectomy

cutting and ligating ductus deferens

after 6-8 weeks, its nearly 100 effective form of BC b/c sperm can be stored

Urethra

conveys both urine and semen (at diff times)

3 regions

3 Regions of Urethra

prostatic urethra, membranous urethra, spongy urethra

Prostatic Urethra

surrounded by prostate

Membranous Urethra (intermediate part)

urogenital diaphragm

spongy urethra

runs through penis, opens at external urethral orifice

Seminal Glands (male)

on posterior bladder surface

contains smooth muscle that contracts during ejaculation

produces viscous alkaline seminal fluid

joins with ductus deferens to form ejaculatory duct

Alkaline Seminal Fluid (from seminal gland)

fructose, citric acid, coagulating enzyme, and prostaglandins

70% volume of semen

Prostate

encircles urethra inferior to bladder (size of peach pit)

consists of smooth muscle that contracts during ejaculation.

secretes milky, slightly acid fluid'.

Prostate secretion

milky, slightly acidic

contains citrate, enzymes, and prostate-specific antigen

role in sperm activation (1/3 of semen volume)

enters prostatic urethra during ejaculation

Prostatitis

inflammatory disorders

bacterial infection, acute or chronic, treated with antibiotics

Inflammatory type of Chronic Prostatitis

also called pelvis pain syndrome

most common form (chronic)

UTI symptoms, pain in external genitalia & lower back

leukocytes in urine

Non-Inflammatory Type of Chronic Prostatitis

also called pelvis pain syndrome

most common form (chronic)

UTI symptoms, pain in external genitalia & lower back

no leukocytes or bacteria in urine

Benign Prostatic Hyperplasia

age-related

distorts urethra

treated with surgery, using microwaves or drugs to shrink prostate, ballon compression, radio-frequency radiation.

Prostate Cancer

2nd most common cause of cancer death (more common in older males)

digital exam screenings

treated with surgery and sometimes radiation, castration, and drugs

Bulbo-urethral Glands

Pea-sized glands inferior to prostate.

Produces thick, clear mucus during sexual arousal (lubricates glans penis & neutralizes traces of acidic urine in urethra)

Semen

Milky-white mixture of sperm and accessory gland secretions.

2-5ml of semen=20-150 million sperm

Contains fructose for ATP (protects and activates sperm for movement)

Erection

enlargement and stiffening of penis

sexual excitement causes CNS activation of parasympathetic neurons, releasing nitric oxide, causing relaxation of smooth muscle

Spermatogenesis

production of sperm in seminiferous tubules.

46 chromosomes split into…

2 sets of 23 chromosomes

1 maternal and 1 paternal (homologous chromosomes)

Homologous chromosomes are…

1 maternal (23) and 1 paternal (23)

Body Cells have…

46 Chromosomes and are referred to as Diploid Chromosomal Number (2n)

Sex (Gametes) Cells

have 23 chromosomes

haploid chromosomal number (n)

Meiosis

2 consecutive cell divisions, with only 1 round of DNA replication.

Produces 4 daughter cells.

Functions of Meiosis

Number of chromosomes are cut in half (2n to n)

Creates genetic diversity

Meiosis 1

Reduction division - reduces chromosome number from 2n to n

Synapsis (Meiosis 1)

Homologous chromosomes (46-2n) pair up forming tetrads consisting of 4 chromatids

Crossover (Meiosis 1)

exchange of genetic material between male and female chromatids (results in unique chromosomes - mix of maternal and paternal chromosomes)

Meiosis 2

Reduces chromosomal number by half

Introduces genetic variability (random alignment of homologous pairs, resulting in no 2 gametes being exactly alike)

Women reproductive anatomy is more complex because of …

pregnancy

Ovaries

female gonads

produce female gametes (ova)

secrete female sex hormones (estrogen and progesterone)

Internal Genitalia

located in pelvic cavity

ovaries, duct system

external genitalia

external sex organs

Each ovary is held in place by …

several ligaments

Ovarian Ligament

anchors ovary medially to uterus

Suspensory Ligament

anchors ovary laterally to pelvic wall

Mesovarium

suspends ovary

Broad Ligament

supports uterine tubes, uterus, and vagina

made up of suspensory and mesovarium ligaments

Blood Supply for Ovaries

Ovarian Arteries and branches of uterine arteries

Each ovary is surrounded by…

fibrous tunica albuginea, also covered by germinal cuboidal epithelium

Outer Cortex

houses forming of gametes

poorly defined

Inner Medulla

contains large blood vessels and nerves

poorly defined region

Ovarian Follicles

Tiny saclike structures embedded in cortex.

Contains oocyte surrounded by follicle cell (only one call layer) and granulosa cells (more than one layer)

Ovulation

ejection of oocyte from ripening follicle.

corpus luteum develops from ruptured follicle after ovulation.

Does the uterine tube system have direct contact with ovaries?

NO

Uterine Tube System contains…

uterine tubes, uterus, vagina

Uterine/Fallopian Tubes

each tube is 4in long and extends from ovary to superolateral region of uterus.

site of fertilization.

Regions of Fallopian Tube

Isthmus, Ampulla, Infundibulum

Isthmus (part of fallopian tube)

constricted area where tube joints uterus

Ampulla (part of fallopian tube)

distal end of tube that curves around ovary

Infundibulum (part of fallopian tube)

distal expansion near ovary

Functions of Fallopian Tube

oocyte is carried to the uterus by smooth muscle peristalsis and ciliary action.

noncilated cells - nourish oocyte and sperm

externally - covered by peritoneum and supported by mesosalpinx

Ectopic Pregnancy

oocyte is fertilized in peritoneal cavity or far fallopian tube and begins developing there.

aborts naturally with a lot of bleeding.

Pelvis Inflammatory Disease (PID)

spread of infection from reproductive tract to peritoneal cavity.

may lead to infertility.

Uterus

hollow, thick-walled, muscular organ

function - receive, retain, and nourish fertilized ovum.

Regions/Definitions of Uterus

Body - major portion

fundus - rounded superior region

isthmus - narrowing inferior region

cervix - narrow neck that projects into vagina

cerivical canal - communicates with vagina (by external os) & uterine body (interal os)

Cervical Glands

secrete mucus that blocks sperms entry expect during midcycle

Cervical Cancer

Ages 30-50

Risks: STIs and frequent cervical inflammation

Pap smear for detection (every 3 years for 21-30, 5 for 30-65)

Supports of The Uterus

Mesomerism, Cardinal Ligaments

Uterosacral Ligaments, Round Ligaments

Mesomerism

lateral support of broad ligament

Cardinal Ligaments

from cervix and superior vagina to pelvic lateral walls

uterosacral

secures uterus to sacrum

Round Ligaments

bind uterus to anterior wall

Uterine Wall (3 layers)

perimetrium, myometrium, endometrium

perimetrium of uterine wall

outermost serous layer

myometrium

bulky middle layer of interlacing smooth muscle.

contracts during childbirth.

endometrium

mucosal lining (simple columnar epithelium on top of think lamina propria)

fertilized egg burrows into endometrium and resides there throughout development