Transcript INTEGUMENTARY SYSTEM - Orange Coast College

REPRODUCTIVE SYSTEM
REPRODUCTIVE SYSTEM:
Design
Not for Homeostasis; Instead to
Perpetuate the Species
Sexual Reproduction Results in Genetic
Variability
Internal Fertilization & Gestation
One Offspring per Pregnancy is Typical
REPRODUCTIVE SYSTEM:
Functions
Production & Support of Gametes
Males - Formation, Transport &
Delivery of Sperm
Females
- Formation & Transport of Ova
- Protect & Support Developing Embryo,
and Nourish Fetus
- Deliver the Fetus
REPRODUCTIVE SYSTEM:
Overview of Anatomy
Reproductive Organs
Associated Ducts
Accessory Glands
External Genitalia
MALE ANATOMY: TESTES
From the Greek for “witness” (e.g.,
testify)
Essential organs of reproduction in the
male (Male Gonad)
Site of sperm production
Suspended in scrotum by spermatic
cord
MALE ANATOMY:
SCROTUM
Pouch of skin and fascia evaginated
from anterior abdominal wall
Subdivided into two lateral
compartments
Houses testes, keeps them cool (93F)
Cremaster muscle brings testes closer to
body
Dartos muscle causes wrinkling
MALE ANATOMY: TESTES
Develop initially in abdominal cavity
(retroperitoneally)
Descend into scrotum
- Starts 7th month of gestation
- Pass through inguinal canal
- Should be in scrotum by birth
Continued ...
MALE ANATOMY: TESTES
CONTINUED
Seminiferous tubules: Sites of sperm
production
Interstitial Cells: Secrete Testosterone
Efferent ductules: Carry sperm from
testes to:
Epididymis:
- Store sperm
- Site of sperm maturation (2 weeks)
Continued ...
MALE ANATOMY:
SPERMATIC CORD
Contains structures passing to and from
testes
Coverings derived from abdominal wall
Contents include:
- Vas deferens
- Spermatic artery and vein
- Spermatic nerve
- Lymph vessel
- Cremaster muscle
MALE ANATOMY: VAS
(DUCTUS) DEFERENS
Carries sperm from epididymis to
seminal vesicle
Passes through inguinal canal into body
cavity
Crosses surface of urinary bladder
Joins with duct of seminal vesicle to
form the ejaculatory duct
Vasectomy
MALE ACCESSORY GLANDS:
SEMINAL VESICLES
Paired structures posterior to urinary
bladder
Secrete ~60% of seminal fluid
Fluid is sugary, alkaline
Rich in carbohydrates, Vitamin C
- Nourishes sperm
- Enhances motility
MALE ACCESSORY GLANDS :
PROSTATE GLAND
Located inferior to urinary bladder,
anterior to rectum
Surrounds prostatic urethra
Secretes ~25% of seminal fluid
Enzymes to liquify semen
MALE ACCESSORY GLANDS :
BULBOURETHRAL GLANDS
Also called Cowper’s glands
Lateral to membranous urethra
Secrete a drop of alkaline mucus
- Cleans, lubricates urethra
- Neutralizes acidic urine
- Does not contribute towards semen
MALE ANATOMY: PENIS
Male copulatory organ
Functions to introduce sperm into
female
Consists of three erectile bodies
- Two corpora cavernosa
- One corpus spongiosum
MALE ANATOMY: PENIS
Corpus spongiosum
- Surrounds penile (spongy) urethra
- Forms 1/3 of shaft
- Distal end forms glans penis; Urethral
orifice opens through glans
- Proximal end forms bulb of penis
Continued ...
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MALE ANATOMY: PENIS
CONTINUED
Corpora cavernosa
- Paired, lie laterally
- Form 2/3 of shaft
Prepuce (foreskin):
- Covers glans penis
- Optionally removed by circumcision
MALE PHYSIOLOGY:
SPERMATOGENESIS
- Occurs in seminiferous tubules
- Spermatogonia divide mitotically
- One Spermatocyte eventually gives
rise to Four Sperm via meiosis
- Fertilization by Y sperm result in
male embryo
- Fertilization by X sperm results in
female embryo
MALE SEXUAL RESPONSE
Erection
- Arteries dilate, increasing blood in
spongy tissue
- Constricts veins, causes erection
Ejaculation (expulsion)
- Semen passes through urethra
- Contractions of urethra, penile
musculature, ducts
MALE HORMONAL CONTROLS
Gonadotropic Hormones
- Follicle Stimulating Hormone
(stimulates sperm production)
- Luteinizing Hormone or ICSH
(stimulates testes to secrete
testosterone)
Testosterone (Male Sex Hormone)
- Male Secondary Sex Characteristics
FEMALE ANATOMY:
OVARY
Female Gonad
Follicles – sites of ova production
Ova development pauses at birth,
resumes following puberty
- Approximately 400,000+ follicles
- Only about 400 ever reach maturity
Paired, oval, almond sized
Supported by ligaments
FEMALE ANATOMY:
UTERINE (Fallopian) TUBES
 Site of Fertilization
 Paired, ~10 cm long
 Attach to uterus, one on each side
- Intramural Portion: Within uterus
- Isthmus: Narrow portion adjacent to uterus
- Ampulla: Long, wide portion
- Infundibulum: Funnel-shaped end with
branches, fimbriae, that drape over ovary
 Transport via Cilia & Peristalsis
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FEMALE ANATOMY:
UTERUS
Usually unpaired, hollow, muscular,
pear-shaped organ
Receives uterine tubes, empties into
vagina
Site of Implantation & Development
Supported by ligaments:
- Broad ligament: Double layer of
peritoneum
- Round ligament: Passes through
inguinal canal
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FEMALE ANATOMY:
UTERUS continued
Uterine wall has three layers
- Perimetrium (broad ligament):
Visceral Peritoneum
- Myometrium: Thick layer of smooth
muscle
- Endometrium:
* Epithelial layer
* Undergoes cyclic changes in
response to hormones
*Endometriosis
FEMALE ANATOMY:
UTERUS
Fundus: Raised region above entry of
uterine tubes
Body: Central region w/large triangular
lumen
Isthmus: Narrowed region between body
& cervix
Cervix:
- Most inferior portion
- Extends down into vagina
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FEMALE ANATOMY:
VAGINA
Functions:
- Receives penis during intercourse
- Passage for removal of menstrual
debris
- Serves as a birth canal
Located between urethra and rectum
Lined with stratified squamous E.T.
Acidic environment (Resident Bacteria)
FEMALE ANATOMY:
VAGINA continued
Fornix: Circular recess around cervix;
upper portion of vagina
Hymen:
*Fold of mucous membrane
*Does NOT signify virginity!
Bartholin’s glands (Greater Vestibular):
- Distal End Vagina
- Homologous to Cowper’s glands
- Very little secretion (mucus)
Vulva
FEMALE ANATOMY:
VULVA (External Genitalia)
Mons pubis: Fatty mound
Labia majora: Outer folds of skin;
Homologous to scrotum
Labia minora: Inner folds, encircle
clitoris, form prepuce
Clitoris: Homologous to penis;
composed of corpora cavernosa
FEMALE ANATOMY:
CLITORIS
Partially covered by prepuce (foreskin)
Function – Sexual Pleasure
Orgasm controlled by Sympathetic
Division of ANS
FEMALE ANATOMY:
BREASTS
Structurally – Integument
Functionally – Reproductive
- Colostrum
- Breast Milk
HORMONAL CONTROL:
ADULT FEMALE
Four hormones involved:
- FSH and LH (from pituitary)
*Target - ovaries
*Follicles w/ova grow & mature
*Ovaries secrete:
- Estrogen and progesterone (from
ovaries)
*Target - uterus
*Endometrium thickens & secretes
THE OVARIAN CYCLE
Includes:
- Follicular Phase
*Follicle development/maturation &
Oogenesis
- Ovulation
- Luteal Phase
*Development of corpus luteum from
ruptured follicle
FOLLICLE DEVELOPMENT
Up to 20 follicles begin maturation
process monthly
Only one secondary follicle reaches
maturity
Others undergo atresia (degradation)
Controlled primarily by FSH
FSH causes follicle cells to secrete
estrogen
OVULATION
Caused by LH surge
Day 14 (28-day cycle)
Expels ovum into abdominal cavity
Fimbriae on uterine tube sway
vigorously, producing a current
Fimbriae scratch Graafian follicle,
rupture it, sweep ovum into tube
FORMATION OF CORPUS
LUTEUM
Ruptured Graafian follicle becomes
corpus luteum
Corpus luteum secretes estrogen,
progesterone
Maintains endometrial lining during
pregnancy
THE UTERINE CYCLE
Menstrual phase (Day 1 of 28-day cycle)
Proliferative phase
- Follows Menstruation
- Estrogen from follicle stimulates
proliferation of endometrium
Secretory phase
- Follows Ovulation
- Progesterone from corpus luteum
stimulates secretion by endometrium
Ovarian Hormones Control the Endometrial
Changes of the Uterine Cycle
Ovarian Cycle
Follicular phase 
(Estrogens)
Luteal phase 
(Progesterone)
Uterine Cycle
Proliferative phase
Secretory phase