M12S1: MALE REPRODUCTIVE SYSTEM Flashcards
Male verse female reproductive system
Female - x
Male x or y
Make reproductive organs - testes (sperm and testosterone) , sperm stored in epididymis
Female reproductive organs - ovaries (eggs, estrogen, progesterone)
Male and female similaies
2 testes/ovaries
1 penis/uterus
Duct system to transport gametes
Same embryological origin
Male and female differences
Structure of gametes, hormonal production and influences and external genitalia
Male reproductive system
-involves a variety of structures working in synchrony to create and transport the male gamete cell, sperm
-sperm are produced in testes and transported through duct system to reach external world
Focus on:
Testes
Sportsman
Male duct system
Accessory glands
Penis
*refer to goodnotes
Testes
-site sperm creation and development in male reproductive system
-two oval-shaped organs that measure 4-5 cm in length and 2.3-3 cm in diameter
*refer to goodnotes
Covering of testes
2 protective tissues:
- Tunica vaginalis
-outer protective covering - Tunica albuginea
-inner fibrous coat or capsule
-extensions from the tunica albuginea penetrate into testis, dividing into around 250-300 compartments known as lobules
-each lobule contains up to 4 thin and elongated seminiferous tubules
*refer to goodnotes
Seminiferous tubules
-within testes
-tightly coiled
-sperm producing factories
-each testis contains about 600-1000 seminiferous tubules in its lobules, which each tubule approximately 80 cm in length when uncoiled
-in loose connective tissue between tubule, leydig cells found, which produce and secrete testosterone
*refer to goodnotes
(When spread out in straight line, total length of seminiferous tubules in both testes around 0.5 miles)
Sperm
-gametes of males
-carry paternal genetic information
-4 regions
- Head
-flat and oval shaped
-contains nucleus
-contributes X or Y chromosome to fertilization process
-contains acrosomal cap which contains enzymes that released prior to fertilization to help sperm penetrate layers of egg - Neck
-connected head to midpiece - Midpiece
-continuation of neck with a mitochondrial collar to help produce energy - Tail (aka flagellum)
-source of movement for sperm
(Average volume of ejaculate is 2-5 ml with approx 15-200 million sperm per ml
Scrotum
-sac of skin and fascia surrounding testes
-derived from anterior abdominal wall and reside outside abdominopelvic cavity
*refer to goodnotes
Muscles of scrotum
2 muscles that function to control temperature of testes
Dartos muscle
-located superficially in Skin of scrotum
-responsible for rugose (wrinkly) appearance of scrotal sac
-helps regulate temperature by altering exposed surface area of scrotum
Cremaster muscle
-covering of testis found deep to scrotal wall
-reflexively contracts in cold environment, drawing testes superiorly in scrotum, closer to body wall where absorb body heat
*refer to goodnotes
Male duct system
-following production in testes, sperm travel through duct system to exit body
-right and left testes have own duct system
Epididymis
-first portion of male duct system
-lies on superior and posterior boarder of each testis
-shaped like comma
-measures 4 cm in length but contains long coiled tubules (4-5 meters total length)
Regions:
Head -> contains and receives sperm from seminiferous tubules
Body -> lies on posterior-lateral boarder of testis and contains highly coiled duct of epididymis
Tail -> located near inferior boarder of testis. Coiling duct has diminished and tube reverses its direction and ascends into vas deferens. Where sperm stored prior to ejaculation
Histology:
Lined with pseudostratified columnar epithelium
Vas deferens (ductus deferens)
-next portion
-stores and transports sperm from epididymis to urethra
Histology:
-lined with pseudostratified columnar epithelium containing stereocilia
-has small lumen, but thick muscularis composed of layers of smooth muscle
-thick muscular layer propel sperm through vas deferens
Structures associated with vas deferens:
Ampulla of vas deferens -> expanded distal portion of vas deferens
Ejaculatory duct -> formed from joining of ampulla of vas deferens and duct if seminal vesicle
-seminal vesicles are accessory glands of male reproductive system that secrete nutritive fluid for sperm
Urethra
-around 15-20 cm long
3 regions: prostatic urethra, membranous urethra, penile urethra
-part of urinary system and terminal portion of duct system and transport sperm out of body
*refer to goodnotes
Accessory glands
-three that nourish the sores as they travel through the duct system
Seminal vesicle
-2 that are located on posterior surface of bladder, in front of rectum
-large, coiled tubular glands
-provide fluid and nutrients to ejaculate and make up 60% of volume of semen
Prostate gland
-single
-size of walnut
-located beneath bladder
-consists of tubular glands embedded in mass of smooth muscle and connective tissue
-produces and secretes sugars and enzymes, accounting for 33% of volume of seminal fluid
-rich in proteases, particularly prostate-specific antigen that aid in liquefaction and dissolution of cervical mucus in female reproductive system
Bulbourethral glands
-two pea-sized and located immediately below prostate, at base of penis
-secrete thick, clear, alkaline mucus that drain into penile urethra
-secretion released before ejaculation to neutralize traces of acidic urine into urethra and to lubricate urethra and penis
*refer to goodnotes
Pathway of sperm
-produced in seminiferous tubules of testes and transported through series of ducts before exiting body
-from testes, through epididymis, vas deferens, ejacualtory duct and urethra
-along course, fluid secreted from glands that contribute to volume of semen
*refer to goodnotes
Penis
-both urinary and reproductive functions as serve as conduit for pathway of urine and sperm
Root of penis
-fixed portion that attaches penis to ischium (pelvic bone)
Body of penis
-tubular, moveable portion of penis that consists of 3 cylinders of erectile tissues and contains urethra
Glans of penis
-expanded distal end (tip of penis), containing external urethral opening
*refer to goodnotes
Penile tissue
-penis made of 2 erectile tissues
-two tissues create three cylinders of tissue
Corps cavernosa
-2 erectile cylinders on the dorsal surface of penis, which make up most of mass
-proximal portions are known as Crura (singular crus) of penis and attached to bony pelvis by muscles
Corpus spongiosum
-this cylinder contains urethra and expands distally to form glans of penis
-proximal end is enlarged and called bulb of penis
*refer to goodnotes
*refer to goodnotes
