Reproductive System Flashcards
What are the components of the male reproductive system?
Testes Epididymis Ductus deferens Accessory glands Urethra Penis
Describe how testes move into the scrotum
Develop in abdomen at level of kidneys
Migrate through hole in abdominal wall/inguinal canal into scrotum around time of birth, carrying spermatic cord and some fascia to cover sac
Descent is guided by gubernaculum
What is in the spermatic cord?
Blood vessels
Nerves
Ductus deferens
What is the risk of leaving testes undescended?
Germ cell tumours
Where is sperm produced in the testes?
Seminiferous tubules
Describe the structure of mature sperm
Head- streamlined, acrosome head with enzymes to penetrate ovum, nucleus with highly condensed chromosomes
Midpiece- lots of mitochondria
Tail- flagellum for propulsive forward swimming
What is the role of the epididymis?
Collect sperm from seminiferous tubules to mature, store, concentrate and transport sperm
What causes sperm maturation in the epidiymis?
Maturation factors
How long does it take for sperm to move through the epididymis?
12-14 days
Why is thermoregulation of the testes important?
Allow normal function and production of sperm
How are the testes thermoregulated?
Pampiniform plexus, small network of veins
What is the role of the ductus deferens?
Transport sperm from epididymis to urethra
What are the walls of the the ductus deferens made of and why?
Thick smooth muscle
Contract to propel sperm movement
What is the pathway of the structures the ductus deferens passes through?
Inguinal canal
Abdomen
Around bladder
Accessory sex glands
What is the role of the urethra?
Carry ejaculate and urine from base of bladder to external urethral opening
What is the lining of the urethra?
Urothelium
What are the parts of the urethra?
Prostatic- passes through prostate
Membranous- passes through perineal membrane
Spongy/penile- runs through penis
What is the perineal membrane?
Divides pelvic area from whats below and provides attachment for external genitalia
List the accessory sex organs
Ampulla Seminal vesicles Prostate Vagina Bulbourethral glands
What is the role of the accessory sex glands?
Make up seminal fluid part of semen
Where are the ampulla located and what do they produce?
Dilated distal ends of the ductus deferens
Minor amounts of seminal fluid
What does seminal vesicles fluid contain?
Fructose- energy
Fibrinogen- coagulation
Enzymes
Where are the seminal vesicles located?
Connected to ductus deferens to form short ejaculatory duct whihc joins the urethra
Describe the secretions of the prostate glands
Thin and milky
What does prostate secretions contain?
Buffers- acidic urethra and vagina
Clotting factors- act on fibrinogen to coagulate
What is the role of bulbourethral glands?
Produce small amounts of clear pre ejaculatory fluid to help flush urethra before ejaculate comes through
Where are the bulbourethral glands located?
Level of perineal membrane
Describe the process of ejactulation
Sympathetic mediated contraction of ductus deferens walls
Sperm propelled to combine with secretions from accessory glands
Joins ejaculatory duct then enters urethra at seminal colliculus
Prostate contractions help release prostatic secretions
Powerful somatic urethral contractions propel semen out of the body
What are the two stages of ejaculation?
Seminal emission
Ejaculatory phase
What are the different parts of the penis?
Root- attached to perineal membrane and partly to crura
Body- two crura running side by side
Glans- swollen distal end, contains external urethral orifice for passage of semen
What are the two types of erectile penile tissue?
Corpora cavernosa- paired cavernous bodies, main erectile tissue attached to perineal membrane
Corpora spongiosum- surrounds urethra forming bulb which joins perineal membrane and forms glans
What and where are the vessels in the penis?
Dorsal artery, deep artery and artery of bulb branching off internal pudendal artery, branch of internal iliac artery
Found dorsal to corpus spongiosum
How does testicular orientation vary between species?
Horizontal- cats
Vertical- bull, ram, humans
Diagonal- dogs, boar, stallion
Snakes- internal
How do bulbourethral glands vary between species?
Dog- none
Ox- small
Pig- long and vertical
Horse- long and diagonal
What is the gland equivalent to humans seminal vesicles?
Vesicular glands
What are the two types of penis?
Musculocavernous
Fibroelastic
Describe a musculocavernous penis and name species with this type
Flaccid when not in use
Engorges with blood to become erect
Man, horse, dog, cat
Describe the fibroelastic penis and name species with this type
Solid structure that elongates due to relaxation of retractor penis muscle allowing sigmoid flexure to straighten
Ox, boar, ram
Name the components of the female reproductive system
Ovaries Uterus Vagina Cervix Uterine tube External genitalia
What does the ovarian ligament connect together?
Uterus to ovaries
What is the role of the ovaries?
Oogenesis/egg maturation
Hormone production to maintain structures linings
Describe the structure of the human ovaries
Tunica albuginea- fibrous outer coat
Outer cortex- contains follicles and reserve of eggs
Primordial- reserve follicles
Inner medulla- contains vessels and nerves
Maturing and matured follicles
What does the broad ligament connect together?
Ovary to uterine tube
What supplies uterine tube with blood vessels?
Suspensory ligament
What are the regions and roles of the uterine tube?
Infundibulum- finger like fimbriae to collect ova and waft down tube by cilia and peristalsis
Ampulla- wider, site of fertilisation
Isthmus- join uterus, narrowed part of tube
What is the role of the uterus?
Implantation and pregnancy, shedding lining when no pregnancy established
What causes the uterus lining to be shed?
Declining levels of progesterone
Describe the structure of the uterus
Fundus- uterine tubes enter
Body- bulk of uterus, site of implantation
Cervix- external os, barrier between uterus and vagina
What are the uterus walls made of?
Thick smooth muscle lined with endometrium which thickens for implantation
What is the cervix made of?
Collagenous dense smooth muscles lined with squamous epithelium
What are the different shaped cervixes?
Nulliparous- circle shaped
Parous- slit shaped after vaginal birth