Lecture 27: Anatomy and Physiology II (reproductive) Flashcards
What is spermatogenesis?
Sperm cell production
What are some features of spermatogonia?
- diploid germ cell with 46 chromosomes in humans
- divide by mitosis to create spermatocyte
- The spermatocyte differentiates the divides by meiosis
- Creates 4 haploid sperm cells where there is 23 chromosomes in humans
What is spermatogonia?
The undifferentiated spermatogenic cell
What is the structure of sperm?
- oval head
-haploid nucleus
-acrosome: contains enzymes to penetrate oocyte - midpiece
-cylindrical shape
-mitochondria for energy - tail
-flagellum: made microtubule
What are the testes composed of?
- seminiferous tubules
- epididymis
- vas deferens`
What is the seminiferous tubules composed of?
- spermatogenic cells
- interstitial cells
What are spermatogenic cells?
Germ cells that give rise to sperm cells (spermatogonia)
What are the interstitial cells?
Lydig cells, produce testosterone
What is the epididymis?
Passage between seminiferous tubules and vas deferens
What is the vas deferens?
Ductus deferens and is the passage for sperm towards ejaculatory duct
What is the seminal vesicle?
The glandular tissue located near the base of the bladder
What are some features of the seminal vesicle?
- secretion
-slight alkaline fluid to help neutralize the acidic pH of vagina
-fructose to nourish sperm cells
-prostaglandins to stimulate muscular contractions in the uterus to aid in sperm movement - empties into ejaculatory duct along with vas deferens
Where is the prostate gland located?
Below bladder and surrounds proximal part of urethra
What are some features of the prostate gland?
- Citrate to nourish sperm
- prostate specific antigen PSA: enzyme that helps liquefy semen so sperm can stay motile
Where is the bulborethral gland(cowper’s gland)?
It is located below prostate gland
What are some features of the bulborethral gland?
It secretes lubricating fluid in response to sexual stimulation. Also, the corresponding gland in a female is the vestibular gland
What is the average volume of semen?
2-5 mL
What are some features of semen?
The fluid that is ejaculated and contain sperm cells, secretion of seminal vesicle, prostate gland, and bulborethral gland
What is the scrotum?
The pouch of skin that holds the testes. The testes hang outside of the body to remain 3 C below body temp. Higher temps affect spermatogenesis and sperm survival
What is the penis?
The cylindrical organ that conveys urine and semen through the urethra
What is the body?
The shaft that contains erectile tissue that becomes stiff when filled with blood
What is the glans?
Cone on distal end
What is the prepuce in the glans?
The foreskin or loose fold of skin covering glans
What is circumcision associated with?
Reduced risk of HIV, HPV, and UTI
What is circumcision?
The surgical procedure that removes the prepuce
What are the ovaries composed of?
- medulla
- cortex
What is the medulla in the ovaries?
The inner layer that is composed of loose connective tissue and blood vessels
What is the cortex in the ovaries?
The outer later and ovarian follicles
What are some features of primordial follicles?
- primary oocyte
- follicular cells
- undergp meiosis early, but process halts as a fetus
- no new primordial follicles form
What is a primary oocyte?
A single large cell
What are follicular cells?
Epithelial cells surrounding primary oocyte and are the supply nutrient to oocyte
What is oogenesis?
egg formation
What is the process of oogenesis/oocyte?
- primary oocyte resumes meiosis beginning at puberty
- meiosis is uneven, cytoplasm distributed unequally
- meiosis I: secondary oocyte gets all the cytoplasm
-secondary oocyte
-first polar body - meiosis II: ovum gets all the cytoplams
-happens at fertilization
-ovum is fertilized becoming a zygote
-second polar bodies - polar bodies give up cytoplasm and organelles to create massive zygote
-early rounds of cell division in embryonic development can be faster
What is zona pellucida in ovulation?
The layer of glycoprotein surrounding oocyte
What is the corona radiata in ovulation?
The layer of follicular cells surrounding oocyte
When is a new follicle released?
Every 28 days
What is the uterine tube?
The fallopian tube
What is the infundibulum in the uterine tube?
The funnel shape of uterine tube that encloses each ovary
What is the fimbrae?
The fringe of the infundibulum
What is uterine tube lined with?
Simple ciliated columnar epithelium to sweep oocyte toward the uterus
Where does fertilization occur?
Uterine tube
What does the uterus do?
Receives and sustains the developing embryo
What is the fundus?
The dome shaped top of the uterus
What is the body?
The top 2/3 of uterus
What is the cervix?
The bottom 1/3 of the uterus that extends towards vagina
What is the uterine wall composed of?
- endometrium
- myometrium
- perimetrium
What is the endometrium?
The inner layer of the uterine wall
What is the myometrium?
The smooth muscle of the uterine wall
What is the perimetrium?
The outer layer of the cervix
Where is the vagina located?
From the uterus to the outside
What is the hymen?
The thin membrane of connective tissue and stratified squamous epithelium that partially covers the vaginal orifice
What is the vulva?
The external structures that surrounds opening for urethra and vagina
What is the labia majora?
Rounded folds of adipose tissue and thin layer of smooth muscle
What is the mons pubis?
The labia majora merge at anterior end of pubic region also has the same tissue that develops into scrotum in males
What is the labia minora?
Flattened longitudinal folds between labia majora. It is pink in appearance because of blood vessels
What is the clitoris?
The small projection at anterior end of vulva. It is also the same tissue that develops into penis in males and has columns of erectile tissue. Also, has glans with rich supply of sensory nerve fibers
What is the vestibule?
The space in between labia minora. Contains the urethra opening at midline, vagina opening in posterior portion and vestibular glands
What is the vestibular glands?
Secrete lubrication in response to sexual stimulation(Bartholin’s glands)
What is the ovarian cycle process?
- gonadotropin releasing hormone (GnRH) triggers release of FSH and LH
- follicle stimulating hormone FSH- stimulate ovarian follicle to mature
- luteinizing hormone LH- stimulates ovarian follicle to mature
- ovulation occurs(oocyte is released)- remains of ovarian follicle becomes corpus luteum
- corpus luteum secretes progesterone and estrogen
- progesterone and estrogen promote thickening of endometrium
- FSH and LH levels drop
- If there is no embyo implantation, corpus luteum degenerates, proge and estro levels drop, and uterine lining sheds (period basically)
What happens in the ovaria. cycle when there is an embryo?
- Embryo produces human chorionic gonadotropin (hCG)
- acts like LH to maintain corpus luterum
- maintains progesterone and estrogen levels
-uterus continues to prepare for pregnancy
-inhibits GnRH release(prevents ovulation while pregnant)
- contraceptive pill is progesterone and estrogen
