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Reproduction - Medsci


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Molecules that are released on one part of the body but regulate the activity of cells in other parts of the body.
Exocrine Glands
Secrete products into ducts that carry them into body cavities, lumens of organs and outer body surface.

Eg. Sudoriferous (sweat)
Sebaceous (oil)
Mucous & digestive

Endocrine Glands
Secrete products into interstitial fluid, not ducts. These products then diffuse from the interstitial fluid into the blood capillaries for transport around the body

Eg. Pituitary

Paracrine Hormones
Local hormones that act on neighboring cells
Autocrine Hormones
Local hormones that on on the same cell
Lipid Soluble hormones such as Testosterone, estrogen, T3, T4 and NO can/cannot enter a cell directly
CAN as they are Lipid soluble
Three types of water soluble proteins are
Eg. Catecholamines (Norepinephrine & Epinephrine)

2)Peptides and Proteins
Eg. Oxytocin, ADH, FSH, TSH, GnRH & LH

Eg. Prostaglandins & Leukotrienes

What are the 3 Lipid Soluble Steroid Hormones?
Androgens, Oestrogens and Progestagens
2 Main Androgen hormones
Testosterone & 5alpha Dihydrotestosterone (stronger)
3 Main Oestrogen hormones
Oestradiol, Oestrone & Oestriol
1 Main Progestagen hormones
What does the Pituitary gland use to attach to the hypothalamus?
Infundibulum (Posterior Pituitary)
The anterior pituitary is also called the ________?
The Adenohypophysis counts for about ____% of the weight of the gland.
The Anterior Pituitary (Adenohypophysis)has 2 parts in the adult. What are they?
Pars Distalis
Pars Tuberalis (forms a sheath around Infundibulum)
The posterior pituitary is also called the ______?
The Posterior Pituitary (Neurohypophysis) also has 2 parts in the adult. What are they?
Pars Nervosa
Infundibulum (Stalk)
What is the name of the third region of the pituitary gland and why is it not present in the adult?
Pars Intermedia ATROPHIES during human fetal development and ceases to exist in adults
Portal system
Blood flows from one capillary network into a PORTAL VEIN and then into a second capillary network without passing through the heart
Superior hypophyseal arteries
Branches of the internal carotid arteries that bring blood into the hypothalamus
What is the pathway of the Hypophyseal Portal System?
Superior Hypophyseal Arteries -> Primary Plexus of the Hypophyseal Portal System -> Hypophyseal Portal Veins -> Secondary Plexus of the Hypophyseal Portal System -> Anterior Hypophyseal Veins
What part of the hypothalamus releases hormones which will eventually diffuse into the Primary plexus of the hypophyseal system?
Hypothalamic Neurosecretory cells produce these hormone which travel down axons and released at axon terminals
Tropic Hormones
Anterior pituitary hormones that act on other endocrine glands
Homeostatic Regulator for reproduction, stress, temperature, hunger and sleep.

[Neuroendocrine organ]

Which part of the pituitary gland has a portal system? Anterior or Posterior
Anterior Pituitary
Which part of the pituitary gland has the longer neurosecretory cell axons? Anterior or Posterior
Where are the neurosecretory peptide hormones stored and released in regards with the Posterior Pituitary?
Travel down to axon terminals and stored as secretory vesicles.

Nerve impulses down the axon causes exocytosis to release the peptide hormones

Oxytocin has 3 effects
1)Affects Smooth Muscle Contraction
2)Stimulates Milk Ejection
3)Induces uterine contractions for child birth

What is the pathway of hormone release in the Anterior pituitary?
Neurosecretory neurons (parvicellular) secrete hormones(GnRH) -> Stored at axon terminals -> nerve impulses release them into primary plexus of the portal system -> act on secretory cells in the pars distalis -> produces gonadotrophins FSH and LH
What is the pathway of hormone release in the Posterior pituitary?
Neurosecretory neurons (Magnocellular)secrete ADH and Oxytocin -> Stored at axon terminals in Posterior pituitary -> Nerve impulses release them
Pulsatile release
Hypothalamic secretions that are released in discrete bursts, separated by periods of little or no secretion.
What does pulsatile release prevent?
1) Receptor desensitisation - After repeated exposure, the hormone does not bind to the receptor
2)Down regulation - Overstimulation causes receptor to INTERNALISE itself (go in inside cell) so hormones cannot bind to receptor anymore
Antidiuretic Hormone (ADH or Vasopressin)
Stimulates kidney to regulate and maintain water to maintain blood volume
Follicle-Stimulating Hormone
Helps the growth of Sperm and Ovarian Follicles.
Average Number of oocytes released
~ 400
Mature oocyte released every ___?
28 days
The NZ fertility rate is ___?
On average, how long is the elastic muscular tube, the vagina?
7.5-9.0 cm
What is the function of the ampulla of the uterine tube?
A marker for the area where fertilisation occurs
What is the function of the isthmus of the uterine tube?
A marker for the area where sperm is stored
What are the functions of the uterus for the developing embryo & fetus?
- Mechanical Protection
- Nutritional support
- Waste Removal

Which level of the uterus wall is important for ejection the fetus at birth?
Contractions in the myometrium
Which level of the uterus wall is the source of menstrual flow?
Endometrium Lining
Which zone of the endometrium ( Stratum Functionalis or Stratum Basalis) attaches the endometrium to the myometrium?
Stratum Basalis
What is the average weight of the uterus?
The uterine tube provides a rich, nutritive environment containing ___ and ___ for spermatoza, oocyte and developing embryo.
Lipids and Glycogen
The epithelium lining of the uterine tube is made up of which type of cells?
BOTH cilliated and noncilliated secretory cuboidal cells
Transport along the uterine tube is due to ___ and ___?
Ciliary movement and Peristaltic contractions.
Adult human ovaries weigh around...?
Which region of the ovary contains the ovarian follicles?
Outer ovarian cortex
What is contained in the central ovarian medulla?
Ovarian Stroma and Steroid Producing cells
Which part of the ovary acts as the point of entry for NERVES and BLOOD VESSELS?
The Inner Hilum
Formation of gametes in the ovaries
The process germ cells degenerate
What promotes the development of Primordial follicles into Primary Follicles?
Release of FSH & LH by the Anterior Pitutary
As the ovarian follicle enlarges, follicular fluid accumulates in a cavity called?
The Antrum
Theca Folluculi
Organised layer of stromal cells
What is the clear, glycoprotein layer between the primary oocyte and the granulosa cells?
Zona Pellucida
Out of the Theca Interna and Theca Externa, which becomes a highly vascularized layer of cuboidal secretory cells that secrete estrogen?
Theca Interna
What secretes the follicular fluid that fills the Antrum in a secondary follicle?
The granulosa cells
Corona Radiata
Innermost layer of granulosa cells surrounding the Zona Pellucida
Cumulus Oophorous
Mass of loosely attached granulosa cells from the oocyte to the granulosa cells
Which stage of follicle development does the primary oocyte complete meiosis I?
Mature (Graafian) Follicle
Corpus Luteum
Yellow body containing the remnants of a mature follicle after ovulation.
Corpus Albicans
Fibrous Scar Tissue
What does the Corpus Luteum produce after ovulation?

When does LUTENISATION occur?
After Ovulation, due to an increasing secretion of Progestagens as the granulosa cells form large Lutein cells forming the Corpus Luteum
What are the 2 phases in the ovarian cycle?
Follicular Phase (Day 1-Ovulation)
Luteal Phase (Ovulation - Menstration)
Increase in FSH means
Stratum Functionalis is at its Lowest
Follicle Growth is occuring
Increase in Estrogen means
Dominant Follicle is Selected
Increase in LH means
Increase in Progesterone means
Stratum Functionalis is at its Thickest
Preparation of the Uterus for the foetus
SRY gene
Sex-Determining Region on the Y-chromosome
Mesonephric (Wolffian) Duct
Develops into structures of the Male reproductive system
Paramesonephric (mullerian) Duct
Develops into structures of the Female reproductive system
What week of development do the gonads develop?
fifth-sixth week
The protein product from the SRY gene causes which cells to differentiate?
Sertoli cells
Human chorionic gonadotropic (hCG) stimulates which cells?
Leydig cells
Leydig cells secrete which hormone?
The androgen Testosterone which stiumlates the development of the Mesonephric (Wolffian) ducts
If Testosterone stimulates development of internal male genitals, which androgen develops external male genitals?
Dihydrotestosterone (DHT)
In females, how many weeks does it take for Wolffian ducts to regress?
10 weeks
In males what happens to the urethal folds?
They fuse, forms the shaft of the penis
In Males, what forms the scrotum?
Labioscrotal swellings
At what mass does menarche occur?
What is the sequence of events in puberty for girls?
Breast increase -> Pubic Hair -> Height spurt -> Merache
What is the sequence of events in puberty for boys?
Testis -> Pubic Hair -> Penis -> Height spurt
PERMANENT cessation of menstruation
Why does menopause occur?
The consequence of the ovaries running out of follicles
Ovarian Senescence
One year after menopause, the ovary had stopped producing hormones
From age ~40-46, the end of REGULAR cycles
Menopausal transition
From end of regular cycles (~45 years) to the last menstruation (~50-52 years)
From the last Menstruation
Menopause transition (counts till hormones begins to cease)
Testes do not move from the scrotum to the pelvis = infertile
Spermatogenisis takes how many days?
65-75 days
Where does spermatogenisis occur?
In the Seminiferous tubules
What unique process occurs in spermatogenesis?
They constantly fail to complete cytoplasmic seperation (cytokinesis) so they remain in cytoplasmic contact throughout entire development
How many sperm complete spermatogenesis per day?
300 million
Which section of the sperm tail contains the centrioles?
Which section of the sperm tail contains mitochondria?
Middle piece
After ejaculation, how many hours can sperm survive?
48 hours (within the female reproductive tract)
How much sperm is produced in males per second?
20,000 sperm per sec
What is the function of the Androgen-Binding protein (ABP)?
Binds to testosterone to keep its concentration high.
What are the 3 effects resulting from Testosterone and DHT binding to androgen receptors?
- Prenatal Development
- Development of sexual characteristics
- Anabolism (protein synthesis)

What does Sertoli cells produce to inhibit FSH?
What does Leydig cells produce to inhibit GnRH and LH?
No sperm
Describe the pathway of the sperm in the testis
Seminiferous tubules -> Rete testis -> Epididymus -> Vas Deferens
How long does it take for sperm to become motile?
10-14 days
Where do sperm acquire the ability to be motile?
Where does the urethra join the ejaculatory duct?
At the prostate
Seminal Vesicles
Secretory glands that secrete a mucoid sticky substance into the ejaculatory duct to wash down sperm.
Does the prostate secrete anything?
Yes, the prostate secretes Prostatic Fluid into the Prostate urethra ahead of sperm
Fluid from the seminal vesicles constitutes to about __% of semen.
Prostate Specific Antigen (PSA)
Helps to break down coagulum
Fluid from the Prostate constitutes to about __% of semen and contribute to sperm motility and viability.
Cowpers glands produce an alkaline fluid into the urethra to do what?
Protect the sperm by neutralizing acids from urethra
Bulbourethral Glands also secretes mucus for what purpose?
Lubricating the end of the penis and the lining of the urethra to decrease the number of sperm damaged during ejaculation.
What is the ph of semen?
Release of which hormones causes the Corpora cavernosa to relax?
NO and Prostaglandin E1
How does Viagra (sildenafil) work?
Inhibits Phosphodiesterase, Increases GMP, Relaxes arteries of corpora cavernosa resulting in an erection
Benign Prostatic Hyperplasia (BPH)
Enlargement of the prostate (2-4 times its normal size) decreasing size of the prostatic urethra causing many urinary problems
Two ways to treat BPH are:
Selective 5-alpha-reductase inhibitors (Finasteride and Duasteride)


What does corpus luteum mean?
Yellow body
What does corpus albicans mean?
White body - fibrous scar tissue
What does the broad ligament suspend?
part of the uterus and the parietal peritoneum
What does the mesovarium do?
Connect the ovaries to the uterus (double layered fold of peritoneum)
What does the ovarian ligament do?
Anchors the ovaries to the uterus
What does the suspensory ligament do?
Attaches the fallopian tubes to the uterine wall
What secretes progesterone in the female ovary?
Corpus luteum
What part of the female ovary produces Relaxin and what is its purpose?
Corpus luteum secretes relaxin.
This is done to inhibit contractions of the myometrium as well as increasing the flexibility of the pubic symphysis to help delivery

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