Reproduction, Development and Health

what are the paired gonads

ovaries

what are the duct systems

paired uterine tubes, single midline uterus, single midline vagina

The ovary

Produce gametes and hormones, endocrine and exocrine function

Blood supply, venous and lymphatic drainage of the ovaries

Blood supply - ovarian artery, arises from aorta at level of the kidney

Venous drainage - ovarian vein, drains to IVC on right and left renal vein on the left

Lymphatics - drain to aortic nodes at the level of renal vessels

What are the ligaments of the female reproductive system and their roles

broad - peritoneal sheet draped over uterus and uterine tubes, ovaries attached to the posterior layer by short mesentery

Ovarian - fibrous cord which links ovary to uterus

Suspensory ligament - carries ovarian artery and vein, lateral wall of pelvis to ovary

Round - connects uterus to the labia majora

What are the 2 peritoneal pouches of female reproductive system

Rectouterine - extension of peritoneum into the space between the posterior wall of uterus and the rectum

Uterovesicle - fold of peritoneum over the uterus and bladder

What are the parts of the uterine tubes

infundibulum - funnel shaped opening to peritoneal cavity, fimbriae projections

ampulla - middle section where fertilisation occurs

interstitial part

isthmus - short narrow section connected to uterine wall

The uterus

lies in midline, where the embryo/foetus grows

Parts of the uterus

body

cervix - cervical canal, internal os and external os

Fundus - rounded part which projects up above the level of uterine tubes

isthmus - narrowing between body and cervix

blood supply, venous and lymphatic drainage of the uterus

uterine artery, branch of internal iliac artery

uterine vein - drains to internal iliac vein

lymphatics - drainage of body and cervix differ

• body to para-aortic nodes

• cervix to internal iliac nodes

The testes - duct system and accessory glands

exocrine and endocrine glands

duct system - closely associated with urinary system, share final duct urethra

accessory glands - one prostate, two seminal vesicles, two bulbourethral glands

what is the scrotum made up of

skin

dartos muscle

external spermatic fascia

cremaster muscle

cremaster fascia

internal spermatic fascia

cremaster muscle

skeletal muscle

deep to dermis

runs within the spermatic cord

contracts to raise testes in cold weather

Position and covering of the testes

Extra abdominal

suspended at different levels

tunica vaginalis of the testes:

a closed sac of peritoneum;

• visceral and parietal layers

• space between containing film of peritoneal fluid

what happens when there is excess fluid in the tunica vaginalis

hydrocoele

Duct system of the testes

The ends of a coiled seminiferous tubule join to form a straight tubule

all the straight tubules join to a network rete testes

from this network, efferent ductules leave and join epididymis

The epididymis

a very coiled tube, continuous with the ductus deferens

lined by pseudostratified columnar epithelium with stereocilia

• stereocilia increase the area for absorption of fluid and can monitor and adjust the fluid composition

blood supply, venous and lymphatic drainage of the testis

testicular artery

pampiniform plexus → testicular vein → IVC on right and renal vein on left

Different lymphatic drainage of testes and scrotum:

• testes to paraaortic nodes

• scrotum to inguinal node

The ductus deferens

thick walled, smooth muscle in the wall which contracts by peristalsis

Runs in spermatic cord, through inguinal canal

lies on side pf pelvis and turns medially to base of bladder

enlarges at end - ampulla region

also attached here to seminal vesicles

Seminal vesicles

convolted tubular glands

secretes alkaline viscous fluid which helps to neutralise the acidic environment of the vagina

fluid also contains:

• fructose used for ATP production by sperm

• prostaglandins which aid sperm mobility and viability and may also stimulate muscle contraction in the vagina and uterus

Ejaculatory duct

duct of the seminal vesicle joints with the ductus deferens on each side to form the ejaculatory duct

penetrates the prostate gland empties into the urethra

The prostate gland

surrounds the beginning of the urethra

secretes a slightly acidic fluid containing citrate, acid phosphates and proteolytic enzymes which liquidity coagulated sperm

passes its secretions to the urethra

Bulbourethral glands

produce a mucus like secretion

ducts open to spongy urethra

what is meiosis

a special form of cell division which is used to form gametes

prophase 1

chromosomes condense, bivalent forms between homologous chromosomes and crossing over occurs

metaphase 1

spindle fibres attach to the bivalents and they will line up along the metaphase plate at the equator of the cell

anaphase 1

bivalents are pulled to opposite poles of the cell

telophase 1

chromosomes decondense, nucleus may reform, cytokinesis to form 2 haploid daughter cells

prophase 2

chromosomes condense, nuclear membrane disintegrates and centrioles move to the opposite poles

metaphase 2

spindles attach to the chromosomes at the centromere and they will line up along the equator of the cell

anaphase 2

spindles will pull the sister chromatids to opposite poles and they are now referred to as chromosomes

telophase 2

the chromosomes decondense, nucleus reforms, cytokinesis to form 4 haploid daughter cells

what is crossing over

occurs at meiosis 1, this is when he maternal and paternal genetic information will cross over, this occurs between homologous chromosomes

what is random assortment

when the chromosomes will line up in a randomised order

what is the starting germ cell of gametogenesis

primordial germ cell

Outline the process of oogenesis

primordial germ cell will move and find a home in the developing gonad, they will divide to populate the area and then undergo meiosis to form gametes. Firstly they will become oogonia, oogonia will then become a primary oocyte, this is halted at prophase 1 and will remain like this until puberty and are not primary oocytes, once puberty occurs a few of these oocytes will be selected to proceed and will undergo meiosis up until metaphase 2, they are now secondary oocytes. Each month from puberty one of these secondary oocytes will be selected to be fertilised, if fertilisation occurs when it will undergo the rest of meiosis.

what are polar bodies and when are they produced

polar bodies are produced in order to allow the oocyte to keep cytoplasm and loose as much genetic material as possible, this is lost in the polar bodies at metaphase 2 and fertilisation

what is happening parallel to the development of oocytes

the development of the follicle from primordial → primary → secondary → release of oocyte → corpus luteum

Outline the process of spermatogenesis

again it starts with primordial germ cells which will become spermatogonia, there is two types of spermatogonia - type a and type b, type a is used to populate the testes and type b is used in gamete formation, this process occurs via mitosis.

the type b spermatogonia is going to divide via mitosis to form primary spermatocytes

the primary spermatocyte will divide by meiosis to become two secondary spermatocytes

these secondary spermatocytes will divide to become 4 spermatids

outline the process of spermiogenesis

this is when the spermatids will undergo differentiation to become spermazoa, they will loose their cytoplasm to make them more motile, they will gain an acrosome over the nucleus which contains enzymes to allow them to penetrate the egg and the midpiece (the neck) which contains mitochondria which will provide energy, and will gain flagellum to allow them to be motile.