16.1 Reproductive System - Female

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Reproductive Systems:

Reproductive Systems Female Reproductive System Male Reproductive System General Training Module RK

Reproductive Systems:

Reproductive Systems Introduction to reproduction Part A : T he Female Reproductive System Anatomy & Functions of External Genitalia Internal Organs of the Female Reproductive System Puberty and Secondary Sexual Characteristics in the Female Ovulation and its hormonal regulation Menstrual Cycle and the Uterus The Uterus & Pregnancy Menopause Breasts Part B : The Male Reproductive System

Reproduction:

Reproduction The ability to reproduce is a key feature of all living things that differentiate them from the non-living. It helps the continuation of the species. The more primitive the animal simpler the reproductive process. In simpler organisms reproduction is asexual (like binary fission seen in bacteria which is unicellular – that has only one cell) That is they do not have male and female forms among them. All of them are the same and they reproduce by dividing the cell into to and becoming two cells

Reproduction:

Reproduction In humans the reproduction is sexual. It is achieved through the union of male and female cells specially formed for reproduction within each male and female body. The union of these two cells is accomplished under natural conditions through sexual intercourse. The males and females are different anatomically and physiologically in a way that help them to fulfill their reproductive roles

Reproduction:

Reproduction The cells formed within our bodies for reproductive purpose are called germ cells or gametes. In the male these are spermatozoa, more commonly known as sperm (Colloquially called seeds) – produce in the testes In the female they are ova (Colloquially called eggs) – produced in the ovaries

Reproduction:

Reproduction How do the sperm and ova differ from normal cells? Each cell has what we call genetic material made up of DNA – Deoxy -ribose Nucleic Acid They are large organic molecules located in the nucleus of the cell. They have the instructions for the synthesis of functional and structural components of cells and cellular processes in order to grow and develop the organism and then sustain life.

Reproduction:

Reproduction DNA within the nuclei are arranged into structures known as chromosomes Each human body cell nucleus has 23 pairs of chromosomes (46 in total) that contains the DNA required for human life. One chromosome in each pair is received from the mother and the other from the father Reproductive cells or gametes are special in that way they only have 23 chromosomes (not pairs) These are formed from a different type of cell division called MEIOSIS in the reproductive organs. So that when they unite through reproduction the new cell formed has the usual 23 pairs (46) of chromosomes

Reproduction:

Reproduction The function of the male reproductive organ is therefore to produce sperms and transmit them to the female reproductive system where they unite with the ova. This is called FERTILIZATION and the new cell formed is called the ZYGOTE The function of the female reproductive system therefore is to produce ova, receive the sperm, accomplish fertilization. In addition the female reproductive organ also provides the template for the zygote to implant and grow, nurture and protect the growing embryo/fetus until birth. Thereafter it produces nutrition to the young infant through lactation (breast milk) until it can take other forms of food.

Female Reproductive System:

Female Reproductive System

Anatomy of the Female Reproductive System:

Anatomy of the Female Reproductive System External Genitalia: collectively known as vulva consists of: Vaginal orifice, Hymen, Vestibule of the vagina, Vestibular glands, Labia M inora , Clitoris, Labia M ajora , Mons Pubis Internal organs: Vagina, Uterus, Uterine tubes, Ovaries lie in the pelvic cavity Accessory Glands: Breasts (in the male they are present but rudimentary – does not carry out any important reproductive function)

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External Genitalia of the Female

Vulva:

Vulva Labia Majora is the two large skin folds on either side of the vulva forming its lateral boundaries. Posteriorly they merge with the perineal skin and anteriorly they join in front of the pubic symphysis and form the mons pubis. At puberty, pubic hair grows on the mons pubis and the lateral folds of the labia majora . Has many sebaceous glands on them.

Vulva:

Vulva Labia Minora : they are the two smaller folds within Labia Majora . Between them is the vestibule. The urethra and the vagina open in to the vestibule. Urethra anteriorly . Vagina Posteriorly . Labia Minora contain many sebaceous glands which too open in to the vestibule. Posteriorly they unite to form the fourchette , a skin fold. Anterior where they unite is the clitoris partially covered from the skin folds of the labia minora

Vulva:

Vulva Clitoris: Is similar to the male penis but smaller and has no urethra in it. Contains erectile tissue. It has little function as a reproductive organ. However due to its high sensitivity - it is considered to be one of the most important anatomical part of the female anatomy in deriving female sexual pleasure. Hymen: Is a thin muccous membrane that partially covers the opening of the vagina

Vulva:

Vulva Greater vestibular glands also known as Bartholins Glands are located one on each side of the opening of the vagina. Their ducts open into the vestibule immediately lateral to the attachment of hymen, in between the hymen attachment and the labia minora . They secrete mucus that keeps the vulva moist.

Vulva:

Vulva Blood supply: Internal Pudendal arteries – from internal iliac arteries External Pudendal arteries – from the femoral arteries Veins form a large plexus that drains to internal iliac vein Lymph drain through superficial inguinal nodes Nerve supply is by branches of pudendal nerves

Internal anatomy of the Female Reproductive System:

Internal anatomy of the Female Reproductive System

Vagina:

Vagina Vagina is a fibromuscular tube line with a stratified squamous epithelium. It connects the external and internal organs of reproduction in the female and receives the male penis during copulation. It runs upwards and backwards at about 45 degrees angle in the pelvis in between the bladder in the front and rectum and anus behind.

Vagina:

Vagina Blood supply: an arterial plexus is formed round the vagina derived from uterine and vaginal arteries which are branches of the internal iliac arteries A venous plexus in the muscular wall drains to internal iliac veins Lymphatics drain through deep and superficial iliac glands Nerve Supply: Parasympathetic sacral outflow, Sympathetic lumbar outflow, Somatic sensory Pudendal nerve

Uterus:

Uterus Hollow muscular pear shaped organ in the pelvis in between the bladder anteriorly and rectum posteriorly . It is flattened in the antero -posterior plane . In the normal position it is bent anteriorly and is almost in right angles to the vagina. It has three main parts: The fundus , the body and the cervix. Fundus is the dome shaped upper end above the openings of the tubes. Body the main part narrows inferiorly to open into the cervix at the internal os . The cervix or the neck opens to the vagina through the external os .

Uterus:

Uterus There are three layers of the uterine wall: Perimetrium Myometrium Endometrium Perimetrium consists of the peritoneum which extends laterally as a double fold to attache the uterus to the pelvic wall. The superior border of the this called the broad ligament contains the uterine tubes.

Uterus:

Uterus Myometrium is the thickest layer and contains smooth muscle along with connective tissues and blood vessels and nerves. Grid iron arrangement of smooth muscle and blood vessels passing through the grid. Endometrium consists of columnar epithelium. Has large number of mucus secreting tubular glands. The cervical canal is lined with mucus membrane in its upper part while the lower part is lined with squamous epithelium which is continuous with that of the vagina

Uterus:

Uterus Blood supply: The blood supply is through uterine arteries from the internal iliac artery. They pass along the lateral aspect of the uterus in the broad ligament and supply the tubes and the uterus and join ovarian arteries to supply the ovaries as well as inferiorly anastomose with the vaginal arteries to supply vagina. Venous drainage is to internal iliac vain. Lymph drain is to aortic and iliac lymph nodes. Nerve Supply: Sympathetic from lumbar outflow and Parasympathetic from sacral outflow.

Uterus - Functions:

Uterus - Functions Functions of the Uterus: After Puberty the uterus undergo cyclical changes regulated by hormonal cycles this is known as the menstrual cycle. The menstrual cycle prepares the uterus to receive, implant, protect and nourish the fertilized ovum. If a succesfull conception occurs it provides the environment for the growing fetus, during the 40 week gestation period at the end of which the baby is born.

Uterine Tubes:

Uterine Tubes Extends laterally from the sides of the uterus between its fundus and the body. The tubes lie in the upper border of the broad ligament. The trumphet shaped lateral end of the tubes penetrate the round ligament posteriorly to open into the peritoneal cavity. They has finger like projections called fimbria which are in close association with the ovaries. They have a middle smooth muscle layer and lined by the ciliated epithelium.

Uterine Tubes - Function:

Uterine Tubes - Function Uterine tubes also known as the fallopian tubes transport the ovum released by the ovaries to the uterus. Peristaltic movements and the ciliary movements in the tubes help this. Also the mucus in the tubes provide an ideal environment for this movement. The Fertilization occurs in the fallopian tube. Therefore the sperm travels along the tube to meet the oncoming ovum. Once the fertilization occurs the zygote is transported to the uterus for implantation.

Ovaries:

Ovaries The are the female gonads or glands. They are located laterally to the uterus in the pelvic cavity on the posterior surface of the broad ligament. It is attached to the posterior surface of the broad ligament by mesovarium and to the upper part of the uterus by ligament of the ovary. Blood vessels and nerves of the ovary pass through the mesovarium to supply the ovary. They have two layers of tissue: the medulla in the middle and the cortex surrounding it.

Ovaries:

Ovaries The cortex is made of a connective tissue framework called stroma covered by the germinal epithelium. It contains the ovarian follicles each of which contains an ovum. Before puberty ovaries are inactive. However the stroma already contains immature follicles. It is only after puberty and during child bearing age that follicles mature and release an ova at a time in a cyclical manner under hormonal regulation. These cyclical changes occur during the menstrual cycle of the females.

Puberty:

Puberty It is a developmental stage during which secondary sexual characteristics appear and both males and females acquire the capacity to carry out sexual reproduction. It occurs between the ages of 10 to 14 years In the Female ovaries are stimulated by the gonadotrophins from the anterior pituitary, the Follicle Stimulating Hormone (FSH), and Luteinizing Hormone (LH)

2ry Sexual characteristics of the female:

2ry Sexual characteristics of the female The uterus, tubes and ovaries reach maturity The ovulation starts The menstruation starts and the menstrual cycles begins The breasts develop and enlarge Pubic and axillary hair in the female appear There is a general increase in the rate of growth in height and weight Widening of the female pelvis There is an increased fat deposition in the subcutaneous tissue

Menstrual Cycle:

Menstrual Cycle This is a series of events, occurring regularly in females approximately every 28 days starting from puberty, throughout the child bearing age up to menopause. Changes mainly occur in the ovaries and in the uterus at the same time and is regulated by blood concentrations of hormones from the hypothalamus (LHRH), anterior Pituitary (FSH & LH) Ovaries ( Oestrogen & Progesterone)

Menstrual Cycle:

Menstrual Cycle Luteinizing Hormone Releasing Hormone (LHRH) from the hypothalamus stimulates the anterior pituitary to secrete FSH & LH Follicle Stimulating Hormone: Promotes the maturation of ovarian follicles Secretion of Oestrogen from the maturing follicles Ovulation Luteinizing Hormone: Promotes the formation of Corpus Luteum Secretion of Progesterone from the Corpus Luteum Hypothalamus responds to blood levels of oestrogen and progesterone. Depressed by high levels and stimulated by low.

Ovaries:

Ovaries

Hormonal Regulation of Ovulation:

Hormonal Regulation of Ovulation Menstrual cycle is regulated by hormones of the anterior pituitary The Follicle Stimulating Hormone (FSH) secreted by the anterior pituitary stimulates the ovaries and maturation of the follicle. The lining cells of maturing follicle secrete the hormone oestrogen . At the peak of FSH which is controlled by a feed positive loop, the ovulation occurs and an ova from the maturing follicle is released out of the ovary.

Hormonal Regulation of Ovulation:

Hormonal Regulation of Ovulation After ovulation, the lining cells of the follicle develop into Corpus Luteum (yellow body) under the influence of the Luteinizing Hormone (LH) of the anterior pituitary. The Corpus Luteum secretes the hormone Progesterone. If the ovum is fertilized it is implanted in the uterine wall where it grows and develops producing the hormone – Human Chorionic Gonadotrophins ( hCG )

Hormonal Regulation of Ovulation:

Hormonal Regulation of Ovulation Human Chorionic Gonadotrophins ( hCG ), stimulates the Corpus Luteum to continue secreting progesterone for the first three months of the pregnancy. However if the ovum is not fertilized the Corpus Luteum degenerates and a new cycle begins with menstruation. The degenerated Corpus Luteum becomes an inactive mass of fibrous tissue called Corpus Albicans .

Menstrual Cycle - Uterus:

Menstrual Cycle - Uterus Cyclical hormonal changes act on the uterus and changes its lining in preparation for the conception to take place. When the fertilization does not occur the uterine wall is shredded causing menstruation that occurs once in every 28 days in the female. This is what we called the menstrual cycle as we can witness the monthly menstruation (as opposed to changes taking place in ovaries)

Menstrual Cycle - Uterus:

Menstrual Cycle - Uterus Conventionally the days of the menstrual cycle are numbered from the first day of the menstruation – this usually occurs about 14 days after the ovulation. Cycle has three phases: Menstruations Proliferative Phase Secretory Phase Menstruation lasts about 4 days.

Menstrual Cycle - Uterus:

Menstrual Cycle - Uterus The Proliferative phase (about 10 days): When the progesterone levels in the blood goes down beyond a critical level the hypothalamus secrete LHRH that stimulates the anterior pituitary to secrete FSH. FSH acts on the ovaries and a new ovarian follicle starts to mature secreting oestrogen . Oestrogen proliferates the endometrium of the uterus in preparation for implantation The endometrium thickens due to cell multiplication, increase its glandular secretions and blood capillaries The proliferative phase ends when the ovulation occurs and the Oestrogen levels drop.

Menstrual Cycle - Uterus:

Menstrual Cycle - Uterus Secretory Phase (about 14 days): Soon after ovulation the ovarian follicle becomes the Corpus Luteum (stimulated by LH from the anterior pituitary). The corpus luteum secrete Progesterone. Under the influence of Progesterone the endometrium become oedematous and sectretory – starts producing large amounts of watery mucus. This is thought to help the spermatazoa to travel through the uterus to the tubes where fertilization usually takes place.

Menstrual Cycle - Uterus:

Menstrual Cycle - Uterus Secretory Phase (about 14 days): The tubes and the cervix also start producing increased amounts of watery mucus to help this passage of spermatazoa . Though the sperm could live about up to 5 days within the female reproductive system it is only fertilizable for up to about 24 hours. Similarly the ovum is fertilizable only up to about 8 hours after ovulation.

Menstrual Cycle - Uterus:

Menstrual Cycle - Uterus Menstruation (about 4 days): The day of ovulation is difficult to predict even if the cycles are regular If the ovum is not fertilized and does not implant in the uterus – in the absence of the stimulation of Human Chorionic Gonadotrophin ( hCG ) produced by the implanted developing embryo – the corpus luteum regress to become Corpus Albicans and stops secreting progesterone This drop in progesterone cause the uterine wall to shred and menstruation occurs. Takes about 4 days to complete.

Uterus in Pregnancy:

Uterus in Pregnancy If fertilization occurs – usually happens in the tubes – the zygote ( the fertilized ova) gets implanted in the uterine wall and start secreting a hormone called Human Chorionic Gonadotrophin ( hCG ) hCG is similar to LH from anterior pituitary and helps to keep the corpus luteum from regressing into corpus albicans and therefore production of progesterone up to 3 months of pregnancy. Therefore no menstruation take place. No new follicles start maturing in ovaries During this time the placenta develops and start secreting oestrogen , progesterone and gonadotrophins

Menopause:

Menopause Menopause is the cessation of reproductive activity of the female. They could no longer have children after menopause This occurs between 45 to 55 years of age Could occur suddenly or gradually over a period of time – sometimes over ten years This is due to changes in the ovaries making them less responsive to sex hormones and low concentration of sex hormones making menstrual cycles irregular and eventually ceasing

Menopause:

Menopause Other phenomena that occur at the same time: Flushing: short term unpredictable vasodilation , sweating, palpitations causing dyscomfort and sleep disturbances. The breasts shrink The pubic and axillary hair become sparse The sex organs atrophy

Breasts:

Breasts

Breasts:

Breasts Breasts are accessory organs of the female reproductive system In males though they are present they are rudimentary Breasts are glands – Mammary Glands Before puberty they are small in size but thereafter they grow and develop to their mature size under the influence of oestrogen and progesterone. During pregnancy these hormones promotes further growth After the baby is born the hormone prolactin from anterior pituitary stimulates the milk production and the baby’s suckling induce oxytocin production from the posterior pituitary which stimulates the release of milk

Breasts:

Breasts Externally it has a nipple and areolar surrounding the nipple Breasts consists of glandular tissue, fibrous tissue and fatty tissue. Each breasts has about 20 lobes and within each lobe there are several lobules Lobules consists of cluster of alveoli within milk is produced. They open into small ducts which unite to form large lactiferous ducts. Lactiferous ducts converge towards the middle of the breast. Underneath the areola the lactiferous ducts dilate to form a sinus where milk is stored. Narrow ducts from the sinuses open them into the surface of the nipple. Fibrous and fatty tissue provide a supportive structure for the lobes

Breasts:

Breasts The nipple is a small conical projection at the center of the breasts surrounded by a pigmented area called the areola. There are numerous sebaceous glands on the areola which lubricate the nipple in the pregnancy Breasts are active only during pregnancy and soon after child birth when they produce milk.

Breasts:

Breasts Blood supply: Thoracic branches of axillary arteries Internal mammary artery Intercostal arteries Venous drainage is through a plexus surrounding the base of the nipple that drains to axillary and mammary veins Lymphatics drain to axillary nodes Nerve supply: Sympathetic – thoracic nerves T4,T5,T6 There are many somato - sensory nerve endings in the breast especially surrounding the nipple – which is highly sensitive Stimulation of touch receptors in the nipple by suckling send impulses to hypothalamus and the hormone oxytocin is released from the posterior pituitary to promote release of breast milk

End of Unit 12 – Part A:

End of Unit 12 – Part A

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