Unit one Review of anatomy and physiology of female reproductive system 1.1.
Anatomy of female reproductive system
1.1.1. Anatomy of of female pelvis
A. Bones of female pelvis- pelvis is made up of three type of bones which are four un number these are:
Two innominate bones
One sacrum and
One coccyx
1. Innominate bones - are the widest bones of the pelvis. Each innominate bone is constituted by the
fusion of three bones namely the illium, ischium and pubis around a cup like cavity called acetabulem . All the three part of the bone contribute to the acetabulemin the following proportion: two fifth ilium, two fifth ischium and one fifth pubic bone.
The ilium-is the large flared out part of the pelvic bone. When the hand is placed on the hip it rests on the iliac crest which is the upper border of the bone. At the front of iliac crest is a bony prominence known as anterior superior iliac spine . A short distance below it is anterioinferior iliac spine . There are two similar points at the posterior end of the iliac crest namely the posteriosuperior and posteriorinferior iliac spines. The concave anterior surface of the ilium is the called iliac fossa.
The ischium - is the thick lower pare of the innomonate bones. It has a large prominence known as the ischial tubiresity on which the body rests when setting. Behind and a little above the tuboresity is an inward projection of the bone called the ischial spine . During labour the station of
the fetal head is estimated in relation re lation to the ischial spines.
The pubis- is the anterior part of the innominate bones. It has a body and two oars like projection, the superior ramus and the inferior ramus . The two pubic bones meet at the symphysis pubis and
the two inferior rami forms the pubic arch merging in to the similar ramus in the ischium. The space enclosed by body of pubic bone, rami and ischium is called obturator foramina. 2. Sacrum- is a triangular shaped bone having its base above and its apex below. It is formed by fusion of five sacral vertebras. The upper border of the first sacral vertebra forms a prominence called sacral promontory . At the side the side the sacrum has two wings like processes called ‘ ala’ of the sacrum
which articulate with innominate bones. The anterior surface of the sacrum is concave and is referred to us the hollow of the sacrum . It has four pairs of opening in which nerves that are emerged from the cauda equine passes through to supply the pelvic viscera called sacral foramina. The posterior surface of the sacrum is roughened to receive attachments of muscle. 3. Coccyx- is formed by the fusion of four vertebrae and it articulate superiorly with tip of sacrum. B. Joints of the pelvis - there are four joints with in the pelvis that joins the four pelvic bones in to one. Two sacroiliac joint One symphisis pubis
One sacro coccygeal joint
-is a joint in which the sacrum is articulated with the innominate bones. It is The sacroiliac joint -is the strongest joint in the body.
The symphisis pubis - is a cartilaginous joint formed by the junction between the two pubic bones
along the mid line.
The sacro-coccygeal joint - is formed where the base of coccyx articulate with the tip of the
sacrum. It has a great obstetric importance during delivery. During pregnancy the hormone progesterone relaxes the ligaments and allows greater mobility and increase the available space in the pelvis.
The ischium - is the thick lower pare of the innomonate bones. It has a large prominence known as the ischial tubiresity on which the body rests when setting. Behind and a little above the tuboresity is an inward projection of the bone called the ischial spine . During labour the station of
the fetal head is estimated in relation re lation to the ischial spines.
The pubis- is the anterior part of the innominate bones. It has a body and two oars like projection, the superior ramus and the inferior ramus . The two pubic bones meet at the symphysis pubis and
the two inferior rami forms the pubic arch merging in to the similar ramus in the ischium. The space enclosed by body of pubic bone, rami and ischium is called obturator foramina. 2. Sacrum- is a triangular shaped bone having its base above and its apex below. It is formed by fusion of five sacral vertebras. The upper border of the first sacral vertebra forms a prominence called sacral promontory . At the side the side the sacrum has two wings like processes called ‘ ala’ of the sacrum
which articulate with innominate bones. The anterior surface of the sacrum is concave and is referred to us the hollow of the sacrum . It has four pairs of opening in which nerves that are emerged from the cauda equine passes through to supply the pelvic viscera called sacral foramina. The posterior surface of the sacrum is roughened to receive attachments of muscle. 3. Coccyx- is formed by the fusion of four vertebrae and it articulate superiorly with tip of sacrum. B. Joints of the pelvis - there are four joints with in the pelvis that joins the four pelvic bones in to one. Two sacroiliac joint One symphisis pubis
One sacro coccygeal joint
-is a joint in which the sacrum is articulated with the innominate bones. It is The sacroiliac joint -is the strongest joint in the body.
The symphisis pubis - is a cartilaginous joint formed by the junction between the two pubic bones
along the mid line.
The sacro-coccygeal joint - is formed where the base of coccyx articulate with the tip of the
sacrum. It has a great obstetric importance during delivery. During pregnancy the hormone progesterone relaxes the ligaments and allows greater mobility and increase the available space in the pelvis.
C. Pelvic ligaments - each of the pelvic joints is held together by ligaments for example: Inter pubic ligament at the symphysis pubis Sacroiliac ligament at the Sacroiliac joint Sacrococcygeal ligament at at the Sacrococcygeal joint
There are two important ligaments important in obstetrics Sacrotuberous ligament - runs from the sacrum to the ischial tuberosity and
-from the sacrum to the ischial spine. Sacro spinous ligament -from p elvis and the true pelvis. D. Parts of the pelvis -the female pelvis consists of two parts; the false pelvis
False pelvis - is the part of the pelvis above the pelvic brim. It is formed by the upper flaired
out part of the iliac bones bo nes and it does not play any significant role in the process of child birth.
True pelvis - is the true bony birth canal through which the baby must pass during birth. It
has a brim, a cavity and an out let. 1. The pelvic brim - id rounded except where the sacral promontory project in to it. The promontory
forms its posterior border, the iliac bones its lateral border and the pubic bones its anterior border. The nurse needs to be familiar with the fixed points on the pelvic brim which are known as land marks. Starting from the posterior these are: Sacral promontory ‘ala’ of the sacrum Sacro-iliac joint Iliopestineal line Iliopectinial eminence Superior ramus of pubic bone Upper inner border of the body of pubic bone Upper inner border of symphysis pubis
Diameters of the brim - there are three type of diameters measured with in the pelvis. The anterioposterior diameter - is a line from the sacral promontory to the upper border of
symphysis pubis. When the line is taken to the upper most point of symphysis pubis it is called the anatomical conjugate and is 12cm. when it is taken to the posterior border of the upper part of sumphysis pubis it is called the obstetric conjugate (true conjugate) and measured to be 11cm. the obstetric conjugate tells us the true available space for the passage of the fetus. The diagonal conjugate is also measured anterio posteriorly from the lower border of the symphsis pubis to the sacral promontory. It may be estimated per vaginum as part of pelvic assessment and should measure 12-13cm. The transverse diameter -is a line between the points furthest apart on the iliopectineal lines
and measures 13cm. The oblique diameter - is a line from one sacroiliac joint to the iliopectineal eminence on the
opposite side of the pelvis and it measures 12cm. There are two oblique diameters each takes its name from the sacroiliac joint it arises ar ises that is, the left oblique diameter arises from the left iliac joint. 2. The pelvic cavity - extends from the brim above to the out let below. The anterior wall is formed by
the curve of sacrum which is 12cm in length. The cavity is circular in shape and although it is difficult to measure its diameters exactly they are all co nsidered to be 12cm. 3. The pelvic out let – there are two out lets in the pelvis; the anatomical and obstetric out let. The
anatomical outlet is formed by the lower border of each bone; lower border of symphysis pubis, the ischial tuberosity, and the tip of the coccyx while the obstetric out let is formed by the lower border of symphysis pubis, the two ischial spines, and the sacro coccygial joint. The obstetrical out let has great obstetric significance because it is the narrow pelvic outlet through which the baby must pass. This out let is a diamond shape and its three diameters are as follows. The anterioposterior diameter - is a line from the lower border of symphysis pubis to the
sacrococcygeal joint. It measures 13cm. The oblique diameter - is said to be between the obturator foramina and the sacrospinous
ligament although there is no fixed point. The measurement is taken to be 12cm. The transverse diameter - is a line between the two ischial spines and measures 10-11cm. it is
the narrowest diameter in the pelvis.
E. Types of pelvis - can be grouped in to four categories according to the shape of the pelvis brim. The gynacoid pelvis is the ideal pelvis for child bearing. Its main feature are rounded brim,
straight side wall, shallow cavity with a broad, well curved sacrum, blunt ischial spine, a wide sciatic notch and pubic arch of 90o. It is found in women of average build and height. The android pelvis - is so called because it resembles the male pelvis. Its brim is heart shaped. It is
found in short and heavy build women who have a tendency to hirsute. This type of pelvis predisposes for OPP (ociputoposterior position) and is least suited for child bearing. The anthropoid pelvis –has long oval brim in which the AP diameter is longer than the
transverse. Women with this type of pelvis tend to be tall with narrow shoulder. Labour does not usually present any difficulty. The platiploid pelvis - is flat with kidney shaped brim in which the AP diameter is reduced and the
transverse one increased. In this type of pelvis the head must engage with the sagital seture in the transverse diameter but descends with the pelvic cavity with out any difficulty. NB:-keeping all the above measurements in mind the fetal head is the best pelvimeter.
1.1.2.Anatomy of genital organs A. External genitalia (syn: vulva, pudendum)- is a term used to describe the externally visible pat of
female genitalia and is composed of mones pubis, labia majora, lavia mainora, clitoris, vestibule and perineum. This vulva is bounded by mones pubis anteriorly, labua majora laterally, and the perineum posteriorly. Mons pubis (monis veneris) - is a pad of subcutaneous fatty tissue above the pubic bone. In adults
it is covered by pubic hair in an inverted triangle fashion. Labia majors- are also called the greater lips of vagina. They are an elevation of skin and
subcutaneous tissue arising from monis pubis anteriorlly and will fuse medially to form the posterior commeasure. It contains the sebaceous gland and the hair follicule. It is richly supplied with venous plexus and it is homologus with scrotem of male. Labia manors- are also called the lesser lip of vagina. It is a thick fold of skin devoid of fat lying on
either sides and with in the labia majora. It is composed of two devided lip that will fuse at some points with in the vulva for example the upper part of labia minoras fuses in front and behind the clitoris to form pre puse and franulem respectively and the lower part of labia manor fuse posteriorly to form forchette. Alike the labia majoras it doesn’t contain hair follicle and it is homologues with the veneral aspect of penis.
Clitoris - is a small cylindrical erectile body situated in the most anterior part of the vulva. It
consists of glans, body, and two crura. The glans is richly supplied with nerves. Clitoris is homologues with penis of male.
Vestibule - is a triangular space bounded by clitoris anteriorly, forchette posteriorly, and the two
labia majors laterally. There are four openings with in the vestibule. 1. Urethral opening - mid line just in front (above) the vaginal orifice. 2. Vaginal orifice - is an opening situated in the posterior end of the vestibule and it is of varying
size and shape. In virgins, it is incompletely closed with septum of mucus membrane called hymen. The membrane will rupture during six, child bearing and rarely during stranious exercise. There are different types of hymen. 3. Openings of bartholin’s gland - bartholin’s glands are two pea sized glands situated on either
sides of the vaginal orifice. During sexual excitement it secret an alkaline mucous which helps in lubrication. Each gland has got a duct that opens in the vestibule out side the hymen opening but with in the labia minora. It is homologues with the bulbo urethral gland of the male.
Perineum- is the area located between vagina and anal opening
B.Internal genitalia : - these are genital organs that are not visible in the normal circumstance that means
they need special instrument for inspection. They include vagina, uterus, fallopian tube and ovary.
Vagina: - is a fibro-muscular membranous sheet communicating the uterine cavity with the external
environment at the valve. Position -The canal of vagina is upward and backward forming 90% with cervix and 450with the
horizontal in erect position. The diameter of the canal is about 2.5 cm being wider in the upper part and narrow at the introits. Function of vagina : - is excretory channel for the uterine secretion and menstrual blood
Is the organ of copulation
It forms the birth cannel of parturition.
Walls: - vagina has get and anterior, posterior and two lateral walls. The length of the anterior
wall is about 7cm and that of posterior wall is 9cm Farnices : - the projection of cervix through the anterior vaginal wall at the top of vagina forms a
cleft known as fornices. There are four fornicel (anterior , posterior and two lateral), the posterior one being deeper and the anterior one is the most shallow. Layer : - the vaginal wall is composed of 4 layers. The four layers from within to out ward are:
1. Mucous layer: - is lined by stratified squamous epithelium with out any secreting gland. 2.
Sub mucus layer
3.
Muscular layers:- consist of inner circular and outer longitudinal
4.
Fibrous coat
Epithelium: - the vaginal epithelium is under the action of sex hormone especially estrogen.
At birth and up to 10-14 days, the epithelium is stratified squamous under the action of
maternal estrogen circulating in the newborn Form puberty till menopause the vaginal epithelium is stratified squamous and is composed
of 3 district layers; the basal call, intermediate call and superficial call. The intermediate and superficial cells contain glycogen. The superficial calls exfoliate constantly and replacement occurs from basal calls when they become exposed to the dry external environment during which karatinization will occur. Unlike it does not contain hair follicle, sweet and sebaceous gland.
Secretion :- the vaginal secretion is vary small in amount but it become little excess
During mid menstrual or just prior to menstruation,
During pregnancy and
During sexual excitement
The pH of the vagina - ranging form 4- 5.5 the average being 4.5 secretion is acidic but it varies
during phases of life. The acidic nature of vaginal is because of the conversion glycogen to lactic acid by the red shaped bacteria known as dodaril’s bacillus which is dependant on estrogen. Relations
Antariarly :- it is related with the upper base of bladder and urethral
Postariarly:- it is related with rectal wall separated with pouch of Douglas, recto vaginal septum & perennial body
Superiorly:- it is in relation with the uterus specially cervix
Uterus: - is hallow muscular organ situated within pelvic cavity Parts : - the uterus has three parts which are: 1. Body or corpus : - is apart of uterus found above the isthmus and is further divided in to
fundus (dome shaped part that lies above the opening of the tubes) and body proper (a part found b/n the opening of the tube and the isthmus). carnua is the upper outer angle of the body and it is the site of attachment for fallopian-tube, round ligament and ovaries ligament. 2. Isthmus :- is the constricted part b/n the body and cervix 3. Cervix : - is the lower most part of the uterus which is cylindrical in shape. it is divided in
to supra vaginal part, a part that lies about the vaginal and a vaginal part, a part found with in the vagina each measuring 1.25 cm. in null parous the vaginal parts is conical with the external 0s looking circular where as in parous it cylindrical with the external as having bilateral slit, a slit formed by the damage of inner circular muscles of cervix during child birth which will form anterior and posterior lip of cervix. Structure of the uterus : - the wall of the body of the uterus consists of three layers the layers. The
layers from outside to in ward are: 1. Perimetrium : is a double serous membrane that is an extension of the partition , which
cover all but narrow strip on either side and anterior wall of supra vaginal cervix from where it is reflected up over the bladder
2. The myometrium :- is a thick burner of smooth muscle arranged in outer longitudinal
which is continuous with uterine tuba , uterine ligament and vagina ;middle uterine tuber, 3. The endometrium - is the mucus lining of the cavity of the uterus.it consists of
laminaproper and surface epithelium. The surface epithelium is ciliated simple columenar while the lamina proper contain stromal cells, endometrial gland , vessels and nerves. During the time of pregnancy the endometrium is called deciduas. The cervix is mainly composed of fibrous connective tissue only 10-15%is smooth muscle,the endocervix is lined by tall columenar epithelium while the exocervix or the vaginal part is covered by stratified squamous epithelium. Between the two there is a space which consists of endocervical glands and stroma covered by squamous epithelium which is known as squamocolumnar junction or transitional zone.the zone is not static rather it changes with hormonal level of estrogen. This site irritated not only by estrogen but also by infection and trauma. Thus there is a high risk of CIN or even invasive cancer. Secretion - the endometrial secretion is scanty and watery while the physical and chemical
property of cervical secretion changes with menstrual cycle and with pregnancy.the cervix secrets alkaline mucus with PH of 7.8 which is rich in fructose, glycoprotine and muco polysacride. The fructose has nutritive value for the spermatozoa. Relation of the uterus
Anteriorly-it is related with the bladder and uterovesical pauch. Posteriorly- it forms the anterior wall of the pouch of dogulas Laterally- it is related with broad ligament Position of the uterus- the normal position of the uterus is anti version (the long axis of the uterus
especially the cervix makes 900 with the long axis of the vagina which means it leans forward) anti flexion (the long axis of the body of the uterus forms 1200 with the long axis of the cervix which means it is curved by itself at the level of internal os) Function - mainly the uterus shelters the fetus during pregnancy and it expels its content when it
is contracted during labour. Support of the uterus -the uterus is supported by pelvic floor and maintain in position by several
ligaments of which those at the level of cervix are the most important. The transcervical ligament- is some times known as cardinal ligament. It runs out from the
side wall of pelvis to side wall of cervix. The uterosacral ligament- passes backward from cervix to the sacrum. The pubocercical ligament- passes forward from cervix under bladder to the pubic bone.
The broad ligament- is a double fold of peritoneum which spreads from the side of the
uterus to the lateral pelvic wall of the pelvis. The broad ligament- arise from cornua and passes through broad ligament inserted in labia
majora. They have little value as a support but used to maintain the antiverted position of the uterus.
Fallopian tube (syn:uterine tube or oviduct )- are paired structure found in the pelvic cavity. Each
tube has got two opening one communicating with the uterine cavity called the uterine opning and the other on the lateral end of the tube called pelvic opning or abdominal ostium. Parts - the tube has four parts. The part from medial to lateral are: 1.
Intramural (interstitial) - is the part that lies in the uterine cavity.
2.
Isthmus
3.
Ampula- is the widest part through which fertilization occur.
4.
Infundibulem- is the lateral end of the tube.
The abdominal ostium of the tube is surrounded by a number of finger like projections called fimbria. One of which is longer than the other and is attached to the outer pole of the ovary called the ovarian fimbrea. Structure of the tube- the tube consists of three layers.
1. Serous coat 2. Muscular layer- arranged in inner circular and outer longtudnal fasion. 3. Mucous membrane-which is lined by partially ciliated and non ciliated columnar
epithelium. Function -the important function of the tube are:
Transporting male gamete to the site of fertilization and zygote to the uterine cavity by its cilliary function.
Nourish and protect the zygote
Ovaries- are paired sex glands or gonads in the female which are concerned with two function.
Maturation and release of ovum Steroidogenesis
Relation Anteriorly the ovary is attached to the posterior wall of the broad ligament by mesovarium
Posteriorly it is free Laterally it is attached to the cornua and pelvic wall by ovarian and suspensery ligaments
respectively. Structure - the ovary is covered by single layer of cubical cel known as germinal epithelium. The
ovary consists of the outer cortex and inner medulla. The cortex is the functional unit of the ovary and it is composed of primordial follicle, primary follicle, secondary follicle, mature (graafian follicle), corpus luteum and corpus albican. While the medulla consists of losse connective tissue, muscle, blood vessel and nerve.
1.1.3. Anatomy of fetal skull
The fetal head is the most difficult part to deliver weather it comes first or last. It is large in comparison with the pelvis and some adaption must be take place during labour. An understanding of the landmarks and measurements of the fetal skull enable the nurse to recognize the normal presentation and position and to facilitate delivery with least trauma to the mother and the fetus. A. Bones of the fetal skull - the skull is divided in to three regions the vault, the base and the face. 1) The vault- is the large dome shaped part above the imaginary line drowns from the orbit to the
nape of the neck. There are five main bones in the vault of the fetal skull.
One occipital bone - lies at the back of the head and forms the occipital region. At the center
of this bone is a prominence called occipital protuberance. Below this prominence there is a large opening for the passage of spinal cord called foramen magnum.
The two parital bones - lie on either side of the skull. At the center of each parital bones there
is an ossification center called parital eminence.
The two frontal bones - lie on the front of thr skull and forms the forehead or sinciput. At the
center of each is frontal eminence (frontal boss) which is the ossification center of these bines. The frontal bones fuse in to one bone by the age of 8 years. 2) The face 3) The base
B. Sutures of fetal skull - sutures are cranial joints which are firmed where two bones adjoin. There are
several sutures in the fetal skull. That of the most obstetric important ones are: Lambdoidal suture - is so called because it resembles the greek leter lambda (λ ). It separates the
occipital bone fron the two parital bones. Sagital suture - lies between the two parital bones. Coronal suture - separates the frontal bones from the parital bones. Frontal suture - rummes between the two halves of the frontal bone. C. Fontanelles - are membranious gaps between skull bones formed where two or more suture meets.
There are two major fontanels in the fetal skull. Posterior fontanelle (lambda)- is the small triangular junction of sagital and lambdoidal sutures.
It can be recognized vaginally because sutures leave from each of the three angles. It normally closes by the age of 6 weeks. Anterior fontanelle (bregma)- is a diamond shaped fontanel found at the junction of sagital,
coronal and frontal sutures. It also can be recognized vaginally because a suture leave from each of the four corners. It normally closes by the time of 18 months. Advantages of sutures and fontanelles ⇒
Because they consist of membraninos space, they allow some degree of overlapping of the skull bones during labour and delivery the process called moulding.
⇒
Are used as land mark to identify the presenting part and position of the fetus during cephalic (head) presentation.
D. Region and land markes of the fetal skull
The occiput- is a region between foramen magnum and posterior fontanelle. The part below the occipital protuberence is called the suboccipital region. The vertex- is the area bounded by the posterior fontanelle, the two parital eminence and anterior fontanelle. It is the most common and normal presenting part of the fetus (95%).
The sinciput or brow- extends from the anterior fontanelle and coronal suture to the orbit ridg.
The glabella- is the part between the eye brows.
The mentum- is the medical name of chin.
The face- extendes from the orbit ridge to the junction of neck and chin.
E. Diameters of the fetal skull - the measurement of the skull are important because a nurse need a
special understanding of the relation ship between fetal head and maternal pelvis. It will become clear that some diameters are more favorable for easy passage through pelvis canal. Transverse diameters - there are two transverse diameters. Bi parietal diameter - is a diameter between the two parietal eminences and is measured to be
9.5cm. Bi temporal diameter - is between the furthest point of the coronal suture and is measured to be
8.2cm. Anterioposterior or longitudinal diameter Suboccipito bregmatic- is from the below of occipital protuberance (sub occipital region) to
the center of bregma. It is measured to be 9.5cm. Sub occipito frontal - is from the below of the occipital protuberance to the center of frontal
suture. It measures 10cm. Occipitofrontal - from the occipital protuberance to the glagella. It is 10cms long. Mento vertical - is from the point of the chin to the highest point of vertex (slightly nearer to
kposterior than anterior fontanelle). It measure the longest diameter in the skull which is 13.5cm. Submento vertical - is from the point where the chin joins the neck to the highest point on the
vertex. It is 11.5cms long.
Submento bregmatic- is from the point where the chin joins the neck to the cnter of bregma. It
is 9.5cms long. F. Attitude of the fetal head - is the relation ship berween the long axis of the body of the ferus with
fetal head. It is a term used to descrihe the degree of flexion and extension of the head on the neck. The attitude of the head determine which diameter and part will present in labour and there fore influence the out come. For example when the head fully flexes, the vertex presents and the presenting diameter will be suboccipito bregmatic. Flexion of the fetal head enable the smallest diameter possible resulting in easear labour. G. Presenting diameters- are diameters of the fetal head at right angle with the curve of carus. H. Presenting - is part of the presenting part (mostly the head) which lies first at the brim of the pelvis on
the lower pole of the uterus. The most common presentation of the head are: Vertex presentation Brow presentation and
face presentation
