Upload
draleen89
View
220
Download
0
Embed Size (px)
Citation preview
8/9/2019 Physiology of Preg
1/64
Physiology Of The Menstrual Cycle
By Zafirah Hani Bte Ramli
2008289204
8/9/2019 Physiology of Preg
2/64
Menstrual cycle is a cycle of periodic uterine bleeding , in response to cyclic hormonalchanges that begin with the shedding of the secretory endometrium at about 14 days afterovulation.
Menstruation is the term used to indicate the periodic shedding of the stratum functionale ofthe endometrium , which becomes thickened prior to menstruation under the stimulation ofovarian steroid hormone.
A complex interaction between the hypothalmus , anterior pituaitary and the ovarieseventually leads to the process of the ovulation which is repeated with an average of 28days(range25-35 days)
The first phase: Menstruation lasts 3-5 day
Cyclic changes in the secretion of gonadotrophic hormones from the anterior pituaitary causethe ovarian changes during a monthly cycle. The ovarian cycle is accompanied by cyclicchanges in the secretion of estradiol and progesterone, which interact with thehypothalmus and pituaitary to regulate the gonadotrophin secretion. This cyclic changes inovarian hormone secretion also cause changes in the endometrium of the uterus during the
menstrual cycle
8/9/2019 Physiology of Preg
3/64
The menstrual cycle and endometrial
changesIt is convenient to divide the cycle into phases
based on the changes that occur :
In the ovary: 1. follicular phase
2. ovulation
3. luteal phase
In the endometrium: 1. proliferative phase
2. secretory phase
3. menstrual phase
8/9/2019 Physiology of Preg
4/64
8/9/2019 Physiology of Preg
5/64
Changes in the ovary
Follicular phase(days 1-13): At the end of menstrual cycle , estrogen levels are low. Low estrogen level stimulateproduction of FSH by the pituaitary. FSH in turns acts upon the ovary to stimulate growth of ovarian follices. Theincreasing levels of estrogen produced by the developing follicles act on the pituaitary to reduce FSH level by theprocess of negative feedback. In the majority of cycles only one follicles, the so called dominant folliclle , issufficiently large and has greater density of FSH receptors to respond to the lowers FSH level and develop to thestage of ovulation.Estrogen level continue to rise and it will reaches its highest concentrations in the blood at aboutday 12 of the cycle, 2 days before the ovulations .
Ovulation phase( day 14) : In the mid-cycle the nature of the ovarian control of pituaitary function changes.Increasing estrogen level are requires to produce a positive feedback mechanism which cause the surge in FSHand LH levels. This surge evoke the ovulation .
Luteal phase(days 15-28): LH acts to increase local production of prostaglandins and proteolytics enzymes to
allow oocyte extrussion . LH is responsible for the development of corpus luteum , which produce prostglandins
8/9/2019 Physiology of Preg
6/64
Corticol
hypothalmic-
hypophyseal-ovarian
uterine axis
8/9/2019 Physiology of Preg
7/64
Endometrial changes
These alterations in estrogen and progesteron level are responsible for the dramatic changes in the endometriumtroughout the ovarian cycle. At the completion of the menstrual period the endometrium is only one or twomilimeters thick. Under the influence of increasing level of estrogen this increases until the by the day 12 of thecycle the endomerium is 10-12 mm thick. This growth results from the increase in epithelial and stromal cells ofthe superficial layer of the endomnetrium . This proliferative phase is characterized by an increase in estrogenreceptor content and increase in size of the endometrial glands.
As ovulation approaches, the progestrone receptor content increases. Within two days of ovulation the effect ofovarian production of progesterone become apparent as the endometrium enters the secretory phase of thecycle. During this phase the mitotic activity in the epithelium ceases and the glands become dilated and tortuos .The blood vessels become coiled . Glycogen accumulation in the endometrium reaches a peak under thecombined influence of estrogen and progesterone. These processses prepare the endometrium for embedding ofthe embryo. If fertilization does not occur then progesterone and estrogen levels decline and menstruation occurs.
8/9/2019 Physiology of Preg
8/64
PHYSIOLOGICAL CHANGES IN
PREGNANACY in the
-Gastrointestinal tract(GIT)
-Urinary system-Musculoskeletal system
-Central Nervous systemCNS)
JUNAINAH BT MAT JUSOP- 2008277858
8/9/2019 Physiology of Preg
9/64
GITHigh progesterone level will cause relaxation of smoothmuscle.
Relaxation of sphincter regurgitation heartburn.
Slight reduction in gastric secretion and diminished gastric
motility slow emptying more efficient pulping of food.
Reduced motility in small intestine will provide more time forabsorption.
8/9/2019 Physiology of Preg
10/64
Reduced motility of large intestine will increase time for water
absorption and may tends to induce constipation.
Growth of conceptus and uterus will increase appetite andthirst.
In late pregnancy ,pressure of uterus reduces capacity for large
meals.
8/9/2019 Physiology of Preg
11/64
RENAL SYSTEMEarly pregnancy: Large uterus is compressing the bladder and cause
frequency of micturition.Mid-pregnancy: The uterus is lifted out of pelvis normal
micturition.
At term: The head of fetus descends into the pelvis frequency of
micturition.
Urinary output on a normal fluid intake tends to be slightlydiminished.
However there is an increase renal blood flow and also tubular
reabsorption of water and electrolytes.
It is estimated that extracellular water is increased by 6 to 7 litres
during pregnancy.
Glycosuria occurs commonly due to presents the tubules with a
sugar load which cannot be completed reabsorbed.
8/9/2019 Physiology of Preg
12/64
Anatomical changes cause the exist of a degree of
hydronephrosis and hydro-ureters.
These result from loss of smooth muscle tone due to
progesterone and mechanical pressure from the uterus at the
pelvic brim.
Vesico-ureteric reflux is also increase and will lead to
infection(UTI).
It will improve in the latter part of pregnancy as the uterusgrows above the pelvic brim.
8/9/2019 Physiology of Preg
13/64
MUSCULOSKELETAL SYSTEMProgressive lordosis,
mobility of sacroiliac, sacrococcygeal & pubic joints.
Bones & ligaments of pelvis undergo adaptation normal
relaxation.
Skin- linea nigra is prominent due to increase in ACTH.
Palmar erythema due to increase in estrogen.
Facial pigmentation-chloasma.
Pigmentation of the areola of the nipples.
8/9/2019 Physiology of Preg
14/64
CNS
Problems with attention, concentration & memory.
Pregnancy-related memory decline : limited to 3rd trimester (
transient, quickly resolved after delivery).
Difficulty going to sleep, frequent awakenings, fewer hours of
night sleep & reduced sleep efficiency.
8/9/2019 Physiology of Preg
15/64
THANK YOU =D
8/9/2019 Physiology of Preg
16/64
Cardiovascular adaptation
in pregnancy
Prepared by:
Mohd Aizat B Abd Aziz
2008402162
8/9/2019 Physiology of Preg
17/64
Why the changes occur?
Need gaseous exchange for metabolism
metabolismexcess heat
waste product Supply sufficient nutrient(growth of
fetus&uterus)
Demand Increased Blood
Supply
8/9/2019 Physiology of Preg
18/64
8/9/2019 Physiology of Preg
19/64
How The changes Occur?
BP= CO x TPR
CO=SV x HR
BP=SV x HR x TPR
CO Blood supply
8/9/2019 Physiology of Preg
20/64
SV(73 + 9 mL /30%)
Peripheral vascular dilatation Uterine vascular dilatation(hormonal vasodilation:PG,NO)
Reduced peripheral resistance
Lower diastolic pressure
Stimulate adrenal cortex
(secrete aldosretention fluid+
Decreased excretion Na)
8/9/2019 Physiology of Preg
21/64
Heart Rate
70 bpm(norm)
78 bpm @ 20 weeks gestation
Peak at 85 bpm at late pregnancy
CO=SV x HRCO Blood supply
8/9/2019 Physiology of Preg
22/64
Local Vascular Changes
CO sensitive to position of body @ >30 weeks
Exp:
Supine position pressure of uterus on pelvicvein venous return
CO (supine hypotensionsyndrome)
8/9/2019 Physiology of Preg
23/64
Enlarged uterus exert pressure on pelvic vein
varicosities/oedema of the leg
Very prominent during daytime+uprightposture
Oedema fluid reabsorbed(when in supine
position)
venous return
renal output
Nocturnal frequency of urination
8/9/2019 Physiology of Preg
24/64
Respiratory adaptationin pregnancy
8/9/2019 Physiology of Preg
25/64
Mechanical Changes
Chest circumference expands 5-7 cm
Subcostal angle increases from 68 to 103
degrees
Transverse diameter increases by 2cm
Level of diaphragm elevate 4cm
8/9/2019 Physiology of Preg
26/64
Lung volumes & capacity
Tidal volumes (35-50%)as pregnancy
progresses.
Total lung capacity is (4-5%) (d/t elevation of
diaphragm)
Large tidal volume and small residual volume
alveolar ventilation (65%)
8/9/2019 Physiology of Preg
27/64
&
8/9/2019 Physiology of Preg
28/64
Tidal volume
Increased
inspiration
Increased
expiration
Low maternal pCO2
Easy CO2 exchange
High arterial
O2
Improved supply
to fetus
8/9/2019 Physiology of Preg
29/64
Changes In Reproductive Organs
Uterus
Body of uterus affected >than isthmus/cervix
Oestrogenhypertrophy/hyperplasia of muscle fibers
No of connective tissue,elastic tissue,blood
vessel,nerve increases.
Its weight can increase from 50g1000g
8/9/2019 Physiology of Preg
30/64
Cervix
Oestrogen vascularity,changes inconnective tissuesoftens
secretion of mucusform protective plug incervical os(operculum)
8/9/2019 Physiology of Preg
31/64
Breast
Oestrogen+progesteroneproliferation of
gland & duct
size of breast
Veins may become visible
Nipple will grow and darken.
Secretion of colostrum may begin in 1st
trimester
8/9/2019 Physiology of Preg
32/64
Vagina and Pelvic Floor
vascularity,muscular hypertrophy,softening
connective tissue
Allow distention at birth
8/9/2019 Physiology of Preg
33/64
Pelvic Ligament
Oestrogensoftening of the ligament
Pelvis more mobile and capacity
8/9/2019 Physiology of Preg
34/64
HORMONAL CHANGES
DURING PREGNANCY
MUHAMAD HAZMI BIN JUAIDI
2007294732
8/9/2019 Physiology of Preg
35/64
Hormones Produced within the
pregnant uterus
Pregnancy specific
hCG
hPL Hypothalamus related
GnRH
CRF
8/9/2019 Physiology of Preg
36/64
Pituitary related
Prolactin
hGH
ACTH Other peptides
IGF
Calcitriol
PTH-related peptide Renin
Angiotensin 2
8/9/2019 Physiology of Preg
37/64
Steroids
Estradiol
Progesterone
8/9/2019 Physiology of Preg
38/64
Human chorionic gonadotrophin ( hCG
)
Secreted by the trophoblast cells within 9 days ofconception-positive urine beta hCG
Peaked at 10 weeks of gestation
Declined by 12 weeks ofgestation-placenta take over the
function over the later weeks of first trimester Composed of alpha and beta subunit, beta is pregnancy
specific, alpha unit is simmilar to a unit of FSH,LH, andTSH-can interact with the receptors
Function is to maintain the corpus luteum, so that it willcontinue to secrete estrogen and progesterone-maintainthe endometrium & prevent menstruation
8/9/2019 Physiology of Preg
39/64
8/9/2019 Physiology of Preg
40/64
8/9/2019 Physiology of Preg
41/64
ESTROGEN
Secreted by corpus luteum in early part of pregnancythen by placenta
Concentration rises substantially from earlier part ofpregnancy-about 30 times than normal
Main actions are: On the uterus-it stimulates myometrium cells
hypertrophy-uterine enlargement for fetal growth andinhibit menstruation
Breast enlargement-ducts grow and branch
Widen the pubic symphsis- by altering the chemicalcomp. of the connective tissues
8/9/2019 Physiology of Preg
42/64
8/9/2019 Physiology of Preg
43/64
Progesterone
Secreted by the corpus luteum and then
placenta
Main actions are :
Supress the FSH and LH to inhibit follicular
development
Prevents menstruation and thickens the
endometrium
Stimulate development of acini in the breast
8/9/2019 Physiology of Preg
44/64
Other actions are :
1. Relaxes the smooth muscle tone leading to
discouragement of uterine contraction, GIT
symptoms like nausea and constipation
2. Reduces the vascular tone-venous
dilatation-reduced diastolic bp
3. raises temperature
8/9/2019 Physiology of Preg
45/64
8/9/2019 Physiology of Preg
46/64
Insulin like growth factor 1 &2
Produced by fetal cells in the liver and
maternal cells in the uterus
Function is to regulate fetal growth
Fetal growth is not influenced by the growth
hormone
8/9/2019 Physiology of Preg
47/64
Human placental Lactogen
Produced by the palcenta
Lactogenic
Antagonistic to insulin actions
8/9/2019 Physiology of Preg
48/64
8/9/2019 Physiology of Preg
49/64
Corticosteroids
Placenta produces the corticotopin-releasing
hormone (CRH)
leads to increase in ACTH
Mother adrenal cortex will secerete cortisols
Cortisol causes increase in blood sugar
CRH also stimulate the fetal adrenal cortex torelease cortisol-stimulates maturation of lung
tissues
Th f h l b
8/9/2019 Physiology of Preg
50/64
The onset of human labour-
placental clock theory
Initiation of labour is not well understood
Theory suggest that labour in all mammals is
initiated by the activation of fetal adrenalcortex
Upon stimulation by CRH
Outer part secrete cortisol
Inner part secrete DHEAS (
dehydroepiandosterone )
8/9/2019 Physiology of Preg
51/64
DHEAS from fetus travel to placenta and stimulate
coversion ofprogesterone to estrogen Level of estrogen increases and stimulate the uterus to :
1. produces receptors for oxytocin
2. produces receptor for prostaglandin
3. produce gap junctions between
myometrial cells in the uterus
* uterus becomes more sensitive to pros. And oxytocin,
contractions begin and increasing in intensity
8/9/2019 Physiology of Preg
52/64
GASTROINTESTINAL SYSTEM
High progesterone level leads to :
Relaxation of sphincter -> regurgitation -> heartburn
Diminished gastric motility result in slow emptying ->
causes nauseaReduced motility in small intestine -> more time for
absorption-> more nutrition
Reduced motility in large intestine -> more time for
water absorption -> constipationLate pregnancy -> pressure of uterus -> reduces
capacity for large meal-> frequent small snacks
8/9/2019 Physiology of Preg
53/64
NOR AKMA BINTI SULAIMAN
2008402192
8/9/2019 Physiology of Preg
54/64
WEIGHT INCREASE
Increase in weight around 25%
(~12.5kg)
Rate: around 0.5kg per week
Due to:
- Growth of the conceptus
- Enlargement of maternal
organs,maternal storage of fat
and protein
- Increase in maternal bloodvolume and interstitial fluid
COMPONENT AMOUNT (KG)
UTERUS
FETUS
PLACENTA
AMNIOTIC
FLUID
FAT
BLOOD
BREAST
ECF
1
~3.4
0.7
0.8
3.5
1.3
0.4
1.5-4.5
TOTAL 12.5 KG
8/9/2019 Physiology of Preg
55/64
CARBOHYDRATE METABOLISM
Increase demand on the part
of the fetus for an easily
convertible source of energy
Future demands
lactation,increasing growth of
pregnancy,provide a more
steady source of energy
Sensitivity of insulin reduced
due to an increase in specific
antagonists to insulin- Human
Placental Lactogen (HPL)
8/9/2019 Physiology of Preg
56/64
PROTEIN METABOLISM There is on average a 20% increase in dietary protein intake.
- Growth of the fetus,placenta,uterus,mothers breasts andother tissue.
Both chorionic gonadotrophin and the placental lactogen tend to reduce
the deamination process blood & urine urea reduced
8/9/2019 Physiology of Preg
57/64
FAT METABOLISM Fat is the major form of stored energy during pregnancy
- Abdominal wall,back,thighs and breast (modest amount)
8/9/2019 Physiology of Preg
58/64
Hematological changes ofnormal pregnancy
8/9/2019 Physiology of Preg
59/64
Hematological changes of normal pregnancy
Blood volume
# The maternal blood volume increases# results from an increase in both plasma and erythrocytes.
# However, plasma volume increase in greater rate than red cell
mass.
# there are increase in red cell mass about 18% while plasmavolume increases by 40- 45%.
#Thus there is a reduction in red cell count per milliliter.
#Toward the term as the plasma volume diminishes the red cellcount increase slightly which also cause rise of haematocrit
8/9/2019 Physiology of Preg
60/64
The factors contributing to increase of plasma volume
including:
Increase sodium retention.
Decrease in plasma osmotic pressure.
Decrease in thirst threshold.
8/9/2019 Physiology of Preg
61/64
8/9/2019 Physiology of Preg
62/64
Why ?
Meet the demands of the enlarged uterus with it greatly
hypertrophied vascular system.
.
To safeguard the mother against the adverse effects of bloodloss associated with parturition.
8/9/2019 Physiology of Preg
63/64
HYPERCOAGULABLE STATE: Increase in fibrinogen and factor VII and X To meet the sudden hemostatic demand during
placenta separation
INCREASE LEUKOCYTES: due to increase in neutrophil cells WCC may rise markedly during labour
DECREASE PLASMA FOLATE: Due to in renal clearance of folate in pregnancy
DECREASE TOTAL IRON STORES: Even though absorption from gut is , but there is
increasing demand for iron due to increase in bloodvolume.
l i l h
8/9/2019 Physiology of Preg
64/64
Hematological changes
Decrease in:
o red cell count.
o hemoglobin concentration.
o haematocrit.
o Plasma folate concentration
Increase in :
o white cell count.o fibrogen concentration.