Skin + Reproductive Flashcards
What are the 4 main layers of the epidermis of the skin?
- Keratinised squames.
- Granular layer.
- Spinous layer (the thickest layer).
- Germinative layer.
What is the role of Filaggrin?
Produces natural moisturising factor.
Why are protease inhibitors in the skin important?
Protease inhibitors prevent the breakdown of corneodesmosomes.
What is the ideal pH of the skin?
5.5
What is the SRY protein called?
Testis determining factor: under its influence male development takes place.
What is the importance of testis determining factor?
Under its influence male development takes place.
What cells are responsible for secreting testosterone?
Interstitial cells of Leydig.
What is the blood supply to the upper 2/3 of the anal canal?
The superior rectal artery (branch of IMA).
What is the blood supply to the lower 1/3 of the anal canal?
The inferior rectal artery (branch of internal pudendal artery).
What part of the anal canal receives autonomic innervation?
The upper 2/3 (lower 1/3 is somatic innervation).
Which anal sphincter receives autonomic innervation and is involuntary?
The internal anal sphincter.
Which urethral sphincter is composed of smooth muscle?
The internal urethral sphincter.
When is the periaqueductal grey suppressed?
In storage. (Active in voiding).
What is the external urethral sphincter?
Skeletal muscle, voluntary sphincter.
Composed of the rhabosphincter and pelvic floor.
Do the urethral sphincters receive parasympathetic or sympathetic innervation?
Sympathetic.
When are the urethral sphincters activated?
In storage - activation causes contraction of the sphincters.
Spermatogenesis: what do type B cells differentiate into?
They differentiate into primary spermatocytes that will then go onto meiosis.
Spermatogenesis: where are type A cells located?
Outside the blood-testes-barrier.
Spermatogenesis: what does meiosis 1 produce?
2 secondary spermatocytes.
Spermatogenesis: what does meiosis 2 produce?
4 spermatids.
What changes does the sperm make with regards to its structure?
- It discards excess cytoplasm.
- Grows flagellum.
- Lots of mitochondria.
- Acrosomes at its head.
What is the function of the epididymis?
Storage and maturation of sperm. Sperm normally stay in the epididymis for 60 days.
What is the affect of FSH on the testes?
Stimulates spermatogenesis and sertoli cells. Sertoli cells produce MIF (mullerian inhibiting factor) and inhibin and activin which acts on the pituitary gland to regulate FSH.
What is the affect of LH on the testes?
Stimulates Leydig cells to produce testosterone.
What is ovulation?
The release of an oocyte from a follicle.
What hormone stimulates ovulation?
LH.
In humans, is the sex of the embryo determined by the sperm or egg?
The sperm - can contribute an X or Y. The egg is always X.
What is the secretory phase?
When the corpus luteum releases progesterone and the endometrium generates blood vessels and proteins etc needed for the implantation of a fertilised embryo.
What is the proliferative phase?
When the endometrium grows rapidly under the influence of oestrogen.
What does the corpus luteum degenerate into?
The corpus albicans.
What is capacitation?
The final stage of sperm maturation that occurs in the female genitalia. Before this spermatozoa would be unable to fertilise an oocyte.
What is block to polyspermy?
After a sperm has fertilised the egg, the egg needs to prevent further sperm fertilising it.
What are the mechanisms to ensure block to polyspermy?
Enzymes are released that harden the zona pellucida and inactivate sperm binding sites.
What hormone does the hypothalamus release that stimulates release of the gonadotropins?
GnRH - gonadotropin releasing hormone.
What cells does FSH act on in males?
Sertoli cells.
What cells does FSH act on in females?
Granulosa cells.
What cells does LH act on in males?
Leydig cells.
What cells does LH act on in females?
Theca cells.
What is the function of sertoli cells?
They release MIF, inhibin and activins (regulate FSH secretion), and androgen binding protein (increases testosterone concentration).
What is the function of granulosa cells?
They convert androgens into oestrogen using aromatase enzyme.
What is the function of leydig cells?
they produce testosterone.
What is the function of theca cells?
They produce androgens (oestrogen precursors) which diffuse into granulosa cells to form oestrogen.
What enzyme converts androgens into oestrogen?
Aromatase.
What is the predominant hormone responsible for the proliferative phase?
Oestrogen.
What is the predominant hormone responsible for the secretory phase?
Progesterone.
Where do primordial germ cells originate from in the embryo?
The epiblast.
Until what week are male and female primitive gonads identical?
Week 6.
What is the mesovarium?
Mesentery attaching the ovary to the posterior broad ligament.
Define menopause.
Cessation of menstruation.
What physiological changes happen in menopause?
There is depletion of the primordial follicles. Oestrogen levels decrease; FSH and LH therefore increase as they’re not inhibited by negative feedback.
What happens to oestrogen levels at menopause?
They fall.
What happens to LH and FSH levels at menopause?
They increase as they’re no longer inhibited by negative feedback.
What are the short-term symptoms of menopause?
Hot flushes, night sweats, palpitations, irritability, lethargy, decreased libido, vaginal dryness, vaginal pH change, dry skin and hair, brittle nails.
What are the long-term symptoms of menopause?
Osteoporosis and increased risk of cardiovascular disease.
Name 4 treatments that can help with the symptoms of menopause.
- HRT.
- Sedatives.
- Calcium supplements.
- Vitamin D supplements.
What hormones are given in HRT?
Oestrogen and progesterone.
What is the advantage of HRT being given as a patch as opposed to orally?
The hormones go straight into the bloodstream and so bypass the liver.
What are the risks of HRT?
Small increased risk of cervical, breast and endometrial cancer.
What are the two main types of stem cells?
- Embryonic stem cells - pluripotent.
- Somatic stem cells - multi-potent.
Name 3 diseases that stem cells could help to cure.
- Parkinsons disease.
- Alzheimers.
- Type 1 diabetes.
What are the 3 main characteristics of stem cells?
- Self renew over long periods.
- Undifferentiated.
- Can generate other cells: pluripotent/multipotent.
Where in the embryo do embryonic stem cells come from?
The inner cell mass.
What are the 3 histological layers of the uterus?
- Endometrium - mucosal lining, pseudostratified columnar.
- Myometrium - smooth muscle wall.
- Perimetrium.
What is the function of the smooth muscle in the myometrium?
It helps the uterus to expand and acts to protect the foetus. It also provides a mechanism for foetal expulsion.
What are the characteristics of the endometrium in the proliferative phase?
Straight glands, no secretions. Stromal and epithelial mitoses.
What are the characteristics of the endometrium in the early secretory phase?
Coiling of glands and subnuclear vacuoles
What is the decidua basalis?
A part of the endometrium invaded by trophoblast.
What is the decidua capsularis?
A part of the endometrium overlying the blastocyst.
What is the decidua parietalis?
Endometrium lining the rest of the uterine cavity.
What invades the decidua basalis?
Syncytiotrophoblast.
What is the role of the syncytiotrophoblast?
Uptake of oxygen and nutrients from the maternal blood.
Release of CO2 and waste products into the maternal blood. The exchange surface is gradually increased during maturation due to branching of the villi.
What is the role of the cytotrophoblast?
Forms solid masses covered by syncytiotrophoblast - primary chorionic villi. These masses become filled with stroma, forming secondary chorionic villi. Capillaries appear in the stroma – tertiary chorionic villi.
What hormonal pathway is likely to be responsible for a decrease in urine production?
Renin angiotensin aldosterone system.
Why is it important that the chorionic villi branch in maturation?
Branching increases the surface area for exchange of nutrients.
Why can a tumour of the pituitary gland affect vision?
The optic chiasm lies just above the pituitary gland and is likely to be affected if there’s a tumour.
What are the two types of hormone?
- Made at response e.g. steroids.
- Stored and released at response e.g. pituitary hormones (peptides).
Where are the receptors for steroid hormones located?
Steroid receptors are intracellular - steroids pass through plasma membranes bound to proteins.
Where are the receptors for peptide hormones located?
On cell membranes.
What are the purposes of the endocrine system?
- Communication between cells.
- Integrates whole body physiology.
- It can make rapid adaptive changes.
- Maintains the metabolic environment.
Briefly describe the mechanism of ACTH.
Hypothalamus -> CRH -> anterior pituitary -> ACTH -> adrenal glands -> cortisol release -> negative feedback on hypothalamus and pituitary.
Briefly describe the mechanism of LH and FSH.
Hypothalamus -> GnRH -> anterior pituitary -> FSH/LH -> sertoli cells, leydig cells/granulosa cells, theca cells -> oestrogen, testosterone, inhibin -> negative feedback on hypothalamus and pituitary.
How would you describe growth hormone secretion from the anterior pituitary?
It is secreted in a pulsatile fashion and increases during deep sleep.
What factors effect growth hormone secretion?
- Starvation.
- Exercise.
- Trauma.
- Hypoglaecemia.
- Deep sleep.
What clinical abnormalities can occur if there is a problem with growth hormone secretion?
- Gigantism.
- Dwarfism.
- Acromegaly.
What would be the effect on TSH if you had an under-active thyroid?
TSH would be high as there would be little negative feedback as less T4 and T3 are being produced.
What would a low TSH tell you about the action of the thyroid?
Low TSH = overactive thyroid.
Lots of T4 and T3 being produced and so there is more negative feedback on the pituitary and less TSH.
What are the 4 cells to make up the islets of langerhans?
- Beta cells: insulin. (70%)
- Alpha cells: glucagon. (20%)
- Delta cells: somatostatin. (8%)
- Pancreatic polypeptide secreting cells. (2%)
What is the importance of the alpha and beta cells being located next to each other in the islets of langerhans?
This enables them to ‘cross talk’ - insulin and glucagon show reciprocal action.
Insulin release is described as biphasic. Describe the two phases.
- Phase 1 - Stored insulin is released rapidly.
- Phase 2 - Slower release of newly synthesised insulin.
What is glucose converted into when it enters a beta cell?
Glucose-6-phosphate.
Describe the mechanism of insulin secretion from beta cells.
Glucose binds to beta cells -> glucose is converted into glucose-6-phosphate -> ADP is converted to ATP -> K+ channels close -> membrane depolarisation -> Ca2+ channels open -> Ca2+ influx -> insulin release.
What substance can tell you if high insulin levels are due to endogenous insulin production?
The presence of C peptide.
What glucose transporter allows glucose uptake into muscle and fat cells?
GLUT-4.
What is a normal blood glucose?
4-6mmol/mol.
What is the short term response to high blood glucose?
Glycogenesis.
What is the long term response to high blood glucose?
Triglyceride production - lipogenesis.
What is the short term response to low blood glucose?
Glycogenolysis.
What is the long term response to low blood glucose?
Gluconeogensis.
Name 3 places where glucose sensors are located.
- Pancreatic islets.
- Medulla.
- Hypothalamus.
What happens to insulin and glucose levels after a meal?
Insulin release increases. Glucose goes to the liver and muscles to replenish glycogen stores. Excess glucose is converted into fats.
What hormones from the hypothalamus stimulate the anterior pituitary to release GH?
GHRH (+ve affect) and SMS (-ve affect).
What can pituitary tumours cause?
- Pressure on local structures e.g. optic chiasm. Can result in bitemporal hemianopia.
- Pressure on normal pituitary function; hypopituitary.
- Functioning tumour can result in Cushing’s disease, gigantism and prolactinoma.
How much of the total cardiac output does each kidney receive?
10%.
What equation can be used to calculate GFR?
GFR = (Um x urine flow rate) / Pm.
- Um = concentration of marker substance (m) in urine.
- Pm = concentration of marker substance (m) in plasma.
What hormones are involved in pregnancy?
- Human chorionic gonadotropin.
- Oestrogen.
- Progesterone.
- Prolactin.
- Prostaglandins.
- Oxytocin.
- Relaxin.
What is the function of human chorionic gonadotropin?
It stimulates oestrogen and progesterone production. The levels of this hormone decrease when the placenta develops and takes over.
What are the functions of prostaglandins?
They have an important role in labor initiation.
What is the function of relaxin?
It is involved in cervical ripening.
What are the cardiovascular maternal adaptations?
- Cardiac output increases.
- Blood pressure decreases.
- Uterine blood flow increases.
Why does blood pressure decrease in pregnancy?
There is mass vasodilation which reduces the TPR and so BP decreases. (BP=TPRxCO).
Why does uterine blood flow increase in pregnancy?
To ensure enough nutrients are delivered to the foetus.
What are the adaptations to the skin in pregnancy?
Linea nigra and striae gravidarum/stretch marks may appear on the skin, usually the abdomen. There is also darkening of the areola
What are the maternal adaptations to the veins in pregnancy?
Varicose veins are often present in pregnancy.
Define parturition.
Giving birth.
What are the 3 layers of the uterus?
- Perimetrium (inner).
- Myometrium.
- Endometrium.
Describe cervical ripening.
Softening of the cervix that begins prior to labor. It is necessary for cervical dilation. It occurs under the influence of relaxin and placental hormones.
What hormones stimulate cervical ripening?
Relaxin and placental hormones.
What are the 2 main stages of labor?
- Latent: little cervical dilation.
- Active: cervix dilates and opens.
What are the sub-divisions of the active stage of labor?
1st - cervix dilation begins.
2nd - cervix is fully dilated and birth begins.
3rd - birth and expulsion of the placenta.
What hormones are needed for the initiation of labor?
Prostaglandins and oxytocin.
What is the function of PGF2 alpha?
It enhances oxytocin activation.
What does the adrenal medulla produce?
Adrenaline and noradrenaline (catecholamines).
What do steroid hormones bind to so they can be transported through the blood?
CBG proteins.
Why do steroid hormones bind to CBG proteins?
They are H2O insoluble and so need to bind to CBG for transport through the blood.
Where does the anterior pituitary gland originate from?
It is epithelial in origin. Derived from the primitive gut tube.
What happens to adrenal glands if there isn’t enough ACTH?
They will shrink.
What are glucocorticoids released in response to?
Stress!
What regulates secretion of adrenaline and noradrenaline?
Autonomic innervation, mainly sympathetic.
Where does the posterior pituitary gland originate from?
Originates from neuronal tissue.
What are the physiological functions of cortisol in response to stress?
- Mobilises energy sources: increases protein catabolism, lipolysis and gluconeogenesis. This help to maintain blood glucose levels.
- Enhanced vascular reactivity; maintains vasoconstriction with noradrenaline.
- Suppresses inflammatory and immune responses.
- Inhibition of non-essential functions e.g. growth and reproduction.
Why is there increased cortisol released in response to stress?
Stress poses a threat to homeostasis. Cortisol acts to maintain BP, provide extra energy sources and to shut down non-immune functions so homeostasis can be maintained.
Why is infertility a consequence of stress?
When someone is stressed, their cortisol levels increase, the extra cortisol acts to shut down non-essential functions such as reproduction and so can result in infertility.
What is the epithelium of the anal canal above the pectinate line?
Simple columnar.
What is the epithelium of the anal canal below the pectinate line?
Stratified squamous.
What are the functions of a normal bladder?
Continence, sensation of volume, receptibe relaxation. Voluntary initiation of voiding and complete emptying.
What is the bladder composed of?
Multiple segments of smooth muscle with their associated ganglia. Each segment exhibits
spontaneous activity - ‘micromotions’.
Can the bladder be denervated?
NO!
Which urethral sphincter is composed of skeletal muscle?
External urethral sphincter.
External urethral sphincter.
A visceral and somatic control centre for the lower urinary tract.
What fibre input does the periaqueductal grey receive?
A delta fibres.
What is urinary incontinence?
The involuntary release of urine.
Name 2 types of incontinence.
- Stress incontinence.
- Urge incontinence.
What can stress incontinence be due to?
Sneezing, coughing, exercise.
What can cause urge incontinence (desire to urinate)?
Any irritation to the bladder or urethra e.g. a bacterial infection.
How long does spermatogenesis take?
Approximately 60 days.
What forms the blood testes barrier?
Tight junctions between sertoli cells.
What is the function of the blood testes barrier?
It prevents the movement of cytotoxic agents from the blood into the lumen of the seminiferous tubules. This ensures proper conditions for germ cell development.
Describe the hypothalamo-pituitary-testicular-axis.
GnRh from hypothalamus acts on the anterior pituitary to release LH and FSH. LH acts on Leydig cells stimulating testosterone release. FSH acts on sertoli cells stimulating inhibin release. Inhibin and testosterone have a negative feedback affect on the hypothalamus and anterior pituitary.
What does semen contain?
Sperm, fructose, fibrinogen, clotting enzymes, fibrinolysin.
What is the importance of meiosis in gametogenesis?
It prevents polyploidy and increases genetic variability and so diversity.
How many secondary oocytes does each primary oocyte yield?
1 secondary oocyte and 1 non-functional polar body.
Why does each primary oocyte yield only one secondary oocyte?
Because only one ovum can be yielded per primary oocyte. The secondary oocyte divides into one ovum and a second polar body.
Describe the hormonal changes that occur at puberty.
- Increased amplitude of GnRH and GHRH.
- Increased levels of FSH, LH and sex steroids.
- Increased levels of growth hormone.
What factors can influence puberty?
- Nutrition (body mass).
- Leptin, insulin (hormones).
- Genetics.
- Exercise.
- Socio-cultural.
Describe the hypothalamo-pituitary-ovarian-axis?
GnRh from hypothalamus acts on the anterior pituitary to release LH and FSH. LH acts on theca cells stimulating androgen release. Androgen diffuses from theca to granulosa. FSH acts on granulosa cells stimulating the conversion of androgen into oestrogen (aromatase enzyme). Inhibin is also released from granulosa cells. Inhibin and oestrogen have a negative feedback affect on the hypothalamus and anterior pituitary.
What is the function of dihydrotestosterone?
Stimulates the differentiation of the male external genitalia. It is secreted by the testis.
Menstrual cycle: what is the effect of oestrogen at low levels on the gonadotropins?
Oestrogen is released from granulosa cells and also from the developing and dominant follicle.
Menstrual cycle: what is the effect of decreasing FSH levels in the follicular phase?
Decreasing FSH levels cause the non-dominant, immature follicles to degenerate.
Menstrual cycle: what is the effect of oestrogen at high levels on the gonadotropins?
At high levels oestrogen exerts a positive feedback on gonadotropin secretion, this stimulates the LH surge.
Menstrual cycle: what is the importance of the low LH concentration in the luteal phase?
Low but adequate LH acts to maintain the corpus luteum.
Menstrual cycle: what causes oestrogen and progesterone concentrations to fall towards the end of the luteal phase?
The corpus luteum degenerates into the corpus albicans if fertilisation does not occur. Therefore progesterone and oestrogen are no longer released.
Menstrual cycle: why do FSH levels increase at the end of the cycle?
The fall in progesterone and oestrogen concentration means FSH is no longer inhibited and so its plasma concentration begins to rise.
Menstrual cycle: why does the corpus luteum not degenerate if fertilisation occurs?
When the blastocyst implants the invading trophoblast cells release human chorionic gonadotropin (hCG). This acts to maintain the corpus luteum throughout pregnancy.
What is capacitation?
The final stage of sperm maturation that occurs inside the female reproductive tract. Before this stage the sperm would be unable to fuse with the egg.
Describe the mechanism of block to polyspermy.
- The egg releases contents of secretory vesicles by exocytosis.
- Enzymes from the vesicles enter the zona pellucida and inactivate sperm binding sites and harden the zona pellucida.
Describe implantation.
The blastocyst implants into the endometrium on day 6. The trophoblast cells overlying the ICM invade the endometrium. Nutrient rich endometrial cells provide the metabolic fuel for early embryo growth until the placenta takes over.
hCG stimulates oestrogen and progesterone levels to increase rapidly in pregnancy. What are their functions?
- Oestrogen: prepares the uterus and regulates progesterone levels.
- Progesterone: inhibits uterine contractility so the foetus is not delivered prematurely.
What is the effect on LH and FSH of high oestrogen and progesterone levels throughout pregnancy?
Inhibits LH and FSH and so prevents further menstrual cycle’s during pregnancy.
You have isolated a part of the nephron from the lumen of which large quantities of glucose and amino acids are re-entering the circulation. What part of the kidney are you studying?
Proximal convoluted tubule - bulk reabsorption occurs here.
Whilst looking at the lumen of the nephron you find some epithelial cells that flat rather than cuboidal. What part of the nephron are you looking at?
The thin limb of the loop of henle - flat epithelium.
What is the epithelium of the thick limb of the loop of henle?
Columnar epithelium. Structurally similar to the PCT and DCT.
What are tubulopathies?
Mutations of apical sodium transporters.
Where in the nephron would be affected by Bartters syndrome?
The loop of Henle.
What channels are affected in Bartters syndrome?
NKCC2 channels in the loop of Henle.
What is the diuretic equivalent to Bartters syndrome?
Loop diuretics.
What are the features of Bartters syndrome?
Hypokalemia, low blood pressure, alkalosis.
What channels do loop diuretics close?
NKCC2 - reduced Na+ and K+ secretion.
What part of the nephron would be affected by Gitelmans syndrome?
The distal tubule.
What channels are affected in Gitelmans syndrome?
NCC.
What is the diuretic equivalent to Gitelmans syndrome?
Thiazide.
What are the features of Gitelmans syndrome?
Hypokalemia, hypomagnesemia and low blood pressure.
What part of the nephron would be affected by Liddles syndrome?
The collecting duct.
What channels are affect in Liddles syndrome?
ENaC.
What are the features of Liddles syndrome?
Hypertension and Hypokalemia.
What atom is crucial in thyroid hormone formation?
Iodine.
What cells in the thyroid actively take up iodine in the form of iodide?
Follicular cells.
What process needs to occur before T3 and T4 can be released into the blood stream?
Proteolysis.
Is more T4 or T3 produced in the thyroid?
T4 (thyroxine).
Which molecule is active T3 or T4?
T3 (triiodothyronine).
More T4 is produced than T3 in the thyroid. What process produces T3 elsewhere?
As T3 is more active it can be produced peripherally from the conversion of T4.
Describe the GH/IGF-1 axis.
Hypothalamus -> GHRH (+) or SMS (-) -> anterior pituitary -> GH -> Liver -> IGF-1 -> negative feedback on hypothalamus.
What is the function of IGF-1?
It induces cell division.
What is the decidual reaction?
Following implantation of the blastocyst there is differentiation of endometrial cells adjacent to the blastocyst: decidual basalis (cells invaded by syncytiotrophoblast), decidua capsularis (cells overlying blastocyst), decidua parietalis (cells lining the rest of the uterine cavity).
What hormones increase in parturition?
Prostaglandins (initiation of labour) and oxytocin (uterine contractions).
What does the inguinal canal transmit in females?
The round ligament of the uterus.
What is the function of the round ligament of the uterus?
Maintains the anteverted position of the uterus.
Give 2 reasons why the pH of the skin needs to be maintained at about 5.5.
- The low pH switches on protease inhibitors that prevents corneodesmosome breakdown.
- The low pH also stimulates lipid processing. Lipids prevent H2O loss.
What is the anion gap?
The difference between measured cations and anions: [Na+] + [K+] - [Cl-] - [HCO3-]
What pituitary hormone can cause hyperpigmentation?
ACTH.
Give 2 tests that can be used to screen for disorders in pregnancy.
- Ultrasound.
- Amniocentesis.
What is the most abundant glucocorticoid in humans?
Cortisol.
Name the effect cortisol has on three other hormones.
- Adrenaline - up-regulates beta2 receptors therefore potentiates adrenaline.
- Insulin - inhibits. Cortisol acts to increase blood glucose.
- Glucagon - activates. Cortisol acts to increase blood glucose.
What hormone causes production of sperm?
FSH.
In what specific cell in the testes do sperm mature?
Sertoli.
Name 2 hormones that regulate melanin secretion.
- ACTH.
- MSH.
Give 6 functions of the skin.
- Barrier to infection.
- Protection against trauma.
- Protection against UV.
- Thermoregulation.
- Vitamin D synthesis.
- Waterproof.
What organelle stores melanin in melanocytes?
Melanosomes.
Give 3 histological characteristics of the secretory phase.
- Spiral arteries.
- Decidualised stroma.
- Secretions.
- Torturous glands.
What type of receptor does ACTH act on?
G protein coupled receptor. (All pituitary and hypothalamus hormones act on these receptors).
What hormone acts on the uterus in the proliferative phase?
Oestrogen.
What changes happen to the endometrium in the proliferative phase?
Growth of the endometrium and myometrium is stimulated. Receptors for progesterone are also stimulated.
What hormone acts on the uterus in the secretory phase?
Progesterone.
What changes happen to the endometrium in the secretory phase?
It becomes a secretory tissue: endometrial glands are coiled and filled with glycogen, blood vessels become more numerous and spiralled. Progesterone also inhibits myometrial contractions to ensure that
a fertilized egg can safely implant once it arrives in the uterus.
What are the histological characteristics of the endometrium in the mid-secretory phase?
Tortuous glands, vacuoles above and below the nucleus, stroma-oedema and secretions.
What are the histological characteristics of the endometrium in the late-secretory phase?
Prominent spiral arteries and decidualised stroma. More secretions and elongated glands.
What effects does oestrogen have on the endometrium?
Hyperplasia and hypertrophy of endometrial cells. Also stimulates myometrial growth.
Name one hormone from the pituitary gland one from the chorion/decidua that induces labour.
Pituitary – oxytocin.
Decidua/chorion – prostaglandins.
What do the macula densa cells release when they detect low NaCl?
Prostaglandins.
Prostaglandins act on granular cells and trigger renin release.
What enzyme is found only in the zone glomerulosa?
Aldosterone synthase.
What 2 structures make up the metanephros?
- Metanephric blastema.
- Ureteric bud.
What is dihydrotestosterone?
An active metabolite of testosterone. It modulates external genitalia differentiation -> penis, scrotum and prostate.
What is the ureteric bud an outgrowth of?
The mesonephric duct.
What are the start and end products of mitosis in oogenesis?
Start: oogonia.
End: primary oocyte.
What are the start and end products of meiosis in oogenesis?
Start: primary oocyte.
Middle: secondary oocyte.
End: 1x ovum.
Define tubulopathies.
Mutations of apical Na+ transporters.
What part of the nephron is affected by Bartter’s syndrome?
The loop of henle.
What channels are affected by Bartter’s syndrome?
NKCC2.
What is the diuretic equivalent to Bartter’s syndrome?
Loop diuretics.
What are the characteristic features of Bartter’s syndrome?
Hypokalemia, low BP, alkalosis.
What part of the nephron is affected by Gitelman’s syndrome?
The DCT.
What channels are affected by Gitelman’s syndrome?
NCC.
Name 2 hormones that are produced elsewhere but are activated in the kidney.
- Angiotensinogen.
- 25-hydroxyvitamin D.
What are the 6 stages of implantation?
- Apposition.
- Attachment.
- Differentiation of trophoblast.
- Invasion of endometrium.
- Decidual reaction.
- Maternal recognition.
What are C-cells also known as?
Parafollicular cells.
What amino acid and dietary nutrient are needed for hormones to be secreted from the thyroid gland?
Amino acid - tyrosine.
Dietary nutrient - iodine.
Name 2 proteins in the blood that hormones from the thyroid gland bind to?
- Albumin.
- Thyroxine binding globulin.
Name 2 prostaglandins released in labour.
- PGE2.
- PGF2-alpha (main one).
Give 3 functions of the placenta.
- Provides nutrition to the foetus.
- Gas exchange.
- Waste removal.
- Endocrine and immune support.
Placental abnormalities often require caesarian delivery. What is placenta accreta?
Abnormal adherence, no decidua basalis.
Placental abnormalities often require caesarian delivery. What is placenta perceta?
Where the villi penetrate the myometrium.
Placental abnormalities often require caesarian delivery. What is placenta praeria?
The placenta overlies the internal os, there is abnormal bleeding.
What 2 hormones are secreted in the kidney?
EPO and renin.
Give 2 causes of metabolic acidosis.
Ketoacidosis and lactic acidosis.
What hormones do acidophils in the anterior pituitary secrete?
GH and prolactin (Somatotrophs and lactotrophs).
What hormones do basophils in the anterior pituitary secrete?
FSH, LH, TSH and ACTH. (Corticotrophs, thyrotrophs and gonadotrophs).
Give an example of a steroid hormone.
Oestrogen, testosterone, cortisol.
Give an example of a peptide hormone.
Insulin, GH, FSH, LH, TSH etc.
Which has a faster response, steroid or peptide hormones?
Peptide hormones have a rapid response.
Which is stored, steroid or peptide hormones?
Peptide hormones are stored.
Importance of hormones during pregnancy
- Maintains pregnancy
- Prepares for delivery
- Prepares for breast feeding e.t.c
Important hormones involved in pregnancy
- B-hCG
- Oestrogen
- Progesterone
What produces B-hCG
Placenta
Physiological changes during pregnancy
Respiratory :
Increase in Intraabdominal pressure.
Increase in tidal volume
More diaphragmatic breathing
Cardiovascular:
Increase CO
Decrease in systemic vascular resistance → Increase SV
Drop-in B.P
Haematological:
Increase in plasma volume (40%)
Increase in red blood cell volume
Increase in clotting factors
MSK:
Increase in BMI
Stretch marks
Lower back pain
Endocrine:
Increase anterior pituitary gland secretion
Pregnancy hormone: Oestrogen, Progesterone, B-hCG
Thyroid
Dermatological
Increase in skin pigmentation
Distension + proliferation of blood vessels
Deficiences developed during pregnancy
Anaemia
Gestational diabetes
