Notes on Physiology for competitive examinations

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exam22Notes on Physiology for competitive examinations

Dr. Preetha .B, M.D (HOM-MM)
Dept. of Physiology & Biochemistry, GHMC, Trivandrum

GIT

  • GIT is a tubular structures extending from the mouth up to anus with a length of about 30 feet.
  • A normal healthy adult consumes about 1kg solid diet & about 1 – 2 liters of liquid diet / day.
  • Auerbach’s plexus regulate the movements of GIT.
  • Meissner’s plexus regulate the secretory functions of GIT.
  • Auerbach’s plexus is present between the middle circular muscle layer & outer longitudinal muscle layer & its major function is to regulate the movements of GIT.
  • The total volume of GIT secretions per day is about 8000 ml.
  • Properties & composition of Saliva:
  • Volume: 1000 – 1500 ml / day, (70% by submaxillary glands).
  • Reaction: pH 6.35 – 6.85.
  • Specific gravity: 1.0002 – 1.012
  • Composition: 99.5% water & 0.5% solids.
  • Digestive enzymes: salivary amylase (carbohydrate splitting) & lingual lipase (lipid splitting enzyme).
  • Substances like mercury, potassium iodide, lead & thiocyanate are excreted through saliva.
  • Saliva contains highest conc. of K+.
  • Volume of stomach is 50 ml when empty & can expand up to 4 liters.
  • Properties & composition of gastric juice:
    • Volume: 1200 – 1500 ml / day.
    • Reaction: pH 0.9 – 1.2.
    • Specific gravity: 1.002 – 1.004
    • Composition: 99.5% water & 0.5% solids.
    • Digestive enzymes: Pepsin, Gastric lipase & other gastric enzymes.
    • Action of pepsin: attacks peptide bonds adjacent to aromatic amino acids by hydrolysis.
    • Action of gastric lipase: weak lipolytic enzyme becomes active only when pH is between 4 & 5.
    • Action of HCL: activates pepsinogen into pepsin, bacteriolytic action, causes acidity of the chime & provides acid medium for the action of enzyme.
    • Gastrin is one of the GIT hormones secreted by G cells present in pyloric glands of stomach.
    • Action of Gastrin: stimulates the secretion of pepsinogen & Hcl by gastric glands, increases the motility of stomach, secretion of pancreatic juice & production of hormones by pancreas.
    • Pancreas is a dual organ & has endocrine & exocrine function.
    • Properties & composition of Pancreatic Juice:
      • Volume: 500 – 800 ml / day.
      • Reaction: pH 8 – 8.3.
      • Specific gravity: 1.010 – 1.018
      • Composition: 99.5% water & 0.5% solids.
      • An adult pancreas has 2.5-7.5 lac islets.
      • Total volume of pancreatic secretion per day is 2.5 liters.
      • Pancreas is the only organ that contains Trypsinogen.
      • Ascariasis can also cause acute pancreatitis.
      • Serum amylase and lipase levels are usually not elevated in chronic pancreatitis.
      • Duodenum is the principal site of iron absorption.
      • Most sensitive method for assessing pancreatic exocrine function is Secretin Stimulation Test.
  • Blood flow reaching the liver via portal versus hepatic artery is 4: 1.
  • Hepatic venous pressure is 5 mm Hg.
  • Most common complaints resulting from disorders involving the GIT include pain and alteration in bowel habit.
  • Most potent stimulus for bile secretion is bile salt.
  • Best stimulus for CCK secretion is Fat.
  • Properties of Bile:
    • Volume: 800 – 1200 ml / day
    • Reaction: alkaline
    • pH: 8 – 8.6
    • Sp. Gty: 1010 – 1011
  • Composition of Bile:
    • Water: 97.6%
    • Solids: 2.4%
  • Bile is stored in gall bladder; it undergoes many changes in quality & quantity.
  • There is increase in conc. of bile salts, bile pigments, cholesterol, fatty acids & lecithin.
  • Functions of bile salts:
    • Emulsification of fats, due to emulsification, fat globules are broken down into minute particles.
    • Absorption of fats.
    • Stimulate the secretion of bile from liver.
    • Prevention of gall stone formation.
  • Properties of succus entericus:
    • Volume: 1800 ml / day
    • Reaction: alkaline
    • pH: 8 – 8.3
    • Sp. Gty: 1010 – 1011
  • Enzymes of succus entericus:
    • Proteolytic enzymes: peptidases – amino peptidases, dipeptidase & tripeptidase.
    • Amylolytic enzymes: sucrase, maltase, isomaltase, lactase, dextrase & trehalase.
    • Lipase & enterokinase
  • Bacterial flora of large intestine synthesizes folic acid, Vit B12 & Vit K.
  • Vomiting center is situated bilaterally in medulla oblongata near the nucleus tractus solitarius.
  • Segmentation contraction & pendular movement are involved in mixing of food in small intestine.
  • Peristaltic movements peristaltic rush are the two movements involved in the pushing of chyme towards aboral end on intestine.
  • Desire for defecation is elicited by an increase in the intrarectal pressure to about 20 to 25 cm H2O.
  • Gastrointestinal hormones:

Hormone

Source of  secretion

Actions

Gastrin G cells of stomach; duodenum, jejunum, Ant. Pit & Brain 1. Stimulates the secretion of gastric juice.2. Increase the gastric motility.Stimulates the release of pancreatic hormones.
Secretin S cells of duodenum, jejunum & ileum Stimulates secretion of watery, alkaline & pancreatic secretions.
Cholecytokinin I cells in duodenum, jejunum & ileum Stimulates contraction of gall bladder; Activates secretin; Inhibits gastric motility; Increases secretion of enterokinase & intestinal motility.
Gastric inhibitory peptide (GIP) K cells in duodenum & jejunum Inhibits secretion of gastric juice, gastric motility & increase insulin secretion.
  • Digestion of Carbohydrates:

Area

Juice

Enzyme

Substrate

End Product

Mouth Saliva Salivary amylase Polysaccharides Disaccharides
Stomach Gastric juice Gastric amylase Weak amylase The action is negligible
Small intestine Pancreatic juice Pancreatic amylase PolysaccharidesDisaccharides Disaccharides – dextrins, maltose & maltrioseMonosaccharides
Succus entericus SucraseMaltaseLactase

Dextrinase

Trehalase

Disaccharides Glucose

Skin

  • Skin is the largest organ in the human body.
  • The normal body temperature varies is between 35.8 – 37.30.
  • Axillary temperature is slightly lower, while rectal temp. is slightly higher.
  • Heat lose center is situated in pre-optic nucleus of ant. Hypo thalamus.
  • Heat gain center is situated in post. Hypothalamic nucleus.
  • Primary motor center for shivering is situated in post. Hypothalamus, near the wall 3rd ventricle. 

RESPIRATORY SYSTEM

  • The major phospholipids present in the surfactant are di-palmitoylphosphatidyl choline.
  • Surfactant is secreted by type II alveolar epithelial cells.
  • Total peripheral resistance falls about 50% in moderate exercise.
  • Cyanosis is detectable when arterial oxygen saturation falls below 75% corresponding to PO2 of 40 mmHg.
  • 250ml of oxygen enters the body per min and 200 ml of CO2 is excreted.
  • 5 ml of 02 is transported to the tissues by 100 ml blood in every cycle
  • Pulmonary alveolar macrophages form called “Dust cells”.
  • Size and strength of respiratory muscles is 30-40% above normal in athletes whereas it is 20-30% less in physically weak people.
  • There are about 300 million alveoli in man.
  • There is no stimulation of ventilation by hypoxia until the alveolar O2 falls below 60 mm Hg.
  • Oxygen transported from lung to tissues in chemical combination is 97%.
  • In a healthy adult, 24 hour production of CO2 is about 330 liters.
  • Diffusion capacity for carbon dioxide as compared to that of 02 is 20 times.
  • Average area of the alveolar walls in contact with capillaries in both lungs is about 70 sq. m.
  • Diffusion capacity of lungs for CO2 is 10-30 ml/min/mmHg.
  • Normal composition of venous blood is PO240 mmHg, PCO2 -46 mm Hg and Hb saturation 75%.
  • Peak expiratory flow rate is 400-500 L/mt.
  • The presence of Hb increases the 02 carrying capacity of the blood by 70 fold.
  • Intra-pleural pressure (recoil pressure) required to prevent collapse of the lung — 4 mm Hg in presence of surfactant.
  • Intrapleural pressure at the end of deep inspiration is – 4 mm Hg.
  • Intrapleural pressure during expiration is – 2 mm Hg.
  • Compliance of the normal lungs and thorax combined — 0.13 liter/cm, of H2O.
  • Compliance of the normal lungs alone is 0.22 liter/cm of H2O.
  • During normal quiet breathing only 2-3% of the total energy expenditure is needed for pulmonary ventilation.
  • The amount of alveolar air replaced by new atmospheric air with each breath is only l/7th.
  • Expired air contains 2/3rd alveolar air + l/3rd dead space air.
  • 63% of carbon dioxide is transported as bicarbonate form
  • 97% of O2 is transported by Hb, rest 3% is in dissolved state in the water of the plasma and cells.
  • Carbon mono oxide binds with Hb. 230 times more strongly than ()2.
  • Under resting conditions each 100 ml of blood transports 5 ml of O2 to tissues and carries 4 ml of CO2 from tissues to the lungs.
  • Death occurs usually when the pH of the blood falls to 6.9.
  • The decrease in 02 affinity of Hb when the pH of blood falls is called Bohr’s effect.
  • The degree of stimulation of chemoreceptors depends on arterial PO2.
  • Spirometer cannot measure Functional Residual Capacity.
  • Functional residual capacity is measured by Nitrogen wash out or single breath oxygen method.
  • Most potent respiratory stimulant is carbon dioxide.
  • Kausmaul breathing is seen in diabetic ketoacidosis and it is not a feature of Hypercapnic acidosis.
  • Hering-breuer reflex: impulses from stretch receptors.
  • Peripheral chemoreceptors are carotid & aortic bodies.
  • Respiratory centers:
    • Inspiration – dorsal group of neurons near tractus solitarius nucleus.
    • Expiration – ventral group situated in ventral part of medulla.
  • Normal value of FEV 1 in an adult male is 80%.
  • Muscles of InspirationDiaphragm and External Intercostals muscle (Others – Stcrnocleidomastoid, Serratus anterior).
  • Muscle of Expiration —Internal Intercostal muscle. (Rectus abdominis).
  • Intra alveolar pressure during inspiration — 1 mm Hg.
  • Tidal volume: 500 ml.
  • Inspiratory reserve volume: 3300 ml.
  • Expiratory reserve volume: 1000 ml.
  • Residual volume: 1200 ml.
  • Respiratory minute Volume in a normal person is 6.0 L/min.
  • Inspiratory capacity: 3800 ml.
  • Vital capacity : 4800 ml.
  • Total lung capacity: 6000 ml.
  • Functional residual capacity in a male is 2.2 liters.
  • Normal dead space air volume — 150 ml.
  • Timed vital capacity in 1sec is 83%.
  • Timed vital capacity in 2 sec is 94%.
  • Oxygen dissociation curve is ‘S’ shape or sigmoid shape.

Shift to right

Shift to left

Decrease pH Increase pH
Increase in temp decrease in temp
Excess of 2, 3 DPG Foetal blood
Increase PCO2 (Bohr effect)

Decrease PO2

ENDOCRINE SYSTEM

  • Hormone which acts on the target cell is called as 1st messenger.
  • Cyclic AMP is the most common 2nd messenger for protein hormones.
  • Other 2nd messengers are Ca++, Calmoduline, Inositol triphosphate(IP3) & cyclic GMP.
  • Anterior pituitary hormones are
    • Growth hormone or somatotropic hormone
    • Thyroid stimulating hormone
    • Adenocorticotropic hormone
    • Follicle stimulating hormone
    • Luiteinizing Hormone or interstitial cell stimulating hormones in males
    • Prolactin.
  • Posterior pituitary hormones are
    • Antidiuretic hormone or vasopressin
    • Oxytocin
  • ADH causes conservation of body water & contraction of vascular smooth muscle.
  • Gigantism is due to the hyper secretion of growth hormone in childhood or in the pre-adult life before the fusion of epiphysis of bone with the shaft.
  • Acromegaly is due to hyper secretion of GH in adults after the fusion of epiphysis with shaft of the bone.
  • Dwarfism is a disorder of GH reduction in infancy or early childhood.
  • Diabetes insipidus is a syndrome developed due the defiency of ADH.
  • Hormone responsible for uterine contraction during labour & letting down of milk is Oxytocin.
  • The anterior pituitary has the largest blood flow of any tissue in the body.
  • Anterior pituitary hormones with diabetogenic effect – GH, ACTH, TSH, and PRL.
  • Pigmentation is not a feature of panhypopituitarism.
  • Hormones of thyroid gland are
    • Thyroxine (T4) – 90%
    • Triiodothyronine (T3) – 10%
    • Calcitonin
  • Potency of T3 is four times more than that of T4.
  • Graves’ disease is an auto-immune disease which causes hyperthyroidism.(exophathalmic goiter)
  • Cretinism is hypothyroidism in children & myxedema due to hypothyroidism in adults.
  • Parathormone is secreted by para thyroid gland & its main function is to increase the blood Ca++ level by mobilizing Ca++ from bone.
  • Calcitonin reduces the blood Ca++ level by decreasing the bone re-absorption.
  • Tetany results from hypocalcaemia, caused by hypoparathyroidism.
  • Pancreatic hormones are
    • Alpha cell – Glucagons
    • Beta cells – Insulin
    • Delta cells – Somatostatin
    • F or PP cells – Pancreatic polypeptide
  • Insulin is the only anti diabetic hormone secreted in the body.
  • Glucagons actions are antagonistic to that of insulin.
  • Somatostatin inhibits the secretion of both glucagons & Insulin.
  • Hormones of Adrenal cortex are
    • Mineralocorticoids (secreted by zona glomerulosa)
      • Aldosterone (↑ Na+ & excretion of K+)
      • 11 deoxy corticosterone
    • Glucocorticoids (zona fasiculata)
      • Cortisol
      • Corticosterone
    • Sex hormones (zona reticularis)
      • Dehydroepiandrosterone
      • Androstenedione
      • Testosterone
  • Cushing syndrome is a disorder characterized by obesity due to hyper secretion of glucocorticoids.
  • Conn’s syndrome is primary aldosteronism.
  • Addison’s disease is chronic adrenal insuffiency.
  • Hormones of Adrenal medulla (Catecholamines) are
    • Adrenaline or epinephrine
    • Noradrenaline or norepinephrine
    • Dopamine
  • Pheochromocytoma is a condition in which there is excessive secretion of catecholamines.
  • Melatonin is secreted by parachymal cells of pineal gland, acts on gonads.
  • Severe stress can raise ACTH and cortisol level by 20 folds.
  • Fetal lung maturation depends on increased fetal Cortisol just before birth.
  • Human prolactin causes synthesis of milk in the female breast.
  • The half life of circulating growth hormone in humans is 20 to 30 minutes. 

BLOOD

  • Blood is a connective tissue in fluid form.
  • Blood is 5 times viscous than water.
  • Blood cell count is greater in children than adult.
  • RBC is microcytic in iron defiency anaemia, prolonged forced breathing & increased osmotic pressure.
  • RBC is macrocytic in megaloblastic anaemia, muscular exercise & decreased osmotic pressure in blood.
  • Punctate basophlism is seen in lead poisoning.
  • Goblet ring is seen in certain types of anaemia like malaria.
  • Red cell vol. can be determined by radio isotope 51 Cr.
  • Cyanosis appears when the reduced Hb cone, of the blood in the capillaries is more than 5 gm/dl.
  • In vitro, coagulation is initiated by factor XII.
  • Life of RBC’s in adult human body is 120 days.
  • Average life span of RBC in a newborn is 100 days.
  • Average life span of RBC in transfused blood is 90 days.
  • Life span of transfused platelets is 4 days.
  • Life span of platelets is 9-12 days.
  • Complete erythropoiesis occurs in 7 days.
  • Erythropoiesis occurs in
    • In first trimester RBC’s are formed in Yolk sac. While in second trimester liver is the main organ. Third trimester in liver & bone marrow.
    • Upto age of 5 – 6 yrs – red bone marrow of all bones.
    • 6 – 20 yrs – red bone marrow of all bones & all membranous bones.
    • After 20 yrs – all membranous bones & ends of long bone.
  • Hb starts appearing in intermediate normoblastic stage of erythropoiesis.
  • Nucleus disappears during late normoblastic stage.
  • Factors needed for Erythropoiesis: erythropoietin, thyroxine, interleukins 3, 6, 11, stem cell factors, Vit B, C & D. (maturation factors Vit B12 & folic acid).
  • The iron remains in ferrous state.
  • The affinity of Hb for CO2 is 20 times more than for O2.
  • The affinity of Hb for CO is 200 times more than its affinity for O2.
  • Adult Hb consists of 2 alpha & 2 beta chains.
  • Fetal Hb consist of 2 alpha & 2 gamma chains.
  • In sickle cell anemia, the 2 alpha chains are normal but 2 beta chains are abnormal.
  • In Hb C, beta chains are abnormal.
  • Bilirubin is the final product formed from the destruction of Hb.
  • Total quantity of the iron in the body is 4gm.
  • 1 mg of iron is excreted every day through faeces.
  • Normocytic normochromic anaemia is seen in aplastic aneamia.
  • Marcocytic normochromic anaemia seen in folate deficiency, Vit B12 & hypothyroidism.
  • Pernicious anaemia or addsion’s anaemia is marcocytic normochromic anaemia.
  • Microcytic hypochromic is seen in iron deficiency, thalassemia, heamoglobinopathies & heamolytic anaemia.
  • ESR decreases in allergic conditions, sickle cell anaemia, polycythemia & afibrinogenemia.

 

Character

Normal

1. ESR Male: 3 – 7 mm / hrFemale: 5 – 9 mm / hr
2. PCV (Packed cell volume)(Hematocrit) Male: 40 – 45 %Female: 38 – 42 %
3. MCV (Mean corpuscular volume) 90 cuµ (78 – 90 cuµ)
4. MCH (Mean corpuscular Hb) 30 pg (27 – 32pg)
5. MCHC (Mean corpuscular Hb Conc.) 30% (13 – 38%)
6. Colour index 1 (0.8 – 1.2)
7. WBC 4000 – 11,000 / cmm
8. D.CNeutrophilsEosinophils

Basophils

Monocytes

Lymphocytes

50 – 70%2 – 4 %

0 – 1 %

2 – 6%

20 – 30 %

9. Platelet count 2,50,000( 2 lakhs – 4 lakhs)
10. Bleeding time 3 – 6 min
11. Clotting time 3 – 8 min
12. Prothrombin time 12 sec
13. Activated partial thromboplastin time(APTT) 25 – 40 sec
14. RBCAdult maleAdult female

Birth

4 – 5.5 millions / mm35 millions / mm34.5 millions / mm3

8 – 10 millions / mm3

 

15. Heamoglobin Adult maleAdult female

New born

14 – 18 gm / dl12 – 16 gm / dl

16 – 22 gm /dl

16. RBCDiameter 7.5 µ
17. Blood volume 5 liters
  • Granulocytes are neutrophils, eosinophils & basophils.
  • Agranulocytes are monocytes & lymphocytes.
  • Monocyte is the largest lymphocyte.
  • In hemophilia clotting time is prolonged in presence of normal bleeding time.
  • Christmas disease occurs due to deficiency of factor IX.
  • Clotting factors
Factor I Fibrinogen
Factor II Prothrombin
Factor III Thromboplastin
Factor IV Calcium
Factor V Pro accelerin (labile factor)
Factor VI No such factor
Factor VII Stable factor
Factor VIII Anti hemophilic
Factor IX Christmas
Factor X Stuart-power
Factor XI Plasma thrombplastin antecedent
Factor XII Hegman (Conduct)
Factor XIII Fibrin stabilizing factor (Fibrinase)
  • Blood group:
Group Antigen in RBC Antibody in serum
A A Anti – B (β)
B B Anti – α
AB A & B No anti body
O No antigen Anti A & Anti B
  • Universal recipient are Blood Group ‘AB because it does not contain either Anti A ab or anti B ab.
  • Universal donor is Blood Group “()” because it docs not contain either A or B agglutinogen (antigen).
  • Commonest blood group is O.
  • Diseases associated with blood groups:
    • Group A – C.A stomach
    • Group O – duodenal ulcer
  • Normal basic acid output is 5-10 mmol/hour.
  • Blood is stored in the blood bank at 40C.
  • The number of iron Heme in one Hb molecule is 4.
  • The number of O2 molecules carried by one Hb molecule is 4.
  • Mean corpuscular diameter is 7.5 nm.
  • Maximum concentration of Hb normally found in RBC’s is 34%.
  • In arterial blood, saturated Hb with 02 is 97%.
  • Thromboxane A2 is synthesized by platelets and promotes vasoconstriction and platelet aggregation.
  • In sickle cell anemia, valine is substituted for glutamic acid.
  • Platelets are derived from megakaryocytes.
  • Pus contains — Dead neutrophils, macrophages and necrotic tissues.
  • Cardiac output in anemia is above normal while in polycythemia is about normal.
  • Agglutinins are either IgM or IgG.
  • In Erythroblastosis fetalis, mother is Rh-, father is Rh+, foetus is Rh positive.
  • Hapatoglobin is a plasma protein responsible for carrying free Haemoglobin.
  • Usual anticoagulant used for transfusion is a citrate salt.
  • Earliest feature of iron deficiency anemia is decreased serum ferritin.
  • Arneth count is used in the determination of the percentage distribution of different types of neutrophils on the basis of no: nuclear lobes.
  • Wilson’s disease is due to decrease in caeruloplasmin.

 EXCRETORY SYSTEM

  • Hormones secreted by kidney are erythropoietin, thrombopoitein, renin & 1, 25 dihydroxy cholecalciferol.
  • 1 kidney contains about 1 – 1.3 millions nephrons.
  • Ratio of corical nephrons to Juxtamedullary nephrons 85: 15.
  • The GFR of average sized normal man is approximately 125 ml / minute or 180 liters / day.
  • At the rate of 125 ml/min, the kidneys filter an amount of fluid equal to 4 times the TBV, 15 times the ECF vol. and 60 times the plasma volume.
  • 1 – 1.5 liters of urine formed / day.
  • Urine osmolality in diabetes insipidus is 300 mmol/L.
  • Normal protein excretion is 50 -150 mg%.
  • The quantity of water lost as sweat per day is 600-800 C.C
  • Normal urea clearance is 44 ml/min.
  • Renal blood flow is 25% of cardiac output (1300 ml blood/min).
  • Total length of distal convoluted tubule is 5 mm.
  • Glomerulus membrane permits the passage of substances upto 4 nm and almost totally excludes substance with size greater than 8 nm.
  • Each glomerulus is a net work of approximately 50 parallel capillaries.
  • Urinary osmolality in diabetes insipidus is 300 m mol/Lit.
  • Glucose and amino acid are absorbed in proximal convoluted tubules by secondary active transport or sodium Co-transport.
  • Descending limb of thin segment of loop of Henle is freely permeable to water.
  • Areas impermeable to water — ascending limb of thin segment thick segment of loop of Henle. Proximal half of convoluted tubule.
  • Areas impermeable to urea — Distal convoluted tubule & cortical portion of collecting tubules.
  • Substances completely reabsorbed in PCT — Glucose, proteins, amino acids, vitamins, acetoacetate.
  • Substances partially absorbed in PCT—Na. K, Cl (7/8 reabsorbed in PCT).
  • Substances secreted in PCT — H+, PAH (para amino hippurate). creatinine.
  • H+ are actively secreted in proximal tubules, distal tubules, collecting ducts.
  • Hyperosmilality in the interstitum is the prerequisite for excretion of concentrated urine.
  • Urea is reabsorbed from inner meduallary collecting ducts only in presence of ADH.
  • K+ is actively secreted in Late Distal tubules and Collecting ducts.
  • Macula densa is the epithelial cells of the distal tubule that comes to contact with the arterioles.
  • Juxtaglomerular cells produce renin.
  • Renin acts on angiotensinogen & convert it into angiotensin I.
  • Renal threshold for glucose is reduced in renal glycosuria.
  • Creatinine clearance represents GFR.
  • Clearance test for renal function includes inulin clearance, creatinine clearance & PAHA test.
  • PAHA test is performed to assess renal blood flow.
  • Micturition is primarily a spinal reflex.
  • Thick ascending loop of  henle is impermeable to water.
  • Majority of sodium absorption occur  in the proximal tubule.

Character

Normal

pH 4. 5 – 6
Volume 1000 – 1500 ml / day
Specific gravity 1.010 – 1.025

 MALE REPRODUCTIVE SYSTEM

  • Average pH of semen is 7.5.
  • Life span of spermatozoa within the female genital tract is upto 24 hours.
  • Speed of human sperm in female genital tract is about 3 mm/min.
  • Male sex hormones are called the androgens (secreted by leydig cells); testosterone, dihydro testosterone & androstenedione.
  • Mullerian ducts gives rise to female accessory sex organs such as vagina, uterus & fallopian tube.
  • Wolffian duct gives rise to male accessory sex organs such as epididymis, vas deferens & seminal vesicles.
  • Fetal testes begin to secrete the testosterone at about 2nd to 4th month of embryonic life.
  • The secretion from seminal vesicles contains fructose, phophorylcholine, fibrinogen, ascorbic acid, citric acid, pepsinogen, acid phosphatase & prostaglandin.
  • Fructose & citrate acts as fuel for the spermatozoa.
  • Prostatic secretion is rich in enzymes, fructose & citrate.
  • Androgen appears to be essential for spermatogenesis. Whereas FSH is required for spermatic maturation.
  • Testes do not produce fructose.(seminal vesicle)
  • Sertoli cells provide nutrition to the developing sperm; secrete oestrogen & hormone binding proteins.
  • Testosterone is synthesized from pregnanolone.
  • Testosterone stimulates the process of spermatogenesis, also necessary for the formation of secondary spermatocyte from primary spermatocyte.
  • Growth hormone is essential for the general metabolic processes in testis.
  • Male sex hormone is secreted mainly by interstitial cells of Leydig.
  • Development of male sex organ in fetal life depends on testosterone produced under the influence of HCG.
  • Testosterone circulates in Combination with Gonadal steroid binding globulin.
  • Hormone used for treating osteoporosis in old age — Testosterone.
  • In males FSH promotes spermatogenesis by enhancing the transport of Testosterone to seminiferous tubules and androgen binding protein synthesis from sertoli cells. 

FEMALE REPRODUCTIVE SYSTEM

  • During menstrual period, upto 20 gm of protein may be lost.
  • Quantity of blood expelled during normal menstral cycle is 40 ml (approx) & serous – 35 mls.
  • FSH level is high in post menopausal women.
  • Ovarian hormones are estrogen and progesterone
  • Ovulation occurs on the 14th day of menstrual cycle in a normal cycle of 28 days.
  • Oxytocin causes contraction of smooth muscles of uterus & enhances labour.
  • Hormones secreted are HCG, Oestrogen, progesterone & human chorionic somato mammo tropin.
  • Relaxin is a hormone secreted from the maternal ovary during the later periods of pregnancy.
  • Biological test for Pregnancy can be performed only after 2 – 3 weeks of conception.
  • LH is concerned with follicle maturation and ovulation.
  • Menopausal hot flushes are due to LH surge.
  • Estrogen increases the secretion and ciliary beating in fallopian tubes.
  • Estrogen changes the cuboidal lining of vagina to stratified.
  • Estrogen changes the break down of glycogen into lactate in vagina.
  • Estrogen initiates breast development.
  • Estrogen causes early epiphyseal closure.
  • Estrogen causes water retention.
  • Important function of progesterone is to promote secretory changes in endometrium.
  • Progesterone is the hormone for maintenance of pregnancy.
  • Progesterone inhibits ovulation.
  • The most important function of progesterone is to promote secretory changes in endometrium. 

WATER & ELECTROLYTE / ACID-BASE BALANCE

  • In human beings the total body water varies from 45 – 75 % of body weight.
  • Total water in the body is about 40 liters. (ICF forms 55% & ECF forms 45%).
  • The volume of interstial fluid is about 12 liters.
  • The volume of plasma is about 2.75 liters.
  • Osmolality is the measure of a fluid’s capability to create osmotic pressure, also called as osmotic conc. of a solution.
  • Osmolarity is the no: of particles / per liter of solution.
  • Isotonic solutions are having same effective osmolality as body fluids. Eg: 0.9% Nacl solution & 5% glucose solution.
  • The insensible water loss from the body is about 600 to 800 ml. per day.
  • The quantity of water lost as sweat per day is 600 – 800 C.C.
  • The normal pH of plasma is 7.4
  • Acidosis is pH  below 7.38
  • Alkalosis is pH above 7.42
  • Respiratory acidosis: primary excess of carbonic acid
    • Due to hypoventilation as in respiratory diseases & neural diseases.
  • Metabolic acidosis: primary deficiency of bicarbonate
    • As in lactic acidosis, diabetic ketoacidosis, uremic acidosis & diarrhea.
  • Respiratory alkalosis: primary deficiency of carbonic acid
    • Due to hyperventilation as in hypoxia, neural diseases & psychological conditions.
  • Metabolic alkalosis: primary excess of bicarbonate
    • As in vomiting & treatment with diuretics.