PHYSIOLOGY FACTS
- 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 / hr Female: 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.C Neutrophils Eosinophils 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. | RBC Adult male Adult female Birth | 4 – 5.5 millions / mm3 5 millions / mm3 4.5 millions / mm3 8 – 10 millions / mm3 |
15. | Heamoglobin Adult male Adult female New born | 14 – 18 gm / dl 12 – 16 gm / dl 16 – 22 gm /dl |
16. | RBC Diameter | 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.
