Physiology - Chapter 1 & 2 - PDF

PHYSIOLOGY DR/ MOHAMED YASSER Physiology is one of the very essential branches in medical field It is the branch of 1. How : this function is done ? and 2. Why this function is done by this technique ?...

PHYSIOLOGY DR/ MOHAMED YASSER Physiology is one of the very essential branches in medical field It is the branch of 1. How : this function is done ? and 2. Why this function is done by this technique ? Its importance in dentistry field? 1. it makes the physicotherapist to understand some important medical subjects related to his field , like anemia hemorrhagic diseases of relevance, 2. It clarify some medical problems that might affect physical work 3. It helps physiotherapist to deal with some problems that might face him. physiology HOW Function s 1 | Page PHYSIOLOGY DR/ MOHAMED YASSER Grade distribution 1. Mid-term exam 10 marks 2. quizzes 10 marks 3. assignment 10 marks 4. final written 40 marks 5. practical 30 marks Content *CHAPTER I: INTRODUCTION Includes 1. tissue (= body) fluids 2. homeostasis 3. transport of substance through cell membrane *CHAPTER II : AUTONOMIC NERVOUS SYSTEM ( ANS ) *Chapter III : Blood *Chapter IV Endocrinal glands and Hormones *Chapter V :Physiology of the kidney =renal physiology ‫عناوين بس‬.............‫الحمدهلل الذي بنعمته تتم الصالحات خلصنا المنهج‬ 2 | Page PHYSIOLOGY DR/ MOHAMED YASSER Our body is formed of 75-100 trillion cells Cells form tissues, then organ, then system *CHAPTER I: INTRODUCTION I. tissue (= body) fluids Water is the major constituent of all body fluid compartments. In an adult human, average of 70-kilogram Total body water is about 60 percent of the body weight, or about 42 liters. It is less in obese and adults,but more in infants (75%). It is present in 1.Intracellular fluids 40%=2/3 of body water. 2.Extracellular fluids 20%=1/3 of body water This is divided into A) Extravascular (interstitial fluid) outside blood vessels. B) Intravascular (plasma) inside blood vessels. Intracellular 40% intravascular 3 | Page PHYSIOLOGY DR/ MOHAMED YASSER ‫مهم‬ Extracellular Fluid Intracellular Fluid Amount Less more Main Na K Cation Main Cl Protein Anion Phosphate PHYSIOLOGICAL VARIATION OF BODY FLUID VOLUME Most of the variation in body fluid between individuals is as a result of variation in amount of body fat or adipose tissue (fat is only about 10% water) Infant: 73-80% Male adult: 60% Female adult: 40-50% Old age 45% 4 | Page PHYSIOLOGY DR/ MOHAMED YASSER II- Homeostasis Definition: Keeping internal environment constant for optimum functions of cells e.g. (pH, temperature, concentration of ions, gases, nutrients …etc.) and for protection of the cells This is done by A) help of 2 major systems 1. nervous system, rapid one 2. chemical system, slow one, by help of hormones, vitamins & enzymes B) System of feedback mechanisms 1. negative feedback: in which the response is reverse of the stimulus, most of feed backs inside our body are negative.‫ نتيجة( ف الحالة دي النتيجة بتاعكس و بتبقا ضد السبب‬--‫)سبب—تحفيز‬ 2. positive feedback: in which the response is as stimulus as in labor..‫ نتيجة(ف الحالة دي النتيجة بتبقا نفس تأثير السبب بيبقوا صحاب و مع بعض‬--‫)سبب—تحفيز‬ III- Transport of substance through cell membrane Methods of transport of substance through cell membrane A) Passive methods i.e. does not need energy (downhill transport) We have 3 types: 5 | Page PHYSIOLOGY DR/ MOHAMED YASSER 1. simple diffusion: it is the transport of substance from higher concentration into a lower concentration without need of energy, e.g. a diffusion of CO2 & O2 through alveoli Diffusion increases by a) increase in concentration gradient b) decrease in molecular size c) increase in temperature 2. facilitated diffusion: the same as simple diffusion but with help of carrier, to widen pores for diffusion 3.Osmosis:it is the transport of fluid from higher concentration of fluid to a lower concentration of fluid without need of energy The power by which the fluid is moving, is called osmotic pressure. Osmotic pressure of blood =5000mmHg=osmotic pressure of saline(0.9NaCl%) =osmotic pressure of glucose 5%, So saline (with blue paper label) & glucose 5% (red paper label) are iso osmotic solution with blood. These 2 types of solutions are very commonly used solutions in hospitals 6 | Page PHYSIOLOGY DR/ MOHAMED YASSER Passive diffusion simple facilitated osmosis ATP NO NO NO Carrier NO YES NO Transport Substance from Substance from Water high conc. To low high conc. To low From High conc. conc. water content to the lower one B) Active methods i.e. need source of energy (uphill transport) ,3 types 1. primary active transport: Here the source of energy is from ATP directly e.g. Na-K pump present in cell membrane of every cell. 7 | Page PHYSIOLOGY DR/ MOHAMED YASSER 2. secondary active transport: Here the source of energy is rather than from ATP. Source of energy is from passive transport of another substance, We have 2 types of secondary active transport: A) co-transport: in which the actively transported substance & the passively transported substance are in the same direction. B) counter-transport: in which the actively transported substance & the passively transported substance are in opposite direction. 8 | Page PHYSIOLOGY DR/ MOHAMED YASSER 3. Vesicular transport: If the transported substance is big & has high molecular weight, it is transported by a vesicle formed by cell membrane. We have 2 typed of vesicular transport A) Endocytosis: where the transported substance is from outside to inside the cell (‫)من برا لجوا‬. B) Exocytosis: where the transported substance is from inside to outside the cell (‫)من جول لبرا‬. CHAPTER 1 DONE 9 | Page PHYSIOLOGY DR/ MOHAMED YASSER CHAPTER II: AUTONOMIC NERVOUS SYSTEM (ANS) classification of nervous system: It is classified into 2 main parts: 1.Central nervous system (CNS) Includes: *Brain (cerebrum) *Brain stem (3 parts midbrain, pons & medulla oblongata) *Cerebellum *Thalamus *Hypothalamus *Other many centers *Spinal cord. Its cells are characterized by inability to divide as there is no centriole (‫)االعصاب مش بتتجدد‬. That is why it is protected by bones, e.g. skull & vertebral column. 10 | P a g e PHYSIOLOGY DR/ MOHAMED YASSER 2. Peripheral nervous system (PNS) which is formed of the peripheral nerves arising from CNS, This includes A) 12 pairs of cranial nerves: I&II are arising from brain III&IV are arising from midbrain V, VI, VII & VIII are arising from pons IX, X, XI & XII are arising from medulla oblongata B) 31 pairs of spinal nerves: 8 cervical arising from 8 cervical spinal segments 12 thoracic arising from 12 thoracic spinal nerves 5 lumbar arising from 5 lumbar spinal nerves 5 sacral arising from 5 sacral spinal nerves 1 coccygeal arising from 1 coccygeal spinal nerve Functionally, nerves of peripheral nervous system are classified into Somatic and Autonomic Nerves. 1. Somatic nerves: those nerves that supply skeletal muscle and act voluntary. 2. Autonomic nerves: those nerves that supply autonomic structures (heart, smooth muscle & glands) 11 | P a g e PHYSIOLOGY DR/ MOHAMED YASSER Difference Between Somatic nerve and Autonomic nerves 12 | P a g e PHYSIOLOGY DR/ MOHAMED YASSER Autonomic nerves are subdivided into two types A) sympathetic nerves that supply all autonomic structures and control their function in abnormal conditions like stress, fear fight ……. etc. B) parasympathetic nerves, that supply the same autonomic structure and control their function in the normal resting conditions. Sympathetic = Fight or Flight Parasympathetic = Rest and Digest So ANS: is the part of nervous system that control the function of autonomic structures in normal (by parasympathetic system) and abnormal conditions (by sympathetic) Autonomic Ganglia 13 | P a g e PHYSIOLOGY DR/ MOHAMED YASSER Definition: ganglion is a site of meeting between 2 nerves outside CNS (pleural is ganglia), however site of meeting between 2nerves inside CNS is called nucleus. Types & classification: according to its site into 1.Lateral (paravertebral): There are 23 pairs on 2 sides of the vertebral column, 3 cervical,12 thoracic, 4 lumbar & 4 sacral. All are sites for relay of sympathetic nerves 2.Collateral ganglia (Prevertebral): They are related to the big abdominal blood vessels e.g. renal artery They are sympathetic ganglia,e.g. coeliac g, renal g ,superior mesenteric g …….etc. 3. Terminal ganglia They are near autonomic organs e.g. near eye, near heart, near bronchus……. etc. They are parasympathetic ganglia Functions of autonomic ganglia ‫( مقالي مهم‬DAR ‫)دار‬ 1.Relay station for preganglionic nerves 2.site of Action of many drugs 3.Distributing center, as average ratio of preganglionic to postganglionic in -Parasympathetic is 1:8 -Sympathetic is 1:32, so sympathetic system is more distributed. 14 | P a g e PHYSIOLOGY DR/ MOHAMED YASSER Divisions of ANS A. Parasympathetic nervous system: arises from cranial nerves III, VII, IX & X (3,7,9,10). and lateral horn cells of sacral spinal segments2,3&4. That is why it is called cranio-sacral outflow or division. B. Sympathetic nervous system: arises from lateral horn cells of all thoracic spinal segments & upper 2 lumbar spinal segments. That is why it is called thoraco- lumbar. Differences between parasympathetic & sympathetic nervous system. Sympathetic ----→ ‫اسأل نفسك هتعمل اي لو انت ف موقف صعب زي خناقة مثل‬ ‫ف بالعقل معظم أنشطة الجسم بتشتغل بأقصي قوة عندها علشان تعدي الفترة الصعبة دي‬ ParaSympathetic ---→ ‫اسأل نفسك هتعمل اي لو انت قاعد و مريح و مأنتخ‬ ‫و بنفس الفكرة أنت قاعد و مأنتخ ف مش محتاج اجهزة جسمك تزود شغلها اساسا و بالتالي ف يتشتغل‬ ‫ع اقل طاقة عندها‬ ‫مهم جدا مقالي و امسيكو بالهطل‬ Sympathetic Parasympathetic Origin Thoracolumbar Craniosacral 15 | P a g e PHYSIOLOGY DR/ MOHAMED YASSER Effect on Heart Increase Activity and Decrease Activity and properties properties Effect on Blood V.C Except Coronary V.D Except Coronary Vessels and Skeletal blood and Skeletal blood vessels vessels Effect on Bronchus Bronchodilatation Bronchoconstriction Effect on Glands Trophic (Viscid) Watery (True) Secretion Secretion Effect on Skin *VC of B.V. NO parasympathetic *Increase Sweating fibers to skin *Contraction of Erector Pilae muscles leading to Goosy skin (more in animals) Effect on Spleen Contraction of Splenic NO parasympathetic Capsule fibers to skin Effect on Liver Glycogenolysis *Glycogenesis(‫)العكس‬ ‫بيكسر الجليكوجين علشان يطلع‬ *Increase Bile ‫جلوكوز و طاقة‬ secretion Effect on metabolism *Glycogenolysis *Glycogenesis *Lipolysis *Lipogenesis Effect on Sex organs Ejaculation Erection Especially Male 16 | P a g e PHYSIOLOGY DR/ MOHAMED YASSER Effect on hollow *Contraction of *Relaxation of organs (stomach, etc.) sphincter sphincter *Relaxation of Wall *Contraction of Wall leading to retention of leading to content ( ‫بيقفل الطريق و‬ evacuation(emptying) ‫)يحجزها مكانها‬ Effect on EYE *Pupillo- *Pupillo- dilation(mydriasis) constriction(miosis) *Relaxation of ciliary *Contraction of ciliary muscles leading to muscles leading to decrease power and increase power and thickness of lens thickness of lens *Far Vision *Near Vision *VC of blood vessels. *VD of blood vessels. *Exophthalmos due to * WATERY secretion contraction of muller of Lacrimal duct. muscles. *NO parasympathetic * Viscid secretion supply to tarsal (tears). muscles. *Elevation of upper Eye lid Due to contraction of tarsal muscles. Functions during Abnormal conditions Normal resting (stress, exercise, conditions fight or flight) Anabolic or Catabolic Catabolic Anabolic 17 | P a g e PHYSIOLOGY DR/ MOHAMED YASSER Distribution 1:32 1:8 Chemical transmitter Ach or Catecholamines Ach only To summarize, the Parasympathetic system acts during rest, it is anabolic. It increases secretion & contraction of smooth muscle but decreases heart. The Sympathetic system acts during abnormal conditions & it is catabolic. It increases heart but decreases secretion and contraction of smooth muscle. 18 | P a g e PHYSIOLOGY DR/ MOHAMED YASSER Exophthalmos Elevation of Upper eye lid Mydriasis Miosis Chemical transmitters Definition: it the chemical substance that can transmit impulse from a nerve to another nerve, or from a nerve to an organ ( ‫من االخر هو شبه المعدية‬ ‫)اللي بتنقلك من بر ترعة الي البر التاني‬, i.e. impulse is transmitted electrically inside the nerve but chemically from a nerve to a nerve or organ. *Types of chemical transmitters A( Common: they either Acetyl choline, or catecholamines (adrenaline noradrenaline. ) B( Less common, e.g. glycine, dopamine, GABA, serotonin ……etc. We will discuss only Acetyl choline & catecholamines ACETYLE CHOLINE Formation: in cell body of the cholinergic nerve by combination of choline & acetyl Co A by help of an enzyme called choline acetylase. 19 | P a g e PHYSIOLOGY DR/ MOHAMED YASSER Transport: transported through axon. Storage: in the axon terminal in a vesicle called clear vesicle Release: once the impulse reaches the axon terminal the vesicle ruptures by a process called exocytosis to release Acetyl choline. *Cholinergic fibers (nerves that form & release Acetylcholine) 2 groups: A) central cholinergic fibers or nerves include 1. all preganglionic nerves sympathetic or parasympathetic 2. at motor end plate (= junction between somatic nerve & skeletal m 3. at suprarenal medulla 4. inside CNS B) peripheral cholinergic fibers or nerves, include 5. at postganglionic parasympathetic nerves 6. at post ganglionic sympathetic only to skeletal muscle blood vessels & sweat glands 20 | P a g e PHYSIOLOGY DR/ MOHAMED YASSER Cholinergic receptors, either nicotinic or muscarinic ‫مهم‬ Nicotinic Receptors Muscarinic Receptors Other Name central peripheral Present in front of Central cholinergic Peripheral cholinergic nerves nerves or in autonomic organs Present in Preganglionic nerves Postganglionic nerves Skeletal, Adrenal supplying autonomic medulla organs Stimulated By Small dose of nicotine muscarin Blocked By Large dose of nicotine Atropine or hyoscine Actions: resulting from stimulation of cholinergic receptors Actions include (‫)مهم مقالي‬ 1.stimulation of parasympathetic organs. 2.stimulation of the skeletal muscles to do contraction. 3.stimulation of adrenal medulla to release catecholamines. 4.stimulation of sweat gland to produce sweating & skeletal muscle blood vessels vasoconstriction. 21 | P a g e PHYSIOLOGY DR/ MOHAMED YASSER Inactivation of Acetylcholine by 2 ways 1. Enzymatic inactivation by an enzyme called choline esterase (not choline acetylase) =80% 2. Active reuptake again to the vesicle= 20% Drugs acting on cholinergic nerves A. drugs stimulating cholinergic nerves, called cholinomimetics or parasympathomimetic, include 1.choline esters, e.g. carbachol, they are synthetic and resemble structure of A. choline, used in treatment of urinary retention, constipation &paralytic ileus (‫)العلوص الشللي‬ 2.Naturally occurring alkaloid, e.g. pilocarpine, used in treatment of simple glaucoma (= increased intra ocular pressure) 3. anti-choline esterase: are either A. reversible: prostigmine used in treatment of myasthenia gravis (hereditary disease affecting female and characterized by general & severe weakness of the skeletal muscle) 22 | P a g e PHYSIOLOGY DR/ MOHAMED YASSER B. irreversible anti-choline esterase: These drugs bind strongly with choline esterase, leaving acetylcholine to work strongly and permanently. Drugs representing this group are called organophosphorus compounds. These substances are present in A) insecticides e.g. parathion B) war gases: these gases are forbidden from use during wares as they are very toxic & fatal as they are absorbed from all body tissue coverings, e.g. skin, eye nose and reach blood within seconds and have a very rapid and strong action. To treat these patients, Atropine is used in excessive & high dose. B) Drugs inhibiting cholinergic receptors parasympatholytic 1.Muscarinic blockers: Atropine & its derivative Hyoscine They are extracted from Atropa belladonna & datura stramonium Uses (‫)مهم مقالي‬ 1. in treatment of colic 2. to decrease sweating 3. in fundus examination 4. in pre anesthetic medication to A) decrease secretions that might block the tube of anesthesia. 23 | P a g e PHYSIOLOGY DR/ MOHAMED YASSER B) to decrease the increased parasympathetic tone during general anesthesia 5. in treatment of organophosphorus compound toxicity 2. Nicotinic blockers: either I. ganglion blockers as Arfonad; not used now except in treatment of very resistant hypertension II. Skeletal muscle relaxant = neuromuscular blockers = Motor endplate blockers = MEP blockers as curare and succinyl choline (Sch) They are used in A) general anesthesia as pre-anesthetic medication to relax muscles of vocal cords. B) in the treatment of convulsions. Catecholamines Include 1.dopa 2.dopamine Natural 3 noradrenaline (norepinephrine=NE) 4 adrenalines (Epinephrin= E) 5. isoprenaline (synthetic drug) 24 | P a g e PHYSIOLOGY DR/ MOHAMED YASSER Formation:in the cell body of the adrenergic fibers by this reaction Transport: through axon till axon terminal. Storage: in axon terminal in a vesicle called dark vesicle same as Ach Adrenergic fibers A. all post ganglionic nerves except to sweat gland and skeletal muscle blood vessels, most of these are noradrenaline B. adrenal medulla, most of these are adrenaline, as methylase enzyme is more available Release: the same as the release of A.choline. Adrenergic receptors, are either, alpha or beta 25 | P a g e PHYSIOLOGY DR/ MOHAMED YASSER Actions: all sympathetic actions, mentioned before Inactivation: A) mainly 80% by active reuptake again to the dark vesicle B) enzymatic inactivation 20%, by one of 2 enzymes 1. Mono amine oxidase (MAO) degrading catecholamines into Venyl mandelic acid(VMA)& hydroxymandelic acid(HMA), released in urine. 2.Catecholo ortho methyl transferase (COMT) degradating catecholamines into normetanephrine, released in urine So VMA, HMA & normetanephrine are the end products of catecholamines in urine. 26 | P a g e PHYSIOLOGY DR/ MOHAMED YASSER Drugs acting on adrenergic system, either A) Drugs stimulating, called sympathomimetics, or andromimetic B) Drugs inhibiting, called sympatholytic or adrenolytic, these group is more used clinically. They are commonly used as antihypertensives. Sympathomimetics 1.drugs stimulating sympathetic ganglia e.g nicotine in small dose 2.drugs helping release of catecholamines as A) ephedrine used in ttt of bronchial asthma & to stop bleeding. B) amphetamine *Decreases appetite, so used in ttt of obesity. * CNS stimulant, increases mentality& increases ABP. 3.receptor agonists 1.alpha agonists: as noradrenaline & adrenaline 2.beta agonists: as isoprenaline & adrenaline Sympatholytic: 1.sympathetic ganglion blockers: nicotine in large dose 2.drugs decreasing release of catecholamines: reserpine &guanethidine 3.false transmitter eg, alpha methyl dopa (aldomet). This drug is safe to hypertensive pregnant females 27 | P a g e PHYSIOLOGY DR/ MOHAMED YASSER 4. receptor blockers A) alpha blockers as (berzocin & youhimbine) B) beta blockers as indral ( propranolol ) and atenolol **Sympatholytic are commonly used in treatment of hypertension 28 | P a g e