Body Systems Past Papers Flashcards

Question

select the ONE INCORRECT option from those provided The adrenal medulla a. contains chromaffin cells b. possesses nicotinic receptors c. secretes aldosterone into the circulation d. is innervated by the sympathetic nervous system

Answer 1

? c. secretes aldosterone into the circulation ii) Adrenal medulla: -> Sympathetic Nervous system Preganglionic fibre -> adrenal medulla -> releases acetylcholine (ACh) -> stimulates chromaffin cell -> makes epinephrine -> moves along postganglionic fibre -> releases epinephrine ->sent into circulatory system -> stimulates adrenergic receptors of heart -> incr. heart rate.

Answer 2

a. forms sphincters in the urinary tract 2. Smooth  Forms walls of organs, blood vessels & airways  Gastrointestinal movement  Alters diameters -> airways & blood vessels - Short, fusiform (narrow at ends) cells - Non striated (not striped) - Single central nucleus - Innervated -> autonomic nervous system Skeletal muscle forms sphincters in urinary tract

Answer 3

d. reticulocytes Connective tissue - Structural framework for body - Supports surrounds & interconnects tissues - Protects delicate organs - Transports fluids & dissolved materials - Stores energy reserves - Defence -> microorganisms - Classification of connective tissue: 1.Specialised connective tissue 2.Connective tissue proper -> 1. Loose areolar/irregular Variety of cells - Fibroblasts, adiposcytes, macrophages (transient) ->2. Dense irregular connective tissue: ->Few cells - Mainly fibroblasts ->3. Dense regular connective tissue -> Few cells - Mainly fibroblast

Answer 4

c. does not contain valves - >Process of elimination ```  Lymphatic circulation: - Network lymphatic vessels - Lymph - Lymphatic tissues & organs  Defence mechanisms  Drains interstitial fluid ``` - Removal of excess interstitial fluid: 1. Fluid -> out of capillary-> interstitial space -> arterial end of capillary 2. Fluid -> into capillary -> venous end of capillary 15% fluid remains -> interstitial space ->Enters lymphatic system -> lymphatic capillary -> becomes lymph ->Returned to blood - Lymph capillaries -> Blind-ended tubes - > adjacent -> capillary beds  Lymphatic drainage: Lymph capillaries -> Lymph vessels -> Lymph nodes -> Lymph trunks  i) Thoracic duct ii) Right lymphatic duct ``` Lymphatic drainage: - RHS head, neck , thorax & upper limb Right lymphatic duct Right subclavian vein - Rest of body Thoracic duct Left subclavian vein ```

Answer 5

b. deep to the parietal pericardium ``` • Fibrous Pericardium: Characteristics: - Inelastic sac -> dense tissue - Inferior fusion -> diaphragm - Superior infusion -> large vessels Function: - Prevents overfilling of heart - Anchors position ``` ``` • Serous pericardium: Characteristics: - Double-layered serous membrane - Lies -> deep within -> fibrous pericardium - Contains: 1. Parietal pericardium:  Lines inner surface -> fibrous pericardium 2. Visceral pericardium:  Tightly adhered -> surface of heart 3. Pericardial cavity:  Space between parietal & visceral layers Contains tissue fluid. Function:  Prevents friction. ``` ``` • Heart wall: - 3 layers: i) Endocardium:  Inner layer -> Endothelium ii) Myocardium:  Middle layer -> Cardiac muscle iii) Epicardium:  Outer layer -> Visceral pericardium ```

Answer 6

b. low altitude • Erythrocyte Homeostasis:  Low conc O2  Detected by kidneys -> stimulates incr. production -> erythropoietin  Detected -> stem cells -> incr. production of RBCs  More RBCs -> higher O2 transportation capacity -> incr. O2 conc.  Causes of hypoxia (low O2 conc) - Incr. excersise - High altitude - Smoking - Bleeding Production of erythrocyte:  Production of RBCs required  Triggers kidneys -> release erythropoietin hormone  Erythropoietin -> acts on stem cells  Instigates specialisation of stem cell -> production -> RBCs  Proerythroblast -> immature cell -> bone marrow Matures -> Erythroblast  Normoblast -> containing full haemoglobin conc. -->Constant production of haemoglobin during these stages  Normoblast ejects nucleus -> reticulocyte Reticulocyte still contains some ribosomal RNA >If Reticulocyte released -> circulation prematurely -> still some ability to produce haemoglobin. Small number in circulation -> later mature -> RBCs Lots of reticulocytes ->Anaemia  Erythrocyte (RBC)

Answer 7

d. include lymphocytes i) Granulocytes - Neutrophils - Eosinophils - Basophils ii) Agranulocytes - Lymphocytes - Monocytes ```  Neutrophils: - 50-70% of WBCs -> most common - Structure: 9-15 micrometres diameter Distinctive nucleus >>2-5 lobes >>Granular cytoplasm - Function: 1st line defence -> bacterial infection Phagocytic Mobile Circulate -> blood -> approx. 10hrs Major component -> pus ``` ```  Eosinophils: - 2-4% of WBCs - Structure: 10-12 micrometres diameter Bilobular nucleus - Function: Circulate -> blood -> approx. 8-12 hrs >>Migrate -> tissues Lifespan approx. 1-3 days Release toxic compounds Eg. NO & cytotoxic enzymes Allergies >>Athsma Combat -> parasitic infections Attack bacteria, protozoa, debris ``` ```  Basophils: - >1% WBCs -> least common - Structure: 8-10 micrometres diameter Bilobed “S” shaped nucleus >>Large cytoplasmic granules Granules >>Histamine >>Heparin - Function: Inflammatory response Unknown lifespan Possible precursors -> mast cells >>Share common bone marrow precursor ```

Answer 8

d. tissue factor ``` • Coagulation: - Conversion -> soluble plasma protein -> insoluble rigid polymer -> fibrin Fibrinogen -> soluble Thrombin -> enzyme -> polymerisation >>Fibrinogen -> Fibrin. Fibrin -> insoluble Factor XIII -> stabilises Fibrin ```  Initaiation of coagulation: - Extrinsic pathway  Tissue factor >>Binds to Factor VII -> Tissue Factor-FVIIa complex >>Binds -> FX -> activates transformation -> FXa - Intrinsic pathway  Factor IX & co-factor VIII >>Binds -> FX -> activates transformation -> FXa Slower -> extrinsic pathway - Common pathway  Prothrombinase Comprised FXa & FVa as co-factor >>Binds -> Prothrombin -> produces -> thrombin >>Thrombin -> converts -> Fibrinogen -> Fibrin

Answer 9

a. are the least common type ```  Neutrophils: - 50-70% of WBCs -> most common - Structure: 9-15 micrometres diameter Distinctive nucleus >>2-5 lobes >>Granular cytoplasm - Function: 1st line defence -> bacterial infection Phagocytic Mobile Circulate -> blood -> approx. 10hrs Major component -> pus ```

Answer 10

a. has a null point which is towards the arterial end of a capillary network • Dynamics of capillary exchange:  Arterial end  High hydrostatic pressure -> forces fluid out capillary network >> Opposed -> high osmotic potential gradient  Capillary Hydrostatic Pressure (CHP) -> 35mmHg  Blood Colloid Osmotic Pressure (BCOP) -> 25mmHg ->> CHP > BCOP ->> Net filtration pressure -> +10mmHg >> Forces fluid & dissolved substances out -> capillary network  Significant rate of filtration -> 24 L/day  Venous end  Hydrostatic pressure decline -> incr. distance -> heart  Same osmotic potential  Capillary Hydrostatic Pressure (CHP) -> 18mmHg  Blood Colloid Osmotic Pressure (BCOP) -> 25mmHg ->> CHP < BCOP ->> Net Filtration Pressure -> -7mmHg >>Movement of fluid -> into capillary network  Significant Rate of reabsorption -> 20.4 L/Day  Net difference in water -> Rate of filtration & absorption Collected -> Lymphatic System  Centre -> Capillary Network Approx. centre -> capillary network ->Equal values -> CHP & BCOP -> Net filtration pressure = 0. -> No net movement -> fluid.  Max filtration pressure always greater -> max absorption pressure >> Point at which net filtration pressure = 0 -> further towards venous end -> capillary ->> More filtration than absorption along capillary. ¬->> Enables provision -> tissues with required molecules over greater distance -> capillary network > Rapid reabsorption -> molecules & waste products -> venous end.

Answer 11

c. inhibition of the cardiovascular centres in the brain ? Look at treatments & what they cause -> actual hypotension woukd be causing opposite effect of that as treatment inhibiting/counteracting it. Also look at risks associated and what causes those risks to occur. • Hypertension:  Affects nearly one billion  One of the main causes -> premature death.  Nearly 8 million fatalities per year  Types: - Primary Hypertension (Essential / Idiopathic)  Unknown medical cause  Links:  Genetic predisposition  Alcohol consumption  Obesity  Lack of excersise  Diabetes  Intrauterine environment - Secondary Hypertension  Known medical cause 1) Kidney Disease:  Incr. Angiotensin II >> Vasoconstriction & expansion -> cellular fluid 2) General endocrine disorders Eg. Diabetes, Cushing’s 3) Adrenal medulla disease (Phaeochroocytoma)  Excessive adrenaline secretion  Treatment: - Inhibit angiotensin II production -> Angiotensin-Converting-Enzyme (ACE) >> Prevents renal absorption -> Na+/H2O > Prevents incr. blood volume - Ibhibition -> Angiotensin II induced vasoconstriction -> Angiotensin II receptor blocker. >> Inhibitd membrane cardiac / vascular depolarizoation > Decr. CO -> vasodilation. - Calcium-channel blocker / thiazide diuretic >> Incr. loss -> Na+ & H2O > Decreases fluid volume, venous return & cardiac output. - Reduce TBR -> inhibition -> noradrenaline action. - Alpha-adrenoreceptor Antagonists (alpha-Blockers)  Reduce TBR -> inhibition -> noradrenaline action. - Beta-adrenoreceptor Antagonists (beta-Blockers)  Decr. CO2,  Decr. central activity -> Symapthetic nervous system  Decr. release -> Renin ->> Favourable secondary actions  Risks: - Atherosclerosis - Stroke / Cerebrovascular Accident - Heart Failure - Renal Failure - Aneurysms

Answer 12

b. is defined as an increase in heart rate • Arrhythmias:  Deviation of heart’s normal sinus (SAN) rhythm.  Relatively rare -> 1 in 5000-10000  Found -> young individuals ; <25yrs  Many arise -> Defects in ion channels regulating ventricular action potentials  Cause spontaneous multiple depolarizations >> Ventricular arrythmias  Produce sustained abnormal rhythm  Asymptomatic  Palpitations  Dizziness  Syncope  Heart Failure  Sudden Death ``` 1. Bradycarida:  Slow Rhythm (<60bpm) Causes:  Slowed signal -> sinus bradycardia  Pause / sinus arrest  Blockage >> Due to SAN / conducting tissue damage Treatment:  Artificial pacemaker ```

Answer 13

a. described as a chronotropic variable The heart rate is influenced by chronotropic variables! ``` • Chronotropic Effect: - Influence effecting heart rate. • Innervation of Heart: 1. Cardioregulatory centre & chemoreceptors -> medulla oblongata Via -> Sensory Nerve Fibres ->> Baroreceptors -> wall of internal carotid artery ->> Carotid body chemoreceptors ->> Baroreceptors -> Aorta 2. Adrenal Medulla i) Via -> Parasympathetic nerve fibres ->> Sinoatrial (SA) Node ii) Via -> Sympathetic nerve fibres ->> Heart 3. Adrenal Medulla Via -> Sympathetic nerve fibres -> adrenal gland >Release adrenaline/noradrenaline -> circulation ->>Heart ``` • Regulation of blood pressure: 1. Decreased blood pressure detected by baroreceptors. 2. Baroreceptors send signals along glosso-pharyngeal nerve to the Medulla oblongata -> brain. 3. Medulla oblongata sends incr. impulses along autonomic nerves to heart blood vessels. 4. Incr. no of impulses -> incr. cardiac output & vasoconstriction of heart blood vessels. -> Blood pressure increases to optimal level. 5. Increased blood pressure detected by baroreceptors. 6. Baroreceptors send signals along glosso-pharyngeal nerve to Medulla oblongata. 7. Medulla oblongata decr. impulses along autonomic nerves to blood vessels of heart. 8. Blood vessels decr. cardiac output & vasoconstriction -> preventing further fluctuation of pressure.

Answer 14

d. originates from defects in the sinoatrial node Long QT syndrome (LQTS) is a disorder of the heart's electrical activity, usually caused by a faulty gene inherited from a parent. It can cause sudden, uncontrollable, dangerous arrhythmias

Answer 15

d. is caused by elevated aldosterone levels - >Other anseers imply causes ; or associations however this states this is the cause ; despite cause is unknown. Essential hypertension (also called primary hypertension or idiopathic hypertension) is the form of hypertension that by definition has no identifiable cause. It tends to be familial and is likely to be the consequence of an interaction between environmental and genetic factors.

Answer 16

b. gas exchange The conducting portion consists of the air-transmitting passages of the nose, nasopharynx, larynx, trachea, bronchi and bronchioles. This part of the respiratory system serves to filter, warm and humidify air on its way to the lungs.

Answer 17

- Hilum of lung:  Located -> mediastinal surface Region of entry -> lungs for blood vessels, lymphatics, nerves & bronchi.

Answer 18

b. rectus abdominus ``` • Inspiration: - Active process - At rest:  Diaphragm (75%)  External intercostal muscles (25%)  Contracted diaphragm flattens -> Vertical diameter of thorax increased.  External intercostals elevate ribs -> incr. Anterior Posterior & Transverse diameters. - Forced:  Pectoralis major  Pectoralis minor  Scalenes  Serratus anterior  Sternocleidomastoid  Assist -> rib elevation -> Incr. speed & amount of movement ```

Answer 19

Type II Alveolar Cell: >> Secretes Surfactant b. is a mixture of phospholipids Pulmonary surfactant is a mixture of lipids and proteins which is secreted by the epithelial type II cells into the alveolar space. The main function of pulmonary surfactants is to reduce the surface tension at the air/liquid interface in the lungs. As the alveoli increase in size, the surfactant becomes more spread out over the surface of the liquid. This increases surface tension effectively slowing the rate of expansion of the alveoli. This also helps all alveoli in the lungs expand at the same rate, as one that expands more quickly will experience a large rise in surface tension slowing its rate of expansion. It also means the rate of shrinking is more regular, as if one reduces in size more quickly the surface tension will reduce more, so other alveoli can contract more easily than it can. Surfactant reduces surface tension more readily when the alveoli are smaller because the surfactant is more concentrated.

Answer 20

b. how insoluble gases (oxygen and carbon dioxide) are in blood

Answer 21

Hypercapnia, also known as hypercarbia and CO2 retention, is a condition of abnormally elevated carbon dioxide (CO2) levels in the blood

Answer 22

a. active transport

Answer 23

c. protein is low Extrarcellular fluid has : - Lower K conc - Higher Na conc - Slightly higher (but sill low) conc of Ca - Higher conc. Cl - Lower Org conc - Lwer Protein conc

Answer 24

d. transverse plane ``` • Anatomical position:  Position of the upright body -> arms at sides -> palms facing forwards. - Anterior (Ventral):  Front / Underside - Posterior (Dorsal)  Behind/ Upperside/back - Superior  Towards the head - Inferior  Towards the feet - Medial  The core/centre - Lateral  Towards the side/ away from core/centre - Proximal  Closer towards the trunk - Distal  Further from the trunk - Coronal/frontal plane:  Divides into front & back planes -> Anterior/ventral & posterior/dorsal - Horizontal/transverse plane  Divides into top & bottom planes -> Above & below waist -> Superior & Inferior - Midsagittal plane  Divides into right & left halves -> medial & lateral ```

Answer 25

c. hemidesmosomes • Intercellular junctions: - Specialised areas of cell mem -> bind cells to one another. - Types of intercellular junction:  Desosomes: Strong Join adjacent cells Resist stretching & twisting.  Hemidesosomes: Stabilising  Attach cells to basement mem Anchor to underlying tissue  Tight junctions Binds adjacent cells -> interlocking proteins Prevents passage of water & solutes between cells Found on Apical side of cells Eg. Digestive tract -> Prevents digestive fluids passing between epithelial cells.  Gap junctions: Interlocking mem proteins (connexons) bind cells together  Connexons – central pore enabling movement of small molecules & ions between cells  Cardiac muscle

Answer 26

c. intima  Endothelium -> simple squamous epithelium  Basal lamina of epithelial cells  Subendothelial connective tissue - Tunica media:  Smooth muscle fibres -> loose connective tissue  May contain elastic fibres - Tunica adventitia:  Connective tissue  Merges -> surrounding connective tissue  May contain vaso vasroum

Answer 27

``` • Foetal circulation: - Oxygen & nutrients received from placenta Umbilical vein - Bypasses non-functional lungs  3 shortcuts: i) Ductus venosus >> Umbilical vein -> inferior vena cava ii) Foramen ovale >> Right -> left atria iii) Ductus arteriosus >> Pulmonary trunk -> arch of aorta. ``` ``` • Portal circulations: - Blood drains -> one capillary bed ->Vein -> 2nd capillary bed ->Heart. Eg. Hypophyseal portal system  Hypothalmus -> pituitary gland Eg. Hepatic portal system  Gastrointestinal tract -> liver. The right-hand side of the heart collects deoxygenated blood from the body and pumps it to the lungs (to collect more oxygen). This is called pulmonary circulation. ```  Systemic circulation:  High pressure -> arterial  Transports oxygenated blood -> LHS heart -> body tissues  Returns deoxygenated blood – RHS heart

Answer 28

b. bicuspid valve • Blood flow through heart: 1. Deoxygenated blood from body tissues - > Superior & Inferior vena cava -> right atrium 2. Right atrium - > Tricuspid (right atrioventricular) valve -> right ventricle. 3. Right ventricle - > Pulmonary semilunar valve -> pulmonary trunk & arteries. 4. Pulmonary trunk & arteries - > Lungs -> Oxygenated -> Pulmonary veins. 5. Pulmonary veins - > Left atrium 6. Left atrium - > Bicuspid (mitral/left atrioventricular valve) -> Left ventricle 7. Left ventricle - > Aortic semilunar valve -> aorta. 8. Aorta - > Body tissues.

Answer 29

a. all types of blood cell •Haematopoiesis/Haemopoiesis:  Process -> formation -> blood cells  All cells produced -> 1 haematopoietic stem cell Self-renewing Differentiates -> different cells -> depending on requirements of body i) Common myeloid progenitor -> production -> all cells except lymphocytes ii) Common lymphoid progenitor -> production -> lymphocytes • Erythropoiesis:  Production of erythrocyte (RBCs) ``` • Haemoglobin:  Transports O2 & CO2  Synthesis begins -> proerythroblast 65% -> erythroblast 35% -> reticulocyte  280 million per RBC  15g/dl  4 subunits: 2 alpha & 2 beta Each contains haem >Bound -> globin -> long polypeptide chain Ferrous iron atom Fe2+ at centre of each subunit >>Can reversibly bind -> O2 ```

Answer 30

 Eosinophils: d. have a bilobed nucleus ``` Eosinophils: - 2-4% of WBCs - Structure: 10-12 micrometres diameter Bilobular nucleus - Function: Circulate -> blood -> approx. 8-12 hrs >>Migrate -> tissues Lifespan approx. 1-3 days Release toxic compounds Eg. NO & cytotoxic enzymes Allergies >>Athsma Combat -> parasitic infections Attack bacteria, protozoa, debris ```

Answer 31

d. tissue factor ``` Coagulation: - Conversion -> soluble plasma protein -> insoluble rigid polymer -> fibrin Fibrinogen -> soluble Thrombin -> enzyme -> polymerisation >>Fibrinogen -> Fibrin. Fibrin -> insoluble Factor XIII -> stabilises Fibrin ```  Initaiation of coagulation: - Extrinsic pathway  Tissue factor >>Binds to Factor VII -> Tissue Factor-FVIIa complex >>Binds -> FX -> activates transformation -> FXa - Intrinsic pathway  Factor IX & co-factor VIII >>Binds -> FX -> activates transformation -> FXa Slower -> extrinsic pathway - Common pathway  Prothrombinase Comprised FXa & FVa as co-factor >>Binds -> Prothrombin -> produces -> thrombin >>Thrombin -> converts -> Fibrinogen -> Fibrin

Answer 32

• Rh [D] Blood group: c. Rh +ve foetus and Rh -ve mother - Rh -ve -> Antigen present - Rh +ve -> Antigen absent >> Rh -ve -> does not usually contain anti-Rh [D] antibodies >Requires sensitisation -> exposure -> Rh +ve RBCs Transfusion Pregnancy/ birth ->Rh -ve mother & Rh +ve baby ->Haemolytic disease -> newborn -> HDN

Answer 33

b. changes in the heart rate • Pulmonary Circulation: - Decr. O2 & Incr. CO2 -> constriction -> arterioles. Response & Regulation of Blood Pressure: Homeostasis: - Altered Blood pressure / volume Physical stress Eg. Trauma, high temp, etc. Chemical changes Eg. Decr. O2 / decr. pH / Incr. CO2 / Incr. vasodilatory metabolites Increases tissue activity / Intrinsic Control - Inadequate blood pressure & flow >>Autoregulation:  Decr. resistance & incr. blood flow > Homeostasis returned. - Insufficient Autoregulation: Stimulates receptors -> sensitive to systemic changes -> blood pressure / Chemistry. Activates cardiovascular centres -> Central Nervous System Elevates Blood pressure -> Short Term >>Stimulation -> heart rate & peripheral vasoconstriction -->> Sensory Nervous System. Return -> Homeostasis.

Answer 34

d. detect changes in vascular pressure ``` • Baroreceptors: Wall -> internal carotid artery Aorta Baroreceptors & Control -> Blood Flow: • Inadequate Blood supply / Decr. Blood Pressure: - Inhibition -> baroreceptors  Activation  Cardioacceloratory Centre Vasomotor Centres  Inhibition  Cardioinhibitory Centre >> Incr. Cardiac Output & Heart Rate - Vasoconsriction ``` ``` • Rise -> Blood Pressure: - Stimulation -> Baroreceptors  Activation Cardioinhibitory Centre  Inhibition Cardioacceloratory Centre Vasomotor Centres >> Decr. Cardiac Output & Heart Rate - Vasodilation. ```

Answer 35

b. is an endocrine gland Avg. HR per min = 75 So (75 x 60 ) x 24 = 108,000• Endocrine glands are ductless glands of the endocrine system that secrete their products, hormones, directly into the blood. The major glands of the endocrine system include the pineal gland, pituitary gland, pancreas, ovaries, testes, thyroid gland, parathyroid gland, hypothalamus and adrenal glands. Innervation of Heart: 1. Cardioregulatory centre & chemoreceptors -> medulla oblongata Via -> Sensory Nerve Fibres ->> Baroreceptors -> wall of internal carotid artery ->> Carotid body chemoreceptors ->> Baroreceptors -> Aorta 2. Adrenal Medulla i) Via -> Parasympathetic nerve fibres ->> Sinoatrial (SA) Node ii) Via -> Sympathetic nerve fibres ->> Heart 3. Adrenal Medulla Via -> Sympathetic nerve fibres -> adrenal gland >Release adrenaline/noradrenaline -> circulation ->>Heart

Answer 36

?? Cardiac electro-mechanical coupling is known to contribute to sudden cardiac death, a significant public health issue, but its role in the intact human heart Described in terms of P-wave, QRS complex, T-wave & QT interval Cardiac cycle occurs throughout heart.

Answer 37

b. generally the same as that of a highly-trained individual at rest Untrained -> Rest ; Excersised --> Trained -> Rest ; Excersised CO (L/min) ~5 ~20 ~5.5 ~30 CO = HR x SV

Answer 38

• Ischaemic Heart c. most commonly caused by atherosclerosis of a coronary artery Disease (Coranary Heart Disease -> CAD)  Leading cause of death -> Developed world  30% Males  23% Females  Common cause:  Atherosclerosis -> coronary artery  Most frequent -> Left anterior interventricular artery  Occurs in Left ventricle  Insufficient Blood flow to myocardium >> Angina Pectoris (ischemia-induced pain) ->>Mediated by endogeneous vasodilators >> Results -> myocardial infarction ->> Death of heart muscle within 20 mins

Answer 39

d. type II alveolar cells  Alveoli  Site -> gas exchange  Surrounded by network of capillaries  150-250 mill per lung  Blood Supply  Structure:  Type I Alveolar Cell: >> Simple squamous epithelium > Forms wall of alveolus  Type II Alveolar Cell: >> Secretes Surfactant  Macrophage: >> Phagocytozes small inhaled particles & bacteria  Capillary  Respiratory membrane >> Epithelium -> Type I alveolar cell >> Basement membrane -> Type I alveolar cell >> Basement membrane -> Capillary >> Endothilium -> Capillary ->> Basement membranes often fused together. In the nose; one of the functional adaptations, the mucosa; contain goblet cells which produce mucous to trap particles.

Answer 40

- Bony Thorax:  Forms skeleton of chest wall  d. transverse process of the thoracic vertebra ->Says attached, specifically articulated to sternum & thoracic vertebra ``` Components:  12 pairs ribs -> 7 true pairs -> 3 false pairs -> 2 floating  12 thoracic vertebrae  Sternum - Sternum:  Breast bone  Components:  Manubrium  Body  Xipisternum - Ribs:  Differ -> shape & size  Slope downwards & forwards  Attached by head & tubercle -> thoracic vertebrae  Ribs 1-10 attached by costal cartilage -> sternum - Thoracic Vertebrae:  Head of rib articulates with body of thoracic vertebra  Tubercle of rib articulates with transverse process of thoracic vertebra - Intercostal muscles:  Span intercostal spaces  External intercostals  Superficial layer  Fibres run supero-lateral to infero-medial -> Tubercles to costochondral junction -> (Downward-diagonally from shoulder to core - / )  Internal intercostals  Middle layer  Fibres run infero-lateral to supero-medial -> At angles to ends of intercostal spaces. -> (Upward-diagonally from hip to core - \ )  Innermost intercostals  Innermost layer - Intercostal Vessels & Nerves:  Intercostal spaces  Supply muscles. Adjacent skin & pleura. - Diaphragm:  Dome shaped-skeletal muscle with central tendon  Attached:  Xiphisternum  Costal Margin  11th & 12th ribs  Left & Right Crus -> Arise -> Lumbar vertebrae  Innervated -> phrenic nerve  Most important muscle -> ventilation.  Structures / components:  Skeletal muscle -> outside  Centrally-placed tendon -> No body attachments ```

Answer 41

a. contraction of the diaphragm • Incr. Thoracic Volume: - Incr. Vertical diameter  Contraction of diaphragm incr. vertical diameter Responsible for 75% incr. thoracic capacity - Incr. Anterior Posterior diameter  Elevation of ribs incr. Anterior Posterior diameter -> (Joint with Transverse Diameter) Responsible for 25% thoracic capacity.  Elevation of ribs -> external end -> makes them more horizontal & pushes sternum forward (pump handle movement) Incr. AP diameter - Incr. transverse diameter  Elevation of ribs incr. transverse diameter -> (Joint with Transverse Diameter) Responsible for 25% thoracic capacity.  Many of the ribs  Lowest near their middle  Rise at each end Eg. Bucket handle  Rise of middle of rib -> movement away from midline of body Transversally widens chest (Left -> Right) ``` • Inspiration: - Active process - At rest:  Diaphragm (75%)  External intercostal muscles (25%)  Contracted diaphragm flattens -> Vertical diameter of thorax increased.  External intercostals elevate ribs -> incr. Anterior Posterior & Transverse diameters. - Forced:  Pectoralis major  Pectoralis minor  Scalenes  Serratus anterior  Sternocleidomastoid  Assist -> rib elevation -> Incr. speed & amount of movement ```

Answer 42

d. located just beneath the ventral surface of the medulla ?? ``` • Central Chemoreceptors: - Located -> Medulla oblongata of brainstem - Respond to changes in PCO2 & pH • Peripheral Chemoreceptors: - Detect changes -> PO2, PCO2 & pH - Aortic Bodies  Located -> Aortic Arch  Innervated -> Vagus (CN X) - Carotid Body  Located -> Common Carotid Artery  Innervated -> Glossopharyngeal (CN IX) ``` • Respiratory Centres: - Group of neurons -> Brain stem - Send impulses to muscles of ventilation - Medullary Rhythmicity Area  Dorsal Respiratory Group (DRG)  Sets rhythm, stimulates muscles of quiet inspiration  Ventral Respiratory Group (VRG)  Involved in forced inspiration & expiration - Pneumotaxic area (Pons)  Influences DRG by regulating duration of inspiration.

Answer 43

c. pneumotaxic centre • Respiratory Centres: - Group of neurons -> Brain stem - Send impulses to muscles of ventilation - Medullary Rhythmicity Area  Dorsal Respiratory Group (DRG)  Sets rhythm, stimulates muscles of quiet inspiration  Ventral Respiratory Group (VRG)  Involved in forced inspiration & expiration - Pneumotaxic area (Pons)  Influences DRG by regulating duration of inspiration

Answer 44

c. 152 mmHg | - > 20% of 760?

Answer 45

c. urine The fluids that are not inside cells, but are separated from plasma and interstitial fluid by cellular barriers (e.g., cerebrospinal fluid, synovial fluid, pleural fluid). Transcellular fluids are also a component of ECF and are found in the cerebrospinal column, pleural cavity, lymph system, joints, glandular secretions, and eyes Synovial fluid is found in the cavities of synovial joints. It reduces friction between the articular cartilage of synovial joints during movement & is a small component of the transcellular fluid The vitreous humor is a transparent, colorless, gelatinous mass that fills the space in the eye between the lens and the retina. It is surrounded by a layer of collagen called vitreous membrane separating it from the rest of the eye. Blood plasma liquid component of blood that normally holds the blood cells in whole blood in suspension; this makes plasma the extracellular matrix of blood cells. It makes up about 55% of the body's total blood volume. It is the intravascular fluid part of extracellular fluid (all body fluid outside cells).

Answer 46

c. urine The fluids that are not inside cells, but are separated from plasma and interstitial fluid by cellular barriers (e.g., cerebrospinal fluid, synovial fluid, pleural fluid). Transcellular fluids are also a component of ECF and are found in the cerebrospinal column, pleural cavity, lymph system, joints, glandular secretions, and eyes Synovial fluid is found in the cavities of synovial joints. It reduces friction between the articular cartilage of synovial joints during movement & is a small component of the transcellular fluid The vitreous humor is a transparent, colorless, gelatinous mass that fills the space in the eye between the lens and the retina. It is surrounded by a layer of collagen called vitreous membrane separating it from the rest of the eye. Blood plasma liquid component of blood that normally holds the blood cells in whole blood in suspension; this makes plasma the extracellular matrix of blood cells. It makes up about 55% of the body's total blood volume. It is the intravascular fluid part of extracellular fluid (all body fluid outside cells).

Answer 47

c. innervate skeletal muscle - Parasympathetic nerves comprise the autonomic nerves -> innervate smooth & cardiac mucle & involved in subconscious activity ``` 2. Parasympathetic Nervous system -> Spinal cord & base of brain. Outflow from CNS:  Parasympathetic -> Cranial & sacral  Parasympathetic -> Long - Ganglionic transmitter:  Parasympathetic -> ACh (N2) - Postganglionic fibre:  Parasympathetic -> Short - Neuroeffector transmitter:  Parasympathetic -> ACh (M) ```

Answer 48

c. are striated 3. Muscle: c. are striated - Produces movement -> specialised for contraction - 3 types – skeletal , smooth & cardiac.  Similarirties - Elongated parallel to axis of contraction - Numerous mitochondria -Contractile elements ``` 1. Skeletal  Moves & stabilises skeleton  Forms sphincters in digestive & urinary tracts -> controls urges to pee etc.  Involved in respiration - Long cylindrical cells - Striated (striped) - Multinucleated (multiple per cell) - Innervated -> somatic nervous system ``` 2. Smooth  Forms walls of organs, blood vessels & airways  Gastrointestinal movement  Alters diameters -> airways & blood vessels - Short, fusiform (narrow at ends) cells - Non striated (not striped) - Single central nucleus - Innervated -> autonomic nervous system

Answer 49

?? - Simple squamous  Exchange of nutrients & gases -> Blood vessels & alveoli - Non-keratinised stratified squamous Protection -> Oral cavity & oesophagus - Keratinised stratified Squamous  Waterproof protection/barrier -> Skin - Simple cuboidal epithelium Secretion & absorption -> Glands & kidney tubules - Simple columnar epithelium Absorption & secretion -> Gastrointestinal tract --> also have microvilli -> Enabling absorption of nutrients. - Pseudostratified ciliated columnar epithelium with goblet cells Mucociliary escalator -> produce mucous -> particles inhaled -> trapped in mucous. -> Cilia moves mucous upwards to back of throat for swallowing. -> Trachea & large respiratory airways. -> Also has cilia & goblet cells. Trachea appears stratified -> some cells don’t reach free surface -> All touch basement mem. Serous cavities are cavities lined by serous membrane serous cavity a coelomic cavity, like that enclosed by the pericardium, peritoneum, or pleura, not communicating with the outside of the body and lined with a serous membrane,(mesothelium)

Answer 50

a. appear to have a larger lumen

Answer 51

b. carotid artery - > Carotid = neck ``` • Major arteries: - Arm:  Axillary -> Shoulder  Brachial -> Upper arm  Radial -> Lateral  Ulnar -> Medial - Leg:  External iliac -> Hip area  Femoral -> Upper leg  Popliteal -> Back of knee  Anterior tibial - Core:  Right common carotid -> Right -> neck  Left common carotid -> Left -> neck  Brachiocephalic trunk -> Lungs  Right subclavian -> Right -> under collarbone  Left subclavian -> Left -> under collarbone  Aortic arch -> Main part of heart  Descending thoracic aorta -> Down inside lower end of rib cage -> spine  Abdominal aorta -> Abdominal -> inside spine  Common iliac -> Top of hip  External iliac -> Lower hip -> top of leg  Internal iliac -> Backbone ```

Answer 52

c. pulmonary veins The coronary sinus is a collection of smaller veins that merge together to form the sinus, located along the heart's posterior surface between the left ventricle and left atrium It drains deoxygenated blood into the right atrium of the heart. so it can be pumped to the lungs to acquire oxygen. Pulmonary veins are responsible for carrying oxygenated blood from the lungs back to the left atrium of the heart.

Answer 53

d. transports O2 from tissues to lungs ``` • Haemoglobin:  Transports O2 & CO2  Synthesis begins -> proerythroblast 65% -> erythroblast 35% -> reticulocyte  280 million per RBC  15g/dl  4 subunits: 2 alpha & 2 beta Each contains haem >Bound -> globin -> long polypeptide chain Ferrous iron atom Fe2+ at centre of each subunit >>Can reversibly bind -> O2 ``` ``` • Structure of RBCs: - Biconcave disc Enables easy passage through vessels - 7-8 micrometeres -> diameter - Foldable & flexible -> deforms easily - Stable - No organelles more room for haemoglobin - Function: Transportation -> oxygen & CO2 - Life span  120 days > Broken down & recycled. -> So no ability to produce haemoglobin as no organelles/ nucleus ``` Production of erythrocyte:  Production of RBCs required  Triggers kidneys -> release erythropoietin hormone  Erythropoietin -> acts on stem cells  Instigates specialisation of stem cell -> production -> RBCs  Proerythroblast -> immature cell -> bone marrow Matures -> Erythroblast  Normoblast -> containing full haemoglobin conc. -->Constant production of haemoglobin during these stages  Normoblast ejects nucleus -> reticulocyte Reticulocyte still contains some ribosomal RNA >If Reticulocyte released -> circulation prematurely -> still some ability to produce haemoglobin. Small number in circulation -> later mature -> RBCs Lots of reticulocytes ->Anaemia  Erythrocyte (RBC)

Answer 54

c. not able to migrate out of the bloodstream ``` • White blood cells:  Also known -> Leukocytes  Nucleated  Act mainly outside tissues In-transit -> sites of activity  Can migrate out of bloodstream -> extravastation (diapedesis)  Capable -> amoebid movement  Attracted -> specific chemical stimuli  2 groups: i) Granulocytes - Neutrophils - Eosinophils - Basophils ii) Agranulocytes - Lymphocytes - Monocytes  Neutrophils, eosinophils & monocytes -> phagocytosis  Functions: - Defence -> pathogens - Toxin & waste removal - Removal -> damaged cells ```

Answer 55

a. can accept blood from a person with A antigens on their red blood cells A antigens on RBCs = A Blood Type -> A blood type cells produce anti-B antibodies which would then cause individual's blood to clot by agglutination In addition, their B Blood type cells will produce Anti-A antibodies to cause agglutination of type A cells for elimination.

Answer 56

b. when blood flow to the kidneys is increased ?? • Erythrocyte Homeostasis:  Low conc O2  Detected by kidneys -> stimulates incr. production -> erythropoietin  Detected -> stem cells -> incr. production of RBCs  More RBCs -> higher O2 transportation capacity -> incr. O2 conc.  Causes of hypoxia (low O2 conc) - Incr. excersise - High altitude Production of erythrocyte:  Production of RBCs required  Triggers kidneys -> release erythropoietin hormone  Erythropoietin -> acts on stem cells  Instigates specialisation of stem cell -> production -> RBCs  Proerythroblast -> immature cell -> bone marrow Matures -> Erythroblast  Normoblast -> containing full haemoglobin conc. -->Constant production of haemoglobin during these stages  Normoblast ejects nucleus -> reticulocyte Reticulocyte still contains some ribosomal RNA >If Reticulocyte released -> circulation prematurely -> still some ability to produce haemoglobin. Small number in circulation -> later mature -> RBCs Lots of reticulocytes ->Anaemia  Erythrocyte (RBC)

Answer 57

a. always higher in arteries than veins  Blood flow determined: - Resistance -> R - Pressure difference -> P  F = ▲P / ▲R ``` Determined by: ->> L = length of vessel ->> r = radius of vessel ->> ꞃ = fluid viscosity >>(protein conc.) ```  R = (8Lꞃ) / (πr4)  F = ▲P((πr4) / (8Lꞃ))

Answer 58

c. is dependent upon higher blood pressure at the venous end of the capillary compared with the arterial end ' - > This would mean more molecules still forced out of blood into extracellular fluid, further decr. vol. of fluid & dissolved subs. in capillaries & hence no time for reabsorption of waste products for removal. • Dynamics of capillary exchange:  Arterial end  High hydrostatic pressure -> forces fluid out capillary network >> Opposed -> high osmotic potential gradient  Capillary Hydrostatic Pressure (CHP) -> 35mmHg  Blood Colloid Osmotic Pressure (BCOP) -> 25mmHg ->> CHP > BCOP ->> Net filtration pressure -> +10mmHg >> Forces fluid & dissolved substances out -> capillary network  Significant rate of filtration -> 24 L/day  Venous end  Hydrostatic pressure decline -> incr. distance -> heart  Same osmotic potential  Capillary Hydrostatic Pressure (CHP) -> 18mmHg  Blood Colloid Osmotic Pressure (BCOP) -> 25mmHg ->> CHP < BCOP ->> Net Filtration Pressure -> -7mmHg >>Movement of fluid -> into capillary network  Significant Rate of reabsorption -> 20.4 L/Day  Net difference in water -> Rate of filtration & absorption Collected -> Lymphatic System  Centre -> Capillary Network Approx. centre -> capillary network ->Equal values -> CHP & BCOP -> Net filtration pressure = 0. -> No net movement -> fluid.  Max filtration pressure always greater -> max absorption pressure >> Point at which net filtration pressure = 0 -> further towards venous end -> capillary ->> More filtration than absorption along capillary. ¬->> Enables provision -> tissues with required molecules over greater distance -> capillary network > Rapid reabsorption -> molecules & waste products -> venous end.

Answer 59

b. described as an inotropic variable • Chronotropic Effect: - Influence effecting heart rate. • Inotropic effects:  Effects which alter the contractility of the heart ```  Negative chronotropic effect:  Slows Heart Rate Eg. Acetlycholine ->> Via positive end -> muscarinic (ACh)-receptor gated K-channels Component of ‘vagal tone’  Positive chronotropic effect:  Increase Heart Rate Eg. Noradrenaline & adrenaline ->> Via stimulation -> hyperpolarisation-activated ion channels ``` In addition to its metabolic effects, glucagon is considered to increase heart rate and contractility, stimulation of glucagon receptors causes adenylyl cyclase activation and the consequent increase in 3′,5′-(cAMP) production.

Answer 60

c. involves slowing of the heart beat • Arrhythmias:  Deviation of heart’s normal sinus (SAN) rhythm.  Relatively rare -> 1 in 5000-10000  Found -> young individuals ; <25yrs  Many arise -> Defects in ion channels regulating ventricular action potentials  Cause spontaneous multiple depolarizations >> Ventricular arrythmias  Produce sustained abnormal rhythm  Asymptomatic  Palpitations  Dizziness  Syncope  Heart Failure  Sudden Death 2. Tachycardia:  Fast Rhythm (>100bpm)  Sinus Tachycardia  Innapropriate Sinus Tachycardia (IST) Invlolves: >> Caffeine >> Amphetamines >> Overactive thyroid gland -> SNS  Non-sinus Tachycardia -> Addition of abnormal inpulses -> normal cycle > Uncontrolled twitching / quivering -> muscle fibres (fibrils) > Blood not removed from heart -> ventricular fibrillation > Sudden cardiac death Caused by: >> Automaticicity (enhanced pacemaker) >> Triggered Beats (Early / delayed depolarization) >> Re-entry Activity / Circus Activity (Conduction profile defects) >> Conduction Block >>Heart Damage

Answer 61

c. is unrelated to ion channel gene defects ?? Long QT syndrome (LQTS) is an inherited condition that can cause abnormal heart rhythms (arrhythmias) which affects repolarization of the heart. Usually caused by a faulty gene inherited from a parent which affects the proteins that make up the ion channels regulating electricity in the heart. The ion channels may not work well, or there may not be enough of them, which disrupts the heart's electrical activity. It results in an increased risk of fainting (syncope) drowning, or sudden death

Answer 62

• Hypertension:  Affects nearly one billion  One of the main causes -> premature death.  Nearly 8 million fatalities per year  Types: - Primary Hypertension (Essential / Idiopathic)  Unknown medical cause  Links:  Genetic predisposition  Alcohol consumption  Obesity  Lack of excersise  Diabetes  Intrauterine environment - Secondary Hypertension  Known medical cause 1) Kidney Disease:  Incr. Angiotensin II >> Vasoconstriction & expansion -> cellular fluid 2) General endocrine disorders Eg. Diabetes, Cushing’s 3) Adrenal medulla disease (Phaeochroocytoma)  Excessive adrenaline secretion  Treatment: - Inhibit angiotensin II production -> inhibition of Angiotensin-Converting-Enzyme (ACE) >> Prevents renal absorption -> Na+/H2O > Prevents incr. blood volume - Ibhibition -> Angiotensin II induced vasoconstriction -> Angiotensin II receptor blocker. >> Inhibitd membrane cardiac / vascular depolarizoation > Decr. CO -> vasodilation. - Calcium-channel blocker / thiazide diuretic >> Incr. loss -> Na+ & H2O > Decreases fluid volume, venous return & cardiac output. - Reduce TBR -> inhibition -> noradrenaline action. - Alpha-adrenoreceptor Antagonists (alpha-Blockers)  Reduce TBR -> inhibition -> noradrenaline action. - Beta-adrenoreceptor Antagonists (beta-Blockers)  Decr. CO2,  Decr. central activity -> Symapthetic nervous system  Decr. release -> Renin ->> Favourable secondary actions  Risks: - Atherosclerosis - Stroke / Cerebrovascular Accident - Heart Failure - Renal Failure - Aneurysms

Answer 63

b. bronchioles ```  Bronchi  Series of tubes  Smaller in diameter  Display histological chabges >> Decr. quantity cartilage >> Incr. quantity smooth muscle >> Decr. height epithelial cells  Pseudostratified ciliated columnar epithelium with goblet cells  Cartilage plates  Types:  Primary bronchus >> Supply each lung >> 2-3cm long >> Right -> wider & more vertical -> left >> C-shaped cartilages  Secondary bronchus >> Lobar >> Supply lobes of lung > 3 on right > 2 on left >> Plates of cartilage  Tertiary bronchus >> Segmental >> Supply lung segments > 10 on right > 8 on left >> Plates of cartilage ``` ```  Bronchioles  No cartilage  Smooth muscle >> Can constrict & dilate  Simple columnar epithelium with some goblet cells  Each has 50-80 terminal bronchioles  Types:  Terminal >>Simple columnar epithelium with cilia >> No goblet cells / mucous glands >> Clara cells > Produce surfactant >> Each gives 2 or more respiratory bronchioles  Respiratory >> Simple cuboidal epithelia >Clara cells ->> Produce surfactant >> No cilia >> Alveoli extend from lumen > Site -> Gas exchange ``` ```  Larynx  Functions:  Maintenance -> open airway  Prevents consumed substances entering lower respiratory system.  Sound production  Involved:  Coughing  Defacecation  Structure: Cartilaginous skeleton >> Epiglottis >> Thyroid cartilage (Adam’s Apple) >> Cricoid cartilage >>Arytenoid cartilage  Lined by memebranes  Moved using muscles  Paranasal tissues  Functions:  Warms & moistens air  Filters air  Involved -> Olfaction  Resonates sound ``` ```  Trachea  Tough, flexible tube  4.5cm length  2.5cm diameter  Extends -> larynx to carina  Anterior to oesophagus  15-20 horseshoe-shaped cartilages  Keep airway open  Pseudostratified ciliated columnar epithelium with goblet cells  Dust particles -> stuck in mucus layer  Cilia move mucus layer towards mouth >> Transports / removes dust particles ```

Answer 64

c. bronchioles ? - > States bronchi only explicitly. Bronchioles may be too small / further down respiratory tract & wouldn't need to enter lungs as attached to bronchi which already doing so. Hilum of lung:  Located -> mediastinal surface Region of entry -> lungs for blood vessels, lymphatics, nerves & bronchi. Bronchial arteries supply high-pressure oxygenated blood to the supporting structures of the lung, including the pulmonary arteries

Answer 65

a. internal intercostal ``` • Inspiration: - Active process - At rest:  Diaphragm (75%)  External intercostal muscles (25%)  Contracted diaphragm flattens -> Vertical diameter of thorax increased.  External intercostals elevate ribs -> incr. Anterior Posterior & Transverse diameters. - Forced:  Pectoralis major  Pectoralis minor  Scalenes  Serratus anterior  Sternocleidomastoid  Assist -> rib elevation -> Incr. speed & amount of movement ```

Answer 66

c. is less concentrated in smaller alveoli Pulmonary surfactant are formed by type II alveolar cells Greatly reduce surface tension, increasing compliance allowing the lung to inflate much more easily, reducing the work of breathing. It reduces the pressure difference needed to allow the lung to inflate. As the alveoli increase in size, the surfactant becomes more spread out over the surface of the liquid. This increases surface tension effectively slowing the rate of expansion of the alveoli. Hence Surfactant reduces surface tension more readily when the alveoli are smaller because the surfactant is more concentrated.

Answer 67

c. protein is high Compared to the extracellular fluid, the intracellular fluid has: - Higher K conc. - Lower Na conc - Lower Ca conc. (though extracellular is still low) - Lower Cl conc - Higher Org conc - Higher Protein conc.

Answer 68

b. are short 1. Sympathetic Nervous system -> Spinal cord - Outflow from CNS:  Sympathetic -> Thoracic & lumbar ``` - Preganglionic fibre:  Sympathetic -> Short - Ganglionic transmitter:  Sympathetic -> ACh (N2) - Postganglionic fibre:  Sympathetic -> Long - Neuroeffector transmitter:  Sympathetic -> NA (alpha or beta) ``` ``` Sympathetic: i) Symapthetic: Preganglionic fibre -> ganglion -> releases acetylcholine (ACh) -> activates nicotinic (N2) receptor -> action potential moves along postganglionic fibre -> releases norepinephrine (NA) -> activates (alpha/beta) adrenergic receptor. ```

Answer 69

Examples of epithelial tissue: d. stratified squamous epithelium - Simple squamous  Exchange of nutrients & gases -> Blood vessels & alveoli - Non-keratinised stratified squamous Protection -> Oral cavity & oesophagus - Keratinised stratified Squamous  Waterproof protection/barrier -> Skin - Simple cuboidal epithelium Secretion & absorption -> Glands & kidney tubules - Simple columnar epithelium Absorption & secretion -> Gastrointestinal tract --> also have microvilli -> Enabling absorption of nutrients. - Pseudostratified ciliated columnar epithelium with goblet cells Mucociliary escalator -> produce mucous -> particles inhaled -> trapped in mucous. -> Cilia moves mucous upwards to back of throat for swallowing. -> Trachea & large respiratory airways. -> Also has cilia & goblet cells. Trachea appears stratified -> some cells don’t reach free surface -> All touch basement mem.

Answer 70

2. Connective tissue - Structural framework for body b. fibroblasts - Supports surrounds & interconnects tissues - Protects delicate organs - Transports fluids & dissolved materials - Stores energy reserves - Defence -> microorganisms - Cells within Extracellular matrix i) Cell types: > Fibroblasts -> Main cell type -> Synthesises extracellular matrix >Apipocytes >Macrophage cells >Mast cells ii) Exctracellular matrix:  Ground substance  Tissue (extracellular fluid)  Fibres: ->Collagen ->Reticular ->Elastic

Answer 71

d. withstand the pressure changes in the cardiac cycle - > Muscles enable constriction - > Elastic fibres flexible therefore wouldn't prevent distension / relaxation of walls - > From conducting arteries -> high pressure • Characteristics of blood vessels: - Resilience - Flexibility - Constantly remain open - Tunica media:  Smooth muscle fibres -> loose connective tissue  May contain elastic fibres

Answer 72

b. portal circulation  Pulmonary circulation: Low pressure  Deoxygenated blood -> RHS heart -> lungs  Oxygenated blood -> Lungs -> LHS heart  Pulmonary arteries -> Low O2  Pulmonary veins -> High O2 ``` • Portal circulations: - Blood drains -> one capillary bed ->Vein -> 2nd capillary bed ->Heart. Eg. Hypophyseal portal system  Hypothalmus -> pituitary gland Eg. Hepatic portal system  Gastrointestinal tract -> liver. ``` Hepatic portal system: Liver:  Oxygenated blood -> LHS heart -> Abdominal aorta -> Hepatic artery  Liver -> respiring cells  Deoxygenated blood -> RHS heart -> Inferior vena cava (IVC) 1st Capillary beds:  Oxygenated blood -> LHS heart ->1st capillary beds i) Stomach, pancreas, spleen & large intestine ii) Splenic vein -> Hepatic portal vein. iii) Small & large intestines, stomach iv) SMV-> hepatic portal vein -> liver  Nutrients from 1st capillary beds deposited -> liver  CO2 from liver collected -> blood from 1st capillary beds  Deoxygenated blood -> RHS heart -> hepatic vein. ``` • Systemic circulation:  Artery -> capillary -> vein • Portal circulation:  Artery -> capillary -> portal vessel -> capillary -> vein. ```  Foetal circulation: - Specialised - Lungs, liver & GI tract -> not sufficiently developed -> foetus - >Bypassed.

Answer 73

d. tricuspid valve • Heart Valves:  Prevent backflow of blood Atrioventricular: - Tricuspid (Right AV) valve - Bicuspid/mitral (Left AV) valve  Between atria & ventricles  Open -> blood flow -> atria to ventricles  Anchored -> Chordae tendinae to papillary muscles.  When ventricular pressure < atrial pressure  Valve opens -> loose chordae tendinae  When ventricular pressure > atrial pressure Valve begins to close -> pulls chordae tendinae -> papillary muscle contracts -> prevents inversion of valve -> backflow of blood. Semilunar: - Pulmonary - Aortic  Guard entrances -> aorta & pulmonary trunk  Open -> force of blood -> contraction of ventricles  Bloodflow -> backwards -> aorta & pulmonary trunk -> ventricular relaxation Accumulates in cusps -> shut.  Prevent backflow of blood -> ventricles. • Blood flow through heart: 1. Deoxygenated blood from body tissues - > Superior & Inferior vena cava -> right atrium 2. Right atrium - > Tricuspid (right atrioventricular) valve -> right ventricle. 3. Right ventricle - > Pulmonary semilunar valve -> pulmonary trunk & arteries. 4. Pulmonary trunk & arteries - > Lungs -> Oxygenated -> Pulmonary veins. 5. Pulmonary veins - > Left atrium 6. Left atrium - > Bicuspid (mitral/left atrioventricular valve) -> Left ventricle 7. Left ventricle - > Aortic semilunar valve -> aorta. 8. Aorta - > Body tissues.

Answer 74

b. normally consists of 2 alpha and 2 beta subunits - > No nucleus / organelles in fully mature cell -> so cannot synthesise haemoglobin anymore. ``` • Haemoglobin:  Transports O2 & CO2  Synthesis begins -> proerythroblast 65% -> erythroblast 35% -> reticulocyte  280 million per RBC  15g/dl  4 subunits: 2 alpha & 2 beta Each contains haem >Bound -> globin -> long polypeptide chain Ferrous iron atom Fe2+ at centre of each subunit >>Can reversibly bind -> O2 ``` ``` • Structure of RBCs: - Biconcave disc Enables easy passage through vessels - 7-8 micrometeres -> diameter - Foldable & flexible -> deforms easily - Stable - No organelles more room for haemoglobin - Function: Transportation -> oxygen & CO2 - Life span  120 days > Broken down & recycled. ``` Production of erythrocyte:  Production of RBCs required  Triggers kidneys -> release erythropoietin hormone  Erythropoietin -> acts on stem cells  Instigates specialisation of stem cell -> production -> RBCs  Proerythroblast -> immature cell -> bone marrow Matures -> Erythroblast  Normoblast -> containing full haemoglobin conc. -->Constant production of haemoglobin during these stages  Normoblast ejects nucleus -> reticulocyte Reticulocyte still contains some ribosomal RNA >If Reticulocyte released -> circulation prematurely -> still some ability to produce haemoglobin. Small number in circulation -> later mature -> RBCs Lots of reticulocytes ->Anaemia  Erythrocyte (RBC)

Answer 75

c. being the first line of defence - > Mobile - > Major cons. pus - >Leukocytes - > many first line defence - > Many diff shaped nuclei ``` • White blood cells:  Also known -> Leukocytes  Nucleated  Act mainly outside tissues In-transit -> sites of activity  Can migrate out of bloodstream -> extravastation (diapedesis)  Capable -> amoebid movement  Attracted -> specific chemical stimuli  2 groups: i) Granulocytes - Neutrophils - Eosinophils - Basophils ii) Agranulocytes - Lymphocytes - Monocytes  Neutrophils, eosinophils & monocytes -> phagocytosis  Functions: - Defence -> pathogens - Toxin & waste removal - Removal -> damaged cells ``` ```  Neutrophils: - Function: 1st line defence -> bacterial infection Phagocytic Mobile Circulate -> blood -> approx. 10hrs Major component -> pus  Eosinophils Bilobular nucleus Circulate -> blood -> approx. 8-12 hrs >>Migrate -> tissues Release toxic compounds Eg. NO & cytotoxic enzymes Allergies >>Athsma Combat -> parasitic infections Attack bacteria, protozoa, debris  Basophils: Bilobed “S” shaped nucleus Inflammatory response  Monocytes: Large kidney/Horse-shoe shaped nucleus Migrate out -> circulation after 3-4 days Phagocytic  Lymphocytes: Central role -> all immunological defence mechanisms Circulate between -> various lymphoid tissues & all other body tissues >>Via blood & lymphatic vessels T-cells >>Mediate -> cell-mediated immunity Eg. Transplant rejection B-cells >>Differentiate -> plasma cells >Secrete antibodies -> humoral immunity NK cells >>Immune surveillance -> prevent cancer ```

Answer 76

-> Antigens A & B , No Anti-A or Anti-B antibodies -> Produce Anti-A & Anti-B bodies to bind to foreign bodies & cause agglutination for elimination. ```  Type A Surface antigen A Anti-B antibodies  Type B Surface antigen B Anti-A antibodies  Type AB Surface antigens A & B Neither anti-A nor anti-B antibodies  Type O Neither surface antigen A or B Anti-A & anti-B antibodies  Rh [D] Blood Group:  Rh [D] +ve D antigen present  Rh [D] -ve D antigen absent ```

Answer 77

a. arteries ?? -> For pure reason of most contributing factors • Arteries: Elastic -> conducting Continuous blood flow Muscular -> distributing  Distribute blood -> muscles & organs  Vasodilation & vasoconstriction -> control rate of blood flow to organ Arterioles -> resistance  Vasoconstriction & vasodilation -> control blood flow to organs  Involved -> control of blood pressure • Veins:  Valves -> prevent backflow. • Valves -> prevent backflow of blood -> low pressure • Musculovenous pump -> contracts to close valves & ensure constant bloodfow • Capillaries: - Connect arterioles & venules -> microcirculation - Site of gaseous exchange - Thin walls -> lined with endothelial cells -> enable diffusion

Answer 78

b. plasma hydrostatic pressure • Dynamics of capillary exchange:  Arterial end  High hydrostatic pressure -> forces fluid out capillary network >> Opposed -> high osmotic potential gradient  Capillary Hydrostatic Pressure (CHP) -> 35mmHg  Blood Colloid Osmotic Pressure (BCOP) -> 25mmHg ->> CHP > BCOP ->> Net filtration pressure -> +10mmHg >> Forces fluid & dissolved substances out -> capillary network  Significant rate of filtration -> 24 L/day  Venous end  Hydrostatic pressure decline -> incr. distance -> heart  Same osmotic potential  Capillary Hydrostatic Pressure (CHP) -> 18mmHg  Blood Colloid Osmotic Pressure (BCOP) -> 25mmHg ->> CHP < BCOP ->> Net Filtration Pressure -> -7mmHg >>Movement of fluid -> into capillary network  Significant Rate of reabsorption -> 20.4 L/Day  Net difference in water -> Rate of filtration & absorption Collected -> Lymphatic System  Centre -> Capillary Network Approx. centre -> capillary network ->Equal values -> CHP & BCOP -> Net filtration pressure = 0. -> No net movement -> fluid.  Max filtration pressure always greater -> max absorption pressure >> Point at which net filtration pressure = 0 -> further towards venous end -> capillary ->> More filtration than absorption along capillary. ¬->> Enables provision -> tissues with required molecules over greater distance -> capillary network > Rapid reabsorption -> molecules & waste products -> venous end.

Answer 79

a. damage to the sinoatrial node ?? Normal heart rate approx. 60bpm SAN gives regular electrical pulses. If it fails, the AV node should take over. But the spontaneous rate is lower than the SAN, Hence the heart rate will be lower. impulses are also transmitted simultaneously to atria and ventricles. Hence both atria and ventricles contract simultaneously. This prevents atrial contraction from helping the ventricular filling. This can lover the stroke volume, especially in those with stiff ventricles Ventricular fibrillation is a heart rhythm problem that occurs when the heart beats with rapid, erratic electrical impulses. Extrasystole: A premature contraction of the heart that is independent of the normal rhythm of the heart and that arises in response to an impulse in some part of the heart other than the normal impulse from the sinoatrial (SA) node.  P-wave: >>Atrial depolarization & contraction  QRS Complex: >>Spread -> electrical signal >Causes ventricular myocyte depolarisation & contraction ->>Arterial relaxation event masked -> larger ventricular event.  T-wave: >>Ventricle repolarisation & relaxation  QT interval: >>Time from initiation -> ventricular contraction -> end -> ventricular relaxation.

Answer 80

a. 4.9 L/min ``` CO = HR x SV SV = 110-45= 65ml = 6.5 x 10^-2 HR = 800ms -> 1 contraction 800 x 10^3 = 0.8s 60/0.8= 75bpm HR = 75 CO = 75 x (6.5 x 10^-2) = 4.875L/min ```

Answer 81

d. pump blood with greater pressure To distribute around body to tissues

Answer 82

b. calcium channel agonist Risk factor associated with Hypertension & coronary heart disease, which are treated as follows: -> " possible treatments; where atherosclerosis risk of nayerism due to incr. blood volume enlargement etc therefore decr. blood vol more effective so CA agonist. - Inhibit angiotensin II production -> inhibit Angiotensin-Converting-Enzyme (ACE) >> Prevents renal absorption -> Na+/H2O > Prevents incr. blood volume - Ibhibition -> Angiotensin II induced vasoconstriction -> Angiotensin II receptor blocker. >> Inhibitd membrane cardiac / vascular depolarizoation > Decr. CO -> vasodilation. - Calcium-channel blocker / thiazide diuretic >> Incr. loss -> Na+ & H2O > Decreases fluid volume, venous return & cardiac output. - Reduce TBR -> inhibition -> noradrenaline action. - Alpha-adrenoreceptor Antagonists (alpha-Blockers)  Reduce TBR -> inhibition -> noradrenaline action. - Beta-adrenoreceptor Antagonists (beta-Blockers)  Decr. CO2,  Decr. central activity -> Symapthetic nervous system  Decr. release -> Renin ->> Favourable secondary actions • Atherosclerosis:  Narrowing of vessel lumen:  Fibrous cap of dense extracellular matrix Accumulation -> Plaque Formation:  Lipids  Macrophages  Proinflammatory mediators  White blood cells  Endothelial cells  Smooth muscle cells >> Arterial remodelling & neovessels occur -> compensatory enlargement >>Fragments of plaques can detach & lodge in small vessels > Cause thrombosis ->> Restricts blood flow > Lead to aneurysm formation & rupture • Ischaemic Heart Disease (Coranary Heart Disease -> CAD)  Leading cause of death -> Developed world  30% Males  23% Females  Common cause:  Atherosclerosis -> coronary artery  Most frequent -> Left anterior interventricular artery  Occurs in Left ventricle  Insufficient Blood flow to myocardium >> Angina Pectoris (ischemia-induced pain) ->>Mediated by endogeneous vasodilators >> Results -> myocardial infarction ->> Death of heart muscle within 20 mins

Answer 83

b. primary bronchus ``` • Lungs:  Main features: - 2 lungs - Located -> Thoracic cavity - Separated by mediastinum - Extend from neck -> diaphragm  Gross Anatomy: - Trachea - Primary Bronchi - Right & Left Lungs  Structure: - Conical shaped structures - Soft, spongy texture - Each lung contains:  Apex (top, tip of lung)  3 surfaces  Diaphragmatic (basal surafce)  Costal (outside-facing surface)  Mediastinal (inside surface -> facing other lung) ```

Answer 84

b. body of the third thoracic vertebra - > Articulates being key word - > Head of rib articulates -> therefore body of thoracic vertebra - Ribs:  Differ -> shape & size  Slope downwards & forwards  Attached by head & tubercle -> thoracic vertebrae  Ribs 1-10 attached by costal cartilage -> sternum - Thoracic Vertebrae:  Head of rib articulates with body of thoracic vertebra  Tubercle of rib articulates with transverse process of thoracic vertebra - Intercostal muscles:  Span intercostal spaces  External intercostals  Superficial layer  Fibres run supero-lateral to infero-medial -> Tubercles to costochondral junction -> (Downward-diagonally from shoulder to core - / )  Internal intercostals  Middle layer  Fibres run infero-lateral to supero-medial -> At angles to ends of intercostal spaces. -> (Upward-diagonally from hip to core - \ )  Innermost intercostals  Innermost layer

Answer 85

a. includes the alveolar ducts The terminal bronchiole is the most distal segment of the conducting zone. It branches off the lesser bronchioles. Each of the terminal bronchioles divides to form respiratory bronchioles which contain a small number of alveoli. The respiratory tract is lined with respiratory mucosa or respiratory epithelium ``` • Respiratory tract organised according to function: - Conductive:  Filteration, warming & moistening air  Conducting air into lungs Structures:  Nasal cavity & paranasal sinuses  Pharynx  Larynx  Trachea  Primary bronchi  Secondary bronchi  Tertiary Bronchi  Bronchioles  Terminal Bronchioles - Respiratory:  Sites of gas exchange Structures:  Respiratory Bronchioles  Alveolar Ducts  Alveolar Sacs  Alveoli ```

Answer 86

a. abdominal muscles ``` • Expiration: - At rest:  Passive process  Diaphragm  External intercostals  Relaxation of diaphragm & external intercostal muscles - Forced:  Active process  Internal intercostals  Abdominal muscles -> Rectus abdominis -> External oblique -> Internal oblique -> Transversus abdominis  Internal & innermost intercostals depress ribs -> Reduce size of thoracic cavity  Abdominal muscles compress abdomen & force diaphragm upwards ```

Answer 87

b. 148 mmHg O2 = 20% of 740 = 148mmHg

Answer 88

a. decreased heart rate 2.Sympathetic: i) Symapthetic: Preganglionic fibre -> ganglion -> releases acetylcholine (ACh) -> activates nicotinic (N2) receptor -> action potential moves along postganglionic fibre -> releases norepinephrine (NA) -> activates (alpha/beta) adrenergic receptor. ii) Adrenal medulla: Preganglionic fibre -> adrenal medulla -> releases acetylcholine (ACh) -> stimulates nicotinic receptor of chromaffin cell -> makes epinephrine -> moves along postganglionic fibre -> releases epinephrine ->sent into circulatory system -> stimulates adrenergic receptors of heart -> incr. heart rate. The sympathetic nervous system's primary process is to stimulate the body's fight-flight-or-freeze response. It is, however, constantly active at a basic level to maintain homeostasis homeodynamics. Can accelerate heart rate; widen bronchial passages; decrease motility of the large intestine; constrict blood vessels; increase peristalsis in the oesophagus; cause pupillary dilation. perspiration and raise blood pressure.

Answer 89

d. secretes acetylcholine into the circulation ``` ii) Adrenal medulla: Preganglionic fibre -> adrenal medulla -> releases acetylcholine (ACh) -> stimulates N2 (nicotinic) receptor of chromaffin cell -> makes epinephrine -> moves along postganglionic fibre -> releases epinephrine ->sent into circulatory system -> stimulates adrenergic receptors of heart -> incr. heart rate. ``` It is the innermost part of the adrenal gland, consisting of cells that secrete epinephrine (adrenaline), norepinephrine (noradrenaline), and a small amount of dopamine in response to stimulation by sympathetic preganglionic neurons.

Answer 90

b. are vascular 1. Epithelia: - Covers inner & outer surfaces - Line cavities & tubes eg. Hollow organs, airways, blood vessels - Glands Characteristics:  Attachment  Avascularity -> no blood vessels run through it  Regenerates  Polarity (apical -> faces surface & basal -> bottom)  Closely packed cells supported by basement mem  Classification based on no of cells and shape in most superficial layer 1. No. of cell layers: > Simple -> one layer > Stratified -> more than one layer 2. Shape: > Squamous (flat) > Cuboidal (cube) > Columnar (rectangle) Examples of epithelial tissue: - Simple squamous  Exchange of nutrients & gases -> Blood vessels & alveoli - Non-keratinised stratified squamous Protection -> Oral cavity & oesophagus - Keratinised stratified Squamous  Waterproof protection/barrier -> Skin - Simple cuboidal epithelium Secretion & absorption -> Glands & kidney tubules - Simple columnar epithelium Absorption & secretion -> Gastrointestinal tract --> also have microvilli -> Enabling absorption of nutrients. - Pseudostratified ciliated columnar epithelium with goblet cells Mucociliary escalator -> produce mucous -> particles inhaled -> trapped in mucous. -> Cilia moves mucous upwards to back of throat for swallowing. -> Trachea & large respiratory airways. -> Also has cilia & goblet cells. Trachea appears stratified -> some cells don’t reach free surface -> All touch basement mem.

Answer 91

c. bronchioles Examples of epithelial tissue: - Simple squamous  Exchange of nutrients & gases -> Blood vessels & alveoli - Non-keratinised stratified squamous Protection -> Oral cavity & oesophagus - Keratinised stratified Squamous  Waterproof protection/barrier -> Skin - Simple cuboidal epithelium Secretion & absorption -> Glands & kidney tubules - Simple columnar epithelium Absorption & secretion -> Gastrointestinal tract --> also have microvilli -> Enabling absorption of nutrients. - Pseudostratified ciliated columnar epithelium with goblet cells Mucociliary escalator -> produce mucous -> particles inhaled -> trapped in mucous. -> Cilia moves mucous upwards to back of throat for swallowing. -> Trachea & large respiratory airways. -> Also has cilia & goblet cells. Trachea appears stratified -> some cells don’t reach free surface -> All touch basement mem. Both the endothelial lining of blood vessels and the mesothelial lining of the body cavities are simple squamous epithelium. Bronchiole walls consist of ciliated cuboidal epithelium and a layer of smooth muscle. Line several body cavities including the pleural cavity housing the lungs, peritoneum (abdominal cavity containing the stomach and intestines) and the mediastinum (part of the thoracic cavity that contains the heart, lungs, trachea and esophagus). These tissues are also called the endothelium when they form the inner lining of blood and lymph vessels ``` • Fibrous Pericardium: Characteristics: - Inelastic sac -> dense tissue - Inferior fusion -> diaphragm - Superior infusion -> large vessels Function: - Prevents overfilling of heart - Anchors position ``` ``` • Serous pericardium: Characteristics: - Double-layered serous membrane - Lies -> deep within -> fibrous pericardium - Contains: 1. Parietal pericardium:  Lines inner surface -> fibrous pericardium 2. Visceral pericardium:  Tightly adhered -> surface of heart 3. Pericardial cavity:  Space between parietal & visceral layers Contains tissue fluid. Function:  Prevents friction. ``` ``` • Heart wall: - 3 layers: i) Endocardium:  Inner layer -> Endothelium ii) Myocardium:  Middle layer -> Cardiac muscle iii) Epicardium:  Outer layer -> Visceral pericardium ```

Answer 92

d. palms facing posteriorly • Anatomical position:  Position of the upright body -> arms at sides -> palms facing forwards. - Anterior (Ventral):  Front / Underside - Posterior (Dorsal)  Behind/ Upperside/back - Superior  Towards the head - Inferior  Towards the feet - Medial  The core/centre - Lateral  Towards the side/ away from core/centre - Proximal  Closer towards the trunk - Distal  Further from the trunk - Coronal/frontal plane:  Divides into front & back planes -> Anterior/ventral & posterior/dorsal - Horizontal/transverse plane  Divides into top & bottom planes -> Above & below waist -> Superior & Inferior - Midsagittal plane  Divides into right & left halves -> medial & lateral

Answer 93

• Major arteries: d. ulnar ``` - Arm:  Axillary -> Shoulder  Brachial -> Upper arm  Radial -> Lateral  Ulnar -> Medial - Leg:  External iliac -> Hip area  Femoral -> Upper leg  Popliteal -> Back of knee  Anterior tibial - Core:  Right common carotid -> Right -> neck  Left common carotid -> Left -> neck  Brachiocephalic trunk -> Lungs  Right subclavian -> Right -> under collarbone  Left subclavian -> Left -> under collarbone  Aortic arch -> Main part of heart  Descending thoracic aorta -> Down inside lower end of rib cage -> spine  Abdominal aorta -> Abdominal -> inside spine  Common iliac -> Top of hip  External iliac -> Lower hip -> top of leg  Internal iliac -> Backbone ```

Answer 94

c. pulmonary arteries • Major arteries: Pulmonary artery: carrying blood from the right ventricle of the heart to the lungs for oxygenation. the subclavian arteries are paired major arteries of the upper thorax, below the clavicle. They receive blood from the aortic arch. ``` - Arm:  Axillary -> Shoulder  Brachial -> Upper arm  Radial -> Lateral  Ulnar -> Medial - Leg:  External iliac -> Hip area  Femoral -> Upper leg  Popliteal -> Back of knee  Anterior tibial - Core:  Right common carotid -> Right -> neck  Left common carotid -> Left -> neck  Brachiocephalic trunk -> Lungs  Right subclavian -> Right -> under collarbone  Left subclavian -> Left -> under collarbone  Aortic arch -> Main part of heart  Descending thoracic aorta -> Down inside lower end of rib cage -> spine  Abdominal aorta -> Abdominal -> inside spine  Common iliac -> Top of hip  External iliac -> Lower hip -> top of leg  Internal iliac -> Backbone ```

Answer 95

d. haemoglobin haemoglobin found in RBCs, not plasma ``` • Composition of blood: - Plasma: 55% Water -> 92% Plasma proteins -> 7% -->Albumin, Globulin, Fibrinogen, regulatory proteins Other solutes -> 1% -->Electrolytes, organic nutrients, waste. - Red Blood Cells: 45% - White Blood cells: <1% - Platelets: <1% ```

Answer 96

c. Lymphocytes ``` • White blood cells:  Also known -> Leukocytes  Nucleated  Act mainly outside tissues In-transit -> sites of activity  Can migrate out of bloodstream -> extravastation (diapedesis)  Capable -> amoebid movement  Attracted -> specific chemical stimuli  2 groups: i) Granulocytes - Neutrophils - Eosinophils - Basophils ii) Agranulocytes - Lymphocytes - Monocytes  Neutrophils, eosinophils & monocytes -> phagocytosis  Functions: - Defence -> pathogens - Toxin & waste removal - Removal -> damaged cells ```

Answer 97

c. do not contain granules ``` • Platelets: - Structure: Small Oval No nucleus 2-3 micrometres diameter Contain granules - Functions: Megakaryocyte cytosplasm Production controlled by >>No. circulating platelets -> negative feedback >>Thrombopoietin (TPO) release -> incr. platelet no.s Lifepsan 7-10 days Variety functions -> essential -> haemostasis ```

Answer 98

• Factors Influencing c. normally rises when a person suddenly stands up Venous Return / Central Venous Pressure: 1. Posture: - Blood volume influenced by gravity -> posture. - Standing  venous pooling in legs >>Decr. venous return. 2. Muscle pump: - Venomotor tone involving constriction -> veins -> skeletal muscles. - Venous return facilitated -> valves >>Prevent backflow of blood 3. Respiratory Pump: - Inspiration creates internal pressure difference by lowering intra-thoracic pressure & incr. intra-abdominal pressure.

Answer 99

c. physical stress/trauma ? -> See below -> processes -> Physical stress/ trauma & angiotensin not a process/ internal regulation it is likely a cause but not a mediator. Physical stress/trauma cannot be regulated by body, angiotensin II can -> Angiotensin -> Autoregulatory nervou system -> Diurtetic hormones -> long term control -> P • Blood vessel tone controlled -> interrelated processes  Automatic / intrinsic  Short term  Long term Control measures. • Response & Regulation of Blood Pressure: Homeostasis: - Altered Blood pressure / volume Physical stress Eg. Trauma, high temp, etc. Chemical changes Eg. Decr. O2 / decr. pH / Incr. CO2 / Incr. vasodilatory metabolites Increases tissue activity / Intrinsic Control - Inadequate blood pressure & flow >>Autoregulation:  Decr. resistance & incr. blood flow > Homeostasis returned. - Insufficient Autoregulation: Stimulates receptors -> sensitive to systemic changes -> blood pressure / Chemistry. Activates cardiovascular centres -> Central Nervous System Elevates Blood pressure -> Short Term >>Stimulation -> heart rate & peripheral vasoconstriction -->> Sensory Nervous System. Return -> Homeostasis.

Answer 100

c. extraction of oxygen at the capillaries is greater than in most other tissues ? - > elimination? • Haemodynamics: Anything that makes the coronary supply routes restricted can build danger of angina -> Pressure at ventricular systole highest as blood forced out of ventricles at high pressure.  Blood flow determined: - Resistance -> R - Pressure difference -> P  F = ▲P / ▲R ``` Determined by: ->> L = length of vessel ->> r = radius of vessel ->> ꞃ = fluid viscosity >>(protein conc.) ``` • Afterload:  Pressure opposing ejection of blood from heart Influenced -> Blood vessel tone -> Vasoconstriction/dilation Major effect -> cardiac output. • Blood Pressure = Cardiac Output x Total Peripheral Resistance  Cardiac Output -> ▲HR & SV • Response & Regulation of Blood Pressure: Homeostasis: - Altered Blood pressure / volume Physical stress Eg. Trauma, high temp, etc. Chemical changes Eg. Decr. O2 / decr. pH / Incr. CO2 / Incr. vasodilatory metabolites Increases tissue activity / Intrinsic Control - Inadequate blood pressure & flow >>Autoregulation:  Decr. resistance & incr. blood flow > Homeostasis returned. - Insufficient Autoregulation: Stimulates receptors -> sensitive to systemic changes -> blood pressure / Chemistry. Activates cardiovascular centres -> Central Nervous System Elevates Blood pressure -> Short Term >>Stimulation -> heart rate & peripheral vasoconstriction -->> Sensory Nervous System. Return -> Homeostasis.

Answer 101

a. closes as a result of contraction of the papillary muscles --> Remains closed from previous ventricular contraction & is only opened again by pressure changes during systole. The sound of a heartbeat is caused by the heart valves opening and closing as they pump blood. The papillary muscles attach to the cusps of the atrioventricular valves via the chordae tendineae and contract to prevent inversion or prolapse of these valves on systole • Heart Valves:  Prevent backflow of blood Atrioventricular: - Tricuspid (Right AV) valve - Bicuspid/mitral (Left AV) valve  Between atria & ventricles  Open -> blood flow -> atria to ventricles  Anchored -> Chordae tendinae to papillary muscles.  When ventricular pressure < atrial pressure  Valve opens -> loose chordae tendinae  When ventricular pressure > atrial pressure Valve begins to close -> pulls chordae tendinae -> papillary muscle contracts -> prevents inversion of valve -> backflow of blood. Semilunar: - Pulmonary - Aortic  Guard entrances -> aorta & pulmonary trunk  Open -> force of blood -> contraction of ventricles  Bloodflow -> backwards -> aorta & pulmonary trunk -> ventricular relaxation Accumulates in cusps -> shut.  Prevent backflow of blood -> ventricles.

Answer 102

Baroreceptors & Control -> Blood Flow: c. parasympathetic nerve activity ``` • Inadequate Blood supply / Decr. Blood Pressure: - Inhibition -> baroreceptors  Activation  Cardioacceloratory Centre Vasomotor Centres  Inhibition  Cardioinhibitory Centre >> Incr. Cardiac Output & Heart Rate - Vasoconsriction ``` ``` • Rise -> Blood Pressure: - Stimulation -> Baroreceptors  Activation Cardioinhibitory Centre  Inhibition Cardioacceloratory Centre Vasomotor Centres >> Decr. Cardiac Output & Heart Rate - Vasodilation. ``` -> Vasodilation -> Incr. diameter of vessels -> decr. resistance -> decr. pressure • Blood Pressure = Cardiac Output x Total Peripheral Resistance  Cardiac Output -> ▲HR & SV  Total Peripheral Resistance -> ▲Arteriolar Radius - Parasympathetic more active -> vegetative (passive/calm) situations. Parasympathetic controls when in relaxed state -> decr. activity of active mecahnisms controlled by sympathetic Therefore would decr. increases in heart rate

Answer 103

``` • Hypertension:  Affects nearly one billion  One of the main causes -> premature death.  Nearly 8 million fatalities per year a. ACE-activators ``` Types: - Primary Hypertension (Essential / Idiopathic)  Unknown medical cause  Links:  Genetic predisposition  Alcohol consumption  Obesity  Lack of excersise  Diabetes  Intrauterine environment - Secondary Hypertension  Known medical cause 1) Kidney Disease:  Incr. Angiotensin II >> Vasoconstriction & expansion -> cellular fluid 2) General endocrine disorders Eg. Diabetes, Cushing’s 3) Adrenal medulla disease (Phaeochroocytoma)  Excessive adrenaline secretion  Treatment: - Inhibit angiotensin II production -> inhibit Angiotensin-Converting-Enzyme (ACE) >> Prevents renal absorption -> Na+/H2O > Prevents incr. blood volume - Ibhibition -> Angiotensin II induced vasoconstriction -> Angiotensin II receptor blocker. >> Inhibitd membrane cardiac / vascular depolarizoation > Decr. CO -> vasodilation. - Calcium-channel blocker / thiazide diuretic >> Incr. loss -> Na+ & H2O > Decreases fluid volume, venous return & cardiac output. - Reduce TBR -> inhibition -> noradrenaline action. - Alpha-adrenoreceptor Antagonists (alpha-Blockers)  Reduce TBR -> inhibition -> noradrenaline action. - Beta-adrenoreceptor Antagonists (beta-Blockers)  Decr. CO2,  Decr. central activity -> Symapthetic nervous system  Decr. release -> Renin ->> Favourable secondary actions  Risks: - Atherosclerosis - Stroke / Cerebrovascular Accident - Heart Failure - Renal Failure - Aneurysms

Answer 104

• Respiratory tract organised according to function: b. respiratory bronchioles ``` - Conductive:  Filteration, warming & moistening air  Conducting air into lungs Structures:  Nasal cavity & paranasal sinuses  Pharynx  Larynx  Trachea  Primary bronchi  Secondary bronchi  Tertiary Bronchi  Bronchioles  Terminal Bronchioles - Respiratory:  Sites of gas exchange Structures:  Respiratory Bronchioles  Alveolar Ducts  Alveolar Sacs  Alveoli ```

Answer 105

d. relaxation of the diaphragm ``` • Incr. Thoracic Volume: • Ventilation: - Atmospheric pressure > Intrapulmonary / Intraalveolar pressure  Air enters lungs - Intrapulmonary / intraalveolar pressure > atmospheric pressure  Air expelled from lungs - Change -> volume = change -> pressure - Atmospheric pressure = 760mmHg ``` • Incr. Thoracic Volume: - Incr. Vertical diameter - -> Incr. thoracic volume incr. movement of air to lungs  Contraction of diaphragm incr. vertical diameter Responsible for 75% incr. thoracic capacity - Incr. Anterior Posterior diameter  Elevation of ribs incr. Anterior Posterior diameter -> (Joint with Transverse Diameter) Responsible for 25% thoracic capacity.  Elevation of ribs -> external end -> makes them more horizontal & pushes sternum forward (pump handle movement) Incr. AP diameter - Incr. transverse diameter  Elevation of ribs incr. transverse diameter -> (Joint with Transverse Diameter) Responsible for 25% thoracic capacity.  Many of the ribs  Lowest near their middle  Rise at each end Eg. Bucket handle  Rise of middle of rib -> movement away from midline of body Transversally widens chest (Left -> Right) ``` • Inspiration: - Active process - At rest:  Diaphragm (75%)  External intercostal muscles (25%)  Contracted diaphragm flattens -> Vertical diameter of thorax increased.  External intercostals elevate ribs -> incr. Anterior Posterior & Transverse diameters. - Forced:  Pectoralis major  Pectoralis minor  Scalenes  Serratus anterior  Sternocleidomastoid  Assist -> rib elevation -> Incr. speed & amount of movement ```

Answer 106

Pulmonary surfactant are formed by type II alveolar cells Greatly reduce surface tension, increasing compliance allowing the lung to inflate much more easily, reducing the work of breathing. It reduces the pressure difference needed to allow the lung to inflate. As the alveoli increase in size, the surfactant becomes more spread out over the surface of the liquid. This increases surface tension effectively slowing the rate of expansion of the alveoli. Hence Surfactant reduces surface tension more readily when the alveoli are smaller because the surfactant is more concentrated.

Answer 107

? -> small surface area decr. rate of diff but still has an effect on g.e. Q isn't specific on whther dpendency is negative or positive so is this incorrect or not?? Henry’s law states that the concentration of gas in a liquid is directly proportional to the solubility and partial pressure of that gas. The greater the partial pressure of the gas, the greater the number of gas molecules that will dissolve in the liquid. The concentration of the gas in a liquid is also dependent on the solubility of the gas in the liquid. Ventilation causes partial pressures of oxygen and carbon dioxide change, affecting the diffusion process that moves these materials across the membrane. This will cause oxygen to enter and carbon dioxide to leave the blood more quickly. -> Short diffusion distance -> faster diffusion Higher conc. gradient -> faster diffusion -> small surface area -> decr. rate of diffusion

Answer 108

d. respond to hypoxia • Neural Control of Ventilation: - Chemoreceptors detect changes in PO2, PCO2 & pH -> Send impulses / signals  Vagus (CN X) & Glossopharyngeal (CN IX) nerves (Afferent pathway) - Impulses transported -> Vagus (CN X) & Glossopharyngeal (CN IX) nerves  Respiratory Centres of Brain Stem - Respiratory Centres of Brain stem -> Send impulses / signals  Phrenic, intercostal & other nerves (Efferent pathway) - Impulses transported -> Phrenic, intercostal & other nerves  Muscles in ventilation • Central Chemoreceptors: - Located -> Medulla oblongata of brainstem - Respond to changes in PCO2 & pH Hypercapnia, also known as hypercarbia and CO2 retention, is a condition of abnormally elevated carbon dioxide (CO2) levels in the blood. Hypoxia is a condition in which the body or a region of the body is deprived of adequate oxygen supply at the tissue level ``` • Peripheral Chemoreceptors: - Detect changes -> PO2, PCO2 & pH - Aortic Bodies  Located -> Aortic Arch  Innervated -> Vagus (CN X) - Carotid Body  Located -> Common Carotid Artery  Innervated -> Glossopharyngeal (CN IX) ``` • Respiratory Centres: - Group of neurons -> Brain stem - Send impulses to muscles of ventilation - Medullary Rhythmicity Area  Dorsal Respiratory Group (DRG)  Sets rhythm, stimulates muscles of quiet inspiration  Ventral Respiratory Group (VRG)  Involved in forced inspiration & expiration - Pneumotaxic area (Pons)  Influences DRG by regulating duration of inspiration.

Body Systems Past Papers Flashcards

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