Phys Rewrite Notes (1) PDF

Auditory 1. Outer ear: collect amplify sound, directs sound into ear canal, aids in determining direction and distance of sounds · 2. Ear canal: S shape amplify certain frequencies, protects eardrum from foreign...

Auditory 1. Outer ear: collect amplify sound, directs sound into ear canal, aids in determining direction and distance of sounds · 2. Ear canal: S shape amplify certain frequencies, protects eardrum from foreign substances, cerumen produced by glands to trap 3. Incus, malleus, stapes: aka auditory ossicles, transmit sound vibrations from eardrum to inner ear 4. Semi circular canals: three loop shaped structures, maintaining balance and spatial orientation, each loop different plane (horizontal, anterior, posterior) 5. Cochlea: fluid filled, takes sound vibrations ~> neural signals sent to brain 6. Auditory tube (eustachian tube): narrow canal that connects middle ear to nasopharyngeal (upper part of throat) equalizes air pressure on both sides of ear drum and drains any fluid from middle ear Base 7. Tympanic membrane (ear drum): thin cone shaped, separated external ear and middle - high ear, sound wave strikes this ~> vibrates malleus Top - low 8. Round window: waves dissipate through here 9. Oval window: stapes will vibrate here, waves detected by specialized hair cells gat Apex -> lowest transmit info to nerve cells, carry AP to auditory centre of brain. Cochlea: divided into three parts 1. Upper scala vestibili (vestibular duct) 2. Middle cochlear duct 3. Lower scala tympani 1 and 3: filled w perilymph fluid (ionic solution, high Na, low K concentrations Cochlear duct filled w endolymph, high K, low Na Basilar membrane separates cochlear duct and tympanic duct (contains spiral organ) Taka Organ of corti where sound waves are converted to AP by special hair cells Hair cells called sterocillia (one long Anterior: detects forward and backward kinocilia) move based on waves in endolymph head movement fluid in ampulae (base of semi circular Posterior: detects head tilts towards canals) shoulders Hair embedded by gelatinous structure called Lateral: detects horizontal head movement cupula (head shake) The Hairs normal = base line neurotransmitter release Hair movement = stimulate more or less release Towards kinocilia = more Vestibulo-Ocular Reflex (VOR): The semicircular canals play a key role in the VOR, which stabilizes vision by producing eye movements that counteract head movements. This reflex allows for clear vision even while the head is moving. Cardiovascular system 3 components of cardiovascular system 1. Heart - pump that creates pressure to move blood through rest of body 2. Vessels - tubes that’s blood flows through 3. Blood - fluid that carries important gases ⑨ Interventricukar septum: wall b/w right and left · ventricle to stop blood from mixing ⑨ Apex of heart: contractions start here, spread upwards · Left ventricular myocardium: sm thickets than other wall must be forceful to move blood issue iin ar Heart valves: prevent back-flow of blood that tries to head to wrong chamber ge Heart sounds: “lub” and “dub” Lub - AV valves closing (contraction) Dub - aortic and pulmonary valves closing Heart is made up of cardiac muscle cells called (relaxation) cardiomyocytes which allows for contraction and relaxation Backflow is prevented by CUSPS, the valves. When blood tries to flow backwards, cusps fill with 2 types: blood,causing them to expand and close 1. Contractile cells ACTION POTENTIAL striated cells (due to how thin and thick myofilament is formatted) AP moves through gap junctions Needs calcium (stored in SR/ECF) calcium from Intercalated discs help lock cells tg through ECF inhibits release from SR special proteins called desmosomes ATP required AP influx on Ca causes depolarization K leak channels repolarization 2. Nodal/conducting cells (behave similar to Reaches somewhat relax but doesn’t stay neurons) there Don’t contract, very little actin and myosin Every 0.8 seconds (70 beats/min) Take AP and take it through heart Self excitable (create own AP) AP created by SA node, moves through gap junctions to contractile cells in atrium AP enter so AV node (AP slows down to allow atrial cardiomyocytes to finish contracting) AP goes to atrioventricular bundle Max HR equation: 220 - your age in years before heading to bundle branches to spread AP to both ventricles PSNS releases Ach which binds to Subendocsrdial branches excite muscaranic receptors on SA node to keep ventricular cardiomyocytes to contract heart beats below 100 by decreasing Na and FROM BOTTOM TO UP, to bring blood Ca permeability, increases permeability of to arteries and veins k ECG SNS releases norepinephrine and binds to P WAVE - depolarization on atria adregenic receptors on SA node to increase QRS WAVE - depolarization on ventricles HR, increases permeability of Na and Ca, T WAVE - repolarization of ventricles decreases permeability of K Cardiac cycle Systole: cardiomyocytes contracting ESV - End Systolic Volume Diastole: cardiomyocytes relaxing Amount of blood remaining in the ventricles at the end of systole after ventricles contract Cardiac cycle refers to series of events that occurs w/ every heartbeat Indicates efficiency of hearts pumping ability Lower ESV typically means heart contracting 5 phases of cardiac cycle: effectively, higher may indicate heart dysfunction 1. Isovolumetric ventricular systole - ventricles contract but unable to EDV - End Diastolic Volume pump blood of of heart (volume of Amount of blood in ventricles before ventricular ventricles doesn’t change) contraction 2. Ventricular systole - ventricles Ventricles have max volume after ventricular contract and blood moves into aorta diastole (L) and pulmonary arteries (R) 3. Isovolumetric ventricular diastole - SV - Stroke Volume ventricles relax and unable to fill Amount of blood pumped out or ejected by the with blood ventricles w/ each heartbeat 4. Late ventricular diastole - ventricles relax and fill w/ blood If we know how full the ventricle was (EDV) and how 5. Atrial systole - atrial contract, much remained after it contracted (ESV), we can moving blood into ventricles easily determine how much blood left the ventricle in that heartbeat. It is calculated by subtracting the end atrial diastole), but similar to what we saw systolic volume (ESV) from the end diastolic with the ECG, this takes place when the volume (EDV). Therefore, an increase in EDV or a ventricles are contracting, so we don't refer to decrease in ESV can lead to a higher stroke volume. it as one of the cardiac cycle phases. Looking at this as an equation: SV = EDV - ESV Ventricular systole and diastole have two phases, the first phase no volume change, second phase blood refills ventricles  Blood Vessels Aorta is largest artery in body Total volume of blood= 4-6L Blood flows through arteries into arterioles > - pulmonary circuit -15 % Divides into capillaries (smallest vessel in arteries 10 % body) Blood enters venules > - - systemic circuit -851. F capillarres5 Go to veins protect vessel , make sure walls receive O2 2. allows vessels to stretch Celastic Fibres > - ELASTIN) 3. aka - Endothelial cells Blood pressure highest in our arteries and lowest in veins 1. Arteries: Blood away from heart (aka distribution vessels), large diameter (25% thick as diameter walls) contains lots of elastin higher pressure during systole Lower pressure during diastole - Arteries have pulsatile pressure (fluctuating) 2. Arterioles (walls are 50% as thick as diameter) 4. Venules aka resistance vessels (due to vast amount of blood flows from capillaries into these vessels smooth muscle) next Smooth muscle can contract and relax to Pressure is lower than capillaries to allow for various stimuli blood to flow 3. Capillaries (smallest blood vessels) 5. Veins composed of a single layer of endothelial cells allows blood back into heart from organs and Very thin walls tissues Function: act as exchange vessels (O2 will leave Aka capacitance vessels blood and enter cells of systemic circuit) Large diameter, but thin walled (10% of Hormones leave capillaries and bind to receptors diameter) on target cells Contains valves to allow blood to flow in ONE direction  Blood flow Arterioles have the perfect structure the control the amount of blood flow a tissue will receive Regulate blood flow - to increase bloody supply to active tissues and decrease it to inactive tissues Blood supply to vital organs Maintain blood pressure Decrease heat loss from the body by redistributing blood e Blood flow equation Blood flown= pressure gradient (p2-p1)/resistance (nxy R = Factors affecting resistance 1. Viscosity PGXR"R = Yr 2. Length of blood vessel (longer more friction) 3. Lumen radius Capillaries Capillary wall is a single cell thick Substances use trans cellular transport (enters and exits cell) (referred to as endothelial cells) simple diffusion (O2 and CO2) non charged molecule used for exchange and ,over Diffusion using channels (ions and H2O) down a substances across capillary wall [gradient] through protein channel Two plasma membranes in Facilitated diffusion, uses transport proteins that endothelial cells change its shape to move across 1. Luminal membrane (closest to Active transport, against [gradient], uses ATP capillary lumen) Endocytosis, and exocytosis, takes advantage of 2. Basolateral membrane (one flexibility of plasma membrane through use of vesicles closest to interstitial fluid) Small enough ions and substances will move in intercellular clefts (in between endothelial cells) Type of transport is called paracellular transport (bulk flow) Continuous capillaries: less permeable Fenestrated capillaries: has pores that go through endothelial (allows transport from If filtration was left unchecked, we would have edema capillary to interstitial fluid that surrounds due to excessive bulk flow out of capillary Brain has continuous capillaries, but almost STARLING FORCES PROMOTES RETURN OF no permeability, whereas skin is more FLUID BACK INTO CAPILLARY Permeability of intercellular clefts is related to proteins that hold endothelial cells tg. Proteins form tight junctions, tighter the junction the narrower the intercellular cleft. BULK FLOW: When fluid and other substances move OUT of a capillary through bulk flow, we refer to it as filtration. Filtration will increase the amount of interstitial fluid surrounding our tissue cells. Vasoconstriction and vasodilation Regulatory systems for controlling flow: 1. Local regulation - changes in the conditions of organ or tissue. (INTRINSIC MECHANISMS) Seinfeld stimulus to chnage blood flow comes denim w/in very tissue or organ that needs it Yor t 2. Humoral regulation - involve substances that are travelling in blood through blood vessels of tissue/organ. - ve substances ALPR T Sunstabces change radius of blood vessels often binding to receptors that recognize substance. Some cause vasoconstriction while others cause vasodilation. (EXTRINSIC MECHANISMS) since regulation or Atrial natriuretic. 2 peptide-made by atria , binds to receptors ; relaxes Smootha hormones is produced elsewhere in the body.. 3 Epinephrine-binds to BETA adrenergic receptors , cause VD 3. Neural regulation - neurons from the sympathetic nervous system innervate the smooth muscle cells found in tunica media of many blood vessels. sy,pathetic MAP = diastolic pressure + 1/3 releases norepinephrine which binds to adrenergic receptors (systolic pressure-diastolic causing vasoconstriction which reduce blood flow. pressure) (EXTRINSIC MECHANISMS) Neurons originate outside the tissue/organ Local regulation: A. Myogenic theory Hypertension - high BP can cause damage to blood Rise in BP, vasoconstriction vessels leading to heart diseases and stroke Drop in BP, vasodilation Hypotension - low BP, can cause inadequate blood B. Metabolic theory flow to organs, causes dizziness, faint or shock Not enough vasodilator metabolites promotes HR XSY vasoconstriction or arterioles Co =A Too many, increases metabolism, causes vasodilation MAP = CO X TPR Negative feedback loop used for maintaining homeostasis of blood pressure is baroreceptor reflex (aka stretch receptors) detect changes in BP and sens to the medulla oblongata of your brainstem. This initiated to negative feedback loop that I adjust heart rate stroke volume and vessel diameter stabilize MAP Kidney Kidney functions: removal of nonessential substances from blood plasma e Recover essential substances in filtering units of kidney Regulation or total body water and salt balance Kidney location: Posterior to abdomen On each side of spine (11 and 12 rib) Technically outside abdominal cavity Sandwiched between member and that line abdomen and even bones and muscles of the back (positioning called RETROPERITONEAL Kidney stones Precipitation and crystal action of higher than usual concentrations of Nephron minerals and ions (oxalate, phosphate, calcium and uric acid) functional unit of kidney nephron made of two basic structures Renal corpuscle: 1. Renal corpuscle 1. Bowman’s capsule - where fluid - outside of renal corpuscle is called filters into BOWMANS CAPSULE (aka renal capsule), inside 2. Glomerulus - specialized leaky corpuscle is a specialized capillary bed called glomerulus capillaries (very leaky type of capillary network) 3. Juxtaglomerular Apparatus (JGA) - 2. Tubule junction of tubule and arterioles - made up of single layer epithelial cells, around bowman’s capsule functional differences, which gives nephron ability to carefully select item to be excreted as urine specialized epithel a podocytes - blooessa b sl artery Specialized cells (macula densa cells) in the late ascending limb of the loop of Henle can detect [sodium] and Nephrons are positioned in two different ways [chlorine] in the filtrate as it passes 1. Cortical nephron - 80% of nephrons through tubule 2. Juxtamedullary - 20% of nephrons Blood Filtration - refers to movement of fluid from glomerulus into Kidneys receive almost 20% of the total bowman’s capsule cardiac output, blood is filtered by Reabsorption - movement of filtrate nephrons back into capillary bed (peritubular capillaries) Filtration barriers: Filtration is importantly to maintain blood volume, and ion balance Secretion - items dissolved in blood added to filtrate Glomerulus contains many Plasma - mostly water with dissolves Excretion - filtrate collected in renal fenestrations (aka pores) making macromolecules (proteins, amino pelvis then in bladder is called urine it leaky acids, hormones and glucose). Dissolved gases (CO2, O2, Na, K, Cl, Barriers to filtration Endothelial cells of bowman’s Ca, H, and HCO3) size of capsule are fused with podocytes fenestrations Red and white blood cells - cellular and size of Basal lamina - sticky extra component of blood spaces in cellular matrix composed of between collagens and negatively charged endothelial cells glycoproteins. p a Space between fibres of basal Prevents plasma proteins from filtering into bowman’s capsule lamina Spaces between the podocytes  Filtration Forces contributing to Net filtration pressure 1. Hydrostatic Pressure of Glomerular Capillaries (PGC) Blood is pushed through the vessels of the body by the pump of the heart blood flows through the leaky glomerular capillaries into capsule space. pressure favours filtration and is generally the largest force that promotes filtration. 2. Colloid Osmotic Pressure of Glomerular Capillaries (πGC) Proteins dissolved in plasma cannot filter into capsular space due to size and charge Water has an affinity for proteins, and therefore the proteins generate a force, drawing water to where the proteins flow. force that inhibits filtration as the proteins stay in the glomerular capillaries. 3. Hydrostatic Pressure of Bowman’s Capsule (PBC) fluid filters into the capsular space, it fills the capsule. movement out is slow through the first part of the tubule The back pressure of fluid in the capsule limits more fluid from filtering into the capsule space. presence of filtrate is a force that inhibits fluid filtration. 4. Colloid Osmotic Pressure of Bowman’s Capsule (πBC) If proteins were able to filter into the capsular space, the protein would pull fluid with it. a positive force that favours filtration, although it usually doesn’t exist due to the restriction of most proteins from filtering into the capsular ↑ space. Sometimes this pressure is ignored since its force is usually a value of 0 mmHg. Net filtration pressure = (PGC + πBC) - (PBC + πGC) Glomerular filtration rate; Quantity of water and solutes dissolved, filtered ↓or man ma mtg per unit time into bowman’s space from glomerulus capillaries Mostly affected by amount of blood floe into kidney and BP. If total renal blood flow of BP increases so would net filtration. Filtration coefficient, due to leakiness of glomerulus capillaries, influenced by surface area of glomerular capillaries available for filtration and permeability of capillaries Glomerulus Filtration Rate Tubuloglomerular feedback GFR INCREASES - BP increases Man, , Macula densa cells in the ascending loop of henle detect sodium levels and how fast filtration is moving, if too fast, cells will release adenosine, Conserine enspan anim causing vasoconstriction of afferent arteriole Returns GFR back to normal If BP decreases, GFR decreases Macula densa cells detect this, release nitric oxide, causes vasodilation Calculating GFR ↓ i use creatinine (waste product in blood) come se GFR Values 90 normal : ml/min or higher Early stages of Kidney disease : 60-89 ml/min Kidney disease : 15-59 ml/min Kidney failure : less thanI s m / m i n of Stages CKD 1-2 Stage : mild ↓ of GFR 3 ↓ GFR (swell feet? Filtered Stage : hands blood more + less in 4 : symptoms Stage more severe Stage S : Kidney Fail Renal handling Excretion NO rate Substances are processed differently by tubule cells Filtered load [substance] plasma x GFR GFR 120mg x : = 150 LIday EglucosebplasmaGFR FL # [sodium) plasma excretion = = = 8mgk y 150day 10 mg/L X 2 S. 2250mgy/ 1200 = 25 mylday mglday = 2wa X100  GFR 1L 120mg = + 25 h X day 2 mg 150 LIday = FR = 2mg/L x 150 day 300 mylday = Excreted 12 mg/ 2 5 Llday = x. 30 myday = % 30 m excreted = o = 10 %  Tubule transport Proximal tube: 65% Transport mechanisms Glucose, amino acids, H2O, Na, K, Cl 1. Channels: small protein lined pores, passive, [] Descending limb and electrochemical gradient Water, minimal Na 20% 2. Uniporters: permits movement of single Ascending limb molecule through membrane, protein carriers Na, k, Cl that bind to molecule Distal convoluted tubule 3. Symporters: two or more molecules at same Na, k, Cl, Ca 14% time (same direction), “co transport” Collecting Duct 4. Antiporters: two molecules at same time Na, water (opposite direction), one must move to make other move Transporters in Tubule Cells 5. Primary active transport: needs ATP, against [gradient] water channel. Osmosis. Aquaporins (specialized channel) Proxim. Aquaporin II only hormonally regulated channel a socikmina channel Glucoseniporte r Nal glucose symporter Desmbbaspatra · reabsorb glucose No Lendingim AS Na/t Paracellular antiporter · reabsorbs Na ,