Anatomy and Physiology 1 Lectures PDF

QUIZ 2 INFOt Anatomy and Physiology 1 econstantly Shifting (dynamic Homeostasis Home/o = sameness Stasis = standing still Anatomy and Physiology 1 Homeostasis Is BALANCE  Hom...

QUIZ 2 INFOt Anatomy and Physiology 1 econstantly Shifting (dynamic Homeostasis Home/o = sameness Stasis = standing still Anatomy and Physiology 1 Homeostasis Is BALANCE  Homeostasis Definition – The condition of equilibrium in the body’s internal environment due to the interplay of the body’s regulatory processes works best There's where body - an optimal point I centre he i sweat when hot keep body attemptsto - shiver when coid (muscles contracting) , , Homeostasis n Dynamic n Ceaseless shifting - n The range to maintain life is very narrow, and the body does shift within this range (creates a stable internal environment) n All structures from cells to organ systems works to maintain homeostasis n Failure to maintain homeostasis soon leads to illness Homeostasis n The need to maintain balance of anything requires a set of parameters that allow the body to work at its functional best high usually left is usually right side , low on - n This means that within this set parameter there is the optimum “center” with both a left and right high and low (generally high to the left and low to the right) n At either end the values reach a point where the body will be stressed and if it moves further the body will be in crisis to a point where the body may die n The normal parameter can also move ie. Normal blood sugar is between 4-6 millimoles per liter, in diabetics they feel the best at between 8-10 millimoles per liter HOMEOSTASIS RULES!!! Control of Homeostasis n We must remember that we are constantly bombarded with stimuli that can disrupt or take the body away from balance n These may exist within or outside the body n Stresses can also play a role in changing the balanced environment When your stressed + get sick (psychoneuroimmunological effects) > - easily psych , nervous system , Immune system have to n The longer the influence towards the +et work and impact each Other imbalance, the more severe the possibility of a mortal outcome n Two systems control homeostasis: n Nervous System n Uses nerve impulses - quick adjustments but don't last n Quick Short + long n Endocrine system n Uses chemicals (hormones) n Much more powerful of the two n Slower but lasts longer (than system) nervous Anatomy and Physiology 1 Feedback Systems Definition - A cycle of events in which the status of the body condition is monitored, evaluated, changed, re-monitored and reevaluated Three components 1. Receptor baroreceptor measures BP - ex each is. parameter for its own responsible - - monitors and sends messages to control center - Either nerve impulse or chemical signal Anatomy and Physiology 1 2. Control Center - high knows whats How adjustements and makes accordingly - sets the range of values within predetermined parameter - Evaluates - Sends commands via nerve impulse or chemical ↳ make to it more quick Anatomy and Physiology 1 3. Effector - receives the message from control center - nearly all tissues or organs can be effectors - this is how all works homeostasis in body  Anatomy and Physiology 1 Negative Feedback System - REVERSES CHANGE - high too blood suger , neg. FSlowers - slows and eventually stops as environment returns to balance 2 feedback systems : Onegative ② Positive incarotid artery f Anatomy and Physiology 1 Positive Feedback System maintains change the - STRENGTHENS OR REINFORCES CHANGE Increases change - similar to positive feedback system - continues until an outside system shuts it off - ex. Child birth Homeostatic imbalances n At balance all things function efficiently (metabolism) n Out of balance = disease or disorder  conductive Chave a cons enarge) ~ Nat kt eX Salt Ngzt ca"ei Potasslum , -. , , Def.: Solutions that contain ions and lots of water Really great at conducting electricity The human body could not function without them Nervous conduction and muscle contraction would be impossible without When electrolytes are placed in water they divide into positive and negative ions we producesa most electrolytes - come from we excrete beverages fair amount of electrolytes everyday  pH ·erzenyarugen ž Both intracellular and extracellular environments must have balanced quantities of acids and bases ž In a solution, the more hydrogen ions we find, the more acidic the solution becomes › When dissolved in water the solution dissociates into one or more hydrogen ions ž The more hydroxide ions we find the base (alkaline) the solution becomes › When dissolved in water the solution dissociates into one or more hydroxide ions ž When a base is added to an acid it removes hydrogen from that solution making it more base lime = basic ž The more hydrogen ions that exist in a solution, the more acidic the solution ž The more hydroxide ions the more basic (alkaline) the solution ž Acidity or alkalinity this expressed on the Ph scale which runs from 0 – 14the scale is based on the concentration of H+ in a solution - or basic neither addic Ineutral point) ž The midpoint is 7 (H+ and OH- are equal) which is distilled water ž A salt, when added to water dissociates (positiveson) into cations an anions neither of which is (negatives hydrogen or hydroxide ž These salts are necessary to carry electrical charges (nerve impulses, muscle contractions) ž Acids and bases react to one another to form salts ž A solutions alkalinity or acidity is measured on the pH scale (percent hydrogen) ž A pH of 7 is said to be neutral (neither alkaline or acidic) ž As the number moves right, the solution becomes more alkaline (7-8 and so on) ž As the number moves left, the solution becomes more acidic (7-6 and so on) ž It is important to understand that a change of one whole number results in a 10fold change in the number of hydrogen ions X10 (powerofio) ž Various intra and extracellur fluids have specific pH values they must maintain. See table 2.4 page 42 ž The normal pH limits (parameters) for each of these fluids are quite narrow ž Homeostatic mechanisms are constantly at work to maintain the appropriate values (kidneys removing excess acid through urine) to maintain H+ levels ž Strong acids are continually created by the body and consumed into the body but pH levels in the body remain constant. How does this happen? ↳this buffer systems ž The body contains buffer systems Their role is to convert strong acids or bases ISA's 7 ž into weak acids or bases removing SA's not about WEAKENING them) , but about ž Strong acids or bases can ionize easily (release many H or OH into the solution) which could result in a drastic change in pH (not good) ž Weak acids o bases release much smaller amounts of H or OH thereby having less effect on pH ž These compounds that convert the substance into either a weak base or acid is known as a buffer (remove or add H) metata butter does "only i Mt , not OH- ž This is the most abundant buffer in intracellular fluid and blood plasmawhats attaches part , to the iron , Hemoglobin is a good buffer within red blood cells (solid) > - ž and albumin is the main buffer in blood plasma (water) ↳the white ofthe eggs also ž Due to the chemical makeup of proteins they can buffer both acids and bases ž Blood flows through the systemic capillaries where carbon dioxide (CO2) passes from the tissues into the RBC’s where it combines with water to form carbonic acid ž The carbonic acid dissociates which gives us a H+ atom ž As CO2 is entering the RBC’s the hemoglobin is giving up it’s oxygen to give to the tissues ž The deoxygenated RBC’s then pick up most of the hydrogen ž Bicarbonate = weak base (HCO3) ž Carbonic acid = weak acid (H2CO3) ž As part of the previous dissociation HCO3 was produced ž If there is excess H the bicarbonate can act as a weak base and therefore how - > remove the excess H from the solution blood maintains ž If there is a shortage of H the carbonic PH Of - acid can act as a weak acid and blood contribute needed H to the solution  ↳ acidic CO2 is ž Increase in CO2 in body fluids increases H+ concentration thus lowering pH (acidic) ž Carbonic acid can be eliminated by exhaling CO2 ž A decrease in CO2 concentrations raises the pH (alkaline/base) ž The rate and depth of breathing can alter the pH of body fluids within a couple of minutes ž When CO2 levels decrease, the H+ concentration increases and blood pH decreases ž Reducing breathing to ¼ of normal lowers the pH from 7.4 (normal)to 7.0 (terminal) ↑ die If blood phgets to this ž When blood acidity increases, the decrease in pH is detected by central chemoreceptors in the medulla and peripheral chemoreceptors in the aortic and carotid bodies which ž Both of these stimulate the respiratory group in the medulla ž This results in an increase in both the forcefulness and depth of breathing ž Metabolic reactions produce nonvolatile acids ž This produces a large acid load on the body ž To eliminate this load the kidneys excrete H+ in the urine ž Renal failure can quickly result in death ↑ cannot excrete urine  in distrupts blood, product, o bundup balance. wasteexpelled a blood Itshould get form Oto ↑ in ž bicarbonate What would happen if a lung disease which and ,: LHCO) resulted in the patient’s inability to 1 tha e in exhale appropriate amounts of CO2? causes a it circea : und acidosis. ž If the pH is allowed to get as low as 7.2 death is imminent. ž Common conditions that cause this: COPD (Emphysema) difficulty breathing - chronic obstructive pulmonary disease THE HUMAN CELL The Human Cell - Contains the basic components to sustain life - Can be broken down into four main parts: 1. Plasma Cell membrane - outer membrane - helps control what comes into the cell and what can leave maintains appropriate environment - 2. Cytosol - the semifluid liquid found between the membrane and the nucleus - comprised of water, proteins, carbohydrates, ions, lipids, vitamins, minerals and gases - the Cytoplasm includes everything between the cell membrane and the nucleus (cytosol, inclusions and organelles) 3. Organelles - specialized structures within the cell which have a specific form and role which are important to the maintenance of the cell ↑ ex. digestion , 4. Inclusions respiration n... - temporary structures within the cell usually containing secretions or compounds which need to be stored in the cell -not cell has all these every round - not all cells are Cell Membrane - It is known as semi-permeable there's - control of what passes thro it - This means that it is selective as to what passes through - There are three compounds that make up the membrane 1. Proteins - make up approx. 50% of the membrane by mass - there are 2 types: A) Integral Ipasses thro membranes - allows materials to pass through using channels B) Peripheral don't pass - just sits thro membrane, surfaces on - sits on the inside and outside surfaces of the cell membrane  · & rotein peripheral cattached to protein) to lattached lipid Cell Membrane 2. Lipids - there are three types of lipids seen in the membrane A) Phospholipids (75%) /J Phospholipids B) Glycolipids (5%) (fat in carb portion ( C) Cholesterol (20%) type of lipid > - - these combine to form 45% of the membrane 3. Carbohydrates sugars hexagonal shape - , in - these are usually found attached to the integral proteins and lipids - they account for of the cell membrane by mass - these glycoproteins and glycolipids act as receptors Cell Membrane ↑ Stiff strong structure , makes membrane Stiffer Cell membrane ¨ Though the proteins are a greater portion of the membrane by mass, it is the lipids that take the greater area of the membrane since they are not as heavy as proteins ¨ The lipid portions are said to be amphipathic which ¨ means they have a polar and non-polar part water The polar part is the “head” and is hydrophilic ↑ > - likes e whereas the nonpolar parts are two long “tails” hydrophobic talls (fatty acids) which are hydrophobic (fatty (non-polar) acids) ↳ doesn't like water Water soluble compounds CANNOT Pass two membrane 3C of hydrophobic Fat soluble compounds Do pass thro compand ↳ ex. Alcohol can past thro : It effects you quickly Cell Membrane  ¨ There are two layers of lipids that make up the membrane ¨ The hydrophilic portions face the intracellular and extracellular areas (water) ¨ The hydrophobic face into the middle of this lipid bilayer (fill in the centre) cell membrane Aka lipid bllayer (2 layers of Phospholipids) ¨ Therefore the cell membrane is known as the lipid bilayer membrane - Stiff lipid maintain integrity , imp to Cholesterol has a hydrophilic portion which helps create. ¨ the hydrophilic portion of the membrane ¨ It is more rigid than the phospholipid and therefore provides rigidity and strength ¨ The glycolipids are also amphipathic (polar and non- polar segments) and help create the hydrophilic and hydrophobic segments ¨ The CHO segment tends to face the extracellular area carbohydrates Cell Membrane acd tails) (fatty  ¨ The CHO portions of the glycolipids and glycoproteins that form a sugar coating called the glycocalyx repels getthings - bad went to in the cell ¨ The pattern of the carbohydrates varies from cell to cell therefore it is a type of molecular signature ¨ Invaders have a specific glycocalyx = immune response ¨ Helps hold cells together and protects the membrane from enzymes (extracellular) ¨ It also creates a negative charge on the cell’s surface which tends to attract cations and repels anions attacks autoimmune disorder -immune system Its own cells (eX , ineumatoid arthritis) Integral Proteins ¨ These actually pass through the entire width of the lipid bilayer exposure intracellular ↳ to extra They function as: + ¨ ¤ Channels n Pores or holes that allow specific ions to pass n They tend to be selective, only allow certain ions that to transport ¤ Carriers -large compound hepatocell n Help large water soluble compounds (glucose, amino acids) to pass through n Transporters ¤ Receptors n Cellular recognition sites n Specific receptors bind to a specific type of molecule Insulin receptor = insulin the insulin is called the ligand ¤ Enzymes - break down things by speeding up Chemical reactions n Catalyze specific chemical reactions enzymes - are proteins Peripheral Proteins ¨ Found on both surfaces ¨ More common on the cytosol side ¨ Primary function as enzymes ¨ With some integral proteins, they can provide attchment for protein filaments found within the cytosol and help provide strength ¨ There are some integral and peripheral proteins which can act as receptors on the cell’s surface to allow other molecules to recognize the specific cell ¨ Nearly all the integral proteins and a good number of peripheral proteins have a CHO group attached to them These are known as glycoproteins [ cars + protein ¨ ¨ Glycoproteins along with glycolipids help form the glycocalyx sugar coating ↳  Cell Membrane ¨ The bilipid layer is a fluid mosaic meaning, the lipids create a lipid liquid in which the proteins float around (10 million times per second!!!!!) ¨ This allows for lipid and protein molecules to change their positions within the membrane structure ¨ Cellular membranes have various functions: ¤ A. create an electrochemical difference between the intra and extracellular fluid ions ¤ B. Act as a communication vehicle between cells The most important function is to regulate passage into and out of the cell ALL INFO FOR QU12 2444 QUIZ 3 INFO NUV MEMBRANE TRANSPORT