Textbook Notes (362,879)
Canada (158,081)
Biology (652)

Bio Textbook Notes.docx

24 Pages
Unlock Document

McMaster University
Grant B Mc Clelland

Textbook Notes (Test 1) 2/1/2013 5:37:00 PM Chapter 1: Introduction to Physiology (Lecture 1 & 2) Four Major Classes of Cells: 1. Neurons  Branched to receive or transmit signals 2. Muscle cells a. Skeletal muscle- arms/legs (voluntary) b. Cardiac muscle- heart (involuntary) c. Smooth muscle- blood vessels (involuntary) 3. Epithelial cells  continuous sheet-like layer of cells w/ a thin underlying layer of non-cellular material called a basement membrane  layers can be thick and cells have diff shapes/sizes 4. Connective tissue cells  Tissue is made of cells + extracellular matrix (non-cellular materials) with elastin (for elasticity) and collagen (for strength and resist stretching); most diverse Lumen- interior cavity of a hollow organ or vessel Internal Envmt- fluid that constitutes the immediate envmt of most cells  Most cells are not in direct contact w/ external envmt (like the blood vessels) or w/ the bloodstream (like the nerve or muscle cells)  Internal envmt and external envmt are separated by a single layer of continuous epithelial tissue (Lec 2, slide 2). o Skin, linings of lung, gastrointestinal system and kidney tubules Total Body Water (TBW)- volume of water contained in all the body’s compartments (total volume of fluid enclosed within the outer epithelial layer)  Intracellular Fluid (ICF)- fluid located inside cells o Protein rich and K rich  Extracellular Fluid (ECF)- fluid located outside cells o Synonymous to internal envmt o Few proteins and Na rich o 20% ECF is found in blood and the rest outside blood  Plasma- ECF portion found in blood (non-cellular part)  Interstitial Fluid (ISF)- ECF portion present outside blood that bathes most cells in the body  These are very similar in composition but plasma is protein rich and ISF isn’t  Similarity in composition is b/c capillaries (most numerous and smallest blood vessels) are highly permeable to solutes except proteins  ICF and ECF are separated by cell membranes that are low in permeability and selective Negative Feedback:  Regulated variable (r.v)- variable that is regulated to stay within relatively narrow limits o If r.v increases, system responds by decreasing (and vice- versa) to get it to desired value o Only make adjustments when a difference btwn the actual value of the r.v and the desired value, called a set point, is detected o R.v cannot be absolutely constant, fluctuate continuously o Error signal is the diff btwn set point and actual value which is minimized by neg. feedback  Integrating center- receives signal (input) from sensors so that it can compare the r.v to the set point and orchestrate the appropriate response  Effectors- cells/tissues/organs that receive a signal (output) from integrating center to bring about a final response Chapter 2: The Cell- Structure and Function (Lecture 2 & 3) Membranes Proteins:  Integral Membrane Proteins- embedded into the lipid bilayer; o Trans-membrane Proteins- integral membrane proteins that expand to both ends of the lipid bilayer o Other integral membrane proteins can be located on only one side of the membrane, but still embedded in bilayer  Peripheral Membrane proteins- loosely bound to membrane (on surface) Cell Organelles (review):  Nucleus: o contains genetic material (DNA); has a nuclear envelope with nuclear pores to bring material in and out; has a nucleolus where rRNA is synthesized  ER: o Rough ER: has ribosomes (complexes of rRNA and proteins for protein synthesis  Synthesis of proteins for secretion or for plasma membrane or other organelle  Connected to nuclear envelope o Smooth ER: made of tubules  Synthesis of lipids (triglycerides and steroids), Ca ions storage  Connected to rough ER  Golgi Apparatus: o Cis face to smooth ER (in), trans face to plasma membrane (out) o Processes molecules synthesized in ER and prepares them for transport to final location via vesicles  Mitochondria: o Most of cell’s ATP is produced by this organelle  Lysosomes: o Contain enzymes that degrade intracellular debris or extracellular debris that has entered the cell o Use process of endocytosis for extracellular debris  Peroxisomes: o Degradation of amino acids, fatty acids, and toxic foreign matter o Often produce hydrogen peroxide  Endosomes: o Receive protein and lipids to be delivered to the lysosome or recycled back to golgi apparatus o Also receive plasma membrane proteins that are recycled back to plasma membrane or degraded Cell to Cell Adhesions:  Tight Junctions o Common in epithelial tissue for molecular transport btwn lumen of organ and bloodstream o Occludins- integral membrane proteins that fuse the adjacent cells together to form an almost impermeable barrier o Trans-epithelial transport- solutes must cross the epithelial cell layer b/c barrier doesn’t let them around the cells o Apical membrane- separates lumen and cytosol of each epithelial cell o Basolateral membrane- faces the extra-cellular fluid  Desmosomes o Found in tissues subject to high stress (heart, uterus, skin) o Plaque: forms a filamentous junction btwn adjacent cells (like occludin)  Cadherins: intercellular protein filaments that link cells and are connected to intracellular filaments  Gap Junctions o Found in smooth muscle and the heart o Connexons: membrane proteins that link adjacent cells and act as a channel for the mvmt of ions  Mvmt of ions organizes electrical charge btwn cells so that for ex. Cells in heart can contract in unison o Connexins: six smaller membrane proteins that make up a connexon Chapter 3: Cell Metabolism (Lecture 3) Modulation:  Allosteric Modulation o Modulator binds to a regulatory site on enzyme that is not the active site and causes a conformational change of active site  Covalent Modulation o Phosphorylation of an enzyme’s a.a side chain alters active site + spreads out negative charge, rxn catalyzed by protein kinase o Dephosphorylation of the altered enzyme is catalyzed by protein phosphatases Enzyme Kinetics:  Vmax is the same despite the substrate (b/c saturation point doesn’t change as long as something fills the spots) but the Km (and slope of graph) varies b/c need different conditions (ie/ affinity) to get an enzyme to its saturation point  Km is a measure of affinity and it means “conc. of substrate at ½ Vmax” o So, if the Km is lower it means the conc. of substrate present at ½ Vmax is lower and thus, there are more E-S complexes meaning… o Lower Km = higher affinity Chapter 4: Cell Membrane Transport (Lecture 4) Gradients:  Chemical Driving Force: o Concentration gradient: when a substance is present in different concentrations on either side of a membrane o High-Low is down a conc. gradient (chemical driving force) and Low-High is up a conc. gradient  Electrical Driving Force: o Membrane potential: difference in electrical potential (voltage) across a membrane o Ions have electrical driving forces b/c they’re charged Electrochemical Force:  Depends on both the electrical and chemical driving forces  If forces go on opposite directions and not on the same direction, then the net electrochemical force acts in the direction of the larger force  How do you determine which force is larger? o Equilibrium potential- hypothetical value for membrane potential at which the electrical driving force is equal and opposite to the chemical driving force, producing a total force of zero o Thus, ion will be at equilibrium o Magnitude and sign of eqm potential depend on size and direction of conc. gradient and valence of ion o Since eqm potential is a hypothetical value, it is different from membrane potential and it is independent of the electrochemical driving force direction Chapter 5: Chemical Messengers (Lecture 5) Chemical Messenger Communication:  Chemical messengers are secreted by a cell into the interstitial fluid and is aimed at a target cell that has receptors (proteins) that specifically recognize and bind the messenger  Signal Transduction Pathways- the mechanisms through which the target cell produces a response after the receptors bind the messenger Chapters 13, 14, 15: Cardiovascular System (Lectures 6-12) Cardiovascular System: 1. Heart- muscular pump that drives the blood flow through blood vessels 2. Blood Vessels- conduits through which the blood flows 3. Blood- a fluid that circulates around the body, carrying materials to and from the cells The Heart:  Has 4 chambers: o Atria (right & left)- receive the blood that comes back from the vasculature o Ventricles (right & left)- receive blood from atria and generate the force that pushes the blood away from the heart and through the blood vessels  Both left and right halves of the heart consists of an atrium and a ventricle  Septum- wall that separates the right and left halves of the heart so that the blood from each side does not mix o Interatrial septum- divides the atria o Interventricular septum- divides the ventricles  Base- the upper pole of the heart (top)  Apex- the narrower lower pole (bottom) Blood Vessels:  Vasculature- system of blood vessels that carry the blood from the heart, to various organs and back to the heart o As blood flows away from the heart, the blood vessels become narrower and more numerous (like tree branches) o As blood flows back to the heart, the blood vessels become less numerous and large in diameter  Arteries- large blood vessels that carry blood from the heart to organs and tissues (AWAY FROM HEART)  Arterioles- smaller vessels that arteries branch off to  Capillaries- smallest vessels that arterioles branch off to  Venules- larger vessels that capillaries send blood to  Veins- even larger vessels that carry blood back to the heart (BACK TO HEART) Blood:  Half is fluid and nearly half is composed of cells  Erythrocytes- red blood cells, most numerous that contain hemoglobin (protein that carries oxygen)  Leukocytes- remainder of the cells, white blood cells, that help defend body from invading microorganisms  Platelets- cell fragments that aid in blood clotting  Plasma- liquid portion of blood made up of water w/ proteins, electrolytes and solutes Path of Blood Flow:  The heart is two separate pumps, blood from one side NEVER mixes with blood from another site  Circulatory system consists of two circuits: o Pulmonary Circuit- supplied blood by the right heart, consists of all blood vessels w/in the lungs and those connecting the lungs to the heart o Systemic Circuit- supplied blood by the left heart, consists of all other blood vessels in the body except lungs  Capillary beds- dense network of capillaries possessed by both circuits where exchange of nutrients and gases (O2 and CO2) takes place o In systemic, these are found in organs and tissues  Oxygenated blood (“red blood”)- in pulmonary capillaries, O2 moves into blood from air in lungs and CO2 leaves blood  Deoxygenated blood (“blue blood”/ darker blood)- in systemic circuits, O2 is consumed by organs and tissues so CO2 enters blood  Path: o Left ventricle pumps oxygenated blood into the aorta- major artery that pumps blood to capillary beds of all organs and tissues in systemic circuit o Venae cavae- two large veins that bring back deoxygenated blood into the right atrium  Superior vena cava – carries blood from above diaphragm  Inferior vena cava- carries blood from below diaphragm o Blood is sent into right ventricle, which is then sent into the pulmonary arteries- carry deoxygenated blood into the lungs  only arteries that carry deoxygenated blood away from heart o Pulmonary veins- carry oxygenated blood from lungs into the left atrium  Only veins carrying oxygenated blood into heart o Blood goes to left ventricle, which is where cycle starts o Stroke Volume: volume of blood that is pumped from each ventricle with every beat Valves of the Heart  Cardiac cycle: heart chambers contracting in a series of events o Atria contracts first and then ventricles follow o This changes the direction of pressure gradients for blood to flow  Heart has 4 valves that keep blood flowing in the right direction: o Atrioventricular valves (AV valves)- between atria and ventricles  When atrial pressure is higher than ventricular pressure, the valves open (ventricles are relaxed so blood enters atria and pushes past the valve into ventricle)  When ventricular pressure becomes higher than atrial pressure, the valves close (ventricles are contracting so the blood presses back on the AV valve and the valve closes- or else the blood would flow backwards) o Aortic valve- between left ventricle and aorta o Pulmonary valve – between right ventricle and pulmonary trunk  Permit blood flow forward and prevent backward flow  Both of these open when ventricular pressure is greater than arterial pressure so blood flows into arteries  In reverse, they close so blood does not flow back from arteries Fundamental Law of Circulation  Whenever there’s a difference in pressure btwn two locations, the pressure gradient will drive it down to an area of lower pressure  The primary function of the heart is to drive the blood flow through the vasculature, through a pressure gradient  Mean Arterial Pressure (MAP)- the avg pressure in the aorta throughout the cardiac cycle- o MAP is usually about 85 mmHg o It’s the difference in pressure that creates the gradient, not individual pressures  Central Venous Pressure (CVP)- pressure in the large veins in the thoracic cavity that lead to the right atrium o About 2-8 mmHg and about 0 mmHg just outside the right atrium  The difference btwn MAP and CVP is the pressure gradient that drives blood flow through the systemic circuit o Can omit the CVP b/c so low, so that delta P = MAP  Systole: ventricular contraction  Diastole: ventricular relaxation  Venous Return- the blood returning to the hear enters the relaxed atria and passes through AV valves into ventricles; pressure from veins is high enough to send blood into heart (area of lower pressure) o This is during mid/late diastole  Ventricular Filling- late in diastole the atria contracts and drives more blood into the ventricles; which causes systole to begin (once atria relaxes)  *Blood moves through the vasculature during diastole even though no blood is being ejected from the heart at this time (Aortic valve is closed) o the continual exit of blood causes blood volume to decrease and aortic pressure to decrease to a minimum called diastolic pressure  *When aortic valve opens, the aortic pressure increases b/c more blood flows into aorta faster than it can flow out o eventually, blood flow from heart slows and aortic pressure reaches a maximum called systolic pressure o At the end of systole, the aortic valve closes again  *Ventricular and aortic pressure are very similar during ejection (systole) b/c aortic valve is open  *When aortic valve is closed, ventricular pressure falls dramatically (diastole- relaxed) while aortic pressure remains elevated and falls a little bit (this is b/c it’s the force that drives blood flow throughout systemic circuit, need to keep gradient)  Aorta stores pressure during systole as its walls expand (when blood volume increases) and thus, arteries are known as pressure reservoirs o Increase in blood pumped from left ventricle will raise MAP  End Diastolic Volume (EDV)- the volume of blood in ventricle at the end of diastole (max. ventricular volume)  End Systolic Volume (ESV)- the volume of bloo
More Less

Related notes for BIOLOGY 2A03

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.