Bioe 20B W2D2 Oct 10 ANNOTATED SLIDES (1) PDF

REMINDERS ANNOUNCEMENTS 1. Today: Osmoregulation, Circulation Tuesday, 10/10/24 2. Due Sunday: HW 2, Quiz 2, Plain Language Summary Week 2, Day 2 Osmoregulation Circulation TODAY’S AGENDA (8-9:35AM) Finish Osmoregulation...

REMINDERS ANNOUNCEMENTS 1. Today: Osmoregulation, Circulation Tuesday, 10/10/24 2. Due Sunday: HW 2, Quiz 2, Plain Language Summary Week 2, Day 2 Osmoregulation Circulation TODAY’S AGENDA (8-9:35AM) Finish Osmoregulation 5 min break Animal Fun Fact of the Day Circulation Types of Circulatory Systems Anatomy of the Closed System Electrical Conduction System Blood Pressure REVIEW: REGULATION OF KIDNEY FUNCTION ↑ Blood osmolarity DISCUSS: Describe the process of regulating blood osmolarity 1) When blood osmolarity increases, the brain (pituitary gland) releases ADH (antidiuretic hormone). 2) ADH causes aquaporins to be incorporated Pituitary into the membranes of the collecting duct. gland releases 3) Water can then be reabsorbed back into the ADH body and causes blood osmolarity to decrease. Aquaporins insert into collecting duct Water is reabsorbed and blood osmolarity ↓ What kind of feedback loop is this? REVIEW: REGULATION OF KIDNEY FUNCTION On your boards… A B C Urine CONCENTRATION [ADH] Hydrated Dehydrated What is the relationship between ADH and Urine CONCENTRATION? REVIEW: REGULATION OF KIDNEY FUNCTION On your boards… A B C Urine VOLUME [ADH] What is the relationship between ADH and Urine VOLUME? REVIEW: REGULATION OF KIDNEY FUNCTION With your neighbor What would happen if you This is what diuretics do were given a drug that (like caffeine and alcohol) prevented aquaporins from being incorporated into Urine would be diluted Produce high urine volume collecting duct? Lose more water than we should  Key Concepts for: Osmoregulation and Excretion What did we learn? Understand that animals can break nitrogen waste down into different products, and there is a cost/benefit tradeoff to breaking down waste based on energy expenditure and water saving. Understand that different osmotic adaptations depend on the environment animals live in. Understand how to use the terms hypoosmotic and hyperosmotic. Given a novel organism and the osmolarity of the body and the environment, be able to predict which way water would move and mechanisms an animal would use to deal with it. Be able to draw a juxtamedullary nephron and explain what happens at each step of urine formation. Explain why a fish cannot concentrate its urine beyond its body fluid osmolarity, but a bird or mammal can. Be able to explain why the length of the Loop of Henle correlates with the concentrating ability of the kidney. Be able to explain the outcome of the effect of alcohol & ADH on urine output. 7 Circulation & Gas Exchange CIRCULATION EXTREMES IN NATURE Animal Fun Fact of the Day The blue whale is the largest animal and has one of the lowest heart rates at 2 bpm during dives! This is facilitated via the dive response. What’s your resting heart rate? REVIEW: HEART RATE There is a relationship between heart rate, body size, and life expectancy. A Galapagos tortoise has a heart rate of six beats per minute and lives for 177 years. A rabbit, on the other hand, has an average heart rate of 209 beats per minute and lives only nine years!  Key Concepts forforCirculation Key Concepts Today 1. Types of Circulatory Systems 2. Anatomy of the Closed System a. The Heart = The Pump b. Vessels = The Plumbing 3. Electrical Conduction System 4. Blood Pressure REVIEW: Circulatory Systems DISCUSS: What makes up a circulatory system? Muscular pump (heart) Fluid (blood) Conduits (blood vessels) Cardiovascular comes from Greek words kardia = heart and vasculum = vessel REVIEW: Circulatory Systems What are the 3 basic types of circulatory systems? REVIEW: Circulatory Systems Gastrovascular cavities (not a true circulatory system) Why don’t small animals need a circulatory system? Nutrients, respiratory gases, and wastes can diffuse directly between cells of their bodies and their environment Small animals can be more active than larger ones REVIEW: Circulatory Systems Gastrovascular cavities Nutrients enter cavity and waste is flushed out through the same opening Mouth = anus REVIEW: Circulatory Systems Open vs. Closed Circulatory Systems What is the difference between an open and closed circulatory system? In open circulatory In closed circulatory systems, blood and systems, blood and interstitial fluid are mixed interstitial fluid are separate = hemolymph (blood is in vessels) They are similar in that they both have a pumping mechanism (heart) like an aquarium pumping water REVIEW: Circulatory Systems Open vs. Closed Circulatory Systems What advantages do closed circulatory systems have compared with open systems? Fluid can flow more rapidly through vessels than intracellular space Diameter of blood vessels can change to match body’s needs Specialized cells that help transport nutrients can be dropped off where needed REVIEW: Circulatory Systems Single Circuit vs. Double Circuit Circulatory Systems What is the difference between single circuit circulation and double circuit circulation? In double circulation, there are In single circulation, blood two separate pathways through flows to and from the heart which oxygenated and through a single pathway. deoxygenated blood flows. REVIEW: Circulatory Systems Different arrangements of pump and plumbing 2 chambered heart 3 chambered heart 4 chambered heart  Key Concepts forforCirculation Key Concepts Today 1. Types of Circulatory Systems 2. Anatomy of the Closed System a. The Heart = The Pump b. Vessels = The Plumbing 3. Electrical Conduction System 4. Blood Pressure  Anatomy of a closed system DISCUSS: Describe the pathway of blood through the heart Superior and inferior vena cava Venae Aorta Pulmonary cavae artery Right atrium Pulmonary Right ventricle Pulmonary vein side Left Pulmonary artery Right atrium atrium Lungs Left AV valve Pulmonary vein Right Left AV valve ventricle Left atrium Left ventricle Systemic Right side ventricle Semilunar valves aorta Fig. 49.2 body  Anatomy of a closed system Why do arteries have two layers of elastin while veins have valves? Elastin allows blood vessel to expand for high blood pressures Valves help prevent the backflow of blood at low pressures  Anatomy of a closed system DISCUSS: What does this graph tell us? Blood pressure is inversely proportional to total area Blood pressure in the arteries and veins is greater than in the capillaries due to this  5-min Break! Attendance Time Scan the QR code or go to https://tinyurl.com/W2D2Oct10 to answer the following question: 1) Why is the SA node considered the pacemaker of the heart? (This will be used for taking attendance today.)  Key Concepts forforCirculation Key Concepts Today 1. Types of Circulatory Systems 2. Anatomy of the Closed System a. The Heart = The Pump b. Vessels = The Plumbing 3. Electrical Conduction System 4. Blood Pressure  How the heart pumps What is the purpose of gap junctions in cardiac muscle? GAP Junctions Gap junctions allow the electrical signal to be transmitted through the heart very quickly.  How the heart pumps Systole = contraction How does the heart Diastole = relaxation pump blood? 1) Atria and ventricles relax (diastole) allowing blood to enter atria and ventricles 2) Atria contracts (systole) allowing blood to enter ventricles which are relaxed (diastole) à0.1 second delay allows blood from atria to move into ventricles 3) Ventricles contract (systole) and pumps blood out through relaxed atria (diastole) to pulmonary and systemic circuit (lungs) (body) REVIEW: ECGs Fig. 50.6 How are the electrical signals controlled?  REVIEW: ECGs P-Wave – Atrial Depolarization Depolarization leads Label the following QRS Complex – Depolarization of Ventricles to contraction P wave T-Wave – Repolarization of Ventricles Relaxation/repolarization Q wave R-Wave R wave S wave T wave X axis title and units Y axis title and units Electrical potential (mv) P-Wave T-Wave Match the following events to the ECG AV Node fires Atrial contraction S-Wave SA Node fires Ventricles repolarize Q-Wave Ventricles depolarize Ventricles contract Time (ms) Signal pauses REVIEW: ECGs ECG = electrocardiogram à Shows electrical activity of the heart with each beat REVIEW: ECGs A doctor looks at an ECG and determines that the patient has damage to the heart muscle in the area of the AV node causing the signal to be slowed more than normal. On which part of the ECG would such damage show up? FYI – this is called a first degree AV block A D B C Whole QRS complex REVIEW: ECGs 1. Draw two heart beats in a row. 2. Then draw two heart beats in a row that represent a slower heart rate than you originally drew. Type I, also called Mobitz Type I or Wenckebach’s AV block): The less serious form of second-degree heart block. The electrical signal gets slower and slower until your heart actually skips a beat. REVIEW: ECGs DISCUSS: In utero (in the womb) humans like all mammals, have a hole between the right and left atria called the foramen ovale. Shortly after birth this hole has completely healed. Hypothesize the purpose of this hole. (Hint - in the lungs of fetus are filled with fluid while in the womb) This hole allows oxygen rich blood to bypass the lungs in order to supply the brain with oxygen since it gets oxygen from the placenta not the lungs.  Key Concepts forforCirculation Key Concepts Today 1. Types of Circulatory Systems 2. Anatomy of the Closed System a. The Heart = The Pump b. Vessels = The Plumbing 3. Electrical Conduction System 4. Blood Pressure REVIEW: Blood Pressure Blood pressure = Cardiac Output X Total Peripheral Resistance (Heart rate x stroke volume) (Resistance influenced by vessel radius, length and blood viscosity) DISCUSS: You have a patient with chronic high blood pressure. You have a choice of several drugs to use to treat high blood pressure. Please explain why each of these drugs would be effective in this goal. Beta blockers – decrease binding of epinephrine to SA node muscle cells, decreasing heart rate Decrease in heart rate à decrease in cardiac output à decrease in blood pressure Nitroglycerin & ACE inhibitors – causes vasodilation Decreasing resistance à decreases blood pressure  HEART SUMMARY 4 fully divided chambers The mammalian and bird heart has ______ double circuit (what does this mean)? Blood moves through a _______ electrical signals The heart beat is coordinated by ____________ efficiency The heart beat is coordinated to move blood through & out the heart with maximum ________ pressure Changes in _____________ open and close the valves that prevent backwards flow of blood