Biology 20 Unit D
This is a TRANSPORT system that allows every cell: i) uptake of nutrients ( ex. oxygen, glucose) ii) excretes wastes (ex C02, ammonia) requires action of: heart: muscular force to move blood around the body through blood vessels blood: fluid tissue that carries nutrients, wastes and other molecules Your circulatory system is composed of 96,000 km of blood vessels!! Every minute 5 L of blood cycles from the heart to the body and back to the heart.
i) Arteries carry blood AWAY from the heart carry blood with oxygen (red), exception: pulmonary artery walls are thick, strong, and stretchy composed of three layers carry blood at high pressure ii) Arterioles smaller arteries Vasoconstriction: Vasodialation: Major Blood vessels: http://www.nelson.com/abbio20-30/teacher/protect/media/major_vessels.html
iii) Capillaries smallest vessel in body (single cell layer thick) branch through tissues site of fluid and gas exchange ( oxygen, nutrients, carbon dioxide, and wastes) between blood and tissue fluid by diffusion red blood cells must pass through SINGLE FILE fragile eg: bruise
iv) Veins carry blood TOWARDS the heart blood is deoxygenated (blue), exception :pulmonary vein thin-walled; carry blood under low pressure contain VALVES which open in one direction only skeletal muscle contraction aids venous blood flow v) Venules smaller veins where deoxygenated blood collects from capillaries v) Venules smaller veins where deoxygenated blood collects from capillaries
Arteries Arterioles Pulse Autonomic nervous system Vasoconstriction Vasodilation Atherosclerosis Arteriosclerosis Aneurysm Veins Varicose veins Venules Capillaries
Read Pages 310-318 in Textbook Workbook diagrams Definitions Complete Section 10.1 Questions 1-9 on Page 318
Pages 319-327
Use Page 320 of your text book to label your heart diagram located in your workbook
muscular organ, size of your fist surrounded by a fluid-filled membrane: pericardium which reduces friction 1. Circulation PULMONARY CIRCULATION deoxygenated blood pumped from the right side of the heart to the lungs via the pulmonary arteries blood picks up oxygen (oxygenated) and travels back to the left side of the heart via the pulmonary veins. the pulmonary arteries are the only group of arteries that carry deoxygenated blood the pulmonary veins are the only group of veins that carry oxygenated blood
SYSTEMIC CIRCULATION left side of heart pumps blood to the entire body via the aorta (largest artery) from the aorta blood is diverted to: a) coronary arteries - serve heart tissue b) upper body arteries c) lower body arteries d) Hepatic/Portal system (digestive) starts with the intestines and finishes in the liver two large veins: the superior and inferior vena cava return blood to the right side of the heart
2. Chambers each side has two hollow (four chambers total), muscular chambers which is separated by a wall called the septum two thin-walled atria (receives blood) two thick-walled ventricles (pumps blood out of the heart)
3. Valves allow blood to flow in one direction only AV (atrioventricular) valve, separates atria & ventricles SV (semilunar) valve, separates ventricles and arteries (pulmonary trunk and the aorta) tiny chords anchor flaps of valves to ventricle walls Trace the path of blood through the heart starting at the right atrium and finishing with the aorta!
4. Control of the Heartbeat cardiac muscle is able to initiate its own contraction separate from the central nervous system SA node (sinoatrial node) initiates and controls the heartbeat, but external stimulation can speed up or slow down the heart. i.e. adrenaline The SA node is located at the top right side of the right atrium. Electrical impulses are sent through nodal fibers causing the muscle to contract The electrical impulses are delayed from the top to the bottom of the heart. Why? When the atria are contracting the ventricles need to be relaxed and vice versa.
Electrocardiographs (ECG) Electrodes are placed on body surface and record electrical impulses Impulses are displaced on electrocardiogram Doctors analyze graph for proper heart function
External Regulation of Heart Rate The S.A node is regulated externally by the parasympathetic and sympathetic nerves which conduct electrical impulses from the medulla oblongata of the brain Stress Activates sympathetic nerves Signals to S.A Node to increase H.R Relaxed Activates parasympathetic nerves Signals to S.A Node to decrease H.R
5. Heart (Cardiac) Cycle the sequence of heart chamber contraction is called the heart cycle diastole: heart (chamber) relaxation systole: heart (chamber) contraction 6. Heart Sounds lubb-dubb sound of heart beat lubb caused by closing of both the atrioventricular valves Heart Sounds Quick time video dubb caused by closing of both the semilunar valves Heart Sounds Quick time video
Septum Pulmonary circulatory system Systemic circulatory system Atria (atrium) Ventricles Atrioventricular (AV) valves Semilunar valves Aorta Coronary arteries Myogenic muscle Angioplasty
Sinoatrial (SA) node Purkinje fibres Sympathetic nervous system Parasympathetic nervous system Systole Diastole Stroke Heart attack Heart murmur
Read Pages 319-327 in textbook Key Terms Complete section 10.2 Questions Page 327 #1-2, 4-9 Label Heart Diagrams in Workbook Case Study: Diagnosing Heart Conditions Page 324 Q1-4 Mini Investigation: Effects of Caffeine on Heart Rate page 326 Heart Dissection Lab Explore an Issue: Growing a New Heart Page 321 (optional)
Pages 328-335
pulse: heart rate: number of heart beats per minute stroke volume: cardiac output: Heart Rate X Stroke Volume = Cardiac Output Beats ml blood ml blood min X = beat min Examples : At rest: 70 beats 70 ml blood 4900mL blood X = = ~ 5 min beat min liters/min Exercise: 130 beats X 70 ml blood = 9100mL blood = min beat min ~ 9 liters/min
the force that blood exerts on the walls of blood vessels created by the pumping of the heart Blood pressure is highest in the blood vessels closest to the heart (aorta), and lowest in veins blood pressure depends on two factors: the volume of blood pumped (cardiac output) the resistance to blood flow caused by the narrowing of the arterioles (vasoconstriction/ vasodilation)
Blood pressure changes as the heart beats: When left ventricle pumps out the blood Pressure rises to a MAXIMUM SYSTOLIC blood pressure When left ventricle is filling with blood Pressure falls to a MINIMUM DIASTOLIC blood pressure
Blood pressure is described by two numbers: Example of a healthy individual: 120 means: 80 systolic blood pressure is 120 mm Hg diastolic blood pressure is 80 mm Hg healthier values are usually lower, although it is possible to have blood pressure that is too low Determining Blood Pressure: Determined using a sphygmomanometer (pronounced: sphyg momonometer aka: blood pressure cuff) may be done manually using stethoscope or digitally
Also known as hypertension Consistent high blood pressure Especially if systolic blood pressure rises What causes blood pressure to increase? Narrowing of arteries or lack of elasticity caused by atherosclerosis (arteries clogged with fatty deposits) and arteriosclerosis (hardening of arteries) Factors that increase risk of high blood pressure: Stress Diet Exercise Genetics
Why is high blood pressure a problem? The heart must work harder to pump blood which can cause it to enlarge and weaken There is a increased force on the blood vessels, which can cause them to weaken and increase the risk of stroke or heart attacks Increase chance of blood clot formation
Cardiac output Stroke volume Sphygmomanometer Systolic Diastolic Hypertension Thermoregulation Hypothalamus
Read Pages 328 334 Make your own notes for Regulating Body Temperature Pages 332-333. Consider Drawing figure 4 to these notes and label the diagram in your workbook Complete Section 10.3 Questions Page 335 - #1, 3-5, 12 Practice measuring blood pressure Optional Investigation 10.3 Page 344 Design and carry out an experiment that measures the Effects of Exercise on Blood Pressure and Pulse
Pages 336-339
blood travels the following circuit: arteries? blood moves through capillary very slowly this allows time for exchange of materials between blood and tissue fluid (ECF) CO2(g) and O2(g) move in and out of capillary by process of DIFFUSION water moves out of arteriole and carries sugar, amino acids, wastes, hormones, vitamins these diffuse into tissue as well
Two forces control movement of fluid through capillary wall: 1. osmotic pressure: moves water from tissue fluid into blood osmotic pressure constant: 25 mm of Hg (millimeters of mercury) 2. blood pressure: moves water from blood into tissue fluid blood pressure is : 35-40 mmhg at the arteriole end of capillary 10-15 mm Hg at the venule end somewhere in between... solutes diffuse according to their concentration gradient glucose and oxygen diffuse out of capillary wastes and CO2 diffuse into capillary proteins and RBC are too big to move out
Add Figure 1: Fluid movement into and out of the capillaries (Page 336)
lymphatic vessels capture: excess fluids leaked from capillaries collect products of fat digestion (glycerol, fatty acids, and fat soluble vitamins) from small intestine fluid is called lymph and is and dumped into veins flows one way only lymph vessels called lacteals are in villi in small intestine
lymph nodes (small round structures found along lymphatic system mainly in neck, groin, armpit) filter foreign material, such as bacteria and tumor cells, special WBC here destroy pathogens when large numbers of bacteria or viruses are trapped in nodes, they become tender and swollen other lymphoid organs: Spleen - filters and cleanses blood; acts as a blood reservoir; destroys old RBC Thymus - programs certain WBC Tonsils - trap pathogens entering throat
Extracellular fluid (ECF) Filtration Hemorrahage Lymph Lymph nodes Lymphocytes Spleen Thymus gland
Read Section 10.4 in your textbook pages 336-339 Complete Section 10.4 Questions 1, 4-7 on page 339 Prepare for a Chapter 10 Quiz! Review your notes and completed textbook questions Study and Know your diagrams! Chapter 10 Review problems page 346-347 Questions 1-19 Next up: Chapter 11 Blood and Immunity!