Flashcards
BIO151FINAL Circulatory System
Cards in this deck (80)
- 1Function of the Circulatory SystemOrganisms need to exchange nutrients, oxygen, carbon dioxide and waste with the environment
- 2Differences between unicellular organisms and multicellular organisms circulatory systemsUnicellular organisms (aggregated multicellular organisms): exchange occurs directly with the envmt by DIFFUSION (protists and sponges)
Multicellular Organisms: diffusion of molecules can only occur over short distances (cnidarians, flatworms)
-branched gastrovascular cavity- 2 cells thick - 3Example of Moon Jelly circulatory systemGastrovascular cavity leads to radial and circular canals that circulate fluid
- 4Example of Planaria Circulatory System (2)Gastrovascular Cavity branches to permit distribution of fluids
-flat body increases SA and minimizes diffusion distance - 5Characteristics of Circulatory Systems (5)1) Circulatory fluid (blood)
2) A set of interconnecting vessels (blood vessels)
3) A muscular pump (heart)
4) Function of circulatory system: connects extracellular fluid to organs that exchange gases, absorb nutrients and dispose of wastes
5) Circulatory systems can be open of closed and vary in the number of circuits in the body - 6Characteristics of an open circulatory system (4)1) circulatory fluid (hemolymph) bathes the organs directly (arthropods, horseshoe crab, some molluscs)
2) heart contraction pumps hemolymph through vessels to sinuses where exchange occurs
3) heart relaxation draws hemolymph back in through pores with valves that close to prevent back flow
4) uses less energy than closed circulatory systems - 7Name of the open circulatory fluid in open circulatory systemsHemolymph
- 8Closed Circulatory System (How it works, 4 pt)-Blood is confined to vessels and is distinct from the interstitial fluid (annelids, cephalopods, vertebrates)
-one of more hearts pump blood into large vessels that branch into smaller vessels
-exchange takes place between interstitial fluid and body cells
-creates higher blood pressure which permits more efficient exchange of O2 and nutrients - 9What is a vertebrate Circulatory System?Closed circulatory system
- 10What are the 5 main types of blood vessels in vertebrate circulatory systems?Arteries- carry blood from heart to organs
Arterioles- arteries branch to arterioles
Capillaries- arterioles branch to microscopic vessels where exchange takes place with interstitial fluid
Venules- capillaries converge to venules
Veins- veins carry blood back to heart - 11What is a single circulatory system? (3)-Bony fishes, rays and sharks
-single circulation, with a 2 chambered heart
-blood leaving the heart passes through two capillary beds before returning - 12double circulatory system (3)-Amphibians, reptiles, mammals
-oxygen-poor and oxygen-rich blood are pumped separately from the R and L sides of heart
-oxygen-rich blood delivers oxygen through the systemic circuit - 13Difference between amphibian vs reptilian and mammalian circulatory systems?Amphibians: oxygen-poor blood flows through PULMOCUTANEOUS CIRCUIT to pick up oxygen through the lungs and skin
Reptiles and Mammals: Oxygen-poor blood flows through the pulmonary circuit to pick up oxygen through the lungs - 14Amphibian Circulatory system (5)3 chambered heart (2 atria, 1 ventricle)
-ventricle pumps blood into forked artery that splits the ventricle's output into 1) pulmocutaneous circuit and 2) systemic circuit
-heart re-pressurizes blood after it passes through capillary beds of lungs or skin so blood flow to brain, muscles and organs is high
-when underwater, pulmonary flow (lungs) is off
-underwater, gas exchange occurs at the cutaneous level - 15Reptile Circulatory System (2 types, 2 facts each)-turtles, snakes and lizards
-3 chambered hearts: 2 atria and 1 ventricle partially divided by an incomplete septum
alligators, caimans, crocodilians
-septum divides the ventricles but pulmonary and systemic circuits connect where arteries exit the heart - 16Mammalian Circulatory system (4)-mammals and birds
-4 chambered heart w/ 2 atria and 2 ventricles
-L side of the heart pumps and recipes only oxygen-rich blood, while R side receives and pumps only oxygen-poor blood
-mammals and birds are endotherms, require more O2 than ectotherms because of metabolic needs - 17T or F: Mammalian cardiovascular system meets the body's continuous demand for O2 through coordinated cycles of contractionsTrue
- 18Blood flow in mammals (7 steps)1) R ventricle pumps blood to lungs via pulmonary arteries (only arteries with DEOXY blood)
2) in lungs, blood loads O2 and unloads CO2
3) OXY blood from lungs enters heart at left atrium VIA pulmonary veins (only veins with OXY blood)
4) left ventricle pumps blood to body via aorta
5) aorta provides blood to heart through coronary arteries
6) Blood returns to heart via superior vena cava (head neck and arms) and inferior vena cava (trunk and legs)
7)Superior vena cava and inferior vena cava flow into right atrium - 19The mammalian heart (2 parts)-2 atria w/ thin walls (collection chambers for blood returning to heart)
-2 ventricles- thicker walls -contract forcefully - 20The Cardiac Cycle (4)heart contracts and relaxes in rhythmic cycle
Consists of 2 phases:
Systole (contraction phase): pumping
Diastole (relaxation): filling - 213 phases of cardiovascular cycle (3)1) Atrial and Ventricular Diastole: relaxation phase- blood flows into atria (.4 sec)
2) Atrial systole and Ventricular Diastole: Atrial Contraction- all remaining blood into ventricles (.1 sec)
3) Ventricular Systole and Atrial Diastole: .3 sec - 22What prevent back flow of blood in the heart?Valves
- 23Atrioventricular valves (AV valves)separate atrium and ventricle
- 24Semilunar ValvesControl blood flow to aorta and the pulmonary artery
- 25Heart Rate (2)(pulse)
-number of beats per minute - 26Stroke VolumeThe amount of blood pumped in a single contraction
- 27Cardiac Output (2)The volume of blood pumped into the systemic circulation PER MINUTE
-dependent on heart rate and stroke volume - 28What causes the "lug-dup" sound of a heart beat? What causes a heart murmur?The recoil of blood against the AV valves (lub) then against the semilunar (dup) valves.
-the backflow of blood through a defective valve can cause a heart murmur - 29What are autorhythmic cardiac muscle cells??Cardiac muscle cells that contract without any signal from the nervous system
- 30Sinoatrial (SA) node (2)(Pacemaker)
-it sets the rate and timing at which cardiac muscle cells contract - 31What does an electrocardiogram do? (ECG or EKG)Records impulses that travel during the cardiac cycle
- 32The 4 steps of controlling heart rhythm?1)Impulses from SA node travel to the AV node
2) at the AV node, the impulses are delayed
3) Bundle branches pass signals to heart apex
4) Apex of heart spreads signals throughout the Purkinje fibers to make the ventricles contract - 33How is the pacemaker regulated? (4)By two pts of nervous system: sympathetic and parasympathetic
-Sympathetic Division Speeds up the pacemaker
-Parasympathetic Division slows down the pacemaker
-The pacemaker is also regulated by hormones and temperature - 34Blood vessel structure and function (4)-CENTRAL LUMEN- a vessel's cavity
-ENDOTHELIUM- The epithelial layer that lines blood vessels
-Endothelium is smooth and minimizes resistance
-Capillaries are only slightly wider than a red blood cell - 35Capillaries vs Arteries vs Veins (4)Capillaries: endothelium and basal lamina
Arterias and Veins: endothelium, smooth muscle, connective tissue
Arteries: Thicker valls than veins (accommodate high pressure of blood from heart)
Veins: Thinner walls and blood flows back to the heart as result of muscle action - 36Blood Flow Velocity (2)-blood flow is slowest in the capillary beds, as a result of high resistance and large, total cross-sectional area
-blood flow in capillaries is necessarily slow for exchange of gases waste - 37Blood pressure (4)-flows from high pressure to lower pressure
-the pressure that blood exerts in all directions, including against blood vessel walls
-recoil of elastic arterial walls helps maintain blood pressure
-resistance to blood flow in narrow diameters of tiny capillaries and arterioles dissipates much of the pressure - 38Systolic PressureThe pressure in the arteries during ventricular systole (pumping)- the highest pressure in the arteries
- 39Ventricular SystolePumping
- 40DiastoleFilling
- 41Diastolic PressureThe pressure in the arteries during diastole (filling) - lower than systolic pressure
- 42PulseThe rhythmic bulging of artery walls with each heartbeat
- 43Regulation of Blood Pressure (3)-Regulated by diameter of arterioles
-Vasoconstriction = the contraction of smooth muscle in arteriole walls - increases blood pressure
-Vasodilation = the relaxation of smooth muscles in the arterioles - it decreases blood pressure - 44Blood pressure and gravity-generally measured for artery in arm at heart's height
-healthy = 120 mm Hg/70 mm Hg
-gravity has significant effect - 45Blood returns to the heart through veins by (3 and note)smooth muscle contraction
skeletal muscle contraction
expansion of vena cava during inhalation
Note: 1-way valves in veins prevent back flow of blood - 46Capillary Function-Blood in only 5-10% of body's capillaries at a time
-in major organs, usually filled to capacity
-blood flow can be diverted to muscles and skin to regulate body temperature during exercise
-blood flow can be directed to digestive tract after a meal - 47Capillary Blood Flow2 mechanisms regulate distribution of capillary beds
1) Constriction or dilation of arterioles that supply capillary beds
2) Pre-capillary sphincters that control flow of blood btw arterioles and venules - 48What is blood flow regulate by? (3)Nerve impulses, hormones and other chemicals
- 49Exchange btw blood and interstitial fluid (3)-across thin endothelial walls of capilaries
-most blood proteins and blood cells = too large to pass through endothelium
-blood travels along capillary from arterial to venous end, higher blood pressure compared to osmotic pressure drives fluid out of the capillary - 50Lymphatic System (5)-returns fluid that leaks out from the capillary beds
-Lymph = fluid lost by capillaries
-drains into veins in the neck
-Lymph vessel valves prevent black flow of fluid
-Edema = swelling cause by disruptions in the flow of lymph - 51Lymph Nodes (2)Organs that filter lymph
-when body is fighting an infection, lymph nodes become swollen and tender - 52Blood Composition (3)Blood= a connective tissue consisting of several kinds of cells suspended in a liquid matrix called plasma
-cellular elements = 45% of blood volume (White and red blood cells and platelets)
-plasma = 55% of volume of blood (water, ions, plasma proteins, nutrients, wastes, gases) - 53Functions of Blood (5)1) Transport System- transorts dissolved gases, nutrients, hormones, and metabolic wastes
2) Regulates the pH and ion levels of interstitial fluid- eliminates local deficiencies or excesses
3) Clotting- restriction of blood loss at sites of injury, temporary patch
4) Defense- contains cells that fight infection
5) Stabilization of body temperatures- absorbs excess body heat and distributes heat - 54Blood plasma composition (3 components)92% water
7% proteins
1% other: organic nutrients, wastes, ions and electrolytes - 55What are 2 important ways that plasma is different from interstitial fluid?1) Levels of dissolved gases (O and C fluctuate more)
2) Plasma proteins- too large to be exchanged across capillary walls- so not found in interstitial fluid (gives plasma 5x viscosity) - 56Plasma Proteins (1 and 4 classes)1) 90% of plasma proteins are produced by liver- so liver disorders can affect blood composition
4 classes
1. Albumins (60%)
2. Globulins (35%)
3. Fibrinogen (4%)
4. Other specialized proteins (1%) - 57Albumins (2)Major contributors to blood viscosity and osmotic pressure of plasma
-help with pH buffering of plasma - 58Immunoglobulins (Antibodies)Help attack viruses and other pathogens
- 59Apolipoproteins (2)Transport proteins that escort lipids like fatty acids, steroid hormones and thyroid hormones
-lipids are insoluble in water and can travel in blood only when bound to transport proteins - 60Fibrinogen (3)-important in blood clotting
-serum is blood plasma after removal of clotting factors
-under certain conditions (injury to blood vessel wall) fibrinogen forms large, insoluble fibers called FIBRIN , leaving behind SERUM and removing Ca2+ - 61Cellular (Formed) ElementsSuspended in blood plasma are 2 types of cells
1) Red blood cells (erythrocytes) transport O2
2) White blood cells (leukocytes) function in defense
Platelets- fragments of cells that are involved in clotting - 62Erthrocytes (5)Red blood cells
-most numerous blood cells
-contain hemoglobin (iron-containing protein that transports o2)
-each molecule of hemoglobin binds up to 4 O2 molecules
-In mammals, mature erythrocytes lack nuclei and mitochondria - 63Erythrocytes (4)-bi-concave disc shape
-allows flexibility to move through capillaries
-allows large ratio of sa/volume
-cells can stack together for easier movement - 64Erythropoiesis-RBC production
-occurs in red bone marrow (sternum, vertberae, rips, scapula, skull, etc.)
-stimulated by erythropoietin (EPO) a peptide hormone released by kidneys
-Hematocytoblasts->->erythrocytes - 65Hemoglobinglobular, quaternary protein- in great quantities
-makes up 95% of molecules in RBC
-needs amino acids, iron, vitamin B6 and vitamin B 12 to work properly - 66Mammalian erythrocytes (4)-@ maturity have no nucleus and no organelles except cytoskeleton
-do not replicate DNA or synthesize proteins at all
-get energy from glucose in blood plasma via glycolysis
-life span is ~120 days, they get engulfed by phagocytes when damaged - 67Hemoglobin (5)-made of 4 subunits- 2 alpha and 2 beta chains
-each subunit has a heme group (ring surrounding an iron ion)
-interacts reversibly with O2 and CO2
Dooxyhemoglobin + O2 <-> oxyhemoglobin
Deoxyhemoglobin + CO2 <-> carbaminohemoglobin - 68Hemoglobin's Function (2)@ Lungs- absorbs O2 and releases CO2
@peripheral tissues/capillaries- absorbs CO2 and releases O2 - 69Anemia (3)Inability to deliver adequate O2 to tissues. Weekness and lethargy will result if
1) Red blood cell count is low
2) Hb content of RBC is inadequate - 705 Major Types of White Blood Cells (Leukocytes) Where? What?Monocytes, Neutrophils, Basophils, eosinophils, and lymphocytes
-found both inside and outside of blood vessels
-function in defense by phagocytizing bacteria and debris or by mounting immune responses against foreign substances - 71Leukocytes (6)-have nucleus and organelles
-no hemoglobin
-mostly in connective tissue or lymphatic system
-help defend the body against pathogens
-remove wastes, toxins and abnormal cells
-use the bloodstream for rapid transport - 72Leukocyte Characteristics (4)-capable of amoeboid movement
-Emigration: can migrate in and out of bloodstream into tissues
-Positive chemotaxis towards damage
-Capable of phagocytosis- neutrophils, eosinophils and monocytes engulf pathogens and wastes - 73Divide Leukocytes by type of defenseNonspecific: Neutophils, eosinophils, basophils, monocytes
Specific: Lymphocytes - 74Neutrophils "neutral" granules (4)-50`70% of WBC
-2-5 lobes in nucleus
-highly mobile- first to arrive at injury sight
-engulf invadors in a vesicle -> increase metabolic rate-> manufacture H202 and superoxide anion - 75NEUTROPHILS pt 2 (3)-have digestive enzymes that fuse w/ vesicle and digest foreign invader
-releases prostaglandins- increases capillary permeability to cause inflammation, to help block the spread of infection
Leukotrienes: hormones that attract other immune cells and phagocytes to assist - 76Eosinophils (6)-nucleus w/ 2 lobes
-2-4% of WBC
-Attack w/ toxins, NO and cytotoxic enzymes
-attack multicellular parasites like worms, flukes and protozoa
-attack bacteria by phagocytosis
-release enzymes to reduce inflammation - 77Basophils (5)-less than 1% of WBC
-releases chemicals to damage tissues:
Histamine- dilates blood vessels to cause inflammation
Heparin- prevents blood clotting
Other Chemicals: to attract other WBC to the area - 78Monocytes (5)2-8% of WBC
-large and spherical
-nucleus like kidney bean
-very aggressive phagocytes
-Release chemicals to 1) attract other phagocytes and 2) attract fibroblasts (which produce scar tissue) - 79Lymphocytes (3)-20-30% WBC
-located in tissues but can migrate to blood stream
-survive a long time - 803 Types of Lymphocytes1) T cells- cell-mediated immunity
-attack foreign cells and control other lymphocytes
2) B cells- humoral immunity
-produce, secrete, distribute antibodies in defense
3) NK cells- immune system surveillance
-Detect and destroy abnormal (cancer) cells