The Circulatory System. Part 2 Blood, Lymph and ETC. Composition of Blood. Blood will separate into two parts: 55% plasma (liquid) 45% blood cells (solid) (called Formed elements ). list the major components of plasma. Mostly water (92%) with MANY different dissolved substances:
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The Circulatory System Part 2 Blood, Lymph and ETC
Composition of Blood • Blood will separate into two parts: • 55% plasma (liquid) • 45% blood cells (solid) (called Formed elements)
list the major components of plasma • Mostly water (92%) with MANY different dissolved substances: • Nutrients – glucose, amino acids, vitamins, minerals • CO2,O2 • Blood proteins: i. Antibodies ii. hormones iii. clot-forming proteins. (fibrinogen) iv. Albumin (transports bilirubin) v. Globulins (the protein in lipoproteins) d. Salts: Na+, Ca+, K+, Mg+ e.wastes: urea
i. Antibodies -part of the immune system - help fight infections. Foreigner antibodies - tag the foreigners for the killer cells Killer Cells
ii. Hormones • Chemical messengers sent from brain to tell cells or organs what to do; travel via blood
iii. Clot-Forming Proteins- Fibrinogen • Work with platelets to form a thrombus (scab)
describe the shape, function, and origin of red blood cells, white blood cells, and platelets • A. Red Blood Cells • B. White Blood Cells • C. Platelets
Red Blood Cells • Aka. Erythrocytes • Source = stem cell • Disc-shaped • Hemoglobin has iron in it (makes your blood red!) • Delivers gases to and from cells
White Blood Cells • Aka. Leukocyte • Source = stem cells • Larger than RBC • Work together with antibodies to fight infections
Platelets • Aka. Thrombocyte • Source = stem cell • Fragment of larger cells • Clots blood(scab) Blood Clot
Review • Plasma: Water, nutrients, CO2, antibodies, hormones, clot-forming proteins • Blood Cells: RBC’s, WBC’s and Platelets
describe capillary-tissue fluid exchange • Determined by two forces: • Blood Pressure • Osmotic Pressure (the pressure that water feels to move according to the concentration gradient between the tissues and the blood osmotic vs hydrostatic pressure animation
At the arteriole end of the capillary: B.P. = 40mmHg O.P. = 25mmHg Net = 15mmHg Since BP exceeds OP, water, aa’s, and oxygen leave the capillary because they are forced (squeezed) out of the blood and into the cells. Blood cells and proteins are too large – they stay in the blood Moving through the Capillary
BP = 25mmHg OP = 25mmHg Net = 0 mmHg BP and OP are about equal in the middle of the capillary so diffusion causes the nutrients to leave the blood and enter the cells (following their concentration gradient) Wastes will diffuse out of the cells and into the blood at this point as well. Middle of Capillary
BP = 10mmHg OP = 25mmHg Net = 15mmHg (in the opposite direction!) Now OP is greater than BP, so water will move from the tissues and into the blood. Urea and carbon dioxide are also carried with the water Venule End of the Capillary
Lymphatic System 3 main functions: • transportof excess tissue fluid back to cardiovascular system • absorptionof fat from the intestine and transport to blood • fighting infection by distributing germ-fighting white blood cells= lymphocytes
identify and give functions of lymph capillaries, veins, and nodes • considered part of the circulatory systemsince it contains lymph, a moving fluid that comes from the blood and returns to the blood by way of the lymphatic vessels.
The lymphatic system is thus a secondary transport system. Lymph has no pump of its own. Its flow depends on pressure from the blood system, the massaging effect of the muscles and the one-way-valves in it’s vessels.
More water is forced out of the capillary at the arteriole end then re-enters at the venule end. The LYMPHATIC system vessels collect the extra water and return it to the blood at the duct connected to the subclavian vein 1. Excess fluid
2. Absorbs Fat • interstitial fluid, the lymph picks up particles too big to be absorbed through capillary, include: cell debris, fat globules, and tiny protein particles • lymph is filtered by the numerous white blood cells • fluid re-enters the blood through the subclavian vein.
3. Fighting Infection • The lymphatic system also distributes germ-fighting white blood cells. • Lymph resembles plasma • It is formed from bits of blood and other body liquids, called interstitial fluid that collect in the spaces between cells.
Lymph Organs • Lymph nodes – round structures located along lymph vessels (beneath armpits, base of jaw, groin ) • Filters lymph • Produce lymphocytes (WBC) which produce antibodies • Other lymph organs include tonsils, spleen, thymus gland
Blood and Body Temperature • Your blood vessels help control your body temperature by sending extra blood to your skin if you are hot OR by keeping extra blood AWAY from your skin to keep you warm • The capillaries DILATE or CONTRACT to control the blood flow
1. Altering Heart Rate 2. Altering Contactility(how hard it pumps) 3. Altering Blood Vessel Diameter (vasoconstriction or vasodilatation) 4. Altering Blood Volume (kidneys either re-absorb extra H2O or expel extra H2O) Regulation of Blood Pressure occurs by Four Mechanisms:
The Cardiovascular Centre in the Brain (a group of neurons scattered within the medulla) • - will regulate the heart rate using all of these mechanisms to varying degrees causing either an increase or decrease in BP. Hypertension = high blood pressure (over 120/80) Hypotension = low blood pressure (under 120/80)
Keeping your Circulatory System Healthy • Eat a healthy diet (try to keep the saturated fats and cholesterol, and salt levels low) • Get lots of sleep and exercise • Don’t smoke • Drink lots of water
Heart Rate • Average resting heart rate is 60-80 beats per minute (bpm) • The heart is a muscle – exercise makes it stronger • A highly conditioned aerobic athlete (ex. Long distance runner) will have a resting heart rate of 28-40 bpm. • When exercising, a good target range for heart rate in teens is between 150-190 bpm
High Blood Pressure • BP is higher than normal all of the time • Puts extra strain on the heart • Can cause capillaries to burst damaging heart, brain or kidney tissue • Is the leading cause of heart failure • Too much salt in the diet can cause HBP, as can excessive, long term stress
Some Factors that can affect BP: • Exercise: raises BP during exercise, but decreases BP after because the heart is stronger. • Sodium intake: Increases Blood Volume which increases BP • Ca++ and K+ intake: Decreases BP • Alcohol Consumption: Increases BP because in increases the acidity of the blood, which stimulates the CV centre to increase BP
Some more Factors that can affect BP: • Body Weight: Being overweight puts extra strain on the heart: increases BP • Smoking: increases BP • Stress: The autonomic NS thinks that you must prepare for a fight, therefore increasing the BP • Atherosclerosis: Decreases the diameter of vessels - therefore increasing BP • ETC.!!
Cardiovascular Centre • The CV centre receives sensory input from many different sources: 1. Higher brain centers(telling you to prepare for something) 2. Baroreceptors - monitoring blood pressure by using stretch receptors in the blood vessels 3. Chemoreceptors- monitoring O2 , CO2, and H+ concentrations in the blood