The Cardiovascular System
A fluid transport system that consists of the heart, all the body's blood vessels, the blood, and the bone marrow tissue in which red blood cells are formed.
Transports substances (oxygen, carbon dioxide, nutrients, vitamins, hormones, waste products, and immune system cells and proteins) both to and from the body's cells.
Can be compared to a car's cooling system.
Two primary components of blood:
1. Formed elements: red and white blood cells and platelets (red blood cells is 99% of formed elements)
2. Blood plasma: fluid portion of blood in which the formed elements are suspended
Three kinds of formed elements
1. Red blood cells: carry oxygen to, and carbon dioxide from, every part of the body. (Oxygen in blood is carried in hemoglobin.) (AKA erythrocyte)
2. White blood cells: central to the immune system.
3. Platelets: central to the immune system. Made of fragments of cells rather than a complete cell
Components of plasma
3 classes of plasma proteins?
92% water, proteins, nutrients, ions (electrolytes).
1. Albumins, transport hormones and fatty acids
2. Fibrinogen, aids in blood clotting
3. Globulins, aid the immune system and serve as transport proteins
Have no red blood cells! (quiz question)
Water + plasma proteins = 99% of plasma
Low-density lipoproteins (LDLs) carry lipids to bodily tissues from the liver and small intestines.
High-density lipoproteins (HDLs) carry lipids from these tissues to the liver.
Low levels of LDLs and high levels of HDLs is the healthiest.
Arteries: blood vessels carrying blood away from the heart
Veins: blood vessels returning blood to the heart.
Inner layer of epithelial cells, middle layer of smooth muscle, outer layer of connective tissue.
The smallest blood vessels: capillaries, connect arteries with veins. Composed of a single layer of cells, water-tight.
Two blood circulation loops
1. Pulmonary circulation: Blood circulates between the heart and the lungs (with the result that blood is oxygenated).
2. Systemic circulation: Blood circulates between the heart and the rest of the body (with the result that needed materials are transported to and from all parts of the body).
Four muscular chambers of the heart
Two for pulmonary circulation (the right atrium and right ventricle).
Two for systemic circulation (the left atrium and left ventricle).
Heart beat pace control
Heart beat pace is controlled by a specialized set of muscle cells located in the heart, form the heart's sinoatrial node, generate electrical signals that prompt heart muscles to contract.
20% of deaths in U.S. caused by the blockage of the coronary arteries which supply heart tissue with blood.
Blockages caused by:
1. buildup of plaque in the wall of a coronary artery, caused by inflammation of lining where LDLs have attached
2. a movement of plaque into the bloodstream
3. formation of a blood clot.
A heart attack = complete blockage of a coronary artery, which cuts off the blood supply to groups of cells within the heart, thus killing them.
A heart murmur would be associated with the malfunction of the atrioventricular valves.
Capillary beds: delivery vehicles of the cardiovascular system
Arteries near heart --> smaller arterioles --> capillary beds --> feed back into body's system of veins --> returns blood to heart
Fluid that leaks out of capillaries is pulled back to the end of the capillary bed by higher osmotic pressure in the capillaries.
Venules drain blood from a capillary bed.
The Respiratory System
Respiration: the exchange of gases between the atmosphere outside the body and the cells within it.
During gas exchange, oxygen and carbon dioxide always move down their concentration gradients.
the nose, nasal cavity, and sinuses
the pharynx (upper throat), larynx (voice box), trachea (windpipe)
conducting passageways: bronchi/bronchioles
the lungs: composed of tiny hollow sacs called alveoli
compose lungs, lie at the end of each bronchiole and act as air exchange chambers. Enormous surface area of alveoli is used for exchange of oxygen and carbon dioxide.
Steps of respiration
1. Ventilation (breathing)
2. Once in lungs, oxygen diffuses across the thin wall of an alveolus into an adjacent capillary and binds with hemoglobin protein in red blood cells.
3. Oxygen then moves with the blood cells to the heart.
4. Heart pumps blood to body tissues, where the oxygen diffuses into the interstitial fluid and then into nearby cells.
5. Carbon dioxide produced in the body's cells moves into nearby capillaries, to be carried to the lungs.
6. All the oxygen loaded into red blood cells binds initially with the hemoglobin in them.
7. Carbon dioxide is transported both within red blood cells and in blood plasma.
8. Hemoglobin has a great capacity to bind to carbon monoxide as well as to oxygen.
True or False
When the thoracic cavity gets smaller, the pressure inside the lungs increases.
Blood consists entirely of blood cells and water.
The trachea branches into left and right bronchioles.
The formed elements account for about what percentage of the total volume of blood?
When a doctor uses a stethoscope to listen to your heart and hears the lub-dub sound, she is actually listening to the:
valves in the heart closing.
Which vein in the body carries oxygenated blood?
Why do new RBCs only survive for a few months?
Red blood cells do not have most organelles or a nucleus.
The coronary arteries that bring blood to the heart branch off from the:
contains deoxygenated blood
Which chamber of the heart is connected to the aorta?
Blood pressure increases when the diameter of an artery decreases.
Medication in order to lower blood pressure relaxes the smooth muscles in the arteries.
Why is the left side of the heart stronger than the right side of the heart?
The right side pumps only to the lungs, and the left side pumps blood around the whole body.
physical movement of air into and out of the lungs
Pulmonary ventilation occurs because of pressure differences between the lungs and the external environment.