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Prentice Hall Science Explorer Human Biology and Health Chapter 3

Terms in this set (80)

Cardiovascular System
a system carries needed substances to cells and carries waste products away from cells; consists of the heart, blood vessels, and blood
*Cardiovascular System: Wastes
picks up wastes from cells:
- the cardiovascular system carries carbon dioxide (produced by cells) to the lungs, where it is exhaled
*Cardiovascular System: Disease
transports cells that attack disease-causing microorganisms
- helps you from becoming sick/helps you get well
*Blood
most substances that need to get from one part of the body to the other are carried by the blood
*What is Blood Made of?
plasma, red blood cells, white blood cells, and platelets
*What Does Blood Carry?
- transports glucose that your cells use to produce energy
- carries oxygen from lungs to other body cells
Heart
a hollow, muscular organ that pumps blood throughout the body.
*About Heart
- each time heart beats, it pushes blood through the blood vessels of the cardiovascular system
- heart = cardiac muscle: contracts over and over without getting tired
- when blood leaves heart, it travels through arteries
*Heart: Structure
- right and left sides are separated by the septum
- each side has two compartments/chambers
Septum
a wall of tissue that separate the left and right side of heart so the bloods don't mix
Atrium
upper chambers of the heart that receives blood that comes from the heart
*About Atrium
- separated from ventricles by valves
- when the heart relaxes, blood flows into chambers, then atria contacts
- contraction squeezes blood out of atria, through valves, and into ventricles
*Right Atrium
receives blood from the body that is low in oxygen and high in carbon dioxide
*Left Atrium
receives oxygen-rich blood from the lungs
Ventricle
lower chambers of the heart that pumps blood out of heart
*About Ventricles
- contracts to allow the heart to beat
- the force exerted by ventricles contracting pushes blood out of the heart
- contraction of l. ventricle exerts more force than the contraction of the r. ventricle
*Right Ventricle
pumps oxygen-poor blood to the lungs
*About Right Ventricle
pumps blood into arteries that go to lungs
*Left Ventricle
pump oxygen-rich blood to all parts of the body
*About Left Ventricle
pumps blood into aorta - smaller arteries branch off the aorta
Valve
a flap of tissue that prevents blood from flowing backward.
*Location of Valve
located between ventricles and large blood vessels that carry blood away from heart
Pacemaker
a group of heart cells that sends out signals that make the heart muscle contract.
*About Pacemaker
location: right atrium of the heart
constantly receives messages about the body's oxygen needs, then adjusts heart rate to match
*Loop One
blood travels from the heart to the lungs then back to the heart
*Loop Two
blood is pumped from the heart throughout the body and returns again to the heart
*Pattern of Blood Flow
right side: pumps blood to lungs
left side: pumps blood to rest of body
blood travels in one direction
Artery
a thick, blood vessel that carries blood away from the heart
*About Artery
- when blood leaves the heart, it travels through arteries
- after blood goes through arteries, it flows into capillaries
- 3 cells thick
- strength and flexibility; can withstand enormous pressure of blood pumped by heart
*Artery: Inner Layer
epithelial cells: smooth; allows easy blood flow
*Artery: Middle Layer
thick, smooth muscle: regulates blood flow by contracting and relaxing
*About Artery: Middle Layer
- acts as a control gate by adjusting the amount of blood sent to different organs
- when muscle contracts, opening in artery becomes smaller (ex: running)
- when muscle relaxes, the opening becomes larger (ex: eating)
*Artery: Outer Layer
connective tissue: holds and supports vessels
Capillaries
thin, tiny, narrow vessels in which substances/materials are exchanged between the blood and the body cells
*About Capillaries
- after blood flows through capillaries, it flows into veins
- materials can easily pass through capillaries
ex: oxygen and glucose pass from blood, through capillaries, to the cells
- 1 cell thick
*Capillaries: Single Layer
epithelial cells: movement of nutrients and waste into and out of the cells and bloodstream, that is, diffusion
Veins
a larger blood vessel that carries blood back to the heart
*About Veins
after blood from capillaries flows through veins, the veins carry the blood back to the heart
*Factors That Helps Blood Move Through Veins
- contraction of skeletal muscles near veins
- larger veins have valves
- breathing movements, which exert squeezing pressure on veins in the chest
*Veins: Inner Layer
epithelial cells: smooth; allows easy blood flow
*Veins: Middle Layer
thinner, smooth muscle: moves blood toward heart
*Veins: Outer Layer
connective tissue: holds and supports vessels
*Larger Veins
valves: prevents blood from flowing backward
Aorta
the largest artery in the body that carries oxygen-rich blood from the left ventricle to the rest of the body
*Phase 1 of Heart
heart muscle relaxes and heart fills with blood
*Pumping Phase
- blood flows into chambers, then the atria contract, which squeezes blood out of atria, through the valves, and into the ventricles
- ventricles contract, which closes valves between atria and ventricles, making "lub" sound and squeezes blood into large blood vessels
- as valves between ventricles and blood vessels snap shut, they make "dup" sound
*Phase 2 of Heart
heart muscle contracts and pumps blood forward
Coronary Artery
branches from arteries that carry blood to the heart itself
*About Coronary Artery
- other branches carry blood to the brain, intestines, and other organs
- each artery branches into smaller and smaller arteries
Pulse
the artery in your wrist that rises and falls repeatedly caused by alternating expansion and relaxation of the artery wall
*Steps of the Pulse
- heart's ventricles contract, sending a spurt of blood out through all the arteries in your body
- spurt travels through arteries and pushes artery walls and makes them expand
- after spurt passes, artery wall relaxes and becomes narrower again
Diffusion
the process by which molecules move from an area of higher concentration to an area of lower concentration
*About Diffusion
one way materials are exchanged between blood and body cells
ex: glucose: more highly concentrated in blood than in body cells - glucose diffuses from blood into body cells
Blood Pressure
a force, caused by the force with which the ventricles contract
*About Blood Pressure
- as blood moves away from the heart, blood pressure decreases
- blood pressure in arteries farther from the heart is much lower
- blood flowing near heart arteries exerts a high blood pressure
- can be measured with sphygmomanometer
Plasma
the liquid part of the blood in which water makes up 90% of this substance with other 10% being dissolved materials
*About Plasma
- most materials transported in blood travel in the plasma
- carries chemical messengers that direct body activities
ex: carries nutrients such as glucose, fats, vitamins, and minerals
*3 Groups of Plasma Proteins
protein molecules give plasma yellow color
1. helps regulate the amount of water in the blood
2. (produces by white blood cells) helps fight disease
3. interacts with platelets to form blood clots
Red Blood Cells
blood cells that take up oxygen in the lungs and deliver it to cells elsewhere in the body; produced in bone marrow
*About Red Blood Cells
- thin in the middle; can bend and twist easily: flexibility enables them to squeeze through narrow capillaries
- allows you to use oxygen
*Mature Red Blood Cells
have no nuclei, thus they cannot reproduce/repair
Hemoglobin
an iron-containing protein that binds chemically to oxygen molecules; makes up most of the red blood cells
*About Hemoglobin
- with oxygen: cells become bright red
- without oxygen: cells become dark red
- picks up oxygen, and releases it as blood; picks up carbon dioxide produced by cells
White Blood Cells
blood cells that fights disease; produced in bone marrow
*About White Blood Cells
- fewer than red blood cells
- larger than red blood cells
- contains nuclei
Platelets
cell fragments that play an important part in forming blood clots
*About Platelets
- platelets release chemicals that start a chain reaction, eventually producing fibrin
- when more platelets and blood clots become trapped in the net (produced by fibrin), it becomes a blood clot
*Blood Transfusion
the transfer of blood from one person to another
*Fibrin
a protein that weaves a net of tiny fibers across the cut in a blood vessel
*Rh Factor
the pressure of other proteins on red blood cells that determines if blood type is Rh positive or Rh negative (with or without Rh marker)
Lymphatic System
a network of veinlike vessels that return fluid that leaks out of blood vessels to the bloodstream; filters carbon dioxide out of blood
Lymph
the fluid that the lymphatic system collects and returns to the bloodstream; consists of water and dissolved minerals, and some white blood cells that have left the capillaries
*About Lymph
- lymphatic vessels connect to large veins in chest
- lymph empties into these veins and fluid becomes part of blood plasma
Lymph Node
small knobs of tissue that filter the lymph, trapping bacteria and other disease-fighting microorganisms in the fluid
Atherosclerosis
a condition in which an artery wall thickens as a result of the buildup of fatty materials (cholesterol); artery with smaller space in the middle
*About Atherosclerosis
- results in a reduced flow of blood to the affected artery
- can develop in coronary arteries (supplies heart muscle), thus heart receives less blood and less oxygen (heart attack)
Heart Attack
occurs when blood flow to part of the heart muscle is blocked; cells die in the part of the heart that doesn't receive blood & oxygen
Hypertension
a disorder in which a person's blood pressure is consistently higher than normal; also called high blood pressure
*About Hypertension
- makes the heart work harder to pump blood throughout the body; may damage walls of blood vessels
- "silent killer"
*Treatment for Hypertension and Atheroscleosis
regular exercise, a diet low in trans fats, cholesterol, saturated fats, and sodium, and avoid smoking
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