Cardiovascular and Respiratory Systems

The Cardiovascular System

• A fluid transport system consisting of the heart, blood vessels, and blood.

• Transports substances to and from the body’s cells, including:

  • Oxygen

  • Carbon dioxide

  • Nutrients

  • Hormones

  • Waste products

  • Immune system cells and proteins

  • BP; 120/80 is arteries, 120 systolic hesart contact, clood ejected into arteries, 80 diastolic — relaxed need to fill with no blood,which represents the pressure in the arteries when the heart is at rest. This blood pressure reading reflects the health of the cardiovascular system and can indicate potential risks for heart disease or other conditions when elevated.

  • capillary blood prrssure would be 30-60 , then in the vein bp 10-20

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Composition of Blood

• Two primary components:

  • Cellular elements: blood cells and cell fragments.

  • Blood plasma: fluid portion in which cellular elements are suspended.

Cellular Components of Blood

• Three kinds of cellular components:

  • Red blood cells

  • White blood cells

  • Platelets

• Stem cells in bone marrow produce the cellular components of blood.

• Composition breakdown:

  • Cellular elements: 45%

    • Red blood cells: 99.9%

    • White blood cells: 0.1%

    • Platelets

  • Plasma: 55%

    • Water: 92%

    • Plasma proteins: 7%

    • Other solutes: 1%

Functions of Cellular Elements

• Red blood cells: Carry oxygen to and carbon dioxide from every part of the body.

• White blood cells: Central to the immune system.

• Platelets: Important in the blood-clotting process.

Blood Plasma

• 92% water, also contains proteins, nutrients, hormones, wastes, etc.

• Fibrinogen: A plasma protein that aids in blood clotting.

• Blood clot: platelets + net made up of the protein fibrin, which forms a patch over the damaged area.

Blood Vessels (Vascular System)

• Arteries: Blood vessels carrying blood away from the heart.

• Veins: Blood vessels returning blood to the heart.

• Capillaries: Smallest blood vessels connecting arteries with veins.

• Walls of veins are thinner and less elastic than walls of arteries.

• Blood pressure in veins is much lower than blood pressure in arteries.

• Veins contain one-way valves to prevent backflow of blood; skeletal muscles contract to move blood back to the heart.

• Capillaries are the sites of exchange of gases and other materials between blood and body tissues; connect arteries with veins.

• Capillaries are composed of only a single layer of cells, allowing movement of blood-borne materials into and out of them along their length.

The Heart and Blood Circulation

• Two blood circulation loops in the body:

  • Pulmonary circulation: Blood circulates between the heart and the lungs (blood is oxygenated).

  • Systemic circulation: Blood circulates between the heart and the rest of the body (materials transported to and from all parts of the body).

• The human heart contains 4 muscular chambers:

  • 2 for pulmonary circulation (right atrium and right ventricle).

  • 2 for systemic circulation (left atrium and left ventricle).

• Valves ensure that blood flows only one way through the heart.

• The pace at which the human heart beats is controlled by a specialized set of muscle cells that are located within the heart itself.

• These cells, which form the heart’s sinoatrial node, generate electrical signals that prompt heart muscles to contract.

Heart Attacks

• Nearly 20% of all deaths in the United States today are caused by the blockage of one or more of the coronary arteries that supply heart tissue with blood.

• Normally caused by a buildup of plaque in the wall of a coronary artery (followed by a movement of plaque into the bloodstream, and the formation of a blood clot).

• A heart attack occurs when this process results in the complete blockage of a coronary artery (which cuts off the blood supply to groups of cells within the heart, thus killing them).

• Stroke: blood clot blockage occurs in artery bringing blood to the brain, causes death of brain tissue.

The Respiratory System

• Central function: capture oxygen and dispose of carbon dioxide.

• Aids in controlling pH balance in the bloodstream and in producing sounds for speaking.

• Components:

  • The nose, nasal cavity, and mouth

  • Pharynx (throat)

  • The conducting passageways (bronchi and bronchioles) that lead to the lungs

  • Larynx (voice box)

  • Trachea (windpipe)

  • Lungs (composed of alveoli, the air exchange chambers of the body)

Steps in Respiration

• Breathing or ventilation: Physical movement of air into and out of the lungs.

  • Inhalation: Elevation of rib cage and contraction of diaphragm decrease pressure in the lungs, causing air to flow in.

  • Exhalation: Depression of rib cage and elevation of diaphragm increase pressure in lungs causing air to flow out.

  • Diaphragm: dome-shaped muscle that when it contracts it flattens and increases the chest cavity volume

• Gas exchange: The enormous surface area of the alveoli and their associated capillaries is used for the exchange of oxygen and carbon dioxide.

  • Oxygenated blood then moves to the heart, the heart pumps oxygenated blood to body tissues.

  • Oxygen diffuses into the interstitial fluid and then into nearby cells.

  • The carbon dioxide produced in the body’s cells moves into nearby capillaries, to be carried to the lungs.

  • Once in the lungs, oxygen diffuses across the thin wall of an alveolus into an adjacent capillary and binds with hemoglobin protein in red blood cells.

Human Organ Systems

• Humans have 11 major organ systems including:

  • Skeletal system

  • Circulatory system

  • Endocrine system

  • Nervous system

  • Respiratory system

  • Lymphatic/Immune system

  • Digestive system

  • Urinary system

  • Muscular system

  • Reproductive organ system

  • Integumentary organ system (skin, hair, etc.)