General Information

• What makes a circulatory system necessary?-small organisms lack a circulatory system because diffusion is a sufficient means for exchanging gases and transporting materials-larger organisms need circulatory system because all of their cells are not in direct contact with the environment and they need to transport substances made in one part of organism to other areas

• What are makes up human circulatory system?-heart, blood vessels, and blood

Functions of Circulatory System

• Delivery jobs:-nutrients -oxygen -water and vitamins -hormones

• Pick up jobs:-CO2 and carry to lungs-wastes and carry to kidneys

• Other jobs:-maintain homeostasis (body temp.)-protect body from disease

Composition of Blood

• 55% plasma, 45% cells

Composition of Blood

• Plasma: -non-living -90% water-10% proteins, waste, dissolved gases, salts, nutrients, and hormones-3 Types Plasma Proteins:

1) albumin – regulates osmotic pressure, transports fatty acids, hormones, vitamins2) globulin – helps fight infection

(antibodies)3) fibrinogen – helps clot blood

Composition of BloodCellular Portion

• Red blood cells -“erythrocytes” -transport oxygen -contain hemoglobin protein that carries iron which binds with oxygen

• People with iron poor diets become anemic. Iron aids in production hemoglobin.

Composition of BloodCellular Portion

• White blood cells -“leukocytes” -destroys pathogens -makes antibodies -stored in spleen, tonsils, lymph nodes

• -Leukemia is cancer of white blood cells (abnormal division of WBC’s).

Composition of BloodCellular Portion

• Platelets -cell fragments-useful clotting blood

• *Hemophiliacs problems with blood clotting = excessive bleeding

• *Stroke is an abnormal blood clot blocks blood flow to areas of brain

Blood Clotting

• Platelets contact edge of broken blood vessel “stick”= platelet plug

• Platelets release clotting factor called thromboplastin converts prothrombin thrombin

• Thrombin (enzyme) converts fibrinogen fibrin

• Fibrin filaments create a “sticky mesh” acting like a net catching RBC to stop bleeding

Blood Vessels

• Blood travels through the body inside of vessels (closed circulatory system)

• 3 Types of blood vessels1) Arteries -carry

O2 rich blood away from the heart -thick walls to with stand pressure -largest artery is aorta

2) Veins -carry O2 poor blood back toward heart-contain valves help keep blood moving to heart (varicose veins)-largest vein is vena cava

Blood Vessels cont.

3) Capillaries-connect veins and

arteries -extremely thin, only 1 cell thick-O2/nutrients diffuse from here into tissues and CO2/wastes diffuse back into here

Blood Vessels

Human Heart

• Muscular organ- pumps blood

• Enclosed in a protective sac called pericardium

Structures of Heart

• Mammals have a 4 chambered heart• Atria (atrium)- “upper chambers”

collect blood coming to heart• Ventricles- “lower chambers” pump

blood out of the heart• Chambers separated by valves-

prevent blood from flowing backwards• Septum- thick muscle divides right/left

halves

Flow of Blood Through Heart

• Right Side (oxygen-poor)-enters vena cava-collects in the right atrium

-through tricuspid valve-into right ventricle-carried by pulmonary arteries to lungs

***Pulmonary artery is the ONLY artery in the body that carries oxygen poor blood

Flow of Blood Through Heart

• Left Side (oxygen-rich)-leaves lungs, carried to heart

by pulmonary veins-enters left atrium -through bicuspid valve

into left ventricle-forced into

aorta, carried rest of body

Heartbeat

• Muscle fibers through out heart stimulate contraction

• Right atrium (sinoatrial node) sends electrical impulses that starts wave of muscle contraction = pacemaker

• Ventricular node receives contraction impulse and wave and spreads through ventricles

Pathways of Circulation

• Pulmonary circulation- carries blood between heart and lungs

• Systemic circulation- carries blood from heart to rest of the body

Blood Pressure• Measure of the force blood against

the walls of arteries• Pressure helps blood circulate body• Systolic- measures force blood in

arteries when ventricles contract• Diastolic- measures force blood in

arteries when ventricles relax• Healthy blood pressure reading is

about 120/80

Cardiovascular Disease

• Disease of heart and blood vessels• High levels of blood lipids may indicate high

risk of heart disease.• Cholesterol is a lipid.• 2 Types Cholesterol:

-LDL “bad cholesterol” deposits on walls of arteries = “plaque”

-HDL “good cholesterol” carried back to liver for removal from body

• Atherosclerosis- condition caused by build up fatty deposits on wall arteries

• Hypertension- condition in which blood pressure is constantly too high

• Both conditions put person increased risk for heart attack and stroke

Lymphatic System

• Network of vessels, nodes, and organs • Function:

1) collects fluid lost by blood and returns back to circulatory system2) filter fluid3) Absorb fats and vitamins from digestive tract and carry them to blood

Components of Lymphatic System• Lymph = “fluid”• Lymph vessels –

collect fluid and return to vena cava (circulatory system)

• Edema- swelling due to blocked lymph vessels

• Lymph nodes- filter and trap bacteria and other microorganisms

• “Swollen glands”• Thymus and Spleen

Respiratory System

• Respiration- process of gas exchange (carbon dioxide/oxygen) between the cells, blood, and lungs and environment

• Structures of Respiratory System:1) Nose2) Trachea (pharynx/larynx)3) Bronchi4) Lungs

Mechanism for Breathing

• Involves the movement air into and out of lungs • Diaphragm- muscle separates thorax (chest

cavity) and abdomen helps inhale and exhale air

• Pathway air flow and gas exchange:1) Air enters the nose and mouth

(filtered, moistened, warmed)2) Pharynx and larynx (vocal cords)3) Trachea (wind pipe)4) Bronchi (large tube leads to each lung)5) Lungs bronchioles aveoli (air sacs where gas exchange occurs)

Structure of Lungs