Chapter 37: Circulatory and Respiratory Systems

Circulation: Structure and Function Consists of heart, blood vessels, and blood TRANSPORTATION Cells need to get nutrients and oxygen and get rid of wastes

Heart: parts Hollow muscular organ that pumps blood Enclosed by a protective layer called the pericardium The thick layer of muscle is called the myocardium Upper chambers are called the atria (where blood collects) Lower chambers are the ventricles (muscular chambers from which blood exits)

Heart terminology Veins go to the heart Arteries go away from the heart Capillaries join the two and bring blood close to cells Pulmonary circulation refers to blood going to and from the lungs Systemic circulation refers to circulation to the rest of the body One-way valves in the heart keep circulation efficient

Blood Flow through the Heart Low oxygenated blood flows into the right atrium through the superior and inferior vena cava As the heart contracts the blood flows into the right ventricle and out the pulmonary arteries (to the lungs) Oxygenated blood flows into the left atrium through the pulmonary veins As the heart contracts the blood flows into the left ventricle and out the aorta to the rest of the body See page 945

Blood vessels Arteries: Super highways, large, and muscular Carry oxygenated blood (except pulm. art.) Veins: Large and muscular contain valves and return blood to heart Capillaries: Smallest with walls only one-cell thick Bring oxygen and nutrients to tissues and absorb CO2 “Side streets and alley ways”

Blood Body contains about 4-6 liters 45% consists of cells Red blood cells called erythrocytes transport oxygen (hemoglobin) White blood cells called leukocytes fight infection Platelets are cell fragments that aid in clotting 55% consists of straw colored fluid called plasma 90% water Contains albumins, globulins, and fibrinogen

Lymphatic System Consists of a network of vessels, nodes, and organs that collects fluid that is lost by the blood and returns it to the circ. sys. The fluid is called lymph and travels in vessels and sometimes collect in lymph nodes (p 955) which can act as filters The thymus and spleen contribute to fighting infections along with the lymphatic system

Summary

Respiratory System Function: to bring about exchange of oxygen and carbon dioxide between the blood, air and tissues Parts: Air flows from the mouth and nose into the pharynx, larynx (voice box), then trachea, bronchus tubes, bronchioles, and finally alveoli (air sacs surrounded by capillaries) Cilia and mucus act as filters along the pathway

Respiratory System diagram

Breathing Movement of air into (inspiration) and out of (expiration) the lungs Process is driven by air pressure (p 959): When diaphragm contracts, air comes in When diaphragm relaxes, air is exhaled

Cellular Respiration O2 + C6H12O6  CO2 + H2O and ATP