Circulatory System & Respiratory System Chapter 30

Evolution of the Circulatory System Originally Marine animals simply diffused gases and nutrients through their body surface As complexity and terrestrial habitat evolved a pump system formed

Open System vs. Closed System Hemolymph held within a body cavity Hemolymph held within a body cavity Blood diffuses through wall of the blood vessels Single loop- gills, two chambered heart Double loop- lungs

Different forms of Closed Systems

Transports fluid throughout the body Role in Homeostasis –T–T–T–Transports O2, CO2, nutrients, waste, hormones, and immune components Function of the Circulatory System

Blood- 45% cells, 55% plasma Plasma- 90% water, fibrinogen erythrocytes - red blood cells, contain hemoglobin carries oxygen leukocytes- white blood cells, fight infection Blood Vessels Artery - thicker Vein Capillaries - porous walls Cardiovascular System consists of

Flow of blood through the Heart Oxygen poor blood from the body enters the right atrium and travels through the tricuspid valve to the right ventricle where it is pumped into the lungs Oxygenated blood from the lungs enters the left atrium where it flows to the left ventricle through the mitral valve, from there it is pumped throughout the body It is thicker! Why?

The Circulatory System CO2 rich blood enters the lungs via the heart O2 rich blood is carried to the heart then transported by arteries throughout the body The capillaries are where the nutrients and wastes are exchanged between the blood and the cells Veins take the CO2 rich blood back to the heart Arteries Veins

Diseases of the Cardiovascular System Atherosclerosis- Buildup of plaque on walls of arteries Hypertension- high blood pressure, forces heart to work harder Heart Attack Stroke- blood clot from atherosclerosis breaks free and gets stuck in a blood vessel leading to or in brain

The Respiratory System

Evolution of the Respiratory System Diffusion of gases requires a thin moist membrane Larger the surface area, the larger the amount of gases exchanged Invertebrate Lungs Vertebrate Lungs

The Respiratory System Purpose is to bring about the exchange of O2 and CO2 The gases are transported throughout the body by the circulatory system Oxygen is bound on hemoglobin, this increases the carrying capacity of the blood by more than 60 times Oxygen enters the capillaries and Carbon Dioxide leaves

Organs of the Respiratory System Site of gas exchange Warms, humidifies, and filters the air Passage way for food and air Lined with cilia and mucus

Gases diffuse through the capillary membrane at the alveolus

The physiology of breathing The diaphragm (C) contracts and causes a change in pressure in the lungs The diaphragm (C) contracts and causes a change in pressure in the lungs Warmed filtered air comes down the trachea (A) Warmed filtered air comes down the trachea (A)

Asthma

Facts on Asthma 1 in 7 children 1 in 12 adults Nine million children under the age of 18 have asthma Most common form is allergic asthma Non allergic form appears during exercise, cold, dry, or polluted air

A city dwellers lung A smokers lung with cancer Why you should not smoke Smoking paralyzes the cilia in the bronchioles Smoking paralyzes the cilia in the bronchioles