THE CIRCULATORY SYSTEM

The Circulatory System Importance in large multicellular organisms: transport various substances between: ■ external environment (outside body) & internal environment (cells) ■ cells & other cells

The Circulatory System Transports substances such as: 1.nutrients:  digested nutrients, vitamins, minerals, water 2.gases:  O 2 from lungs to tissues (cells)  CO 2 from tissue (cells) to lungs 3.wastes & toxins: taken to...  liver to be broken down  to kidneys to be filtered out

The Circulatory System 4.parts of the immune system  white blood cells  antibodies

THE HUMAN CIRCULATORY SYSTEM

Main components: 1.blood – fluid transportation medium 2.heart – muscular organ that pumps blood 3.blood vessels – tubes to carry blood Human Circulatory System

Blood is a TISSUE consisting of: 1. cells – such as red blood cells & white blood cells (45%) 2. plasma – fluid part of the blood (55%) Blood

Divided into 4 chambers: Right atrium: collects blood from body and heart itself Right ventricle: pumps blood to the lungs Left atrium: collects blood from lungs Left ventricle : pumps blood to body and heart itself Human Heart Acts as a double-pump

Right atrium Right ventricle Human Heart Left atrium Left ventricle

1.Arteries carry oxygenated blood away from the heart* 2.Veins carry deoxygenated blood to the heart * 3. Capillaries (for exchange) bring oxygen & nutrients to tissues take carbon dioxide & other wastes away Blood Vessels * except in the lungs

DO NOT COPY If all the arteries, veins, and capillaries in the human body were placed end to end total length would equal more than 100,000 km could stretch around the earth nearly two and a half times On average, a single red blood cell takes roughly 30 seconds to complete a full circuit through both the pulmonary and systemic circulation One minute is enough to circulate all the blood once around the body Human Circulatory System - Interesting Facts

TRANSPORT IN OTHER ANIMALS

1. closed circulatory system: blood remains inside the vessels or the heart of the animal at all times (more efficient) all vertebrates (i.e. humans, fish, birds, amphibians, reptiles) some invertebrates (i.e. earthworm) 2. open circulatory system: circuit of vessels is incomplete & circulating fluid pours out of the tubes into the body cavity results in slow moving pools of blood that bathe the animal’s tissues & exchange materials with the cell heart(s) continuously pump to return blood to the vessel (less efficient) all other invertebrates (i.e. crayfish, lobster, insects, spiders) Two Main Types of Circulatory Systems

closed circulatory system three main vessels supply the blood to organs within the earthworm 1. aortic arches (5) – function like a human heart (pump) 2. dorsal blood vessels – carry blood to the front of the body 3. ventral blood vessels – carry blood to the back of the body Earthworm Circulatory System

closed circulatory system two-chambered heart composed of one atrium & one ventricle (simple) blood is pumped from the heart to the gills, where it receives oxygen and gets rid of carbon dioxide blood then moves on to the organs of the body, where nutrients, gases, and wastes are exchanged single cycle circulation Fish Circulatory System

closed circulatory system three-chambered heart, consisting of two atria and a single ventricle blood leaving the ventricle has an equal opportunity to travel to the lungs or to the rest of the body blood returning to the heart from the lungs passes into one atrium, while blood returning from the rest of the body passes into the other both atria empty into the single ventricle oxygenated & deoxygenated blood mixes in the single ventricle (therefore organs are not getting blood saturated with oxygen) Frog Circulatory System

Comparison (Fish, Frog, Human) FISH FROG HUMAN

Homework Page 106 # 5, 6 Page 107 # 4 Circulatory System Homework Sheet (# 1 – 10)