Quiz!! Everyone’s going to rock this part of the day. Finally finishing the Digestive System As completely interesting as it is, it has to end sometime. Commencing the Circulatory System Types and functions, along with homework questions Something exciting!! Hopefully we have time to get to this part!!

An Introduction

Open Circulatory System Common in molluscs and arthropods The heart pumps the blood into body cavities Blood then diffuses back to heart between cells Blood passes from: HeartTissuesHeart

Closed Circulatory System Common in earthworms, squids, octopi, and vertebrates At all times, blood moves in a continuous, closed pathway within vessels of different sizes

Closed Circulatory System Blood passes from: Heart Arteries Arterioles Capillaries VenulesVeins

Types of Circulatory Systems Open Circulatory System Closed Circulatory System

Types of Circulatory Systems Circulatory System of a Sponge Sponge is composed of two cell layers Seawater acts as a transport system, carrying nutrients and removing wastes Nutrients and wastes diffuse across cell membranes

Types of Circulatory Systems Circulatory System of a Snail Open circulatory system

Types of Circulatory Systems Circulatory System of an Earthworm Closed circulatory system

Functions of a Circulatory System 1. Transport Gases Water Nutrients (i.e.: glucose) Wastes (i.e.: ammonia) Hormones Enzymes Salts 2. Maintain Water Content Stabilizes ionic water concentration of body fluids

Functions of a Circulatory System (cont’d) 3. Control Body Temperature Transports heat 4. Protects Against Disease Transports white blood cells (WBCs) that engulf and destroy foreign invaders

Monitoring Your Pulse Walking or mild exercise will increase your heart rate by 20% - 30%. For those in good health, increased energy demands during extreme exercise can raise the heart rate to an incredible 200 beats per minute. Although few individuals can sustain such a rapid heart rate, it indicates the capacity of the heart to adjust to changing situations.

Monitoring Your Pulse While sitting still, place your index and middle finger near your wrist, as shown here. The pulse you feel is blood rushing through the brachial artery in your arm. Count the number of heartbeats in 30 s. Record your pulse rate at rest and then calculate the heart rate as beats per minute.

Monitoring Your Pulse Remain sitting quietly and place your index finger and middle finger on the side of your neck. You will feel blood pulse through the carotid artery, which is an artery that carries blood to the head. Take your pulse rate for 30 s and then calculate the heart rate for 1 minute.

Monitoring Your Pulse After running for two minutes, we will be taking our pulse immediately afterwards. Use either the brachial artery or the carotid artery. Record your heart rate. Compare the strength of the pulse in the carotid artery with that in your arm Compare your heart rate before and after the exercise Do you think the difference between resting heart rate and the heart rate after the exercise would be greater for athletes? Explain your answer.

Questions to Answer 1. Describe the main functions of the circulatory system. 2. Differentiate between an open and a closed circulatory system. 3. Identify one advantage and one disadvantage of an open circulatory system. 4. Describe the similarities and differences between the circulatory systems of sponges, snails, and earthworms.

Bill Nye Enjoy  our topic (or his topic) is Blood Circulation Woot woot!!