Animal Body Systems (Ch. 42 - Circulation & Gas Exchange (Circulation,…
Animal Body Systems
Ch. 42 - Circulation & Gas Exchange
Carries blood away from the heart to the rest of the body
Carries blood towards the heart from the rest of the body
Very small, exchanges oxygen, nutrients & wastes from the blood to the tissues. Receive arterial blood from heart and are the starting point for venous blood going to the heart.
Water balance by bringing water to and from tissues, pH by interacting with both bases and acids in the body
Gases, nutrients, waste
Components of blood
Plasma - the liquid that contains RBCs and WBCs
Red blood cells (erythrocytes)
Carry oxygen from lungs to rest of body
White blood cells (leukocytes)
Fight infections, aid in immunity
Help in blood clotting
The pressure of circulating blood on blood vessel walls
Pressure when the heart pushes blood
Pressure when the heart relaxes
Types of circulatory systems
Common in arthropods & molluscs
Pumps blood into a hemocoel with blood diffusing back into the circulatory system through cells. The blood fills body cavities.
Common in vertebrates
Blood is closed at all times within vessels and does not fill body cavities.
Blood only passes through the heart once throughout circulation.
Blood passes through the heart twice throughout circulation.
Types of hearts
Closed circulatory system, 2-chambered: 1 ventricle and 1 atrium
Closed circulatory system, 4-chambered: 2 atria and 2 ventricles
Closed circulatory system, 3-chambered heart: 2 atria and 1 ventricle
Open circulatory system, blood flows freely throughout the body
Colorless fluid that contains white blood cells (leukocytes)
Gas exchange occurs through the alveoli in the lungs
Oxygen is extracted from water and carbon dioxide is excreted
When the diaphragm contracts, the thoracic cavity's volume increases and allows the lungs to take in air and vice versa
Help to form and expand chest cavity
Closing off the nostrils and forcing air into the body
Diaphragm contracts, increasing volume in lungs
Ch. 44 - Osmoregulation & Excretion
Fluid passing through a semi-permeable membrane from a lower concentration to a higher concentration
Freshwater vs. Marine mammals
Retain more salt in their bodies than the water around them
Lose water to environment due to osmosis, must drink a large amount of saltwater to maintain a stable osmotic pressure
What is osmoregulation?
Maintaining a constant osmotic pressure in fluids by controlling concentrations of water and salt
Contains subunits named nephrons that filter blood and remove waste
Excretes waste through urine
Excretes waste into bile or blood, where it will enter the intestine and leave the body through feces
Wastes travel through here and are excreted as feces
Sabaceous glands; sweating excretes excess water and salt
What organisms produce...
Invertebrates and aquatic species
Mammals, including humans
Uric acid wastes?
Birds and reptiles
What is excretion?
Elimination of waste matter from the body