CIRCULATORY SYSTEM
Dec 28, 2015
FUNCTIONS
Transports oxygen and nutrients to the cells
Transports carbon dioxide and other waste for elimination from the body
Maintains homeostasis of the body cells
3 MAIN PARTS
1. Heart
2. Blood
3. Blood vessels – arteries and veins*** Veins: carry blood back to the heart Arteries: carry blood from heart to body
tissues (when you take your pulse, you are checking one of these sights)
Capillaries: smallest blood vessels that connect the veins and arteries
SIMPLE VS. COMPLEX ANIMALS
Simple animals do NOT have a circulatory system. The exchange of materials and waste occur by diffusion across the main body cavity and cells. Example: Cnidarians
Complex Animals have either an open or closed circulatory system.
OPEN CIRCULATORY SYSTEM
The heart pumps blood into open-ended blood vessels.
The blood is pumped from the heart, through the vessels, and it “bathes” the tissues
Example: Grasshopper (Insects)
CLOSED CIRCULATORY SYSTEM
The hearts pumps the blood only through blood vessels which carry the blood to all the body tissues and then back to the heart.
Examples: Annelids, Mammals
Insect:Open Circulatory System
Annelid:Closed Circulatory System
Heartlikestructures
Bloodvessels
Heartlike structure
Small vessels in tissues
Bloodvessels
Hearts
Heart
Sinusesand organs
Open & Closed Circulatory Systems
Fish has a 2
chambered heart
Amphibian has a 3
chambered heart
Mammal has a 4
chambered heart
SINGLE LOOP VS. DOUBLE LOOP SYSTEM
2 CIRCUITS THAT BLOOD TRAVELS
(DOUBLE LOOP SYSTEM)1. PULMONARY CIRUIT: A short loop where
blood is carried between your heart and lungs. In your lungs the blood absorbs oxygen and releases carbon dioxide. Then the oxygenated blood returns to the heart.***
2. SYSTEMIC CIRCUIT: Carries oxygenated blood to all other body cells then the blood releases oxygen to the cells and picks up carbon dioxide and other wastes and returns to the heart.
Your heart is basically 2 pumps, one for each circuit.
CHARACTERISTICS OF YOUR HEART
It is about the size of your fist. It is located beneath the sternum and
near the center of your chest. It is a hollow organ with thick walls
made of cardiac muscle. It is surrounded by a double walled sac
called the pericardium. It has 2 sides separated by a thick wall
called a septum. It has 4 chambers.
Figure 42.5 The mammalian heart: a closer look
Superior
PulmonaryTricuspid
Inferior
Aortic
Mitral
Septum
PARTS OF THE HEART AND THEIR FUNCTIONS
The atria (right atrium and left atrium) are at the top of the heart and the RECEIVE blood.
The Ventricles (right ventricle and left ventricle) are at the bottom of the heart and the PUMP BLOOD OUT.
Valves keep the blood moving in the correct direction.
The right side of the heart carries the deoxygenated blood.
The left side of the heart carries the oxygenated blood.
Figure 42.4 The mammalian cardiovascular system: an overview
Flow of blood through the heart:
Deoxygenated blood
right atriumright ventricle
pulmonary arterypulmonary vein
left atriumleft ventricle
aortabody
BLOOD PRESSURE
Caused by the force with which the ventricles contract.
Measured with a sphygmomanometer (blood pressure cuff)
A healthy adult should have a blood pressure of 120/80Top number is systolic pressure, the
force felt in the arteries when the ventricles contract
Bottom number is diastolic pressure, the force felt in the arteries when the ventricles relax.
BLOOD COMPONENTS
55% PLASMA (a straw colored fluid) 45% Blood Cells
Plasma 90% water 10% dissolved minerals
Blood cells Red blood cells- transport oxygen and get
their color from hemoglobin (an iron containing protein)***
White blood cells- fight disease Platelets- help in blood clotting
Watch This…
http://www.youtube.com/watch?v=KBIdcUxdgo0