The Circulatory System
Which activity caused the pulse rate to increase the most? The activity that was the most rigorous.
What is the relationship between physical activity and pulse rate? Increased physical activity causes an increased pulse rate.
Why do you think activity caused the heart to pump faster? The muscles need more oxygen and need to get rid of waste faster. The heart pumps faster to get more blood to the muscles.
The Circulatory System Made up of (organs): heart blood vessels (veins and arteries) blood smooth muscle cardiac muscle
Main Functions Moves needed materials around the body glucose oxygen water lipids Carries waste away from the cells carbon dioxide lactic acid urea Contains disease fighters
The Heart Hollow, muscular organ that pumps blood throughout the body size of your fist located in the center of the chest
Structure of the Heart The heart has two sides Each side has an upper chamber Atrium Each side has a lower chamber Ventricle
Structure of the Heart Blood enters the heart through the atria From the body – right atrium From the lungs – left atrium Blood leaves the heart through the ventricles To the body – left ventricle To the lungs – right ventricle
How the Heart Works
How the Heart Works The heart’s action has two phases The heart relaxes and the atria fill with blood The atria contract, blood is pumped into the ventricles, then the ventricles contract and send blood out of the heart Blood only travels in one direction, it cannot flow backwards
Regulation of the Heartbeat The heart contains pacemaker cells that tell the heart when to beat When you are exercising, excited, scared etc…, your heart beats faster When you are relaxed, calm, asleep etc…, your heart beats slower
Blood Vessels Blood vessels transport blood around your body They run through all the tissue in your body Some are as wide as your thumb Some are as small as a hair
Arteries Carries oxygen rich blood away from the heart The ventricles of the heart pump into the arteries to get blood to the rest of your body As arteries get further from the heart, they branch and get smaller and turn into arterioles
Artery walls are very thick, strong and flexible They contain smooth muscle that contracts or relaxes to let more or less blood through
Arteries
Regulating Blood Flow The muscles in the middle layer are involuntary smooth muscles When they contract, the artery becomes smaller When they relax, the artery becomes larger
Regulating Blood Flow When an organ needs more blood, the arteries relax to let more flow in Food in your stomach triggers your arteries going to the stomach to relax so more blood is sent there During exercise, the arteries to your stomach contract and the arteries to your legs and arms relax
Capillaries Arterioles turn into capillaries Tiny blood vessels where material is exchanged between the blood and the body’s cells Oxygen and glucose rich blood from the arteries goes into the capillaries From the capillaries needed materials pass into the cells and waste material is removed from the cells
Capillaries
Veins Capillaries then connect to venules Venules widen into veins The veins carry oxygen poor blood back to the heart Blood with carbon dioxide and other cellular wastes pass from the capillaries into the veins
Veins have 3 layers to their walls too but the wall is much thinner Muscle contractions, breathing and valves help move blood through veins
Veins
Oxygen rich blood from an artery Oxygen poor blood from a vein
Functions of the Blood Carries oxygen from lungs to all body cells and removes carbon dioxide from the cells Red blood cell White blood cell http://commons.wikimedia.org/wiki/File:Red_White_Blood_cells.png http://commons.wikimedia.org/wiki/File:Thoracic_anatomy.jpg
Red Blood Cells Contains hemoglobin that carries oxygen disk shape helps them fit into capillaries They have 4 month life span New red blood cells are produced in bone marrow
Functions of the Blood Carries waste products of cell activity to the kidneys to be removed from the body http://commons.wikimedia.org/wiki/File:Red_White_Blood_cells.png http://openclipart.org/people/gmad/nerka.svg
Functions of the Blood Transports nutrients from the digestive system to body cells http://commons.wikimedia.org/wiki/File:Red_White_Blood_cells.png http://commons.wikimedia.org/wiki/File:Digestive_system_whitout_labels.svg
Red Blood Cells there is a rare condition where hemoglobin is replaced by methemoglobin red blood cells can’t carry much oxygen creates blue skin
Functions of the Blood Materials in the blood help fight infection and heal wounds (white blood cells and platelets). White blood cell: fights foreign invaders Platelets: help blood form clots http://commons.wikimedia.org/wiki/File:Red_White_Blood_cells.png http://commons.wikimedia.org/wiki/File:Giant_platelets.JPG
White Blood Cells larger than rbc’s they can leave the blood stream and enter into tissue 13-20 day lifespan they fight disease
Platelets irregularly shaped and colorless they help the blood form clots to stop bleeding 5-10 day lifespan
Body systems that work with the circulatory system; muscular system (cardiac muscle) helps pump blood respiratory systems provides oxygen for the cells digestive system provides energy excretory system helps remove wastes
Which two substances does the blood transport away from body cells? Oxygen & carbon dioxide Carbon dioxide & waste Nutrients & waste Oxygen & nutrients 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
What parts of the blood help fight off disease and heal injuries? White blood cells & platelets Red blood cells & platelets White blood cells & red blood cells White blood cells & plasma 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Which is not a function of the circulatory system? Carry nutrients & oxygen to body cells Carry carbon dioxide & waste away from body cells Attack disease-causing bacteria Produce chemicals that control body processes 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31