THE HEART http://www.youtube.com/watch?v=0Vn5AJ_Mjfs&NR=1 http://www.youtube.com/watch?v=m50596VvDPg&feature=related
K1. Identify & give functions for the following: • Left and right atria • Left and right ventricles • Coronary arteries and veins • Anterior and posterior vena cava • Aorta • Pulmonary arteries and veins • Pulmonary trunk • Atrioventricular valves • Chordae tendinaea • Semi-lunar valves • Septum UNIT K: HEART STRUCTURE & FUNCTION(Ch. 13, pp. 228-233)
K2. Describe the location and functions of the SA node, AV node, and Purkinje fibers K3. Describe the autonomic regulation of the heartbeat by the nervous system K4. Relate factors that affect and regulate blood pressure to hypertension and hypotension K5. Demonstrate the measurement of blood pressure K6. Distinguish between systolic and diastolic pressure
VOCABULARY _____ Inferior Vena Cava _____ Medulla oblongata _____ Pacemaker _____ Pulmonary artery _____ Pulmonary circuit _____ Pulmonary trunk _____ Pulmonary valve _____ Pulmonary vein _____ Purkinje fibres _____ SA node _____ Semi-lunar valve _____ Septum _____ Superior Vena Cava _____ Systemic circuit _____ Vagus nerve _____ Ventricle _____ Aorta _____ Aortic valve _____ Atrioventricular (AV) valves _____ Atrium _____ Autonomic nervous system _____ AV node _____ Blood pressure _____ Brachial artery _____ Bundle of His _____ Chordae tendineae _____ Constrict _____ Coronary arteries _____ Coronary veins _____ Dilate _____ Hypertension _____ Hypotension _____ Hypothalamus
Hold out your hand and make a fist. • During an average lifetime, the human heart will beat more than 2.5 billion times. • Even at rest, the muscles of the heart work twice as hard as the leg muscles of a person sprinting Amazing Heart Facts • Put your hand on your heart. Where is it? size of heart:child = 1 fist; adult = 2 fists! • Your heart beats about 100,000 times in one day and about 35 million times in a year.
In one day, the blood travels a total of 19,000 km. That's 4 times the distance across CANADA from coast to coast. • When you are resting, it takes 35-40 seconds for the blood to move through your body. What about when you are exercising? • How much does your heart weigh? • Give a tennis ball a good, hard squeeze. You're using about the same amount of force your heart uses to pump blood out to the body approximately 10 seconds only 2/3 of a pound!
1 • Transports carbon dioxide and hydrogen ions to the lungs to be removed 2 • Fights infections 4 • Transports oxygen from the lungs to body to be used • Transports nutrients from the small intestine to tissues 3 Basic Functions of the Circulatory System
5 • Carries waste products (ie: urea) to kidneys for removal in urine 6 • Transports water from the digestive system to the body and lungs • Distributes body heat from internal source to skin (to get rid of it) • Seals wounds by forming blood clots 7 8
10 11 • Maintains pH in tissues (acts as a buffer with HHb) Regulates fluid levels in tissues (with Lymphatic system) • Transports hormones around the body 9
The Parts You Need To Know!
The human heart has 4 well developed chambers • Right Atrium • Left Atrium • Right Ventricle • Left Ventricle
The right side of the heart pumps deO2blood to the lungs. PULMONARY The left side of the heart pumps O2blood to the body SYSTEMIC
Left Atrium Right Atrium ATRIA the receiving chambers Receives oxygenated blood from the lungs via the pulmonary veins Receives deoxygenated blood from the body via the anterior & posterior vena cava.
Tricuspid Valve Bicuspid Valve ATRIOVENTRICULAR VALVES 1. Separate the atria from the ventricles. 2. They open when the atria contract. 3. They prevent the blood from going backwards when the ventricles contract.
bicuspid valve tricuspid valve
CHORDAE TENDINAE Tendon-like pieces of tissue They keep the AV valves from inverting when the ventricles contract
They hold & support the chordae tendinae PAPILLARY MUSCLE
Can’t open properly Open Closed Can’t close properly Normal Heart Valves Heart Murmur
Right Ventricle VENTRICLES the sending chambers • When the right atrium contracts, it pushes the blood through the tricuspid valve and into the right ventricle. • When the RIGHT VENTRICLE contracts, BP forces the TRICUSPID valve to close. • The BP forces PULMONARY VALVE open & the blood moves into the PULMONARY TRUNK.
The PULMONARY ARTERIES take the deO2 blood to the lungs. The CO2 is removed from the blood and is replaced with O2. AT THE LUNGS The PULMONARY VEINStake the O2 blood to the heart.
What carries the Oxygen? The protein HEMOGLOBIN binds the O2 tightly and carries it to the body cells as OXYHEMOGLOBIN!
SEPTUM separates the 2 sides A muscular wall that separates the right side of the heart from the left side. Keeps the deO2 blood from mixing with the O2 blood
hole in the septum Some people are born with a hole in their septum
Left Ventricle • When the left atrium contracts, it pushes the blood through the bicuspid valve and into the left ventricle. • When the LEFT VENTRICLE contracts, the BICUSPID VALVE is forced closed. • Blood is forced through the AORTIC VALVE and enters the AORTA. • The left ventricle has a THICKERmuscle layer. WHY?
Aortic Arch Dorsal Aorta • To the head AORTA • To the arms & lungs • Coronary Artery: to the heart • To the lower body the biggest artery The aorta takes O2 blood to the body.
CORONARY ARTERIES & VEINS The first branches of the aorta take the blood to the coronary arteries. Takes blood into the heart muscle itself. The coronary veins return the deO2 blood to the vena cava right atrium.
Superior Vena Cava Inferior Vena Cava VENA CAVA These are the BIGGEST VEINS! They bring the deO2blood back to the heart so that it can be pumped to the lungs.
Aortic Arch Superior vena cava Pulmonary Trunk Coronary artery Right Atrium Coronary Vein Right Ventricle Left Ventricle Inferior Vena Cava exterior view of the heart
draw the arrows Aortic Arch Superior Vena Cava Left Pulmonary Artery Right Pulmonary Artery Pulmonary Trunk Left Pulmonary Veins Right Pulmonary Veins Left Atrium Bicuspid (AV) Valve Right Atrium Pulmonary (semi-lunar) Valve Aortic (semi-lunar) Valve Left Ventricle Tricuspid (AV) Valve Right Ventricle Inferior Vena Cava Dorsal Aorta
CONTROL OF HEART FUNCTION
Why can a heart keep beating outside of the body? ?
Coordination of the Beating • Heart cells naturally beat slowly if ATP is present • If there was no coordination, the heart cells would all beat randomly Beating Human Heart: http://www.youtube.com/watch?v=iX6HnUyzgQ0&feature=related http://www.youtube.com/watch?v=GgPe3k-lK8c&feature=related
How Does The Heart Work to Pump The Blood • There are two spots of specialized tissue in the heart. • Both are located in the right atrium. • Nodal tissue is unique: made of specialized muscle cells combined with nerve cells. • It has the ability to contract independent of other stimuli.
The SA NODE (sino-atrial) SA NODE • This node is found along the wall of the right atrium chamber. • It fires on average, every 0.85 seconds (or 72 times per minute). • It stimulates the simultaneous contraction of the atria. • It also sends a nerve impulse along a nerve trunk called the BUNDLE OF HIS to the AV NODE
S A NODE
The SA node initiates the heartbeat and has been given the nickname of the “PACEMAKER” PACEMAKER a small electronic device that stimulates the SA node to fire http://www.youtube.com/watch?v=CxJS0oEQeBQ People with irregular heartbeats may have to have an artificial pacemaker ‘inserted’.