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Muscles. So exciting . Muscle Control. Involuntary Muscle : not under conscious control Ex: heartbeat, digestion Voluntary Muscle : Under your control Ex: walking, jumping, dancing…. Types of Muscles. Smooth Locations: Walls of hollow organs (Stomach, lungs etc.)
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Muscles So exciting
Muscle Control • Involuntary Muscle: not under conscious control • Ex: heartbeat, digestion • Voluntary Muscle: Under your control • Ex: walking, jumping, dancing…
Types of Muscles Smooth Locations: Walls of hollow organs (Stomach, lungs etc.) Blood vessels Eyes Skin Glands Not striated Uses: Food movement through digestive tract Regulation of blood vessel diameter Pupil dilation Emptying of bladder
Cardiac Location: Heart Striated Involuntary Uses: Pumps blood Major source that moves blood throughout the body
Skeletal Location: Attached to bones Striated Uses: Voluntary and involuntary movements
Types of MusclesTake NOTES!! • http://www.youtube.com/watch?v=bwOE1MEginA
Anatomy of a Muscle Cell • Take notes!!! • http://www.youtube.com/watch?v=uY2ZOsCnXIA
Skeletal Muscle Contraction Acetylcholine reaches the muscle cell Na+ gates on muscle open Muscle fires Ca2+ enters the muscle cell cytoplasm Ca2+ binds to troponin and tropomyosin Troponin moves away from the actin Myosin cross-bridges attach to actin Cross-bridges pull the actin Actin filaments slide past myosin ATP attaches to myosin cross-bridges Cross-bridges release Cross-bridges reattach
Let’s see it in Action! Take notes. • http://www.youtube.com/watch?v=e3Nq-P1ww5E • http://www.youtube.com/watch?v=hqynCsign8E
BLOOD AND THE HEART FUN FACTS ♦ An average adult human contains about 5 liters (5.3qt) of blood. ♦ The blood makes up about onethirteenth of the body’s weight. ♦ The adult heart weighs about 280 grams (10 oz.) ♦ At rest, the heart pumps out about 80 millimeters (2.6 oz) of blood with each beat. ♦ The heart beats, on average, 70 times each minute at rest. ♦ This means all the blood is circulated (goes round the body once) in about one minute. ♦ During strenuous exercise the heart can pump six to eight times the amount of blood that it pumps at rest.
Superior vena cava and inferior vena cava – bring deoxygenated blood to right atrium Pulmonary artery – takes blood away from right ventricle to the lungs for O2 Pulmonary veins – bring oxygenated blood from lungs to left atrium Aorta – takes blood away from left ventricle to rest of the body
Chambers and Valves • SEPTUM divides into R and L halves • Upper chambers – RIGHT ATRIUM and LEFT ATRIUM • Lower chambers – RIGHT VENTRICLE and LEFT VENTRICLE • Four heart valves permit flow of blood in one direction
TRICUSPID VALVE – between right atrium and right ventricle BICUSPID (MITRAL) VALVE – between left atrium and left ventricle Semilunar valves are located where blood leaves the heart - PULMONARY SEMILUNAR VALVE and AORTIC SEMILUNAR VALVE
The heart=a muscular double pump with 2 functions Overview • The right side receives oxygen-poor blood from the body and tissues and then pumps it to the lungs to pick up oxygen and dispel carbon dioxide • Its left side receives oxygenated blood returning from the lungs and pumps this blood throughout the body to supply oxygen and nutrients to the body tissues
Two circulations • Systemic circuit: blood vessels that transport blood to and from all the body tissues • Pulmonary circuit: blood vessels that carry blood to and from the lungs
Chambers of the heartsides are labeled in reference to the patient facing you • Two atria • Right atrium • Left atrium • Two ventricles • Right ventricle • Left ventricle --------------------------------------------------------------------------------
Valvesthree: tricuspidone: bicuspid (cusp means flap) • “Tricuspid” valve • RA to RV • Pulmonary valve • RV to pulmonary trunk (branches R and L) • Bicuspid valve (the bicuspid one) • LA to LV • Aortic valve • LV to aorta
Function of semilunar valves (Aortic and pulmonic valves)
Meet the Heart • http://www.youtube.com/watch?v=Vi1JK6IYVt8
Pattern of flow(simple to more detailed) Body to right heart to lungs to left heart to body • Body • RA • RV • Lungs • LA • LV • Boby Body, then via vena cavasto RA, to RV via tricuspid valve, then to lungs through pulmonary semilunar valve and via pulmonary arteries, then to LA via pulmonary veins, to LV via bicuspid, then to body via aortic semilunar valve and the aorta LEARN THIS
Cardiac Cycle Blood enters the atria through the vena cava (R) and the Pulmonary vein (L) ↓ Atria will contract ↓ Blood is pushed through the AV valves into the ventricles ↓ Ventricles contract and AV valves close ↓ Blood is pushed though the pulmonary and aortic semilunar valves into the pulmonary trunk and the aorta ↓ Ventricles relax and valves close
Cardiac Cycle Tutorial • http://faculty.alverno.edu/bowneps/cardiaccycle/cardiaccycle1map.htm
PHYSIOLOGY OF THE HEART The heart is a double pump. When the heart beats… Right Heart Deoxygenated blood flows into heart from vena Cava ---right atrium ---tricuspid valve--- right ventricle --pulmonary semilunar valve--- pulmonary artery ---lungs (for oxygen) Left Heart Oxygenated blood flows from lungs via pulmonary Veins--- left atrium--- bicuspid valve--- left ventricle--- aortic semilunar valve--- aorta --- general circulation (to deliver oxygen)
Electrical conduction system: specialized cardiac muscle cells that carry impulses throughout the heart musculature, signaling the chambers to contract in the proper sequence (Explanation in next slides)
Control of Heart Contractions SA (sinoatrial) NODE = PACEMAKER • Located in right atrium • SA node sends out electrical impulse • Impulse spreads over atria, making them contract • Travels to AV Node AV (atrioventricular) NODE • Conducting cell group between atria and ventricle • Carries impulse to bundle of His BUNDLE OF HIS • Conducting fibers in septum • Divides into R and L branches to network of branches in ventricles (Purkinje fibers) PURKINJE FIBERS • Impulse shoots along Purkinje fibers causing ventricles to contract
Flow Through the Heart • http://www.youtube.com/watch?v=7XaftdE_h60
Heart Contraction SA Node Sinalarterial node “Pacemaker” AV Node Atrioventricular node Allows impulse to cross into ventricles Purkinje Fibers Bundle of His Bundle Branches
Conduction system • SA node (sinoatrial) • In wall of RA • Sets basic rate: 70-80 • Is the normal pacemaker • Impulse from SA to atria • Impulse also to AV node via internodal pathway • AV node • In interatrial septum
Conduction continued • SA node through AV bundle (bundle of His) • Into interventricular septum • Divides R and L bundle branches become subendocardial branches (“Purkinje fibers”) • Contraction begins at apex
Heart Contraction Flow Chart SA Node fires ↓ Impulse spreads across atria ↓ Atria contract (lub) ↓ Blood is pumped to the ventricles ↓ AV Node receives impulse from SA Node ↓ Impulse passes through bundle of His ↓ Impulse passes through Purkinje fibers ↓ Ventricles contract (dub) ↓ Blood is pumped into the lungs and out to the body
EKG→ measures heart electricity P Wave→ Atria contract & Depolarize PQ Interval→ Impulse is passing through the bundle of His to the Purkinje fibers QRS Wave→ Ventricles depolarize and contract T Wave→ Ventricles repolarize