Cardiovascular System PDF

**CARDIOVASCULAR SYSTEM** - Delivers oxygen and nutrients to the body tissues and carries away wastes such as carbon dioxide via the blood. - If not working properly, waste products will build up in the tissues eventually once depleted with oxygen and the toxins accumulate, organs...

**CARDIOVASCULAR SYSTEM** - Delivers oxygen and nutrients to the body tissues and carries away wastes such as carbon dioxide via the blood. - If not working properly, waste products will build up in the tissues eventually once depleted with oxygen and the toxins accumulate, organs will dies. **STRUCTURES OF CARDIOVASCULAR SYSTEM** - Heart - pumps blood - Blood vessels - carry blood that transports oxygen, nutrients, among others, and also waste products to and from the cells. - TRANSPORTATION - the major function of the cardiovascular system. I. THE HEART - Size of a person's fist, hollow, cone-shaped, and weighs less than a pound. *The size and weight of the heart will give hints of its strength* - Enclosed within inferior mediastinum. *Mediastinum is the medial section of the thoracic cavity. It is a flank on each side by the lungs.* - Pointed apex, toward left hip, rests on diaphragm, at 5th ICS. - *5^th^ ICS - Left mid clavicular line is where one would place a stethoscope to count the heart rate for an apical pules.* - *PMI - point of maximum impulse* - Broad at the base, where great vessels emerge, toward right shoulder, beneath 2nd rib. - Apex is the superior of the heart, base is the inferior of the heart. COVERINGS AND WALLS - The heart is enclosed by a sac which we call the pericardium. **THREE LAYERS OF PERICARDIUM**: - Outer fibrous layer: Fibrous pericardium - helps protect the heart and anchors it to the surrounding structures such as the diagphram and the sternum. - Second and third layer: inner serous membrane pair the visceral and parietal layer. - Parietal - lines the interior of the fibrous pericardium. In the superior aspect of heart, this parietal layer attaches to the large arteries leaving the heart, then u-turn continously in the inferior of the heart's surface. - Visceral layer is also called the epicardium. This is part of the heart wall. The innermost layer of pericardium and the outermost layer of the heart wall. - Lubricating fluid - between the serous membrane that allows the heart to beat easily in a relatively frictionless environment as the serous pericardial layers slide smoothly across each other specially when the heart beats. **THE THREE LAYERS OF THE HEART WALLS:** - Epicardium - the visceral pericardium (described earlier) - Myocardium - consist of thick bundles of cardiac muscles. The layer that contracts. It is reinforced internally by a network of dense fibrous connective tissue which we call the skeleton of the heart. - Endocardium - thin glistening sheath of endothelium and lines the heart chambers. Its is continuous with the linings of the blood vessels leaving and entering the heart. Pulmonary circulation - Link by the heart - Involves the action of the lungs as it recieves an oxygenated blood from the pulmunary artery and sends oxygenated blood to the pulmonary vein. - Transition circulation = oxygenated to oxygenated blood Systemic circulation - Link by the heart - Involves all organ systems of the body as each cells receive oxygenated blood from the aorta.Ginagamit ito ng lahat ng cells to function, and then after ginamit yung oxygenated blood, the waste will now be sent back through the vena cava. - Transition of blood = oxygenated to unoxygenated blood  **CHAMBERS** - Chambers - Hollow Cavities - Atria - always the receiving or collecting chambers - Ventricles - the discharging or pumping chambers The superior atria are primarily receiving chambers which assist with filling the ventricles. ❤ Right Atrium = collects unoxygenated blood from systemic circulation (meaning galing sa mga body cells) ❤ Left Atrium = collects oxygenated blood from pulmonic circulation (means galing sa lungs) The inferior, thick-walled ventricles are the discharging chambers or pumps which contract so blood is propelled out of the heart. ❤ Right Ventricle = pumps unoxygenated blood to pulmonic circulation (papunta ng lungs) ❤ Left Ventricle = pumps oxygenated blood to systemic circulation (papunta ng body cells) - The atria/atrium are superiors - The ventricles are inferior **GREAT VESSEL** 1. ARTERIES: away from the heart ❤ Aorta carries oxygenated blood (from the left ventricle to the systemic circulation) \- *yung dugo na dala-dala ng aorta papunta sa lahat ng body cells.* ❤ Pulmonary Artery carries unoxygenated blood (connecting the right ventricle to the pulmunic circulation) *- yung dugo na dala-dala ng pulmunary artery ay papuntang lungs.* Both arteries are connected to ventricles: - Aorta - left ventricle - Pulmunary artery - right ventricle VEINS: towards the heart ❤ Vena Cava carries unoxygenated blood (connects the blood coming from the systematic circulation to the right atrium) -*galing sa body cells yung dala niyang dugo para makapasok sa heart* ❤ Pulmonary Vein carries oxygenated blood (connecting the pulmunary circulation to the left atrium) -*galing sa lungs ang dugo papasok ng heart* Both veins are connected in the atria: - Vena cava - right atrium - Pulmonary vein - left atrium - Systemic Circulation - Blood flow from aorta to vena cava, oxygenated to unoxygenated blood. - - Pulmonic Circulation - Blood flow from pulmonary artery to pulmonary vein, unoxygenated to oxygenated - - *The left side of the heart is systematic pumpand the right side of the heart is pulmonic pump.* - *Right side of the heart denotes blue because of unoxygenated blood* - *Left side of the heart denotes color red because of oxygenated blood.* **VALVES** - There are 4 valves - Allow blood to flow in only one direction 1. ATRIOVENTRICULAR VALVES \- prevent backflow into the atria when the ventricles contract. ❤ Tricuspid valve - between the right atrium and the right ventricle ❤ Mitral valve - between the left atrium and the left ventricle - When the heart is relaxed and the blood is passively filling its chambers, AV valves cusps, they just hang limply into the ventricles. - When the heart contracts, the AV valves closed. (Prevents the backflow of blood from the ventricles back to the atria) *Kapag may bumababang dugo from the right atrium to ventricle, bukas ang tricuspid.* *Kapag may bumababang dugo from the left atrium to the left ventricle, bukas ang mitral.* *But when the right and left atrium starts to pump, parehong magsasara ang tricuspid at mitral valve because it will prevent the backflow of blood back to the atria.* SEMILUNAR VALVES \- guards the bases of the two large arteries leaving the ventricular chambers. ❤ Pulmonary valve - nasa gitna ng pulmunary artery and right ventricle ❤ Aortic valve - between aorta and the left ventricle *When the ventricles are contracting and forcing blood out of the heart, dapat nakabukas ang semilunar valves.* *Kapag nakabukas ang dalawa (pulmunary & Aortic Valve), dapat nakasarado ang tricuspid and mitral valve. This prevents backflow of blood again to the atria.* *When the ventricles relax, the blood begins to flow backward toward the heart. Yung cusps, it is fill with blood like a parachute filling with air kaya nagsasarado ang semilunar valves. This prevents the arterial blood from re-entering the heart.* *Each set of valves operate at different times:* *AV Valves - open during relaxation and closed when ventricles are contracting* *Semilunar Valves - closed during heart relaxation and are forced open when the ventricles contract.* Heart Valves - simple devices in the heart like other mechanical pump, maaari parin siyang mag function kahit minsan mayroong leak as long as the damage ay hindi malala. However, if there are severely damage or deformed valves, it can seriously hamper cardiac function. **INCOMPETENT VALVES** - 1\. Valvular stenosis - Narrowing of valves (masikip kaya hindi maka-open and close effectively) - 2. Valvular atresia - Closed valves (hindi na nagbubukas) Incompetent valve may be: - Congenital or there are a lot of chds (congenital heat diseases) - Acquired - because of acquired causes (bacterial or viral infection) HEART INFECTIONS: 1\. Carditis 2\. Pericarditis 3\. Myocarditis 4\. Endocarditis 5\. Infection or inflammation of the heart walls Paano magfunction ulit ang heart kapag nag fail ang valve? (replacement if valves are failing to function) 1. Prosthetic Heart Valve 2. Preserved human valve from a donor 3. Chemically treated valve from animal (usually a pig's heart) **BLOOD FLOW IN AND OUT OF THE HEART**  - Cardiac arteries - daanan ng oxygenated blood galing ng aorta na ginagamit ng heart to funtion. - Cardiac veins - dito nagtatravel yung unoxygenated blood papuntang vena cava following the cycle. **ARTERIAL BLOOD FLOW PROBLEMS** - ANGINA PECTORIS - Insufficient oxygen supply to the heart resulting in crushing chest pain. \- *possibleng dahilan ay may blood vessel na sumikip, kaya yung blood flow ay hindi enough* *- could be mild heart attack* - MYOCARDIAL INFARCTION - Oxygen deprivation to the heart cells causing cell death. \- *total blockage in the flow of blood can be cause by clot (heart attack)* **WHAT MAKES THE HEART BEAT? WHO INITIATES EVERY HEARTBEAT?** 1. Nerves of autonomic nervous system - act like breaks and gas pedals either increase or decrease the heart rate depending on which division is activated. 2. Intrinsic conduction system or the nodal system - this is built into the heart tissues and sets a basic rhythm that causes the heart muscle depolarization or contraction in only one direction which is from the atria to the ventricles. *Conduction occurs from 1-4:*  1\. SINOATRIAL NODE ❤ Pacemaker of the heart located at junction of the superior vena cava and right atrium. ❤ Generates electrical impulses approximately 60 to 100 times per minute but can adjust its rate. ❤ Sympathetic and parasympathetic nervous systems control the SA node. ❤ Cardia pacemaker - need if the SA nodes fails to function 2\. ATRIOVENTRICULAR NODE ❤ Located in the lower aspect of the atrial septum. ❤ Receives electrical impulses from the SA node. 3\. BUNDLE OF HIS ❤ Fuses with the AV node to form another pacemaker site. ❤ If SA node fails, the bundle of his can initiate and sustain a heart rate of 40 to 60 beats per minute. (but not normal) 4\. PURKINJE FIBERS ❤ Diffuse network of conducting strands beneath the ventricular endocardium. ❤ They rapidly spread the wave of depolarization through the ventricles. ❤ Activation of the ventricles begins in the septum and moves from apex upward. ❤ Within the ventricular walls, depolarization proceeds from endocardium to epicardium. ❤ Repolarization occurs in reverse, so that last cells to depolarize are the first one to repolarize. ❤ Depolarize - contract; systole; similar to S1; lab (heat sound) ❤Repolarize - relax; diastole; similar to S2; dub (heart sound) **CARDIAC CYCLE AND SOUNDS** - SYSTOLE (contraction) AND DIASTOLE (relaxation) **CARDIAC CYCLE** ❤ One complete heartbeat, where atria and ventricles contract and then relax. ❤ Beats 75 times per minute (60 to 100 range), about 0.8 seconds per cycle. 1\. BRADYCARDIA - slow heartbeat (less than 100) 2\. TACHYCARDIA - fast heartbeat (more than 100) - ECG - test to measure the electrical activity of the heart **HEART SOUNDS** - FIRST HEART SOUND (S1, Lub) \- Closing of atrioventricular valves. \- Whenever the AV valves close ( tricuspid and mitral valve) \- long and loud - SECOND HEART SOUND (S2, Dup) \- Closing of semilunar valves. \- Whenever the semilunar valves close (pulmonic and aorticvalves) -Short and sharp - S1 \> S2 \- S1 is longer, louder than S2  - Diaphragm - best for higher pitch sounds like the breath or normal heart sounds. - Bell - for lower pitch sound like some murmurs and some vowel sounds.  - Pulmunary valve - can be hear best on the 2^nd^ ICS just to the left of the sternum. - Aortic Valve - 2^nd^ ICS just to the right of the sternum - Tricuspid valve - 5^th^ ICS; left of the sternum - Mitral valve - poiny of maximum impulse, the apical pulse on the 5^th^ ICS; left mid clavicular line - Pericordium - Heaves - palpable large beating of the heart - Thrills (palpable vibrations usually from a heart murmur; abnormal heart sound;nanginginig kapag kinapa) **CARDIAC OUTPUT** \- a healthy heart pumps out about 60% of the blood present in its ventricles \- to consider cardiac output, stroke volume must be regulated **REGULATION OF STROKE VOLUME** - Stroke volume is the amount of blood pumped by each ventricle for every heart beat. It is normally 70 ml/beat (50 to 100 range). - **Starling's law of the heart** says that the critical factor controlling stroke volume is how much the cardiac muscle cells are stretched just before they contract. (gaano kagaling magcontract, stretch ang cardiac muscle so that effective ang contraction) - **Venous return** is an important factor to stretch the heart muscle. (gaano kadami ang oxygenated blood na bumabalik sa heart) - **Muscular pump** or the enhanced squeezing action of active skeletal muscles on the veins returning blood to the heart, plays a major role in increasing venous return. **CARDIAC OUTPUT IS THE AMOUNT OF BLOOD BEING PUMPED BY EACH VENTRICLE EVERY 1 MINUTE.** - CARDIAC OUTPUT = HEART RATE x STROKE VOLUME - CO = HR x SV - Hr = 60-100bpm; 75 on average - SV = 70 mL/beat - 5250 ml/minute = 75 beats per minute x 70 ml per beat - CO = 5.25 liter/minute (range of 4 to 6 liters) -cardiac output of average size adult - CO - increased when stroke volume increased or the heart rate increased; vice versa - CO must be equal to venous return SEEN IN PEOPLE WITH CHF: 1. Congestion - pump ng pump pero di lumalabas ang dugo 2. Heart failure - does not pump blood effectively  Blood Vessels - blood circulates inside the blood vessel which forms a closed transport system which we call the vascular system. 3 walls of blood vessels: 1. Tunica intima - innermost layer 2. Tunica media - middle layer; muscles cells are found; responsible for the contraction of blood vessel; *Blood vessel contrat to allow movement of blood inside* 3. Tunica adventitia - **ARTERIES** ❤ Has high pressure, and walls are thicker and heavier than veins. (away from the heart) **VEINS** ❤ Has low pressure, and walls are thinner and lighter than arteries. (towards the heart) **CAPILLARIES** ❤ Has transparent walls, and only one cell layer thick, the tunica intima. ❤ Exchanges are easily made between blood and tissue cells. - *Capillaries of systemic circulation - changes happen between oxygenated blood to unoxygenated blood* - *Capillaries of the pulmunary system - unoxygenated to oxygenated blood in the lungs* ❤ Tiny capillaries form interweaving networks called capillary beds. (*where exchange occur)* - Arteriole - smaller arteries - Venules - smaller veins **GREAT VESSELS** I. AORTA - biggest artery 1\. Ascending Aorta - 2\. Aortic Arch 3\. Thoracic Aorta 4\. Abdominal Aorta II\. VENA CAVA - biggest vein 1\. Superior Vena Cava 2\. Inferior Vena Cava  **SPECIAL CIRCULATIONS** 1\. ARTERIAL SUPPLY OF THE BRAIN AND CIRCLE OF WILLIS 2\. FETAL CIRCULATION 3\. HEPATIC PORTAL CIRCULATION **1. ARTERIAL SUPPLY OF THE BRAIN AND CIRCLE OF WILLIS** *Internal Carotid Artery & Vertebral Artery - small communicating arterial branches which unite anterior and posterior blood supplies of the brain; surrounds the base of the brain and is very important because it provides more than 1 route for blood to reach brain tissue specially in cases of a clot or impaired blood flow.* **A. Internal Carotid Artery** ❤ Anterior, middle, and cerebral artery -- cerebrum **B. Vertebral Artery** ❤ Basilar artery -- brainstem and cerebellum ❤ Posterior cerebral artery -- posterior part of cerebrum - Small, communicating arterial branches which unite anterior and posterior blood supplies of the brain. - Surrounds base of brain. - Provides more than one route for blood to reach brain tissue in case of a clot or impaired blood flow  **2. FETAL CIRCULATION** A. PLACENTA - gives oxygenated blood; recieves unoxygenated blood and waste products. B. UMBILICAL CORD -One umbilical vein. (towards the fetal heart;dala ay oxygenated blood from the placenta to the fetal heart) -Two umbilical arteries. (away from the fetal heart; dala ay unoxygenated blood from the fetal heart to the placenta) C. DUCTUS VENOSUS - connects the umbilical vein to the inferior vena cava of the heart of the baby. (vena cava palang ng baby may oxygenated blood na unlike ng nasa adult; sa adult, all are unoxygenated blood ang nasa vena cava) D. FORAMEN OVALE - Opening between the right and left atrium. ( hindi na dumaan sa tricuspid valve, right ventricle, pulmonic valve, pulmunary artery, lungs and pulmunary veins) E. DUCTUS ARTERIOSUS - Communication between pulmonary artery and aorta. (hindi na dumaan ng lungs, pulmunary vein, left atrium, mitral valve, left ventricle and aortic valve) **3. HEPATIC PORTAL CIRCULATION** ❤ Veins of hepatic portal circulation drain the digestive organs, spleen, and pancreas; and deliver this blood to the liver through hepatic portal vein. ❤ When you have just eaten, hepatic portal blood contains large amounts of nutrients, this system now takes a detour to ensure that the liver processes these substances before they enter systemic circulation. A. Inferior mesenteric vein - Drains terminal part of large intestine. B. Splenic vein - Drains spleen, pancreas, and left side of stomach. C. Superior mesenteric vein. -Drains small intestine and first part of colon. D. Left gastric vein - Drains right side of stomach.  - PULSE - A pressure wave that travels the entire arterial system created from alternating expansion and recoil of an artery that occurs with each beat of the left ventricle. *Why left ventricle? Because it is the one pumping oxygenated blood to the system.* NORMAL FINDINGS UPON PALPATION: VITAL SIGNS UPON CLINICAL SETTINGS 1\. Rate at 60 to 100 beats/minute 2\. Strong, not weak and bounding 3\. Rhythm is regular 4\. Symmetric, equal right and left 5\. Warm to touch **BLOOD PRESSURE -** Pressure that the blood exerts against the inner walls of the arteries, and it is the force that keeps blood circulating continuously even between heartbeats. NORMAL: 120/80 mmHg (Systolic/Diastolic) - Systolic - contraction - Diastolic - relaxation Korotkoff Sounds: The pressure read as the first soft tapping sounds are heard (the first point at which a small amount of blood is spurting through the constricted artery) is recorded as the systolic pressure. As the pressure is reduced still further, the sounds become louder and more distinct. When the artery is no longer constricted and blood flows freely, the sounds can no long be heard. The pressure at which the sounds disappear is recorded as the diastolic pressure. 1\. STETHOSCOPE 2\. SPHYGMOMANOMETE