2 - APP - Unit 5.2 - Cardiovascular System Flashcards
Cardiovascular System
Heart + blood vessels + blood
Cells exchange materials with immediate environment (insterstitial fluid).
To maintain homeostasis, environment must be renewed
As blood flowing through body tissue:
- movement of nutrients & oxygen from blood to cells
- opposite movement of wastes, carbon dioxide & heat from cells into bloodstream
Heart anatomy - Heart
Hollwo, muscular, double pump circulating blood through blood vessel to all body parts
Heart anatomy - Paricardium
Double layer of fibrous tissue surrounding the heart
Heart anatomy - Paricardial fluid
Lubricating fluid filling the space between the two pericardial layers
Prevents the two layers from rubbing against each other & creating friction
Heart anatomy - Myocardium
Cardiac muscle tissue
Major portion offre heart
Heart anatomy - Endocardium
Smooth tissue on the inner lining
Covers heart valves & lines blood vessels providing smooth transit for flowing blood
Heart anatomy - Heart division
Heart separated into right & left halves by the interventricular septum
Each half is divided in two parts, creating 4 chambers
Heart anatomy - Heart division - Atrium
Plural: Atria
= auricles
2 upper chambers
- Right atrium
- Left atrium
They receive & collect blood for both body & lungs
Heart anatomy - Heart division - Ventricles
2 lower chambers
- Right ventricule
- Left ventricle
Pump blood out of the heart into the 2 different circulatory pathways
Heart anatomy - Valves
4 valves:
- 2 atrioventricular valves - between atria & ventricules
- 2 semilunar valves - where blood leaves the heart
Permit blood flow in only one direction
Heart anatomy - Valves - Atrioventricular - Tricuspid valve
Atrioventricular valve
Between right atrium and right ventricle
Tricuspid = 3 points (cusps) of attachement
Heart anatomy - Valves - Atrioventricular - Chordae tendinae
Small fibrous strands connecting the edges of the tricuspid to the papillary muscle that are projections of the myocardium
Heart anatomy - Ventricules & Valves - Right side process
When right ventricule contracts, the papillary muscle contracts pulling on the chordae tendinae to prevent inversion of the tricuspid valve.
Blood flows from right atrium into right ventricle. Not opposite direction.
Heart anatomy - Valves - Atrioventricular - Bicuspid valve
= Mitral valve (resembles a miter = a bishop’s hat)
Atrioventricular valve
Between left atrium and left ventricle
Blood flows from left atrium into left ventricle. Not opposite direction
Heart anatomy - Valves - Semilunar valves
- Pulmonary semilunar valve
- Aortic semilunar valve
Heart anatomy - Valves - Semilunar - Pulmonary semilunar valve
At the orifice (opening) of the pulmonary artery
Allows blood to travel from right ventricle into pulmonary artery and then into the lungs
Heart anatomy - Valves - Semilunar - Aortic semilunar valve
At the orifice of the aorta
Allows blood to pass from left ventricle into aorta, but not backward into left ventricule
Heart anatomy - Structures leading to & from the heart
- Superior vena cava & inferior vena cava
- Coronary sinus
- Pulmonary arteries
- Aorta
- Pulmonary veins
Heart anatomy - Structures leading to & from the heart - Superior vena cava & inferior vena cava
Large venous blood vessels bringing deoxygenated blood (has lesser amount of oxygen) to the right atrium from the entire body
Heart anatomy - Structures leading to & from the heart - Coronary sinus
Transports blood from heart muscle tissue itself to right atrium
Heart anatomy - Structures leading to & from the heart - Pulmonary arteries
Transports blood away from right ventricle to the lungs for oxygenation
Heart anatomy - Structures leading to & from the heart - Aorta
Transports blood away from left ventricule to the rest of the body
Heart anatomy - Structures leading to & from the heart - Pulmonary veins
Transports blood from the lungs to left atrium
Heart physiology
Works as a double pump
Two major functions:
- Right heart
- Left heart
Heart physiology - Right heart
- Deoxygenated blood from body enters right atrium from superior & inferior vena cava
- Then flows through tricuspid valve into right ventricule
- Right ventricule contracts, forcing blood past the pulmonary semilunar valves into the pulmonary arteries, carrying blood to the lungs for oxygenation
Heart physiology - Left heart
- Oxygenated blood from the lungs enters left atrium from pulmonary veins
- Then flows through bicuspid (mitral) valve into left ventricule
- Left ventricule contracts, forcing blood past the aortic semilunar valves into aorta, carrying blood to the rest of the body
Heart physiology - Heart beat
Individual at rest: between 72 to 80 times/minute
Each beat: 60-80 ml of blood ejected from the ventricles (=stroke volume)
Heart physiology - Heart beat - Stroke volume
Quantity of blood ejected from the ventricules at each beat (60-80ml)
Heart physiology - Heart beat - Cardiac output
Total volume of blood ejected from the heart per minute
Adult body average: 5,000ml
So all blood is pumped through the heart about once every minute
Heart physiology - Coronary artery
Heart receives blood from coronary artery
Branches into right and left coronaries arteries, which branch into various coronary arteries feeding heart muscle
Heart physiology - Heart sound - Lubb dubb sounds
Sound made by valves when they close
Heart physiology - Heart sound - Lubb dubb sounds - Lubb sound
Heard first
Closure of Atrioventricular valves (tricuspid & bicuspid)
Heart physiology - Heart sound - Lubb dubb sounds - Dubb sound
= S2 sound
Heard second
Shorter and higher pitched
Closure of Semilunar valves (aortic & pulmonic)
Certain conditions cause changes in action of heart valves.
Control of Heart Contractions
Heart removed from body continues to beat rhythmically
Heartbeat generates in the heart muscle itself
Heart rate: affected by endocrine & nervous systems
Myocardium contracts rhythmically as a forceful pump
Control of Heart Contractions - Sinoatrial (SA) node
= Pacemaker
Group of contracting cells
Control heart muscle contractions
Location: at the opening of the superior vena cava into the right atrium
Sends out electrical impulse that begins and regulate heart
Impulse spreads out over: atria making them contract causing blood to flow downward from the 2 upper atrial chambers through ventricular openings
Impulse eventually reaches Atrioventricular (AV) node
Control of Heart Contractions - Atrioventricular (AV) node
Conducting group of cells between atria & ventricle
From the AV node, the electrical impulse is carries to conducting fibers in the atrioventricular septum (=atrioventricular bundle)
Control of Heart Contractions - Atrioventricular bundle
= Bundle of His
Conducting fibers in atrioventricular septum
Divides into right & left branch, subdividing into fine network of branches spreading throughout the ventricules (=Purkinje network)
Control of Heart Contractions - Purkinje network
Fine network of branches spreading throughout the ventricules (result of division of Atrioventricular bundle)
Electrical impulse shoots along Purkinje fibers to the ventricles causing them to contract.
Heart then rests briefly.
Circulation of Blood
Blood vessels circulate blood through 2 major circulatory systems:
- Cardiopulmonary circulation
- Systemic circulation
Circulation of Blood - Cardiopulmonary circulation
Blood flows from right side of the heart to the lungs and back to left side of the heart
Circulation of Blood - Systemic circulation
Blood flows from left side of the heart to the tissues and cells of the body and back to right side of the heart
Type of blood vessels
Three types of blood vessels arteries arterioles and capillaries
Type of blood vessels - Arteries
Carry blood away from the heart
Transport blood under very high pressure
They are elastic, muscular and thick walled
Larger arteries branch into smaller arteries, branching into arterioles (means tiny arteries)
Arterioles give rise to the capillaries
Type of blood vessels - Arterioles
= tiny arteries
Results of smaller arteries branching
Arterioles give rise to the capillaries
Type of Blood vessels - Capillaries
Smallest blood vessels (seen through a compound microscope)
- Capillary walls extremely thin: allows selective permeability of various substances. Nutrients molecules & oxygen pass out of the capillaries and into the surrounding cells & tissues.
- Metabolic waste products (as carbon dioxide & nitrogenous wastes) pass back from the cells and tissues into bloodstream for excretion at their proper sites.
- Capillaries then drain into small veins (=venules)
Type of Blood vessels - Venules
= small veines
Capilaries drain into venules which drain into larger vessels (=veins)
Type of Blood vessels - Veins
Carry blood towards the heart.
Have valves along their length, allowing blood flow in only in one direction: toward the heart.
Smaller veins converge to form larger veins, ultimately forming the body’s largest veins: the vena cavae
Venous blood from the airport part of the body returns to the right atrium via the superior vena cava
Blood from the lower body parts is conducted to the heart via the inferior vena cava
Blood pressure and pulse
When heart pumps blood into the arteries, the surge of blood filling the vessels creates pressure against their walls.
Pressure in arteries closest to the heart is greatest & gradually decreases as blood travels further away from the heart.
Blood pressure and pulse - Systolic blood pressure
Pressure measured at the moment of contraction.
Average measured in adult upper arm: 120mm/Hg
Blood pressure and pulse - Diastolic blood pressure
Lessened force of a blood measured when the ventricles are relaxed
Average measured in adult upper arm: 80mm/Hg
Blood pressure and pulse - Pulse pressure
Difference between the systolic & diastolic.
If blood pressure is recorded 120/80, pulse pressure is 40
Blood pressure and pulse - Pulse points
Expl: artery at the wrist
Can feel alternating beating throbs: body’s pulse
Blood pressure and pulse - Pulse
Alternating expansion & contraction of an artery as as blood flows through it
Pulse rate usually same as heart rate
Blood pressure and pulse - Pressure point
Where main artery to the injured part lies near the skin surface over a bone.
The 7 location where we can feel pulse may also serve as pressure points.
If direct pressure can’t be applied to a wound, apply pressure to closest pulse point.
Heart disease
One of the leading causes of death in the US: cardiovascular disease
Common signes:
- Arrhythmia
- Bradycardia
- Tachycardia
- Murmurs
- Mitral valve prolapse
Heart disease - Arrhythmia
= Dysrhythmia
Term used to discuss any change or deviation from the normal rate or rhythm of the heart
Heart disease - Bradycardia
Slow heart rate (less than 60 beats per minute)
Heart disease - Tachycardia
Rapid heart rate (more than 100 beats per minute)
Heart disease - Murmurs
Indicate defects in the valves of the heart.
Gurgling or hissing sound when valves fail to close properly
May be classified according to which valve is affected or according to heart’s cardiac cycle:
- when heart is contracting: systolic murmur
- when heart is at rest: diastolic murmur
Heart disease - Mitral valve prolapse
Valve between the left atrium and the left ventricle closes imperfectly.
Symptoms thought to occur as a response to stress.
Include: fatigue, palpitation (heart feels like racing), headache, chest pain and anxiety.
Alleviate symptoms: exercise, restricting sugar & caffeine intake, adequate fluid intake and relaxation
Heart disease - Coronary artery disease (CAD)
Narrowing of the arteries supplying oxygen and nutrient- filled blood to the heart muscle.
Usually results from the buildup of plaque on the artery walls (atherosclerosis).
If artery completely blocked, a myocardial infarction may occur.
Prevention: change lifestyle habits (no smoking, increased exercise & reduction of cholesterol).
One of the most important symptoms: Angina
Heart disease - Angina pectoris
Not a disease but a symptom of underlying coronary circulation problem
Angina pectoris occurs quite suddenly.
Severe chest pain arising when heart does not receive enough oxygen. Radiates from precordial area to the left shoulder down the arm along the ulnar nerve.
Victims often experience feeling of impending death.
Possible causes: stress or physical exhaustion.
Treatment: Nitroglycerine, a drug helping dilating coronary arteries to permit blood flow to the heart
Heart disease - Myocardial infarction
=MI or Heart Attack
Cause: Lack of blood supply to the heart muscle, the myocardium
Origin:
- Blocking of the coronary artery by a blood clot
- Narrowing of the coronary artery as a result of arteriosclerosis
- A loss of elasticity & thickening of the wall
- Atherosclerosis (plaque buildup in the arterial walls)
Heart disease - Infectious heart disease
Cause: usually a bacteria or virus
Treatment: antibiotic therapy
Heart disease - Infectious heart disease - Endocarditis
Inflammation of the membrane lining the heart and covering the valves, causing the formation of rough spots in the endocardium, leading to the development of a fatal blood clot (thrombus).
Heart disease - Infectious heart disease - Myocarditis
Inflammation of the heart muscle.
Symptoms may be same as pericarditis
Heart disease - Infectious heart disease - Pericarditis
Inflammation of the outer membrane covering the heart.
Symptoms:
- pain in the chest area overlying the heart
- cough
- dyspnea (difficulty breathing)
- rapid pulse
- fever
Heart disease - Infectious heart disease - Rheumatic heart disease
Result of a person having freaquent strep throat infections during childhood, which may lead to remain rheumatic fever.
Antibodies formed to protect the child from the strep throat or rheumatic fever may attach lining of the heart, especially bicuspid/mitral valve.
Valve becomes inflamed & may be scarred, leading to valve narrowing. Mitral valve is then unable to close properly, interfering with blood flow from the left atrium to the left ventricle.
Important for children with streptococcal infections to be treated with antibiotic therapy.
Heart disease - Infectious heart disease - Heart failure
Occurs heart ventricles are unable to contract effectively and blood pools in the heart.
Different symptoms depending on which ventricle fails:
- left ventricle fails: dyspnea
- right ventricle fails: engorgement of organs with venous blood occurs, edema (excessive fluid in tissues) & ascities (abnormal accumulation of serous fluid in the abdominal cavity)
- Other symptoms: lung congestion & coughing
Heart disease - Infectious heart disease - edema
Excessive fluid in tissues
Heart disease - Infectious heart disease - Ascities
Abnormal accumulation of serous fluid in the abdominal cavity
Heart disease - Infectious heart disease - Congestive heart failure
Similar to hurt failure with edema of the lower extremities.
Blood backs up into the lung vessels & fluid extends into the air passages.
Treatment: cardiotonics & diuretics (drug reducing amount of fluid in the body)
Heart disease - Infectious heart disease - Diuretic
Drug reducing amount of fluid in the body
Blood vessels diseases - Aneurysm
Ballooning out of an artery, accompanied by a thinning arterial wall, caused by a weakening of the blood vessel ( like having a bubble on a tire). The aneurysm pulsates with each systolic beat.
Symptoms: pain & pressure - Sometime no symptoms
Most common aneurysm site: aorta
Blood vessels diseases - Arteriosclerosis
Occurs when arterial walls thicken because of the loss of electricity as aging occurs.
In Arteriosclerosis & Atherosclerosis, there is an narrowing of the blood vessels opening, interfering with the blood supply to the body parts and causing hypertension.
Symptoms develop where circulation is impaired:
- numbness and tingling of the lower extremities
- loss of memory
Blood vessels diseases - Atherosclerosis
Disease that occurs when deposits of fatty substances form along the walls of the arteries
Blood vessels diseases - Cerebral vascular accident (CVA)
= stroke
Sudden interruption of blood supply to the brain, resulting in a loss of oxygen to the brain cells, causing impairment of brain tissue and/or death.
- 90% of strokes: caused by blood clots, lodging in the carotid arteries, choking off the brain blood supply
- 10% of strokes: hemorrhagic strokes. Caused by rupture of blood vessels within brain.
Symptoms depend on side of the brain with blood supply interrupted:
- Right cerebrum: affects spatial and perceptual abilities and cause weakness or hemiplegia (paralysis) on the left side of the body.
- Left cerebrum: aphasia (loss of speech & memory), right sided hemiplegia.
Common symptoms (No two patients experience same injuries/disabilities)
- vision problems
- communication difficulties
- dysphasia (inability to say what one which is to say)
- emotional lability (uncontrolled, unexplained outward displays of emotions)
- depression,
- coma
- possible death
Blood vessels diseases - Gangrene
Death of tissue due to an insufficient blood supply by disease or injury
Blood vessels diseases - Hemorrhoids
Varicose veins in the walls of the lower rectum and anus
Blood vessels diseases - Hypertension
= high blood pressure = the silent killer (Usually no symptoms)
blood pressure is 140/90 or higher.
Leads to:
- strokes
- heart attack
- kidney failures
Blood vessels diseases - Hypotension
Low blood pressure
Usually systolic reading is under hundred mm/Hg
Blood vessels diseases - Peripheral vascular disease
Caused by blockage of the arteries (usually in the legs).
Symptoms:
- pain or cramping in the legs or buttocks while walking (= claudication)
Symptoms as condition worsens:
- pain in the toes and feet while at rest
- numbness
- paleness
- cyanosis in the foot or leg.
Blood vessels diseases - Phlebitis
Inflammation of the lining of a vein accompanied by clotting of blood in the vein.
Symptoms:
- edema (swelling) of the affected area
- pain
- redness along the length of the vein
Blood vessels diseases - Transient ischemic attacks (TIAs)
Temporary interruption of blood flow (ischemia) to the brain.
Usual cause: narrowing of the carotid artery due to an accumulation of fat.
Stroke-like symptoms:
- dizziness
- weakness
- temporary paralysis lasting less than 24 hours
50% of people having TIAs have major stroke within the following year
Blood vessels diseases - Ischemia
Inadequate blood supply to an organ or part of the body, especially heart muscles.
Blood vessels diseases - Varicose veins
Swollen veins resulting from slowing of blood flow back to the heart.
Blood backs up in the veins if the muscle don’t massage them.
The weight of the stagnant blood distends the vales
The continued pooling of blood then causes distention and inelasticity of the vein walls.
Cause:
- hereditary weakness in vein structure
Other possible causes:
- human posture
- prolonged periods of standing & physical exertion, causing valves in the superficial leg veins to enlarge and weaken
- age
- pregnancy
Blood diseases - Anemia
Deficiency in the number and/or percentage of red blood cells and in the amount of hemoglobin in the blood.
Causes:
- large or chronic loss of blood, decreasing the number of erythrocytes
- other environmental factors (as nutritional deficiencies or chemical exposure)
Blood diseases - Aplastic anemia
Cause: suppression of the bone marrow. S Cause of suppression: - chemical agents - certain drugs - radiation therapy
Bone marrow does not produce enough red or white blood cells
Blood diseases - Deep vein thrombosis (DVT)
Blood clot in a deep vein.
Affects the veins in the lower leg or the thigh.
DVT involves the formation of a clot (thrombus) in the larger veins of the area, which may interfere with circulation, and may break off & travel through the bloodstream (embolize).
Resulting embolus can lodge in the brain, lungs, heart or other area, causing severe damage to that organ.
Risk factors:
- prolonged seating
- bed rest
- immobilization (as long plane or car trips)
- recent surgery or trauma (especially hip, knee or gynecological surgery)
- fractures
- childbirth within the last six months
- use of medication (as estrogen or birth control pills)
Symptoms (in one leg only)
- leg pain
- leg pain
- swelling (edema)
- increased warmth
- changes in skin color
Blood diseases - Embolism
Embolus carried by blood stream until it reaches an artery too small for passage An embolus is foreign to bloodstream: - air - blood clot - cancer cells - fat - bacterial clumps - needle - a bullet that was lodged in tissue and breaks free
Blood diseases - Hematoma
Localized clotted mass of blood found in an organ, tissue or space.
Cause: traumatic injury (as a blow) that can cause a blood vessel to rupture
Blood diseases - Hemophilia
Hereditary disease
Blood clots slowly or abnormally, causing prolonged bleeding with even minor cuts or bumps.
Sex-linked hemophilia occurs mostly in males, is genetically transmitted by females to their sons.
Person with hemophilia may be treated with the missing including factor.
Hemophiliac is taught to avoid trauma & report promptly any bleeding, no matter how slight.
Blood diseases - Iron-deficiency anemia
Often exist in women children and adolescents.
Cause: deficiency of adequate amount of iron in diet
Leads to: insufficient hemoglobin synthesis in the red blood cells.
Easily treatment: ingestion of iron supplements & green leafy vegetables, containing the mineral iron.
Blood diseases - Leukemia
Cancerous or malignant condition
Great increase in the number of white blood cells
Overabundant immature leukocytes replace the erythrocytes, interfering with the transport of oxygen into the tissues.
They can also hinder the synthesis of new red blood cells from bone marrow.
The acute form of the disease, which develops quickly and runs its course rapidly, occurs most often in children & young adults.
Treatment:
- drug therapy
- bone marrow transplants
- radiation therapy (which has given people with leukemia remissions lasting for several years)
Blood diseases - Pernicious anemia
Form of anemia caused by vitamin B12 deficiency and/or lack of the intrinsic factor
Seen in association with some autoimmune and endocrine diseases.
The intrinsic factor produced by the stomach mucosa is necessary for the absorption & utilization of vitamin B 12. Vitamin B 12 & folic acid are necessary for the development of mature red blood cells.
Symptoms:
- Dyspnea
- Pallor
- Fatigue
- Specific neurologic changes
Treatment: involves injection of vitamin B 12
Blood diseases - Polycytemia
Too many red blood cells are formed. This may be a temporary condition which book hers but high altitudes because there is less oxygen prison. The disease policy team yet vera cause unknown is a condition of too many red blood cells. The increase in the number of red blood cells causes a thickening of the blood was possible blood clot formation
Blood diseases - Raynaud’s phenomenon
Cause: exposure to the cold or strong emotions
Blood vessels spasms resulting in interruption of blood flow to the fingers, toes, ears & nose, becoming white, due to lack of blood flow in area.
Then they turn blue, due to tiny blood vessels dilating to allow more blood to remain in the tissues.
When blood flow returns, area becomes red and then returns to normal color.
Associated with: tingling, swelling & painful throbbing. Attacks my last for minutes to hours.
If condition progresses: blood flow to area could become permanently decreased, causing the fingers to be content and tapered, with smooth, shinny skin.
Blood diseases - Septicemia
Presence of pathogenic organisms or toxins in the blood
Blood diseases - Sickle cell anemia
Chronic blood disease inherited from both parents
Red blood cells form in abnormal crescent shape. These cells carry less oxygen and break easily, causing anemia.
The sickling trait: less serious disease, occurs with inheritance from only one parent.
Most prevalent in African-Americans affecting about 1 in 400.
Blood diseases - Thrombocytopenia
Decrease in the number of platelets (thrombocytes)
Blood will not clot properly
Blood diseases - Thrombosis
Formation of a blood clot in a blood vessel.
Blood clot formed = thrombus.
Cause:
- unusually slow blood circulation
- changes in the blood or blood vessels walls
- immobility or a decrease in mobility.
Sometimes the formation of a blood clot is coupled with inflammation of a vein in a condition known as thrombophlebitis
Blood diseases - Thrombosis - Thrombus
Blood clot formed in a blood vessel
Blood diseases - Thrombosis - Thromboplebitis
Formation of a blood clot coupled with inflammation of a vein
