Cardio anatomy/definitions Flashcards
Age Related Structural Changes of the Heart
- Deposition of lipids (fats, oils), lipofuscin (granules), & amyloid (protein aggregates) in smooth muscles tissue
- ↑connective tissue & fibrousity
- Hypertrophy left ventricle
-↑diameter of atria - Valves stiffen and calcify
- ↓pacemaker cells in sinoatrial and atrioventricular nodes
- ↓conduction fibers
- ↓ sensitivity to autonomic innervation
- ↓rate of tension development during contraction
Age Related Functional Consequences of the Heart
- ↓excitability
- ↓cardiac output
- ↓venous return
- Susceptibility to dysrhythmia
- ↓maximal heart rate that can be attained
- ↓(efficiency) dilation of cardiac arteries during activities
- ↓(efficiency) left ventricular filling in early diastole leading to reduced stroke volume
- ↑afterload, leading to weakening of heart muscle
Age Related Structural Changes of the Blood Vessels
- Altered ratio of smooth muscle to connective tissue and elastin in vessel walls
- ↓Baroreceptor responsiveness
- Susceptibility to plaque formation within vessel
- Rigidity & calcification of large arteries (esp. aorta)
- Dilation & ↑tortuosity of veins
Age Related Functional Consequences of the Blood Vessels
- ↓efficient delivery of oxygenation blood to muscle and organs
- ↓cardiac output
- Less efficient venous return
- Susceptibility to venous thrombosis
- Susceptibility to orthostatic hypotension
Pulmonary Function Anatomical and Physiological Changes with age
- Stiffened cartilage in ribs & vertebrae
- ↑stiffness/compression of annulus fibrosis in intervertebral disks
- ↓strength & endurance of respiratory musculature
- ↓elastic recoil for expiration
- ↓vital capacity
- Greater mismatch between ventilation & perfusion within lung
Pulmonary Function Functional consequences with age
- Greater airspace within aveoli = less surface area for O2/CO2 exchange
- ↑work of breathing
- ↓force during inspiration
- ↓efficient cough
- ↓exercise tolerance
- ↓resting PaO2
Cardiovascular Consequences of Bed Rest and Immobility
- ↓ Exercise tolerance
- ↓CO & ↓VO2max
- Due to limited SV resulting from reduced blood volume, limited ventricular filling & limited end-diastolic volume
- ↑Resting HR
- To compensate for ↓CO
- ↓Resting and maximum SV
- ↑Venous Compliance
- Which results in increased venous pooling (especially upon return to upright positions)
- ↓Orthostatic Tolerance
- Venous Pooling
Hematologic Consequences of Bed Rest and Immobility
↓ Blood Volume
↓ Red blood cells (RBCs)
Bed rest reduces RBC mass by 5% to 25%: decreased oxygen carrying capacity (decreasing O2 to exercising muscles)
Combination: decreased RBCs and contracted plasma volume may be represented in an elevated hematocrit (HCT)
↑risk of deep vein thrombosis (DVT)
Elevated HCT: increases the resistance to blood flow that may overly stress a compromised cardiovascular system and increase the risk of DVTs
Apex of heart
The lowest part of the heart formed by the inferolateral part of the left ventricle.
It projects anteriorly and to the L at the level of the 5th intercostal space and the L midclavicular line.
Base of heart
- The upper border of the heart
- Involving the left atrium, part of the right atrium, and the proximal portions of the great vessels.
- It lies approximately below the second rib at the level of the second intercostal space.
Endocardium
The endothelial tissue that lines the interior of the heart chambers and valves.
Epicardium
- The serous layer of the pericardium.
- contains the epicardial coronary arteries and veins, autonomic nerves, and lymphatics.
Myocardium
The thick contractile middle layer of muscle cells that forms the bulk of the heart wall.
Pericardium
A double-walled connective tissue sac that surrounds the outside of the heart and great vessels
Aorta
The body’s largest artery and the central conduit of blood from the heart to the body.
The aorta begins at the upper part of the left ventricle, and after ascending for a short distance arches backward and to the left (arch of the aorta).
It then descends within the thorax (thoracic aorta) and passes into the abdominal cavity (abdominal aorta)
Superior vena cava
The vein that returns venous blood from the head, neck, and arms to the right atrium
Inferior vena cava
The vein that returns venous blood from the lower body and viscera to the right atrium
Pulmonary arteries
The arteries that carry deoxygenated blood from the right ventricle to the left and right lungs.
Pulmonary veins
The veins that carry oxygenated blood from the right and left lungs to the left atrium.
Coronary Arteries
carry oxygenated blood to the myocardium.
R&L coronary arteries arise from the ascending aorta just beyond where the aorta leaves the L ventricle
Sinus node artery supplies
R atrium
R marginal artery supplies
R ventricle
Posterior descending artery supplies
Inferior walls of both ventricles
Inferior portion of the interventricular septum
Circumflex artery supplies
L atrium
Posterior and lateral walls of the L ventricle
Anterior and interior walls of the L ventricle
L anterior descending artery supplies
Anterior portion of the interventricular septum
Innervation of the Heart
- Cardiac automaticity is intrinsic to the SA node
- ANS influences the HR, rhythm, and contractility
- Sympathetic - release of epinephrine and norepinephrine. Stimulates to increase contractility and beat faster
- Parasympathetic - acetylcholine from vagus. Slows HR from influence on SA node.
Cardiac conduction system
SA node
internodal tracts,
AV node
Common AV bundle/bundle of His
R and L bundle branches
Purkinje fibers
Normal blood volume
4-5 L (women slightly less than mens)
Hypovolemia
- Decreased blood volume, specifically the volume of plasma.
- Causes: bleeding, dehydration from vomiting, diarrhea, sweating, severe burns, and diuretic medications used to treat hypertension.
- Signs and symptoms: orthostatic hypotension, tachycardia, and elevated body temperature.
Hypervolemia
- Fluid overload, refers to increased blood plasma.
- Causes: excess intake of fluids (e.g., IV or blood transfusion) and sodium or fluid retention (e.g., heart failure, kidney disease).
- Signs and symptoms: swelling in the legs, ascites (fluid in the abdomen), and fluid in the lungs.
Plasma
- Liquid component of blood, in which the blood cells and platelets are suspended.
- Consists of water, electrolytes, and proteins, and
- Accounts for more than half of the total blood volume.
- Important in regulating blood pressure and temperature.
Red blood cells (aka erythrocytes)
- approximately 40% of blood volume.
- Contain hemoglobin, a protein that gives blood its red color and enables it to bind with oxygen.
Anemia
When the number of red blood cells is too low (anemia), the blood carries less oxygen, resulting in fatigue and weakness.
Polycythemia
Red blood cells is too high (polycythemia)
Blood is too thick
increasing the risk of stroke or heart attack.
Blood platelets (thrombocytes)
- Assist in blood clotting by clumping together at a bleeding site and forming a plug that helps to seal the blood vessel.
Thrombocytopenia
- Low number of platelets
- Increases the risk for bruising and abnormal bleeding.
Thrombocythemia
- High number of platelets
- Increases the risk of thrombosis, which may result in a stroke or heart attack.
Polycythemia
Red blood cells is too high (polycythemia)
Blood is too thick
increasing the risk of stroke or heart attack.
White Blood Cells (leukocytes)
Protect against infection.
A low number of white blood cells (leukopenia) increases the risk of infection.
An abnormally high number of white blood cells (leukocytosis) can indicate an infection or leukemia.
Different types of white blood cells
There are five main types of white blood cells (Fig. 6-3):
* Neutrophils: help protect the body against infections by ingesting bacteria and debris.
- Lymphocytes: consist of three main types - T lymphocytes and natural killer cells, which help protect against viral infections and can detect and destroy some cancer cells, and B lymphocytes, which develop into cells that produce antibodies.
- Monocytes: ingest dead or damaged cells and help defend against infectious organisms.
- Eosinophils: kill parasites, destroy cancer cells, and are involved in allergic responses.
- Basophils: participate in allergic responses.
Right atrium
Receives venous blood from the superior and inferior vena cava.
R ventricle
Receives venous blood from the right atrium through the tricuspid valve.
Pushes blood into the pulmonary artery and pulmonary circulation.
Left atrium
Receives arterial blood from the pulmonary veins.
Left ventricle:
Receives blood from the left atrium. Pushes blood into the aorta and the systemic circulation.
Tricuspid valve
Prevents right ventricular blood from going back into the right atrium.
Pulmonary valve
Prevents blood from returning to the right ventricle.
Mitral valve
Prevents left ventricular blood from returning to the left atrium.
Aortic valve
Prevents the systemic blood from returning to the left ventricle.
Atrioventricular valves
Blood from each atrium flows to each ventricle through these valves. The valves close upon ventricular contraction to avoid backflow.
Atrial systole
The contraction of the right and left atria pushing blood into the ventricles.