Cardiovascular System Flashcards
Where is the heart located?
Between the second rib and fifth intercostal space
Three layers of the heart
- Endocardium (innermost)
- Myocardium (middle)
- Epicardium (outer)
Blood flow through the heart
- Right atrium
- from venae cavae
- tricuspid valve
- Right ventricle
- pulmonic valve
- pulmonary artery
- right and left lungs
- four pulmonary veins
- Left atrium
- bicuspid (mitral) valve
- Left ventricle
- aortic valve
- aorta
How many heart valves are there?
4
Tricuspid valve
- Atrioventricular
- Between right atrium and ventricle
Bicuspid (mitral) valve
- Atrioventricular
- Between left atrium and ventricle
- Think Bishop’s mitre
Pulmonic valve
- Semilunar valve
- Between right ventricle and pulmonary artery
Aortic valve
- Semilunar valve
- Between left ventricle and aorta
Stenosis
Narrowing of valve
Hypertrophy
Englargement of muscle tissue
Ventricular septal defect (VSD)
Hole in interventricular septum
- blood is pumped from left ventricle to right ventricle
- left to right shunting
Pulmonary valve stenosis and VSD
- Right to left shunting
- Pumps deoxygenated blood into systemic circulation
Anastomoses
Coronary arteries can form multiple connections between arteries to allow flow around a blockage
Heart failure: Left sided
Backward
- Poor left ventricular function
- Fluid backs up into lungs (pulmonary edema)
Forward
- Poor left ventricular function
- Decreases blood flow to systemic circulation (cyanotic)
Heart failure: Right-sided
Backward
- Blood backs up into veins that drain blood to the right heart
- Usually caused by left-side failure or emphysema
- Jugular vein distention
- Enlarged liver
- Ankle edema
Five major functions of blood
- Transporting dissolved gases, nutrients, hormones, and metabolic wastes
- Regulating the pH and ion composition of interstitial fluids throughout the body
- Restricting fluid losses at injury sites
- Defending against toxins and pathogens
- Stabilizing body temperature
Blood is made from
Plasma and formed elements (blood cells and cell fragments)
Temperature of blood
Roughly 100.4F
Viscosity of blood
Five times as viscous as water
pH of blood
Slightly alkaline with a pH between 7.35 and 7.45
What accounts for most of the extracellular fluid in the body?
Plasma and interstitial fluid
What makes up most of your blood?
Plasma
Components of plasma
- Albumins- MAJORITY of plasma protein
- Globulins- second most abundant, contains antibodies and transport proteins
- Fibrinogen- functions in blood clotting
Red blood cells
- Most abundant blood cells accounting for 99.9% of all formed elements
- Contain pigment hemoglobin- binds and transports oxygen and CO2
- One drop of blood contains on average, 260 million RBCs
- A biconcave disc that can bend and flex easily through narrow capillaries
Hemoglobin
- 95% of RBGs intracellular proteins
- Responsible for transporting O2 and CO2
- Contains single molecule of pigment heme
- Binds blood to iron to interact with O2
- Hemoglobin with O2 gives blood bright red color
How long does it take a red blood cell to travel from the heart and back?
Less than a minute
The average lifespan of a red blood cell is…
120 days
Red blood cells are _______ roughly at the same rate they are __________
created, destroyed
Approximately ___________ new RBCs enter circulation each second.
3 million
About __% are replaced each day
1
When RBCs hemolyze (rupture), the heme molecule is stripped of its iron and converted to ________
biliverdin
(an organic compound with a greenish color)
Biliverdin is converted to ________ and released into the bloodstream to be absorbed by the liver
Bilirubin
Jaundice is caused by…
Blocked bile ducts that cause bilirubin to diffuse into peripheral tissues.
Causing a yellow discoloration most apparent in skin and sclera of eyes
Concentration of nitrogenous wastes will
Neutralize formaldehyde upon contact
White blood cells are also called
Leukocytes
WBCs help defend the body against
- Invasion by pathogens
- Remove toxins, wastes and abnormal or damaged cells
Five types of white blood cells
- Neutrophils
- Eosinophils
- Basophils
- Monocytes
- Lymphocytes
50-70% of all WBCs are
Neutrophils
Neutrophils are the
First responders
Eosinophils attack objects coated with
antibodies
Basophils
- Rare
- Accumulate in damaged tissues
- Release heparin and histamine
Monocytes
- 2-8% of WBCs
- Begin scar tissue production
Lymphocytes
- Attack foreign cells and abnormal body cells
Platelets
aka thrombocytes
Initiate clotting process
What are the three pathways in the clotting process?
- Contact or intrinsic pathway
- Tissue factor or extrinsic pathway
- Common pathway
