Circulatory System Flashcards
Whole blood consists of:
55% plasma and 45% formed elements
Formed elements:
Erythrocytes, leukocytes, and platelets
How are formed elements produced?
From stem cells in red bone marrow
Erythrocytes:
Modified for transport of oxygen (oxygen binds to hemoglobin)
Leukocytes:
Active in phagocytosis (neutrophils and monocytes) and antibody formation (lymphocytes)
Platelets:
Active in the process of blood clotting
Plasma contains:
10% proteins, ions, nutrients, waste products, and hormones
The circulatory system is associated with:
Transport of oxygen, nutrients, hormones, ions, and fluids throughout the body, as well as removal of metabolic wastes (carbon dioxide and urea)
Blood is supplied to the heart muscle/myocardium:
Blood is drained from the heart muscle/myocardium:
Via coronary arteries
Directly into the right atrium through the coronary sinus
What initiates the heart’s intrinsic beat?
- Sinoatrial node and is transmitted along a conduction system through the myocardium
- This is what is measured on an ECG
Cardiac cycle:
Period from the end of one ventricular contraction to the end of the next ventricular contraction
Contraction phase:
Relaxation phase:
Systole
Diastole
Arteries:
Veins:
Carry blood away from the heart under high pressure (thicker and more elastic)
Carry blood toward the heart under low pressure (thinner and less elastic)
Vascular system includes:
Veins, arteries, and capillaries
Capillaries:
Smallest of vessels where the exchanges of water, nutrients, and waste products take place between blood and surrounding tissues
Arterioles:
Smallest arteries
Vasoconstriction and vasodilation results from:
Contraction and relaxation of smooth muscle in arterial walls
Deflections of the ECG represent:
The electrical activity that precedes the contraction-relaxation events of the myocardium
Where are the pressoreceptors and chemoreceptors (specialized sensory nerves that assist with the regulation of circulation and respiration) located?
Carotid body
3 layers of tissue in the heart from outermost to innermost:
Epicardium
Myocardium
Endocardium
Tricuspid valve:
(or right AV valve) prevents back flow into the right atrium when the right ventricle contracts
Pulmonary semilunar valve:
Prevents blood from entering the right ventricle
Bicuspid valve:
(or left AV valve) prevents blood from entering the left atrium when the left ventricle contracts
Aortic semilunar valve:
Prevents back flow of blood into the left ventricle as it leaves through the aorta
P wave represents:
Atrial depolarization
QRS interval represents:
Ventricle depolarization
ST segment and T wave represent:
Ventricle repolarization
Walls of all blood vessels (except capillaries) consist of 3 layers:
From innermost to outmost:
tunica intima
tunica media (thickest layer)
tunica adventitia
Neutrophils:
- Attack and destroy bacteria and viruses
- Most abundant
Eosinophils:
Fight against parasitic infections
Basophils:
Respond to histamine-releasing allergens
Monocytes:
Macrophages that engulf and destroy foreign material in the body
Lymphocytes:
Infection-fighting antibodies
Which organs are involved with the immune system? (4)
Appendix, spleen, thymus, Peyer’s patches
Neutrophils, eosinophils, and basophils are a collection of WBC known as?
Granulocytes
Yellow bone marrow is responsible for?
Maintaining an environment that allows bone to function
Reb bone marrow is responsible for?
Obliterating old RBC and forming new ones
What carries blood away from the body in order to exchange nutrients, oxygen, and waste with tissues?
Capillaries
Hepatic:
Relating to the liver
Y or T-shaped cells that originate in bone marrow and makes proteins known as antibodies:
B-lymphocytes
Arteries have ______ walls and ______ lumen.
Thick and small
Double layer membrane that surrounds the heart:
Pericardium
