Circulatory system Flashcards
Arteries
blood vessels carrying oxygenated blood away from the heart and to the tissues
Veins
blood vessels carrying blood toward the heart to remove waste and pick up more oxygen
Capillaries
fine-branching blood vessels forming a network between the arterioles and venules, where transport of nutrients and oxygen or carbon dioxide occurs on a microscopic scale
Arterioles
the smaller branches of the arteries leading to the capillaries
Venules
the small branches of the veins gathering blood from the capillaries
Heart
The heart beats about 100,000 times per day.
For every minute of work, the heart pumps five (5) to six (6) quarts of blood around the body.
Atrium
one of the two upper cavities of the heart passing blood to the ventricles. The plural is “atria.”
Ventricle
one of the two lower cavities of the heart passing blood to the body or to the lungs
Pulmonary arteries
blood vessels moving blood from the heart to the lungs
Pulmonary veins
blood vessels returning oxygenated blood to the heart from the lungs
Aorta
the main artery in the body that supplies oxygenated blood to the circulatory system
Superior vena cava
the blood vessel moving blood from the upper body and head to the heart
Inferior vena cava
the blood vessel moving blood from the lower body to the heart
Atrioventricular (AV) valves
valves between the atria and ventricles preventing the backward flow of blood during cardiac contractions
Sinoatrial (SA) node
the pacemaker of the heart that generates the first electrical signal of a heartbeat and stimulates the atria to contract
Atrioventricular (AV) node
the nerve node between the right atrium and right ventricle that propagates the electrical signal from the SA node to more distal heart nerves that cause ventricular contraction
Movement of blood through the circulatory system
deoxygenated blood from body > right atrium > tricuspid valve > right ventricle > pulmonary artery (to lungs) > pulmonary vein (oxygenated) from lungs > left atrium > bicuspid valve > left ventricle > aorta (to body for circulation)
Blood cells types
Red Blood cells
White blood cells
Red Blood cells
Erythrocytes: the most numerous of all blood cells (approx. 40 percent of blood volume) that transfer oxygen to the body tissues
White blood cells
Basophil
Neutrophil
Eosinophil
Monocyte
Lymphocyte
Basophil
a large white blood cell that locates and destroys cancerous cells and is responsible for the histamine response during an allergic reaction
Neutrophil
the most numerous white blood cells responsible for the primary immune response of the ingestion or enzymatic digestion of foreign microorganisms
Eosinophil
white blood cells that play a role in allergic reactions and immune defense against multicellular parasites
Monocyte
an immune cell that helps remove dead or damaged tissues and provides support to the other types of white blood cells
Lymphocyte
white blood cells that include natural killer cells, B cells, and T cells, which kill tumor cells, produce antibodies, and kill infected or cancerous cells, respectively
Systole
the heartbeat phase where muscle contraction moves blood from the heart chambers to the arteries
Diastole
the heartbeat phase where the cardiac muscle relaxes and the heart chambers fill with blood
Stroke volume
the amount of blood pumped by the left ventricle of the heart in one contraction
Heart rate
the number of heartbeats per minute
Average human resting heart rate is 60 to 100 beats per minute
Pulmonary circulation
the blood flow between the heart and the lungs
Systemic circulation
the blood flow between the heart and the rest of the body
Cardiac cycle
the action of the heart from the start of one heartbeat to the beginning of the next
Pulse
rhythmical throbbing of the arteries as blood is propelled through them
Measured at neck (carotid artery) or wrist (radial artery)
Blood pressure
the force of blood pushing against the walls of the arteries during the two phases of the cardiac cycle
‘Normal’ range blood pressure: 120/80 mm Hg
Hypotension
low blood pressure measuring 90/60 mm Hg or lower
Hypertension
high blood pressure measuring more than 140/90 mm Hg
Systolic
the pressure in blood vessels when the heart beats (ventricular contraction)
Diastolic
the pressure in blood vessels when the heart rests (ventricular filling)
Factors influencing blood pressure
Cardiac output: how much blood the heart is pumping per minute
Blood volume: the total volume of blood contained in the circulatory system
Peripheral resistance of arteries: the elasticity (or lack thereof) of artery walls
Blood viscosity: the thickness of blood moving through circulation
