Circulatory System Flashcards
The circulatory system’s function and structure
Structure: Heart, Blood vessels, blood
Function: Transports substances such as oxygen, carbon dioxide, nutrients, waste…
3 main types of blood vessels
Arteries/arterioles: a thick layer of smooth muscle that carries blood away from heart
Veins/venules: a thinner layer of muscle with valves to carry blood back to heart
Capillaries: thin walls to allow exchange of materials…
Blood
Buffers help maintain blood pH at 7.4.
55% plasma, which includes water, proteins, glucose, clotting factors..
Plasma
contains mostly water (90-92%) with nutrients and wastes and plasma proteins (7-8%)
Albumin-blood
large plasma protein that transports bilirubin (spleen to liver)
Lipoproteins-blood
transports cholesterol
Prothrombin + Fibrinogen
aids in blood clotting. Plasmin breaks down fibrin clots
Immunoglobulins - blood
antibodies produced by B lymphocytes to fight infection
Red Blood Cells- Structure and Function
biconcave disc without nuclease-120 day lifespan
transports oxygen (help transport co2)
Erythrocytes
produced in the red bone marrow. 4-6 million RBC’s per mm3
Hormonal control of RBC production
Kidneys produce the hormone erythropoietin, targeting RBM to increase RBC production
Blood pH maintained by kidneys
The kidneys (respiratory system) regulate the acid-base balance of the blood. Urine has a pH of 6 or lower because our diet contains acidic foods.
The White Blood cells- Leukocytes
Have nuclei, made in bone marrow, fights disease,
The White Blood cells- Agranular leukocytes
(monocytes and lymphocytes) have a spherical or kidney-shaped nucleus. Lymphocytes are the smallest WBC.
The White Blood cells- Granular Leukocytes
(neutrophils, eosinophils, and basophils) contain enzymes and protein to protect body
Platelets (Thrombocytes) function
Red bone marrow produces large cells called megakaryocytes that breakdown into platelets, while the liver makes fibrinogen and prothrombin, two proteins that aid in blood clotting.
Capillary Exchange- Arterial end
Blood is hypertonic to tissue fluid.
Blood pressure to osmotic pressure (water and nutrients leave capillary)
Blood clotting
Platelets gather at the injury site and partially block puncture. Platelets and injured tissue release a clotting factor called prothrombin activator.
Capillary Exchange- Venous end
Osmotic pressure to blood pressure (water and wastes re-enters capillary)
Tissue Fluid
interstitial fluid enters lymphatic capillaries (lymph). Returned to blood at subclavian veins
The Heart
Structure: cone-shaped organ between lungs. Heart muscles forms myocardium (cardiac muscle)
Function: Pumps blood through arteries and receives blood through veins
Systole and Diastole
contraction of heart muscles
is their relaxation
SA (Sinoatrial) Node
pacemaker, initiates heartbeat and causes atria to contract 0.85 avg
lup-dup sound
closing of atrioventricular valves (systole), followed by closing of the semilunar valves (diastole)
