Blood Vessels Flashcards
What do arteries do?
Carry blood away from the heart under high/sustained pressure.
Describe the arteries
-elastic walls and smooth muscle
-integrity maintained by connective tissue surrounding vessel (collagen fibres)
About the capillaries
Between arteries and veins
Regulation of flow achieved by smooth muscle.
Microcirculation- flow through capillary bed.
Single layer of endothelial cells and basement membrane.
3 main features of the capillaries
1 cell thick
Large surface area
Good blood supply
What is the function of venules
Collect blood from capillaries and send to veins.
What is the function of the veins?
Returns blood to the heart
About the veins
Larger lumen than arteries
Lower pressure than arteries
Valves allow for 1 way flow
Muscle contraction move blood through valves
Functions of the lymphatic system
-return excess tissue fluid
-lymph nodes filter out foreign material
-produce lymphocytes
-transport digested fats
About the lymphatic system
Return of lymph
Lymph = leaked fluid from blood capillaries.
lymph nodes.
-lymphatic capillaries are widely distributed- merge to form larger lymph vessels
-similar in structure to veins (valves)
Nodes- storage and maturation of lymphocytes (swell when active/infected)
About the blood
5 times thicker than water
pH = 7.4
Its 6-10% total body weight
55% blood = plasma
+fibrinogen (a protein filament)
+erythrocytes, leukocytes and platelets.
