Exam 4: Ch 21 Blood Vessels Flashcards
How many times does the Human Heart beat each day?
100,000 times
How many gallons does the human heart pump each day?
2,000 gallons
How many miles of blood vessels exist in the human body?
60,000 miles
able to wrap the earth twice
3 Major types of Blood vessels and their functions
Arteries: carry blood away from the heart
Capillaries: sites of exchange between blood and tissues
Veins: carry blood towards the heart
What are tunics
layers of the blood vessel wall
3 types of tunics with both names in order from innermost to outermost
- Tunica Interna or Tunica Intima
- Tunica Media
- Tunica Externa or Tunica Adventitia
Describe Tunica Interna
Borders the vessel lumen
innermost layer
thin layer of connective tissue covered by endothelium (simple squamous epithelium)
Describe Tunica Intima
Borders the vessel lumen
innermost layer
thin layer of connective tissue covered by endothelium (simple squamous epithelium)
Describe Tunica Media
Middle layer
composed of smooth muscle with collagen and elastin fibers
the thickest layer in arteries
strengthens vessel wall; prevents rupture from blood pressure
sympathetic nervous system: controls vasoconstriction/vasodilation of vessels
Describe Tunica Externa
Outermost Layer
Composed of connective tissue
Merges with connective tissue of neighboring structures
Anchors vessel
Describe Tunica Adventitia
Outermost Layer
Composed of connective tissue
Merges with connective tissue of neighboring structures
Anchors vessel
What blood vessel has the thickest walls
arteries
Which blood vessels are high pressure
arteries
What is the thickest layer in arteries
Tunica Media
What are the three classifications of Arteries with both names
- Conducting or Elastic Arteries
- Distributing or Muscular Arteries
- Resistance or Small Arteries
Describe Conducting or Elastic Arteries and give examples
Thick walls
Largest diameter
Allows low-resistance conduction of blood
withstand and smooth out large blood pressure fluctuations
elastin fivers in all 3 tunics
Ex: aorta and subclavian artery
Which type of artery has the thickest walls
Elastic or conducting arteries
Which type of artery has the largest diameter
Conducting or elastic arteries
Which type of artery allows for low-resistance conduction of blood
Elastic or conducting arteries
Which type of artery can withstand and smooth out large blood pressure fluctuations
Conducting or elastic arteries
Which type of artery has elastin fibers in all 3 tunics
Elastic or conducting arteries
Describe Distributing or Muscular Arteries and give an example
The tunica media is thick but fewer elastic fibers than conducting arteries; mostly smooth muscle
Active in vasoconstriction
distributes blood to specific organs
Ex: renal artery
Which type of artery has mostly smooth muscle in their tunica media
Distributing or Muscular Arteries
Which type of artery distributes blood to specific organs
Muscular or Distributing arteries