Unit 2- Blood Vessels Flashcards
List the vessels
- arteries
- veins
- capillaries
- arterioles
- venules
What are the differences seen between veins and arteries?
Veins: Have valves, O2 poor blood, carries blood to heart, has the most % of blood at any given time (65%)
Arteries: Thicker tunica media, O2 rich blood, carries blood away from heart
Distinguish the difference between muscular and elastic arteries
- Muscular: further away from the heart, smooth muscle, smaller in diameter, btwn elastic arteries and arterioles, blood pressure is lower
- Elastic: closer to heart, elastin (sheets of elastic connective tissue), more pressure, larger diameter, little resistance
Describe arterioles
Branch off of muscular arteries
Describe the tissue composition of capillaries.
-simple squamous tissue
Describe capillaries
- microscopic vessels
- Function in gas/nutrient exchange
- Branch off of arterioles
- 1 Cell wall think , why cells have to move single file
What mechanism in capillaries allows for there to be a gas exchange
Pressure differences
Describe venules
Capillaries will connect with venules
Describe veins
- valves assist in returning blood to heart
- respiratory pump: aids in return of blood due to changes in pressure within the thoracic cavity when we breathe
- vaicrose veins: pooling of blood due to standing for a long time frame; muscle contractions squeezes blood forward
Describe the tunica media
- Middle layer
- smooth muscle
- controlled through subconsious sympathetic neural impulses
- Norepinphrine from adrenal medulla will also cause contraction
- Thicker in arteries than in veins
Describe tunica externa
- outer layer
- Made up of collagen
- Vasa vasorum: blood vessels for blood vessels ( support system) ;generally found in large blood vessels
Describe tunica interna
- inner layer
- simple squamous tissue
- Smooth lining to reduce friction
What is lumen in regards to vessels?
Space in the middle of the vessel
What maximizes the gas exchange at capillaries
Erythrocytes going thru single file
What layer is only present in capilaries?
Tunica interna layer
What are pericytes
Extra cells along capillaries attached to the walls that will offer extra support and stability. (ESA’s for capillaries)
List components that are related to the capilaries
- precapillary sphincters
- terminal arteriole
- metarteriole
- thoroughfare channel
- postcapillary venule
- vascular shunt
- true capillaries
What is microcirculation
Circulation of blood in the smallest blood vessel and will be how gaseous exchange occurs
What are metarteriole?
- Will go thru the center/middle of the capillary bed
- connects the terminal arteriole to the thoroughfare channel
What is the terminal arteriole?
- Delivers arteriole blood to capillary bed
- Branches into the metarteriole
What is the thoroughfare channel?
venule/distal side of capillary bed
connects to the postcapillary
What is the postcapillary venule
Connected to the thoroughfare channel
What is the vascular shunt?
Shortcut allowing for blood to pass thru the capillary bed
What is true capillaries?
- microcirculation
- regulates quantity of blood flowing thru any particular tissue
What are precapillary sphincters
Determine how much microcirculation occurs
