Intro to Circulatory System of Upper Extremity Flashcards
Definition: arteries
Blood moves away from the heart
Arteries branch to form
arterioles
Arterioles size:
less than 0.5mm diameter
Arterioles disperse O2 and nutrients into:
capillaries
Diffusion takes place in
capillaries
Waste products picked up by
venules
Venules joint to form larger vessels:
veins
Explain the layers of an artery
- Tunica Intima (Interna)
- inner layer (squamous epithelium)
- inner wall form the hole (lumen)
- attached by connective tissue to the middle layer - Tunica Media
- thick intermediate layer (smooth muscle + elastic tissue) - Tunica externa (Adventitia)
- Outermost fibrous layer
- can contain smooth muscle
- similar to serous layer except it’s anchored to surrounding structures
Arteries are flexible due to
flexibility of Tunica media
What is arteriosclerosis
When arteries harden with age
- inc. BP with dec. distention
What is atherosclerosis
lumen narrowing due to deposition of fat on walls
Risks of arteriosclerosis and atherosclerosis
Heart attack or stroke
What is anastomosis
- connecting arteries (e.g. PHC and AHC)
- small adjacent arteries form to accommodate blood flow
- collateral circulation
What is the circle of willis an example of?
Anastomosis
What is the most important part of the circulatory system?
Capillary Bed!! (no smooth muscles on walls!)
Describe capillaries
- 1mm long x 8-10 microns diameter
- simple squamous epithelium
- penetrate almost every tissue of body
- btwn arterioles and venules
- essential exchange of materials to maintain consistency of internal environment
What are venae commitantes?
2 or more veins to accompany each artery
Describe veins
- same 3 coats (tunics) as arteries
- tunica media is much thinner
- limited layer of smooth muscle
- have valves, aid blood flow to heart
- valves made from folds in tunica intima (interna)
What is varicose veins from?
- leaky valves in veins
Describe the aorta a.
- Ascending Aorta
- Aortic arch (3 branches)
- right brachiocephalic trunk a.
- subclavian a. (r/l)
-common carotid a. (r/l) - Descending aorta
Where does the common carotid a. go?
enters the head and neck region
Where are the vertebral a.?
branch from subclavian a. and enter head/neck
When subclavian a. exits from under the 1st rib it changes name to:
axillary a.
Axillary a. becomes
Brachial a.
Between axillary a. and brachial a. :
Ant. and Post. humeral circumflex a. around the humeral surgical neck
Briachial a. splits below elbow into
radial a. and ulnar a.
Radial a. and ulnar a. become
superficial and deep palmar arches
Arches branch into
digital aa.
What are tributaries and where are they often found?
Found in the hand, many join to form larger veins
What are 2 main large veins in the hand, forearm, and arm
- cephalic v
- basilic v.
In the elbow (cubital) region, the cephalic and basilic v. are connected by the
median cubital v.
cephalic v. travels into axillary v. through the
deltopectoral groove
Deep veins in the arm form the
brachial v.
Brachial and basilic v. join to form
axillary v.
axillary a. and v. are together in the
axillary sheath
External Jugular v. enters the
subclavian v.
Internal Jugular v. joins the subclavian v. to form the
brachiocephalic v.
At the heart, the r/l brachiocephalic v. join to form the
superior vena cava
