Blood Vessels and Arteries Flashcards
Describe the composition of the following layers:
tunica intima
tunica media
tunica externa
tunica intima - inner lining of blood vessel
- SS ET + loose irregular CT
- serous membrane
tunica media - smooth muscle
- orientation and # different between vein and artery
- can contain sheets of elastic fibers
- innervated by sympathetic NS - autonomic
tunica externa - outer layer made completely of CT
- large vessel - dense irregular
- small vessel - loose irregular
What are the different arteries in order from proximal to distal?
elastic arteries - aorta and pulmonary trunk
- conducting arteries
- many sheets of elastic fibers
muscular (distributing) arteries - goes to organs
- corrugated internal elastic lamina - allows for some stretching
- external elastic lamina
- smaller in diameter
arterioles: 1-2 layers of smooth muscle
- most numerous vessel that has smooth muscle
- regulate distribution of flow to the cap beds
capillaries - thinnest wall for diffusion and filtration
What vessel is in charge of regulating temperature and BP? Why?
arterioles - smallest blood vessel that contains smooth muscle
- better at changing resistance due to increase surface area and smooth muscle
What are the three types of capillary walls?
continuous - epithelial cells do not have pores, continuous basement membrane
- found in fat, muscle, nervous system (brain)
- RBC single file - increased O2 exchange
fenestrated - filtration - pores in epithelium, continuous basement membrane
- does not allow RBC to cross
- AA, proteins, ions and H2O can cross
- kidneys, endocrine glands, small intestine
sinusoid - large fenestra, incomplete basement membrane
- liver, bone marrow, lymph nodes/spleen
Describe metarterioles and their function. What are pre capillary sphincters and their function?
contain some smooth muscle
- constrict if O2 is needed somewhere else, will dilate where O2 is needed
pre capillary sphincters: dilate to let more flow through capillary bed
opposite in the lungs - directs blood to region of high O2
What is diapedesis and where will it occur?
diapedesis - WBC leaving via gaps between SS epithelium
occurs in the post-capillary venules
What structure do veins have the arteries don’t? How does their pressure compare to arteries?
veins have valves
- gravity can cause blood to stagnate into lower limbs
- contracted skeletal muscle + valves help blood move in one direction
under lower pressure than arteries - same volume
Describe how varicose veins form and the available treatments
developed due to increased pressure of the veins and failure of the valves
tx: surgery, chemical ablation, laser
- no blood flow = no visible vein
- can help prevent with compression stockings
What is the first vessel to branch off the aorta?
R and L coronary arteries
What side is the brachiocephalic trunk on? What does it branch off into?
R side of ascending aorta only
gives rise to subclavian and common carotid artery
L side of aortic arch has branches of common carotid and subclavian
What does the external carotid branch into? What do these vessels supply?
superficial thyroid - thyroid
lingual - tongue
facial - muscles and skin of face
occipital - scalp of posterior head
superficial temporal - temporal scalp
maxillary - chewing muscles
middle meningeal - dura matter
Describe how you get from the heart to the dura matter
ascending aorta - arch or the aorta - brachiocephalic trunk - common carotid - external carotid - maxillary artery - middle meningeal artery
Where does the internal carotid canal go?
through carotid canal to get into brain
- join a circuit with the vertebral arteries via posterior communicating arteries
Where do the vertebral arteries pass through and where to they go? What do they supply?
pass through vertebral canal
- pass through foramen magnum to form circuit with internal carotid arteries via posterior communicating arteries
supplies the medulla - sudden death if blocked bc medulla is respiration center
What do the anterior cerebral arteries supply and how are they connected?
supplies the thalamus, hypothalamus, medial surface
- connected via anterior communicating artery
What do the middle cerebral branches supply and where do they come from?
largest blood supply of brain
supply cerebral, temporal and frontal lobes
- lateral aspect of frontal and parietal lobe
derives from the internal carotid artery
What does the posterior cerebral artery supply?
cerebellum and occipital lobe
What does the basilar artery supply and what is it composed of?
supplies the pons
composed of the fusion of the vertebral arteries
What does PICA stand for and where do they branch off of?
posterior inferior cerebellar artery
- branches off of vertebral artery
What is the thyrocervical trunk? What does it come off of? What does it branch into?
branches off of subclavian
becomes:
suprascapular artery - scapula, lateral neck muscles
inferior thyroid artery - thyroid
What are the branches off of the subclavian?
vertebral, thyrocervical, and internal thoracic artery
What does the brachial artery branch off to? What do those turn into?
radial and ulnar artery
radial turns into deep parlor arch
ulnar turns into superficial ulnar arch
- then becomes digital arteries
Where do the bronchial arteries branch off of? What do they supply?
directly off the thoracic aorta
- supplies the smooth muscle, cartilage, and epithelium of lungs
What do the internal thoracic arteries branch off of? and does it become?
comes off of subclavian
branches into anterior intercostals
