T15 Blood Vessels: Peripheral Circulation Flashcards
1
Q
What are arteries?
A
carry blood away from the heart
2
Q
What are capillaries?
A
- site of exchange of molecules and fluid between blood and tissue
- smallest blood vessels
3
Q
What are veins?
A
carry blood toward the heart
4
Q
What are elastic arteries?
A
- conduct blood
- diameter: 1-2.5cm (largest diameter)
5
Q
What are muscular arteries?
A
- distribute blood
- diameter: 0.3mm-1.0cm (second largest diameter)
6
Q
Order of blood vessels by diameter (smallest to largest)?
A
capillaries, venules, arterioles, musclar arteries, elastic arteries, veins
7
Q
What are the 3 layers (tunics) of arteries?
A
1) tunica intima
2) tunica media
3) tunica externa
8
Q
What is the lumen?
A
central blood-filled space of a vessel
9
Q
What are the 3 parts of the tunica intima?
A
1) endothelium - simple squamous epithelium
2) subendothelial layer
3) internal elastic membrane
10
Q
What is the tunica media composed of?
A
sheets of smooth muscle and elastic fibers and external elastic membrane
11
Q
What does contraction of the tunica media cause?
A
vascoconstriction
12
Q
What does relaxation of the tunica media cause?
A
vasodilation
13
Q
What is the tunica externa composed of?
A
composed of collagen fibers
14
Q
What are the largest arteries?
A
elastic arteries
15
Q
What is an example of an elastic artery?
A
aorta and its branches
16
Q
What dampens the surge of blood pressure in elastic arteries?
A
high elastin content
17
Q
What is the Vasa vasorum in elastic arteries?
A
network of small blood vessels which supply walls of large elastic arteries
18
Q
Where do muscular arteries lie with respect to elastic arteries?
A
lie distal to elastic arteries
19
Q
What is a unique feature of muscular arteries?
A
internal and external elastic membranes that dampen the pulsatile pressure produced by the heartbeat
20
Q
What is the tunica media like in musclar arteries?
A
tunica media = thick, w/ smooth muscle and elastin fibers
21
Q
What are the smallest arteries?
A
arterioles
22
Q
What are the 3 types of arteries?
A
elastic arteries, muscular arteries, arterioles
23
Q
____ arterioles possess all 3 tunics?
A
larger
24
Q
What are the 2 factors that control the diameter of arterioles?
A
1) local factors in the tissues
2) autonomic nervous system
25
What are the smallest blood vessels?
capillaries
26
What passes through capillaries and how?
red blood cells pass through in single file
27
What is the function of capillaries in the lungs?
O2 enters blood, CO2 leaves blood
28
What is the function of capillaries in other tissues?
O2 leaves blood, CO2 enters blood
29
What is the function of capillaries in the small intestines?
receive digested nutrients
30
What is the function of capillaries in the endocrine glands?
release or receive hormones
31
What is the function of capillaries in the kidneys?
remove nitrogenous wastes and other wastes
32
What are poorly vascularized tissues?
tendons and ligaments
33
What connective tissue are avascular but receive nutrients?
epithelia and cartilage = avascular and receive nutrients from nearby connective tissue
34
What are capillary beds?
networks of capillaries running through tissues
35
What is the function of precapillary sphincters?
regulate flow of blood to tissues
36
What do precapillary sphincters do when relaxed?
precapillary sphincters = open and blood runs through true capillaries
37
What do precapillary sphincters do when constricted?
precapillary sphincters = closed and blood runs through the metarteriole throughfare and bypasses true capillaries
38
What are the 3 types of capillaries?
1) continuous capillaries
2) fenestrated capillary
3) sinusoidal capillary
39
What are continuous capillaries?
most common type, least permeable type of capillaries
40
Where are continuous capillaries found?
found in skin, muscle, and blood brain barrier
41
Where is the lowest permeability continuous capillary system in?
CNS
42
What does the lowest permeability continuous capillary system form?
blood brain barrier
43
What type of junctions do capillaries have?
capillaries have complete tight junctions of endothelial cells which prevent movement through intercellular clefts
44
What passes through continuous capillaries and how?
Vital molecules pass through via highly selective trasnport mechanisms through endothelial cell membranes and via pinocytotic vesicles
45
What are continuous capillaries NOT a barrier against?
not a barrier against oxygen, carbon dioxide, and some drugs (e.g. anesthetics and anti-seizure meds) that pass through blood brain barrier
46
What are pericytes?
contractile cells that wrap around endothelial cells around continuous capillaries
47
Where are pericytes embedded?
pericytes embedded in basement membrane of endothelial cells
48
What is the function of pericytes?
to communicate with and help sustain endothelial cells
49
What are fenestrated capillaries?
large fenestrations (pores) result in increased permeability
50
Where are fenestrated capillaries found?
found in kidneys and small intestine
51
What are the most permeable capillaries?
sinusoidal capillaries
52
What are features of sinusoidal capillaries?
wide open intercellular clefts (gaps of unjoined membrane through which small molecules can enter and exit)
53
Do sinusoidal capillaries have a complete basement membrane?
no, have incomplete basement membrane
54
What is the diameter and physical nature of sinusoidal capillaries?
large diameter and twisted course
55
Where are sinusoidal capillaries found?
found in bone marrow, liver, and spleen
56
What do venules and veins do?
conduct blood from capillaries toward the heart
57
What is the blood pressue like in venules and veins in comparison to arteries?
blood pressure much lower than in arteries
58
What are the smallest veins called?
venules
59
What are the smallst venules?
postcapillary venules
60
Venules join to form what?
veins
61
What is the tunica externa like in veins?
tunica externa rich in collagenous tissue and is thickest in veins
62
What are 2 mechanisms to help move venous blood (against gravity)?
valves and skeletal muscle
63
How do valves help move venous blood?
in some veins, particularly in limbs
64
How does skeletal muscle help move venous blood?
skeletal muscle presses against vein walls and help pump blood toward the heart
65
What is formed when vessels interconnect?
vascular anastomoses
66
What is the function of vascular anastomoses?
enable organs to receive blood from more than one blood vessel
67
What do neighboring arteries form?
arterial anastomoses
68
What do arterial anastomoses do?
provide collateral channels
69
What anastomoses more frequently?
veins anastomose more frequently than arteries
70
What is vasa vasorum?
network of small blood vessels which supply large vessels
71
How does vasa vasorum work?
- tiny arteries, capillaries, and veins nourish outer region (tunica externa) of walls of the large vessels
- inner half of large vessels receive nutrients from luminal blood
72
Where does the pulmonary trunk leave from?
pulmonary trunk leaves the right ventricle
73
What does the pulmonary trunk divide into?
divides into right and left pulmonary arteries
74
What does pulmonary trunk carry and to where?
carries DEOXYGENATED blood to lungs
75
What do the superior and inferior pulmonary veins carry?
carry OXYGENATED BLOOD into LEFT ATRIUM
76
What do the systemic arteries carry?
carry OXYGENATED blood away from heart
77
What is the largest artery in the body?
aorta
78
Where does the ascending aorta arise from?
ascending aorta arises from left ventricle
79
What do early branches of the ascending aorta form?
coronary arteries
80
Where does the aortic arch lie?
aortic arch = posterior to the manubrium
81
What are the 3 branches of the aortic arch
1) brachiocephalic trunk
2) left common carotid artery
3) left subclavian arter
82
What branches off the brachiocephalic trunk?
right common carotid and right subclavian
83
What continues from the aortic arch?
descending aorta
84
What region is the thoracic aorta in?
T5 - T12
85
Where does the abdominal aorta end?
L4
86
What does the aorta divide into?
right and left common iliac arteries
87
Where are the common carotid arteries located?
in the anterior triangle of the neck
88
What are the 2 branches of the common carotid artery?
external carotid artery and internal carotid artery
89
What are the external carotid artery branches?
1) superficial temporal artery
2) maxillary artery
3) occipital artery
4) facial artery
5) lingual artery
6) superior thyroid artery
90
What are the internal carotid artery branches?
1) opthalmic artery
2) anterior cerebral artery
3) middle cerebral artery
4) posterior communicating artery
91
What is the cerebral artery circle (circle of WIllis)?
forms a loops around the pituitary gland and optic chiasm
92
What does the cerbral artery circle unite?
unites the brain's anterior and posterior blood supplies (internal carotid and vertebral arteries)
93
What is the anterior blood supply?
internal carotid
94
What is the posterior blood supply?
vertebral arteries
95
Where do vertebral arteries extend off?
extend off subclavian artery and ascend through foramena in transverse processes of cervical vertebrae C6 - C1
96
What do vertebral arteries merge to form?
merge to form the unpaired basilar artery that ascends along ventral midline of brain stem and at border of pons and mibrain
97
What does basilar artery divide into?
posterior cerebral arteries
98
What connects the posterior cerebral arteries to the middle cerebral arteries?
posterior communicating arteries
99
How are the posterior cerebral arteries and the middle cerebral arteries connected?
anteriorly
100
What extends off the middle cerebral arteries?
anterior cerebral arteries
101
What connects the anterior cerebral arteries and middle cerebral arteries?
anterior communicating artery
102
What are the arteries of the arm?
subclavian arter, axillary artery, brachial artery, raidal arter, superficial and deep palmar arches, digital arteries
103
What does the subclavian artery enter the axilla as?
enters as the axillary artery
104
What does the axillary artery become?
brachial artery
105
Where is the brachial artery start?
inferior border of teres major muscle
106
What does the brachial artery divide into?
divides into radial artery and ulnar artery
107
What do the radial and ulnar artery transition into?
superficial and deep palmar arches and digital arteries
108
What are the arteries of the thorax?
- anterior and posterior intercostal arteries
| - lateral and internal thoracic arteries
109
What are the arteries of the abdominal aorta?
- inferior phrenic
- celiac trunk
- superior mesenteric
- supraarenal (adrenal)
- renal
- gonadal (testicular or ovarian)
- inferior mesenteric
- common iliac
110
What does the celiac trunk supply?
main arterial branches supply viscera in the superior part of the abdomen
111
What are the 3 main branches of the celiac trunk?
1) left gastric
2) splenic
3) common hepatic arteries
112
Where do the celiac trunk and its branches send arteries to?
stomach, duodenum, spleen, pancreas, liver, and gallbladder
113
Where does the superior mesenteric artery extend to?
extends to jejunum, ileum, and proximal half of colon (cecum, appendix, ascending colon, and part of the transverse colon)
114
Where does the inferior messenteric artery extend to?
distal half of colon (2nd half of transverse colon, descending colon, sigmoid colon, and rectum
115
What are the arteries that branch off the internal iliac?
- gluteal
- obturator
- internal pudental
- middle rectum
- vesical
- uterine
116
What are the systemic veins?
3 major veins that enter the right atrium
117
Where are systemic veins located with respect to skin?
lie just beneath skin
118
What do veins have that prevent backflow of blood?
valves
119
What are venous plexuses?
multivein bundles
120
What are the 2 unusual patterns of venous drainage?
1) dural sinuses
| 2) hepatic portal system
121
Where does the superior vena cava return blood from?
returns blood from body regions superior to diaphragm
122
Where does the inferior vena cava return blood from?
returns blood from body regions inferior to diaphragm
123
Where does the coronary sinus return blood from?
returns blood from cardiac muscle
124
How does the right atrium receive blood?
via coronary sinus (large vein) which receives blood from cardiac veins (great, middle, and small cardiac veins)
125
Where is the coronary sinus located in?
in posterior party of coronary sulcus
126
What are the dural sinuses in the brain?
venous channels found between periosteal dura mater and the brain
127
What are the walls of dural sinuses lined with?
endothelium
128
What drains the dural venous sinuses?
internal jugular vein drains the dural venous sinuses
129
What are the dural sinuses of the head and neck?
-superior and inferior agittal sinuses
-straight sinus
cavernous sinus
-transverse sinuses
-sigmoid sinus
130
What are the 2 veins of the head and neck that drain into the brachiocephalic vein?
- external jugular
- internal jugular
- vertebral vein
131
Where does the external juglar empty into?
external jugular empties into subclavian vein
132
Where do the internal jugular and vertebral vein drain into?
internal jugular and vertebral vein drain into barchiocephalic vein
133
What are the deep veins of the upper limbs which follow the path of companion arteries?
- subclavian
- axillary
- brachial
- basilic
- cephalic
- raidal
- ulnar
- deep palmar arch
- digital
134
What are the superficial veins of the upper limbs easily visible beneath skin?
- cephalic
- basilic
- medial cubital (common site to draw blood)
- median antebrachial (of forearm)
135
What are the veins of the thorax?
- azygos
- hemiazygos
- accessory hemiazygos
- intercostals
136
What are the veins of the abdomen?
- inferior phrenic
- hepatic
- suprarenal
- renal
- lumbar
- gonadal (testicular or ovarian)
137
What does the hepatic portal system do? (general)
picks up digested nutrients from the stomach and intestine and delivers nutrients to the liver for processing and storage
138
What are the veins that supply the hepatic portal system?
- gastric
- gastroepiploic
- splenic
- inferior mesenteric
- superior mesenteric
139
What is the hepatic portal system?
a series of vessels in which 2 separate capillary beds lie in between arterial supply and final venous drainage
140
Where is the first capillary bed in the hepatic portal system?
in the stomach and intestines
141
What does the first capillary bed in the hepatic portal system do?
receives digested nutrients and then drains into the hepatic portal vein
142
What does the hepatic portal vein deliver?
nutrient-rich but oxygen poor blood
143
Where does the hepatic portal vein deliver to?
delivers to a secondary capillary bed
144
Where is the secondary capillary bed in the hepatic portal system located?
the liver sinusoids
145
What happens to the nutrients in the hepatic portal system once they reach the liver cells?
for processing
146
Where does the blood go after passing through liver sinusoids?
blood enters hepatic veins then inferior vena cava (enters general systemic circulation)
147
What are the superficial veins of the pelvis and lower limbs?
small saphenous and great saphenous veins
148
Where do the small and great saphenous veins arise from?
arise from dorsal venous arch
149
What are the deep veins of the pelvis and lower limbs?
- iliac
- femoral
- popliteal
- anterior tibial
- posterior tibial
- fibular
- dorsalis pedis
- plantar
- plantar arch
- digital
150
What empties into the popliteal vein?
the small saphenous, anterior tibial, posterior tibial, and fibular viens empty into popliteal vein
151
The popliteal empties into ____ which empties into ____?
the popliteal vein empties into the femoral vein which empties into the iliac vein
152
____ empties into the ____ which empties into the iliac vein?
great saphenous vein empties into the femoral vein which empties into the iliac vein
153
What is an aneurysm?
dilation of blood vessel wall that may burst
154
What are some disorders of the blood vessels?
- aneurysm
- deep vein thrombosis (clot) of lower limb
- venous disease
- microangiopathy of small blood vessels (e.g. with diabetes)
- arteriovenous malformation
155
What is atherosclerosis?
fat deposits inside arteries that can begin in young people with consequences becoming evident in middle to old age
156
Which gender experiences more atherosclerosis?
males have more atherosclerosis than females btwn ages 45-65
157
Which gender experiences heart disease and atherosclerosis later in life?
females tend to experience heart disease and atherosclerosis later in life than males
158
What can lead to ischemic heart disease?
atherosclerosis in coronary arteries can lead to ischemic heart disease
