Week 5 Principles of vessels

Question 1

functions of arteries

**

Answer 1

conduction (elastic a’s)
distribution (muscular a’s)
exchange (arterioles)
resistance (capillaries)

oxygenated, except for:
- pulmonary arteries (to lungs)
- umbilical arterioes of fetus (to placenta)

Question 2

wall structure of arteries

**

Answer 2

tunica intima - CT lined by endothelium
tunica media - smooth muscles and elastic fibers
tunica adventitia - CT with small blood vessels

inner - intima
medial - media
outer - adventita

Question 3

types of the arteries

info

Answer 3

elastic arteries
muscular arteries
arterioles
capillaries
sinusoids
avascular structures
arterial branches
preferred channels
haemorrhage
RICER
arteriosclerosis 动脉硬化
atherosclerosis
aneurysm 动脉瘤

Question 4

elastic arteries

Answer 4

close to heart
largest diameter
‘conducting’ vessels
elastic tissue in tunica media

Question 5

muscular arteries

Answer 5

‘distributing’ vessels
smooth muscle in tunica media

Question 6

arterioles 小動脈

Answer 6

• smallest branches before capillary bed
• relatively thick wall: lumen
• regulates blood flow and pressure
• ‘resistance’ vessels
• greatest drop in blood pressure occurs across arterioles
• smooth muscle tone regulated by sympathetic NS

Question 7

capillaries 微血管

**

Answer 7

• smallest vessels
• thin walls
• connect arteries and veins circulation
• permeable (to water, gases, electrolytes, nutrients and wastes)
• permeability varies:
  *increase in organs
  *decrease in limbs
  *increase with inflammation
• ‘exchange’ vessels
• from capillary bed distal to arterioles

Question 8

sinusoids

Answer 8

Specialised capillaries
Wide lumen
Increased permeability
Modified endothelium

Question 9

vascularity of tissues

**

Answer 9

avascular tissues:
- epidermis
- hyaline cartilage

Question 10

classification of arterial branches

**

Answer 10

- parietal (to body wall)
- visceral (to organ)

arteries often give many branches with a change in direction tending to occur where a large branch is given off

where arteries divide into terminal branches, the larger branch tends to be more directly in line with the main trunk

動脈通常會發出許多分支，在發出大分支的地方往往會發生方向變化

當動脈分成終末分支時，較大的分支往往更直接與主幹對齊

Question 11

types of arterial branches

Answer 11

cutaneous
muscular
nutrient (to long bones)
articular (around joints)
arteriae nervorum (to nerves)

Question 12

development of arteries

Answer 12

• preferred channel persists
• potential for ++ variation

Question 13

haemorrhage

**

Answer 13

loss of blood
may external/ internal
blood tends to spurt
噴 from large arteries
surgical management = ligation 結紮
vessels constrict and blood thickens: to plug defect 血管收縮，血液變稠：阻塞缺損

Question 14

first aid to minimise bleeding

**

Answer 14

rest (decrease BP)
ice (increase vasoconstriction)
compression (arrests bleeding)
elevation (decrease hydrostatic pressure)

Question 15

arteriosclerosis
動脈硬化

**

Answer 15

changes tend to occur in arteries with aging
- harder artery walls
- decreased elasticity

Question 16

atherosclerosis

**

Answer 16

pathological changes also occur in arteries

fatty deposits along large arteries walls

elastic and muscular arteries

Question 17

aneurysm 動脈瘤

**

Answer 17

localised dilation (weakness in wall, danger of rupture)

Question 18

types of anastomoses

**

Answer 18

true - communication between artery branches (large calibre)
potential - communication between arterioles
continuous - supply ‘continuous’ organs (muscle, bone, skin)
around joints -
- permit continuous flow when main artery is kinked by flexion
- most are within muscles bellies that cross the joint

Question 19

types of end arteries

Answer 19

 anatomical end artery
 functional end artery
 arterial occlusion:
* internal: eg. embolic (systemic or pulmonary)
* intramural
* external

Question 20

anatomical end artery

Answer 20

• isolated
• entire territory of distribution is dependent on it 整個分銷領域都依賴它

Question 21

functional end artery

Answer 21

• has potential anastomoses only
• sudden occlusion compromises its territory
• gradual occlusion 逐漸閉塞 not necessarily

Question 22

arterial occlusion

Answer 22

may occur from:
within the artery
within the wall
externally - eg: tumour

Question 23

arterial emboli
動脈栓塞

Answer 23

tends to lodge immediately distal to a branch point, where the lumen narrows

Question 24

vascular supply of arteries: endothelium & intima receive nutrition directly by

**

Answer 24

diffusion