Blood Vessels Flashcards
(36 cards)
What are the layers of a blood vessel
What does the lumen of blood vessels contain
Blood
What does the tunica intima of blood vessels contain
Endothelial Cells + Basement Membrane
Supporting connective tissue
Internal elastic lamina
**Remember that this is the basic structure of like everything - Epithelia, BM, connective tissue
Type of Epithelial cells of blood vessels
Simple squamous (like capillary; diffusion doesn’t really occur though so there are just more cells outside it)
What does the tunica media contain
Smooth muscle (and elastin)
External elastic lamina
What is the role of the Tunica Media
Like a thick wall around the vessel that stops the pressure and beating from being dissipated throughout the circulatory system
Tunica Adventitia/Externa
Just a thick wall of supporting connective tissue around blood vessels
Where do cells of the blood vessel get their oxygenation and nutrients from
Blood diffusing from the lumen, or from vasa vasorum in thick blood vessels
Vasa vasorum
Blood vessels that supply blood to the outer cells in thick blood vessels
Vasculature of the vasculature
Think coronary arteries
Structure and function differences between veins and arteries
Arteries have a larger tunica media to allow them to channel that pressurised pumping mechanism
Diameter of arterial lumen is smaller than that of the vein
**Veins have generally thin walls and thick lumen
Elastic Arteries
Arteries near the heart that contain much more elastic tissue in the tunica media than muscular arteries, allowing them to maintain a mostly constant pressure despite the continuous beating of the heart
Layers of the heart vessels
Endocardium (tunica intima); simple squamous epithelium, basement membrane, loose connective tissue
Myocardium (tunica media); cardiac muscle, suppolied by coronary vessels (vasa vasorum)
Epicardium (tunica adventitia/externa); Connective tissue bordered by simple squamous epithelium which forms the visceral pericardium
Main difference in myocardium and tunica media
Myocardium is made of cardiac muscle while the tunica media is made of smooth muscle
When are venous valves needed
Valves are generally not needed in the head and neck as the blood returns through gravity
It is generally needed in the limbs though to fight gravity
How do valves and the muscle pump of veins work
How does blood in vessels flow in the middle versus the edges and how does the surface of the endothelium facilitate this
It moves faster in the middle than it does on the edges - laminar flow
Non-stick surface of endothelium facilitates this
Where can turbulent blood flow occur and what is its effects
Where blood vessels turn at a sharp angle and blood pressure is raised
It eventually damages the endothelium, exposing blood to collagen in connective tissue and other factors that clot blood
Thrombus vs embolism
A thrombus is a blood clot that stays there while an embolism is a clot that travels
Myocardial infarction
Heart muscle doesn’t get enough oxygen; heart attack
Usually caused by ischaemia of coronary arteries
What are symptoms caused by hypertension
Damage to small and large blood vessels
- Atherosclerosis
- Arteriosclerosis
- Aortic dissection
- Abdominal aortic aneurysm
Damage to kidneys, CNS, heart, eyes
RCTs show BP reduction works to reduce stroke, MI, heart failure
10/5mmHg reduction in BP causes
- 40% less stroke
- 15% less CHD
- 21% less CV deaths
- 13% less Total mortality
Atheroma and layers affected
Type of atheroclerosis - Thickening of walls in large and medium sized arteries
Occurs in high pressure systems (arterial not venous)
Initially disease of tunica intima, later affects media
Describe the ubiquity of atheroma
Atheroma is ubiquitous, very mild in young people though and worsens with age
Risk Factors for Atheroma
A - Arterial Hypertension T - Tobacco H - Hereditary E - Endocrine (Diabetes, Hypothyroidism) R - Reduced Physical Activity O - Obesity M - Male sex A - Age
Common sites of Atheroma
Aorta, Coronary , Carotid, Cerebral, Renal, Iliac, Femoral and Popliteal Arteries, Major Intestinal Arteries
