Cardiovascular system Flashcards
Components of cardiovascular system
Heart
Arteries
Capillaries
Veins
Define microvascular bed
anastomosing network of capillary tubules formed in almost every organ
Which structures converge to form veins?
venules
Define elastic artery.
Large vessels whose major role is to carry blood to smaller arteries
Examples of conducting arteries.
Aorta
Pulmonary artery and their largest branches (ex: thyrocervical trunk)
Another name for elastic artery
Conducting artery
All arteries carry oxygenated blood except
Pulmonary artery carrying deoxygenated blood to lungs
umbilical artery
How structure of arteries change as you move farther from the heart.
Elastic lamellae decrease and smooth muscle increases
Difference between elastic and muscular arteries
Elastic arteries
- for conduction
- tunica media has more elastic lamellae, but less smooth muscle
Muscular arteries
- for distribution
- tunica media has more smooth muscle, but less elastic lamellae
Function of elastic lamellae in conducting arteries.
Allow for stretch within a certain limit during systole (contraction) and passively rebound during diastole (relaxation), to maintain constant blood pressure
Thouroughfare channel
distal end of metarteriole lacking smooth muscle
What determines which molecules get to interact with endothelial cells of capillaries?
the type of basement membrane
Composition of diaphragms covering perforations of fenestrated capillaries.
proteoglycans
Location of continuous capillaries.
muscles connective tissue nervous tissue lungs exocrine glands
Types of capillaries found in 1) endocrine glands 2)exocrine glands
endocrine glands have fenestrated capillaries
Exocrine glands have continuous capillaries
Where are sinusoid capillaries found?
liver
spleen
bone marrow
some endocrine organs
3 major layers of the heart.
Endocardium
Myocardium
Epicardium
Purkinje fibers are found in which layer of the heart?
In the endocardium’s subendocardial layer
The thickest layer of the heart
Myocardium
True or false; Myocardium is thicker in atria walls than in ventricle walls
False: it has to be thicker in ventricle walls as they need more pressure to pump it to the rest of the body
Name of the simple squamous epithelium surrounding epicardium layer
mesothelium
Valves of veins project from which layer?
Tunica intima
Classification of veins.
Is based on diameter/size There are 4 types 1. Venules <0.1 mm 2. Small veins <1 mm 3. Medium veins <10mm 4. Large veins >10mm
Distinguishing features of muscular arteries.
- Tunica media most prominent and rich in smooth muscle cells
- Very clear demarcation between tunica media and tunica intima by prominent internal elastic lamina
Distinguishing features of capillaries .
No tunica media or adventitia
What space thickens with age and can cause complications with heart blood supply?
Subendothelial space
Function of smooth muscles in blood vessels
Contraction
Produce fibers
Heart conduction system components
AV
SA
artrioventricular bundle of His
Purkinje fibers
Define cardiac conducting system
modified cardiac muscle fibers that stimulate rythmic contractions of the heart
Type of connective tissue that makes up cardiac skeleton
Dense irregular C.T.
Layers of tunica intima
Endothelium
CT
Internal elastic lamina
Functions of endothelium
- Thrombogenic barrier
- Semipermeable membrane
- produces factors that make adjacent smooth muscle cells to contract/relax
- Produce factors to initiate inflammation
How does endothelium act as a thromobogenic barrier
produces factors that prevent blood clotting
How Embolus forms
when endothelial layer damaged and platelets contact connective tissue, fibrinogen is converted to the insoluble fibrin forming blood clots that can dislodge and are then called emboli
End artery
supplies only one tissue
Virchow’s triad
Describes factors that contribute to thrombosis
Factors of Virchow’s triad
- Endothelial injury
- Stasis (blood not moving)
- Blood content (ex: progesterone makes blood more prone to clotting)/Hypercoagubility
Capillary beds drain into
venules
