Histology Flashcards
Thre major layers of the heart?
- the inner endocardium of endothelium (and subendothelial connective tissue!)
- the myocardium of cardiac muscle
- the epicardium (connective tissue with many adipocytes and covered by mesothelium)
What 4 characteristics are found in the epicardium?
- Mesothelium
- Connective tissue
- Autonomic nerve bundles
- Adipose tissue
What is the function of the cardiac conducting system?
What are the 4 parts in order?
Modified cardiac muscle fibers that stimulates rhytmic contraction (heartbeat)
- Sinoatrial (SA) node (pacemaker)
- Atrioventricular (AV) node
- Atrioventricular bundle (of His) (in interventricular septim)
- Purkinje Fibers
How do Purkinje fiber differ from contractile fibers (3)?
- larger diameter
- abundant glycogen (therefore pale staining)
- closer to the endothelium
What is the cardiac skeleton?
Three functions of the cardiac skeleton?
The cardiac skeleton is dense fibrous/irregular connective tissue primarily found in the endocardium
- anchoring and supporting heart valves
- provides firm points of insertion for cardiac muscle
- coordinates heartbeat by acting as electrical insulation between atria and ventricles
Three layers/tunics of blood vessels?
- intima
- media
- adventitia
In an artery, the thickest layer is the _1_ and the lumen is _2_. In a vein, the thickest layer is the _3_ and the lumen is _4_. In a vein, the intima forms _5_ IOT restrict backflow. _6_ contain no tunics and only endothelium.
- media
- narrow
- adventitia
- large
- valves
- capillaries
Just as the heart wall is supplied with its own _1_ arteries for nutrients and oxygen, large vessels usually have __ 2 __ (arterioles, capillaries and venules in the _3_ tunic and outer part of the media.
- coronary
- vaso vasorum
- adventitia
In arteries and large veins, the intima includes a prominent limiting layer made of elastin. What is the name of this layer?
Internal elastic lamina
3 types of microvasculature?
- Arterioles
- Capillaires
- Venules (drain capillaries)
What type of blood vessel is this?
- endothelium present
- 1-3 layers of smooth muscle
- Thin connective tissue adventitia
Arterioles
What blood vessel type is this?
- Resists and controls blood flow to capillaries
- Major determinant of systemic blood pressure
Arterioles
What type of blood vessel is this?
- Endothelium present
- Pericytes in Media
- No adventitia
Capillary
What type of blood vessel exchanges metabolites by diffusion to and from cells?
Capillaries
What type of blood vessel is this?
- Endothelium present
- scattered smooth cells in media
- no adventitia
Venule (no valves present!)
What blood vessel drains capillary beds and allows leukocytes to exit vasculature?
Venules