Cardio - Anatomy of Capillaries Flashcards
This is the site of exchange between blood and tissues.
Capillaries
Good exchange between blood and interstitial fluid requires what type of flow in the capillaries?
Smooth and steady force
Why is the cross sectional area of the capillary bed much larger in comparison to the arterioles?
Because this ensures that the blood in capillaries has a smooth and steady flow
What lines the capillary wall?
Endothelium
What is the most dominant type of intercellular junction in the capillaries?
Tight junction
What is the significance of tight intercellular junctions in the capillary?
Because these intercellular junctions determine how much substance/blood can go through the capillary
Why is the cytoplasm of capillaries very thin?
To accomodate RBCs
There are composed of smooth muscle cells that control how much blood goes into the capillaries. They specifically constrict and stop blood from going into some branches of the capillary network.
Precapillary sphincters
These are responsible for the deliberate, specific movement of blood through the capillaries. An example of this function would be vasodilation/constriction
Vascular shunts
These change the capillary depending on the type of exchange occurring.
Vascular shunts
What are the two parts of the vascular shunt?
Metarteriole and thoroughfare channel
What kind of muscle are precapillary sphincters made of?
Smooth muscle
What are the 3 types of capillaries?
Continuous, Fenestrated, Sinusoidal
This type of capillary has a basement membrane made of extracellular matrix that involves gas exchange goi ng directly through one cell to another.
Continuous capillary
If gas exchange cannot occur passively, these carry substances that cannot diffuse easily through the cell, across the cell.
Vesicles
Where are vesicles found in capillaries?
In the cytoplasm
This type of capillary has circular/porous openings that allow small enough substances to pass from the lumen surface to basal surface without having to go directly through the cell.
Fenestrated capillary
This type of capillary is deliberately leaky so nutrients can get into the blood in a shorter period of time.
Fenestrated capillary
These two capillaries allow movement through fenestrations (particularly water-soluble substances)
Fenestrated and sinusoidal capillaries
This drains excess tissue fluid and plasma proteins from tissues and returns them the blood.
Lymph/lymph vascular system
When lymph is screened for foreign antigens, and it detects one - how does it usually respond? (2 points)
1st point: lymph vascular system has an immune surveillance system.
2nd point: When it detects a foreign antigen, it responds by releasing antibodies and activated immune cells
The lymph doesn’t absorb fat from intestine and transports to the blood. True or false.
False. Lymph absorbs fat and transports it to blood.
These commence as large, blind ending capillaries.
Lymphatic vessels
This is a special group of lymphatic vessels in the small intestine that drains fat-laden lymph.
proof that lymph absorbs fat - the presence of these specialised structures
Lacteals
This is the collecting vessel where fat-laden lymph from the intestine is collected/deposited.
Cisterna chyli
How many sides does lymph have?
2 (afferent and efferent side)
This is a type of capillary with an incomplete basement membrane. The lumen is significantly larger and there are intercellular gaps in between.
Sinusoidal capillaries
Continuous capillaries can move blood through intercellular clefts. True or false.
True
Lymphatic vessels have thicker walls and numerous valves to prevent back flow. True or false.
False. Lymphatic vessels have thinner walls because remember, much like veins - they are capacitance vessels.
What are the 3 regional lymph nodes?
Cervical, axillary, inguinal nodes
What is the basement membrane of capillaries made of?
Extracellular matrix
What capillaries would be found in your skeletal/cardiac muscle?
Continuous capillary
What capillaries would be found in your small intestine? Why?
Fenestrated capillary - to transport nutrients from cell surface to basal surface in a shorter period of time
What capillaries would be found in the liver?
Sinusoidal capillary
