02: Histology Flashcards
List tissue layers of heart wall, from inner to outer.
- Endocardium
- Myocardium
- Epicardium
T/F: myocardium is highly vascularized.
True
Lipofuscin is a(n) (X) that’s found in (Y) of heart.
X = age pigment (brownish/yellow) Y = sarcoplasmic cone of myocytes
Cardiac myocytes are bound together by delicate (X) tissue matrix.
X = reticular
External heart layer, the (X), is a (low/high)-friction surface. What are the tissue layers it contains?
X = epicardium
Low;
- Mesothelium
- Fibroelastic CT (visceral peridcardium)
Coronary vessels travel in which specific tissue layer of heart?
Subepicardial areolar CT
Serous membrane surrounding heart consists of which layers?
- Visceral pericardium
2. Parietal pericardium
Purkinje fibers found in which specific tissue layer of heart?
Subendocardial loose CT (of ventricles)
Purkinje fibers are distinguishable from other myocytes by which characteristics?
- Enlarged size
- Reduced packing of darkly-stained fibrils (pushed to periphery)
- High content of glycogen in middle
As distance from heart increases, amount of elastic material in (X) (increases/decreases).
X = tunica media
Decreases
Unlike (elastic/muscular) arteries, (elastic/muscular) arteries contain (X) fibers in the tunica (Y).
Elastic;
Muscular;
X = elastic
Y = adventitia
Function of elastic arteries is (X), whereas that of muscular arteries is (Y).
X = conduction Y = distribution
Range of lamellar units in elastic arteries. And in muscular arteries.
Elastic: 40-60
Muscular (large): 20-40
Muscular (small): 3-20
List the vessels in which you’d expect to find internal elastic lamina, between tunica (X) and (Y).
X = intima; Y = media
Primarily muscular arteries and arterioles; also in some large veins
List the vessels in which you’d expect to find external elastic lamina, between tunica (X) and (Y).
X = media Y = adventitia
ONLY in largest muscular arteries
Tunica (X) of (Y) vessels may contain many small blood vessels and peripheral nerves. What are the formal names for these?
X = adventitia Y = elastic and muscular arteries
Vasa vasorum and nervi vascularis
Arterioles contain how many layers of smooth muscle cells?
3 or less
Capillaries contain which tissue types in tunica intima, media, and adventitia?
Intima: endothelium
No tunica media and adventitia!
Functions of venules.
Exchange and capacitance
Functions of veins.
Capacitance and returning
T/F: veins and venules have no smooth muscle.
False - venules typically dont, but veins have 1-12 layers
T/F: endothelium lines the entire CV system.
True
The cardiac skeleton is composed of (X) tissue. It anchors (Y).
X = dense fibrous CT Y = valves and muscle cells
The cardiac skeleton provides a generally impermeable boundary to (X) between (Y) and (Z).
X = electrical signals; Y = atria Z = ventricles
List the three major components of cardiac skeleton.
- Annuli fibrosae (four rings of dense CT)
- Trigona fibrosa (two triangular masses of CT)
- Septum membranaceum (dense fibrous plate)
Annuli fibrosae: how many? What’s their function?
4 rings; surround and reinforce valve openings
Part of cardiac skeleton that forms superior portion of interventricular septum.
Septum membranaceum
Vein valves are formed from tunica (X).
X = intima
Each heart valve is a fold of (X), with (rigid/flexible) core of (Y).
X = endocardium
Flexible;
Y = dense CT
Scarring of valves causes them to become less (X). Thus, they don’t (close/open) properly.
X = elastic
Close (incompetence) or open (stenosis)
“Pacemaker” of heart, (X), is located on (Y) wall/floor of which chamber?
X = SA node
Y = medial wall
RA
Impulses from SA node travel to (X), located in which part of heart?
X = AV node
Interatrial septum
Impulses from AV node travel to (X), located in which part of heart?
X = atrioventricular bundle of His
Passes into interventricular septum
Bundle branches (one for each ventricle) form from splitting of (X). These bundles then split to form (Y).
X = atrioventricular bundle of His Y = Purkinje fibers
(Elastic/muscular) arteries are the largest of the body. They function to provide driving pressure by means of (X) characteristic.
Elastic;
X = elastic recoil
Portal system is a double (X), separated by (Y). List some places in body where you’d find portal system.
X = capillary system Y = artery or vein
Liver, pituitary, kidney
T/F: Veins have more elastic walls than arteries.
False
T/F: Veins have more flexible walls than arteries.
True
T/F: Veins are more numerous than arteries.
True
Some veins, like vena cava, have prominent longitudinal bundles of smooth muscle in tunica (X).
X = adventitia
The richness of capillary network is related to which characteristic of the tissue?
Metabolic activity
You’d expect to have higher capillary density in (dermis/myocardium).
Myocardium (2000 versus 50 in dermis)
There’s about (X)% of body’s blood in capillaries at one time.
X = 5-8
List the three basic types of capillaries. Star the most common type.
- Continuous*
- Fenestrated
- Sinusoid
The (X) cells of continuous capillaries are joined to each other by (Y).
X = endothelial Y = intercellular (tight) junctions
A characteristic of (X) vessels is caveolae, which are (Y) that function in (Z).
X = continuous capillaries Y = micropinocytotic vesicles Z = transendothelial transport
Blood-brain barrier and blood-thymus barrier are formed from which specialized vessels?
Continuous capillaries
(X) vessel wall may contain pericytes. These are (Y)-derived (Z) cells.
X = continuous and fenestrated capillaries Y = mesenchyme Z = stem
(X) type of capillaries present in tissue where rapid/voluminous interchange of substances between tissue and (Y) is important.
X = fenesterated Y = blood
Most diagnostic feature of (X) capillaries is the unusually large lumen.
X = sinusoid
(X) type of capillaries allow blood to communicate directly with surrounding parenchyma.
X = sinusoid
Glomeruli of kidney have which type of capillaries?
Fenestrated
CNS and lungs have which type of capillaries?
Continuous
Liver has (continuous/discontinuous) (X) type of capillaries.
Discontinuous;
X = sinusoid
Exocrine glands have which type of capillaries?
Fenestrated
Bone marrow and lymph node have which type of capillaries?
Sinusoid
Endocrine glands have which type of capillaries?
Fenestrated and sinusoid
T/F: Lymphatic capillaries have fenestrations.
Only lacteals
Basement membrane is well-developed, continuous in (X) capillaries and scanty/absent in (Y) capillaries.
X = continuous and fenestrated Y = sinusoid and lymphatic
T/F: In general, most capillaries have intercellular spaces.
False - but may be present in liver
Which types of capillaries contain intercellular junctions?
- Continuous and fenestrated
2. Sinusoid (only if continuous)
