Cardio Histology Flashcards
What is the diameter of an erythrocyte?
6.5-8.5 microns
What are the granulocytes?
Neutrophil, eosinophil, basophil
Where are red blood cells mainly destroyed?
The spleen
What is the definition of an artery?
carries blood away from the heart
What type of artery is the aorta?
large elastic artery
What is the difference between an elastic artery and a muscular artery?
In an elastic artery the media contains abundant concentric sheets of elastin
In a muscular artery the media contains layers of smooth muscle
why are the walls of the vessels in the pulmonary circulation thinner than the walls of the vessels in the systemic circulation?
Pulmonary circulation is under lower pressure
What layers lie either side of the media in a vessel?
internal elastic lamina and external elastic lamina
What is the main component of the adventitia?
collagen
What can be found in the adventitia of thick walled vessels that supply the media with blood?
vasa vasorum
Describe the arrangement of elastic fibres in an elastic artery
arranged cirumferentially
How can we define an arteriole?
3 or fewer layers of smooth muscle in the media
In what organs will you find sinusoids?
Liver and spleen
What are sinusoids lined by?
endothelium (fenestrated)
Describe the basement membrane in sinusoids
scanty, discontinuous or absent
What are the venules that come immediately after the capillaries called?
post capillary venules
What do post capillary venules have more of than capilllaries?
pericytes
In muscular venules what are the pericytes replaced with?
smooth muscle
What allows arterioles to communicate directly with venules?
arteriovenous anastamoses
What do lymphatics have in common with veins but not with arteries?
valves
What percentage of blood is plasma?
56%
What percentage of blood is white blood cells?
1%
What is the diameter of a red blood cell?
6.5-8,5 microns
Where are red blood cells destroyed?
liver, spleen, bone marrow
What are the agranulocytes?
lymphocytes and monocytes
What do monocytes become in tissues?
macrophages
What do basophils become in tissues?
mast cells
what are polymorphonuclear leukocytes also called?
neutrophils
How many types of cytoplasmic granule does a neutrophil contain?
3
What are primary granules in neutrophils similar to?
lysosomes
What do primary granules in neutrophils contain?
acid hydrolases and myeloperoxidase
What do secondary granules in neutrophils secrete?
substances that mobalise inflammatory mediators
What do tertiary granules in neutrophils contain?
enzymes and adhesion molecules
Describe the nucleus of a neutrophil
multi-lobed
Describe the nucleus of an eosinophil
bi-lobed
Which granulocyte has lozenge shaped granules with crystaline cores?
eosinophils
Eosinophils inhibit the secretion of which cell?
mast cells
How do eosinophils restrict the inflammtory response?
neutralise histamine
Describe the nucleus of a basophil
bi-lobed
Which cell increases in number during a parasitic infection
Eosinophil
What is the least common white blood cell?
basophil
What colour do basophil granules stain?
dark blue
What do basophil granules contain?
histamine
Basophils are the circulating form of which cell?
tissue mast cell
What do basophils have receptors for?
IgE
What do basophils release in response to allergens?
histamine
What is the diameter of a lymphocyte?
10 microns
What colour does the cytoplasm of a lymphocyte stain?
blue/grey
What type of T cell suppresses the immune response?
T suppressor cells
What type of T cell kills previously marked target cells?
T cytotoxic cells
What is NK cells short for? What do these cells do?
natural killer cells
Mainly kill virus infected cells
Describe the nucleus of monocytes?
reniform
Monocytes are classed as agranulocytes. Do they have cytoplasmic granules?
Yes. They have small cytoplasmic granules- mainly lysosomes
What can monocytes differentiate into?
tissue macrophages kupffer cells osteoclasts antigen presenting cells alveolar macrophages
What type of cell are platelets derived from?
megakaryocytes
What is the word for the formation of blood cells?
hematopoeisis
What type of cell do all blood cells come from?
haematopoeitic stem cell (hemocytoblast)
What is the sac called that the heart lies in?
the pericardial sac
What type of cell rests on a thin layer of fibrous connective tissue to make the pericardium?
mesothelial cells
What are the two different types of pericardium?
visceral and parietal
Which layer of the heart contains the coronary arteries?
the epicardium
What is the fancy name for muscle cell?
myocyte
What is the thickest layer of the heart?
The myocardium
Cardiac muscle cells form which layer of the heart?
the myocardium
What do intercalated discs contain?
gap junctions, desmosomes and adhering junctions
Where will you find the largest cardiac myocytes?
In the wall of the left ventricle
What type of granule do atrial myocytes have and what does this granule contain?
perinuclear neuroendocrine granules
atrial natriuretic hormone
What triggers release of atrial natriuretic hormone?
excessive stretching of the atria
Which hormones does atrial natriuretic hormone inhibit?
renin and aldosterone
Which layer in the internal lining of the heart?
the endocardium
Describe the endocardium
thin layer of fibrous connective tissue lined on its innermost surface by endothelial cells
what are the heart valves attached to?
the central fibrous body
Excluding the endothelial layers, what are the layers of a heart valve? And out of these layers which lies closest to the ventricle if we were referring to the aortic valve?
fibrosa
spongiosa
ventricularis- lies closest to the ventricle
What type of cells surround the heart valve?
endothelial cells
