Blood and blood vessels Flashcards
Erythrocytes
- contain hemoglobin + enzymes
- bright pink color ⇒ hemoglobin
- diameter: 6-8 um
- biconcave disc shape
- no nuclei
- function: carries O2 and CO2
Neutrophils
- 40-75% of leukocytes
- highly lobulated nuclei
- diameter: 10-15 um
- azurophilic granules⇒purple, lysosomes
- specific granules ⇒ pink
- function: phagocytosis (innate immune system)
Eosinophils
- 1-6% of leukocytes
- uniform sized, strongly eosinophilic granules
- bilobed nucleus
- diameter: 12-17um
- function: modulate allergic inflammatory responses (parasites)
Basophils
- <1% of leukocytes
- diameter: 9-12um
- large, irregular, strongly basophilic granules
- bilobed nuclei
- functin: release histamine for inflammatory response
Lymphocytes
- 20-50% of WBC
- spherical darkly stained nuclei
- thin rim of slightly basophilic cytoplasm around
- function: B-cells ⇒ release antibodies; T-cells
Monocytes
- diamter: 10-20um
- 2-10% of WBCs
- nucleus is oval, horseshoe or kidney shaped, eccentrically placed
- cytoplasm basophilic + contain azurophilic granules⇒ bluish-grey color
- function: macrophage ⇒ phagocytosis
Thromobytes
- non-nucleated small cell fragments
- size: 2-4 um
- originate from megakaryocytes located in bone marrow
- functin: blood coagulation
- Bone marrow (HE)
- marrow is separated from bony trabeculae by bone lining cells(osteoprognitor or endosteal cells)
- framework of reticular cells⇒ supports haemopoietic cells and network of blood sinusoids
- adipocytes
- Megakaryocytes (35-150um)⇒ platelet formation, huge irregular multi lobar nucleus + basophilic granular cytoplasm
- Elastic artery (HE)
TUNICA INTIMA:
- Endothelium: flat polygonal elongated cells
- Subendothelial layer: elastic fiber, smooth muscle cells, collagen, fibroblast
- Internal elastic lamina: circular lamina of elastic fibers
TUNICA MEDIA:
- 50 concentrically arranged fenestrated elastic laminae
- smooth muscle, collagen, elastic fibers in interlaminar space
- non-striated myocytes: production of elastic laminae and collagen fibers
TUNICA ADVENTITIA:
- broad tissue around aorta
- collagen, elastic fibers, fibroblasts, macrophages, mast cells
- Elastic aorta (orcein)
elastic fibers ⇒ brown color
- Muscular artery and medium-sized vein
ARTERY:
TUNICA INTIMA:
- endothelium
- sub endothelial layer: scant, elastic fibers, rarely smooth muscle, small amount ground substance
- internal elastic lamina: wavy, light pink
TUNICA MEDIA:
- more than 10 circumferentially arranged smooth muscle layers
- reticular + elastic fibers in extracellular space
- wavy external elastic lamina
TUNICA ADVENTITIA:
- collagen, less elastic fibers, fibroblasts, fat cells, nerves, lymphatics, vasa vasorum
MEDIUM-SIZED VEIN:
TUNICA INTIMA:
- endothelium
- sub endothelial layer: few smooth muscle cells, thin CT
- internal elastic lamina: valves
TUNICA MEDIA:
- thinner, less smooth muscle, reticular and elastic fibers circumferentially irregularly arranged
TUNICA ADVENTITIA:
- thicker
- elastic fibers + fibroblasts
- Small arteries, arterioles and small veins, venules (HE)
- in small arteries tunica media ⇒ 5-10 layers of smooth muscle, internal elastic lamina present, no external elastic lamina
ARTERIOLES:
TUNICA INTIMA: thin, collagenous CT
TUNICA MEDIA: 1-4 layers of smooth muscle
TUNICA ADVENTITIA: thin, ill-defined, merges with surrounding loose CT
- Capillaries and postcapilalry venules (toluidine blue)
TUNICA INTIMA:
- single endothelial cell layer of 1-3 cells supported by basal membrane
TUNICA MEDIA:
- absent in capillaries
TUNIC ADVENTITIA:
- pericytes often seen
- supporting cells are flattened + have long cytoplasmic processes
