Histology Flashcards
4 basic types of tissues
- Epithelial
- Connective
- Muscle
- Nerve
T/F Epithelium is vascular
False
Epithelium lining proximal nephron vs. distal
Proximal: squamous
Distal: cuboidal
The primary type of epithelium lining the GIT (distal to the esophagus)
Simple columnar
Lining of mouth, esophagus and vagina
Stratified squamous
Difference between keratinized and nonkeratinized epithelium.
Keratinized: no nucleus
What type of odd epithelium lines duct of sweat gland?
Stratified cuboidal
What makes pseudostratified epithelium pseudostratified?
All cells rest on BM, but not all reach the lumen
Pseudostratified columnar epithelium with stereocilia
Epididymis
Lateral adhesions in epithelium
Zonula occludens: TJ
Zonula adherens: Intermediate junction
Macula adherens: Desmosome [e-cadherins]
What type of collagen (along with laminin and PG) lines basal lamina?
Collagen 4
Hemidesmosome is present
Basal surface of epithelium
Basal plasma membrane infoldings contain
Na-K-ATPase
Stereocilia are cilia or microvilli? Where are they present?
Very long microvilli: present in the epidiymis and vas deferens of male reproductive tract
What is the role of dyenin in cilia?
Splits ATP to liberate energy necessary for active movement of cilium
Differentiate between the cilium body and the basal body
Body: 9+2 doublets
Basal body: Triplets 9+0
Endocrine vs. Exocrine
Endocrine: secrete into B/S
Exocrine: secrete into duct
Eosin vs. Hematoxylin (Color)
Eosin: pink zymogen granules
Hematoxylin: purple
Parotid gland: serous or mucinous
Serous
Submandibular & sublingual gland: serous or mucinous
Mixed
Define holocrine and differentiate from apocrine
Entire cell contents released
Apocrine: part of apical cytoplasm released
Define connective tissue & state its embryologic origin
Diverse group of cells within ECM (derived from mesenchyme)
What comprises the ECM
Fibers: collagen, reticular, elastic
Ground substance: GAG, etc.
Name the collagen: bone, tendon, dentin, skin. Provides tensile strength
Collagen 1
Name the collagen: hyaline and elastic cartilage. Observed as fibrils
Collagen 2
Name the collagen: Reticular lamina of basement membrane
Collagen 3
Name the collagen: Basal lamina. Each binds to binding site of laminin
Collagen 4
Name the collagen: amnion and chorion of fetus, muscle and tendon sheaths; no fibrils
Collagen 5
T/F Collagen synthesis is inhibited by steroids
T
How is collagen degraded?
MMP, macrophages, fibroblasts
The most abundant type of connective tissue cell
Fibroblast: secrete ground substance, well developed Golgi (osteoblast, etc)
Role of brown fat
Heat production: neck, abdomen of neonates
Mast cells have receptors of which Ig?
IgE
Shape of eosinophil nucleus
Bi-lobed
Shape of monocyte nucleus
Kidney shaped
What type of embryonic connective tissue is found in the umbilical cord?
Mucous C/T: Wharton’s jelly = abundant ECM
Loose vs. Dense connective tissue. Which has more cells
Loose: more cells
IL-4 and 13 promote
Synthesis of IgE
The largest WBC in circulating blood
Monocyte
Platelets have a lifespan of
5-9 days
Alpha granules vs. Dense granules of platelets
Alpha: clotting factors, PDGF
Dense: ADP, Ca, Serotonin, COX (TXA2)
The 3 phases of hematopoeisis in development
- Yolk sac: 3rd week
- Hepatic: 2nd trimester
- Bone marrow phase
A CD34+ stem cell will give rise to…
Common myeloid progenitor (G/AG)
Common lymphoid progenitor (B, T, NK)
A stem cell niche is defined as: Where is the stem cell niche found?
A spatial structure (microenvironment) where HSC’s are housed and maintained by allowing self renewal in the absence of differentiation
** Epiphyseal areas / spongy or cancellous bone
Quiescent HSC’s detach from endosteal niche and migrate towards the center of the bone marrow to the vascular zone, also called
Vascular niche
Red vs. Yellow marrow
Yellow: fat, capillaries, reticular cells, inactive hematopoiesis
Red: Active hematopoesis
Where is TPO produced?
Liver
The main stimulus for erythropoiesis is…
Hypoxia
Epididymis is lined by:
Pseudostratified columnar epithelium with stereocilia
Neural crest cells give rise to (in the nervous system)
Peripheral ganglia, dorsal root, Schwann cells
Neuroectoderm gives rise to (in the nervous system)
Most CNS structures
Microglia are derived from…
Monocytes/Mesoderm
3 components of the basement membrane
Lamina rara, densa, reticularis
[R, D = epithelial]
These cells, recognized by their large size and pale nature of cytoplasm, are in what layer of the heart?
Sub-endocardum; Purkinje cells
Electron dense vesicles found in cells of the heart secrete…
ANP
What separates the tunica intima from the tunica media?
Internal elastic lamina
Which tunica of the blood vessels contains nervi vascularis, vasa vasorum and lymphatics?
Tunica adventitia
What anticoagualant signal in secreted by endothelial cells?
Thrombomodulin
What cells produce ACE?
Pulmonary endothelium
The major elastic arteries include…
Aorta and its main branches. 40-70 layers of elastic fibers in the media
The muscular arteries include…
Named vessels; most abundant; contain more smooth muscle than elastic fibers
* External elastic lamina
Which arteries contain an external elastic lamina?
Muscular (named) arteries
Continuous vs. Fenestrated (visceral) vs. Discontinuous (sinusoidal) capillaries
Continuous: tight junction
Fenestrated: eye, ventricles, kidney, LP [includes diaphragm – except the kidney]
Discontinuous: Liver, spleen, BM
The homing effect is achieved with which part of blood vessels?
High endothelial venules
The larger the vein, where are smooth muscle bundles seen?
Tunica Adventitia
What is common to nervous tissue, bone marrow and cartilage (with respect to vascular histology)?
No lymph drainage!
What are the characteristic changes in a muscular artery 2/2 HTN?
Symmetrical hypertrophy of the muscular media, extensive reduplication of the IEL and fibrotic thickening of the intima
_____________ is characterized by lesions of the tunica intima called fibro-fatty plaques that obstruct the vascular lumen and weaken the underlying tunica media
Atherosclerosis
The gold standard heart disease test
Coronary angiography via catheterization
Pathology to what part of the blood vessel is implicated Marfan?
Tunica media
What is the major granule of eosinophils?
MBP
What is ansiocytosis?
A blood abnormality where the RBC’s are of unequal sizes.
Ansiocytosis vs. Poikilocytosis
Ansio: Size
Poik: Distorted shape of RBC
The cell membrane has a polar head made of:
Phospholipids, glycolipids, cholesterol
In the GIT, the sub-mucosal plexus is called… From what tissue is it derived?
Meissner’s plexus [part of the enteric nervous system, derived from neural crest cells]
Where is Auerbach’s plexus?
Myenteric plexus; also dervied from NC cells; innervates peristaltic muscles
Describe the muscular content of the esophagus by 1/3rds.
Upper 1/3: Striated
Middle: Striated/Smooth
Lower: Smooth
