Histology - Connective Tissue Flashcards
Which cell are the least specialized of the connective tissue?
Fibroblast
Which cell synthesize the ECM of connective tissue?
Fibroblast
Which cell do not undergo cell division?
Adipose cell
Which cell are fully differentiated?
Adipose cell
Kupffer cells
Macrofages fixed
Fixed cells?
- Fibroblast
- Adipose cells
- Pericytes
- Mast cells
- Macrophages
Dust cells
Macrophages in the lungs
Which cells are the largest of the fixed cells?
Mast cells
Fibrocyte
Quiescent cells (fibroblast)
“Signet ring” profile
Unilocular fat cell
What kind of ER do the unilocular and the multilocular cells have?
Unilocular: Sparse ER
Multilocular: Lack ER, but have SER
Where will the precusor of mast cells differentiate into mast cells?
Precusor will:
- Originate in the bone marrow
- Circulate in the blood
- Enter the connective tissue where it differentiate into mast cells
Whre are the mast cells concentreted?
Along small blood vessles
Which cell have their own basal lamina?
Pericytes
Langerhans cells
Macrophages of the skin
Annulus fibrosus
- Layer of fibrocartilage whose type I collagen fibers run vertically between the hyaline cartilage of the two vertebrae
- Oriented oblique to each other, providing support to gelatinous nucleus pulposus
Nucleus pulposus
- Gelatinous center in each vertebral disk
- Composed of cells derived from the notorchord, lying within a hyaluronic acid-rich matrix
- Annulus fibrosus surround it
Which cell have acidophilic cytoplasm?
Inactive fibroblast
Lower blood pressure
- Atrial natriuretic peptide
- Act by decreasing the capabilities of renal tubules to resorb sodium and water
Quanta
Acetylcholine (ligand/neurotransmitter) in large quantities
Junctional feet
Voltage gated calcium release channels
Cardiac muscle
Found in the heart and pulmonary vessles
Lamina reticularis
Type I and III collagen
Signaling pathway that lead to activation if the cell cycle, cell differentiation, cytoskeletal reorganization, regulation of gene expression, and even programmed death via apoptosis
Includes:
- Mitogen-activated protein kinase pathway
- Protein kinase C pathway
- Phosphoinositide pathway
Kupffer cell
Macrophages of the liver
Which cells belong to the mononuclear phagocyte system?
- Macrophages:
> Kupffer cells
> Dust cells
> Langerhans cells
> Monocytes
> Macrophages of the connective tissue, spleen, lymph nodes, thymus, and bone marrow
- Osteoclast
- MicrogliaWhat is the function of active phagocytes?
They function in removing cellular debris and in protectingnthe body against foreign invaders
Is the cytoplasm of the macrophages acidophilic or basophilic?
Basophilic
Which cell have a nucleus that resembles a kidney?
Macrophages
Which cell posses microvilli and lamellipodia?
Active macrophages
Which cell do not display nucleoli?
Macrophages
From where do the macrophages arise?
- They arise from monocytes.
- Activated by macrophage colony-stimulating factor (M-CSF)
Epitheloid cells
Are macrophages that have enlarged and become polygonal
Foreign-body giant
- Macrophages fused together.
- The foreign-body giant is multinucleated
Fixed macrophages =?
Resident macrophages
Free macrophages
Elicited macrophages
Macrophages are…..
Active phagocytes
Where does all members of the mononuclear phagocyte system arise from?
They arise from common stem cell in bone marrow
What is degranulation?
The release of the granule contents, namely histamine, heparin, neutral protease, aryl sulfatase, and other enzymes, eosinophil chemotactic factor, and neutrophil chemotactic factor.
What is adenylate cyclase responsible for?
It is responsible for the conversion of adenosine diphosphate (ADP) to cAMP
Which receptors does the mast cells have?
FceRI for IgE
What is and which cell initiate “immidiate hypersensitivity reaction” (anaphylatic reaction?)?
It is an inflammatory response from mast cells
What is the difference in the granules of mast cells in the connective tussue and those of the mucosa of the alimentary tract?
- Connective tissue –> Heparin
- Mucosal mast cells –> Chondroitin sulfate
What does the releasing of histamin from the mucousal mast cell do?
Facilitate the activation of parietal cells of the stomach to produce hyaluronic acid
What does the fat cell manufacture?
Lipoprotein lipase
What is VLDL B synthesized by?
By the liver
Which cells are located along the blood vessles?
Fat cells and mast cells
Where is the norepinephrine and epinephrine relesed from?
Suprarenal medulla
Where is fat cells found?
Fat cells is found through the body in loose connective tissue and are concentreted along blood vessles
Which cell becomes irregular having pseudupod-like projections during fasting?
White adipose tissue
Where are the fixed mast cells located?
In the connective tissue proper
Which cells are the largest of the fixed cells?
Mast cells
Which fat cell is most abundant?
White fat cells, unilocular cells
Which cell has an acidophilic cytoplasm?
Inactive fibroblast
What is in active fibroblast?
- Actin and “alpha”-actin at the periphery of the cell.
- Myosin is throughout the cytoplasm
Myofibroblast have similar characteristics to……?
Fibroblast and smooth muscle cells
Pericytes possess characteristics of…….?
Endothelial cells and smooth muscle cells
Which cells are outside the connective tissue conpartment and why?
The pericytes, because they are surrounded by their own basal lamina.
Where is myofibroblast most abundant?
In areas undergoing wound healing, where they function in wound contraction
What do the smooth muscle cell have which the myofibroblast do not have?
External lamina (basal lamina)
The mast cells resembles?
Basophils
Which cell is most abundant in dense irregular connective tissue?
Fibroblast
What do the different dense connective tissue constitue?
The dermis
The sheaths of nerves
The capsules of the spleen, testes, ovary, kidney, and lymph nodes.
Which connective tissue resists tensile forces?
Dense regular connective tissue
Which connective tissue resists stress?
Dense irregular connective tissue
What connective tissue is the cardiac skeleton comoposed of?
Dense connective tissue
Which cell synthesize the type III collagen?
Fibroblast of reticular tissue
Lamina propria
Loose connective tissue of mucos membrane
Where can we find Wharton’s jelly/mucous tissue?
Umbilical cord and the subdermal connective tissue of the embryo
Specialized connective tissue
- Cartilage
- Bone
- Blood
Connective tissue proper
- Loose (areolar) connective tissue
- Dense connective tissue
> Dense irregular connective tissue
> Dense regular connective tissue
~ Collagenous
~ Elastic - Reticular tissue
- Adipose tissue
Embryonic connective tissue
- Mesenchymal connective tissue
- Mucous connective tissue
Facilitate the uptake and release of free fatty acids and glycerol
- Insulin
- Growth hormone
- Norepinephrine
- Glucocorticoids
Where is the unilocular fat present?
In the subcutanous layer throughout the body
Why do the brown adipose tissue appear tan to reddish brown?
Because of the extensive vascularity and the chytochromes present in its abundant mitochondria
How do the axon end in brown adipose tissue?
Unmyelinated nerve fibers enter the tissue, with the axon ending on the blood vessels as well as in fat cells, whereas in white fat tissue, the neurons end only on the blood vessles
How do the axon end in white adipose tissue?
The neurons end only on the blood vessles
Which substances do the unilocular fat cells have receptors for that facilitate the uptake and release of free fatty acids and glycerol?
- Insulin
- Growth hormone
- Norepinephrine
- Glucocorticoids
What does the neurotransmitter norepinephrine do?
Activates the enzyme taht cleaves triglycerides into fatty acids and glycerol initiating the heat production by oxidation of fatty acids in the mitochondria
Thermogenin
A transmembrane protein located on the inner membrane of the mitochondira, permit backflow of protons instead of utilizing them for synthesis of adenosine triphosphate (ATP); as a result of uncoupling oxidation from phosphorylation, the proton flow generates energy that is dispersed as heat
(Stem cells –> ) Preadipocytes differentiate into adipocytes……
Under the influence of a series of activating factors
Primary fat formation
- Occurs early in fetal life.
- Groups of epitheliod precusor cells are distributed at certain locations in the developing fetus; in these tissues, lipid droplets begin to accumulate in the form of brown adipose tissue
Secondary fat formaton
Near the end of fetal life, other fusiform precusor cells, differentiate in many areas of the connective tissue within the fetus and begin to accumulate lipids that coalesce into the single droplet in each cell, thus forming the unilocular fat cells found in adults
When is the brown adipose tissue present?
In the embryo and, a little bit in adults.
When is white adipose tissue present?
Only after birth. Adults have mostly unilocular fat
