Question 1

A dysfunction of receptors for the protein hormone,leptin,can provoke:&#10;A) Excessive phagocytosis by tissue macrophages&#10;B) Immunoglobulin deficiency&#10;C) Impaired synthesis of collagen&#10;D) Obesity&#10;E) Septic shock

Accepted Answer

Leptin is a protein hormone that regulates energy balance by inhibiting hunger, thereby promoting satiety and energy expenditure. A dysfunction of leptin receptors can lead to a lack of satiety signals, which results in overeating and, consequently, obesity.

Question 2

Which connective tissue cell possesses a dark-staining,round nucleus,a large,basophilic cytoplasm,and an abundant Golgi apparatus?&#10;A) Brown fat cell&#10;B) Fibroblast&#10;C) Lymphocyte&#10;D) Macrophage&#10;E) Plasma cell

Accepted Answer

The description matches that of a plasma cell, which is a type of connective tissue cell involved in antibody production. The dark-staining, round nucleus and large, basophilic cytoplasm are characteristic of plasma cells, and their abundance of Golgi apparatus is related to their role in secreting antibodies.

Question 3

Which connective tissue cell possesses a large,euchromatic,irregular (ovoid)nucleus?&#10;A) Brown fat cell&#10;B) Fibroblast&#10;C) Lymphocyte&#10;D) Macrophage&#10;E) Mast cell

Accepted Answer

Macrophages are large, phagocytic cells that have a distinctive irregular nucleus. They play an important role in the immune system by engulfing and digesting pathogens and cellular debris.

Question 4

Heat generation via nonshivering thermogenesis is accomplished by cells in which tissue?&#10;A) Brown adipose tissue&#10;B) Liver&#10;C) Skeletal muscle&#10;D) Smooth muscle&#10;E) White adipose tissue

Accepted Answer

Nonshivering thermogenesis is primarily achieved by the activity of brown adipose tissue, which contains a large number of mitochondria that generate heat through oxidation of fatty acids.

Question 5

Reticular fibers of connective tissue are composed of:&#10;A) Type I collagen&#10;B) Type II collagen&#10;C) Type III collagen&#10;D) Type IV collagen&#10;E) Type VII collagen

Accepted Answer

Reticular fibers are composed of type III collagen, which is thinner than type I collagen and forms a mesh-like network in tissues such as lymphoid organs and bone marrow.

Question 6

Mature molecules of tropocollagen are found in the:&#10;A) Cisternae of the rough endoplasmic reticulum of a fibroblast&#10;B) Extracellular environment of a fibroblast&#10;C) Golgi apparatus of a plasma cell&#10;D) Secretory vesicles of a fibroblast&#10;E) Smooth endoplasmic reticulum of a macrophage

Accepted Answer

Tropocollagen is synthesized within the rough endoplasmic reticulum of fibroblasts and then secreted into the extracellular matrix where it undergoes further processing to form mature collagen fibers.

Question 7

In adipose tissue,lipoprotein lipase:&#10;A) Forms triacylglycerol from circulating free fatty acids and glycerol&#10;B) Is activated in response to norepinephrine released from synapses upon fat cells&#10;C) Is synthesized by fat cells and delivered to capillary endothelial cells&#10;D) Signals fat cells to form endocytic vesicles for the ingestion of fat&#10;E) Travels from fat depots to the hypothalamus and functions as a signal of adiposity

Accepted Answer

Lipoprotein lipase is synthesized by fat cells and delivered to capillary endothelial cells where it hydrolyzes triacylglycerol in circulating lipoproteins, such as chylomicrons and very low density lipoproteins, to free fatty acids and glycerol. This allows for uptake of these fatty acids into adipose tissue for storage as triacylglycerol.

Question 8

The cytoplasmic granules of mast cells stain intensely with toluidine blue.This is because of the contents of these granules,which contain:&#10;A) Acid hydrolyases&#10;B) Histamine and proteoglycans&#10;C) Lipid&#10;D) Matrix granules&#10;E) Ribosomes

Accepted Answer

Toluidine blue stains specifically mast cell granules, which contain histamine and proteoglycans. The other options do not represent the contents of mast cell granules.

Deck 3: Connective Tissue