Lab Quiz 7 Material (03/20/2025) Flashcards
Individual fat cells.
What are adipocytes?
In what type of connective tissue will you find adipocytes? Loose or dense?
Throughout loose connective tissue
Tissues in which adipocytes are the primary cell type are designated as this.
What is adipose tissue?
What is the key role of an adipocyte?
Energy homeostasis
The body has a limited capacity to store carbohydrates and protein; therefore, energy reserves are stored within {…} droplets of adipocytes in the form of {…}.
1) Lipid
2) Triglycerides
What do triglycerides represent? In essence, what is their function in relation to FOOD INTAKE and ENERGY EXPENDITURE?
To act as a dynamic form of energy storage added when food intake is greater than energy expenditure
The most concentrated form of metabolic energy storage available to humans.
What are triglycerides?
Adipose tissue is considered a major {…} organ.
Endocrine
Considerable evidence links the increased endocrine activity of adipocytes to the metabolic and cardiovascular complications associated with this weight condition.
What is obesity?
The predominant type of adipose tissue in adult humans.
What is white adipose?
This type of adipose tissue is present in large amounts in humans during fetal life. It diminishes during the first decade after birth but continues to be present in varying amounts, mainly around internal organs.
What is brown adipose?
This type of adipose tissue consists of an accumulation of brown-like adipocytes within the subcutaneous white adipose tissue deposits in adult humans.
What is beige adipose?
How does the function of white adipose tissue generally differ from the function of brown and beige adipose tissue?
White - stores excess energy in lipids
Brown/beige - dissipates energy via heat production
This adipose tissue, also called UNILOCULAR, represents at least 10% of the body weight of a normal healthy individual.
What is white adipose?
White adipose tissue forms a fatty layer of the {…} (superficial) fascia in the connective tissue beneath the skin.
Subcutaneous
What is the Latin name for the subcutaneous fascia that white adipose makes up?
Panniculus adiposus
Thermal conductivity of the adipose tissue is only about {…} (fraction) that of skeletal muscle, providing significant thermal insulation against the cold.
One-half
In both sexes, this structure is the preferential site for accumulation of adipose tissue.
What is the mammary fat pad?
In the nonlactating female, this gland is primarily composed of the mammary fat pad.
What is the mammary gland?
What are the 3 important roles of the mammary fat pad in supporting breast function in lactating women?
1) Lipids & energy for milk production
2) Synthesis of growth factors that modulate responses to steroid hormones
3) Synthesis of proteins regulating mammary gland function
Adipose tissue functions as a cushion to many organs and structures. How sound is this structural function in the face of a caloric deficit (i.e., depletion of lipids)?
Adipose tissue retains its structural function even when depleted of lipid
White adipocytes actively synthesize and secrete {…}, a group of biologically active substances, which include hormones, growth factors, and cytokines (Fig. 9.1).
Adipokines
This notable adipokine is involved in the regulation of energy homeostasis and is primarily secreted by adipocytes.
What is leptin?
Leptin fulfills the criteria for this factor that controls food intake when the body’s store of energy is sufficient.
What is the circulating satiety factor?
Leptin acts on the CNS by binding to specific receptors, mainly in this region of the brain.
What is the hypothalamus?
Leptin also regulates the production of {…} hormones (e.g., testosterone, estrogens, and glucocorticoids).
Steroid
List 3 other important adipokines in addition to leptin.
1) Adiponectin
2) Resistin
3) Angiotensinogen (AGE)
These RNA molecules were found in circulating intact exosomes secreted by white adipocytes. They are about 22 nucleotides long and contain intact genetic information specific to adipocytes.
What are microRNAs (miRNAs)?
Obesity associated with increased secretion of these 2 proteins may be linked to metabolic abnormalities and the development of diabetes.
What are growth factors & cytokines?
This key thermogenic tissue is present in large amounts in the newborn. It helps to offset the extensive heat loss that results from the newborn’s high surface-to-mass ratio and to avoid lethal hypothermia (a major risk of death for preterm babies).
What is brown adipose?
This imaging technique detects cancer cells based on their uptake of large amounts of radioactively labeled glucose (18F-FDG) and can detect patterns characteristic of brown adipose tissue.
What is positron emission tomography (PET)?
This term describes brown adipose.
What is multilocular?
Why is brown adipose tissue considered “multilocular,” while white adipose is considered “unilocular?” Define these terms.
Multilocular (brown) - each adipocyte contains many small lipid droplets
Unilocular (white) - each adipocyte contains one large lipid droplet
Brown adipocytes differentiate from these stem cells under the control of PRDM16/PGC-1 transcription factors.
What are mesenchymal skeletal myogenic progenitor (Myf5 positive) stem cells?
The myogenic lineage marker that remains detectable in mature brown adipocytes and in all stages of their differentiation.
What is myogenic factor 5 (Myf5)?
When the zinc-finger protein known as {…} (PRDM16) is activated, myogenic progenitor cells synthesize several members of the {…} (PGC-1) family of transcription factors, activating brown adipocyte differentiation and suppressing skeletal muscle development.
1) PR domain containing 16
2) PPARγ coactivator 1
Loss of {…}from brown adipocyte precursors causes a loss of brown fat characteristics and promotes skeletal muscle differentiation. Therefore, {…} is regarded as a “master-switch” regulator in the differentiation of brown adipocytes.
1) PRDM16
2) PRDM16/PGC-1
PRDM16 & PCG-1, in turn, regulate the expression of genes that encode a specific mitochondrial protein called {…} (UCP-1) or {…} (a 33-kDa inner mitochondrial membrane protein), which is essential for brown adipocyte metabolism (thermogenesis).
1) Uncoupling protein
2) Thermogenin
Clinical observations confirm that under normal conditions, brown adipose tissue can expand in response to increased blood levels of this hormone/neurotransmitter.
What is norepinephrine?
Brown adipose tissue expansion in response to increased levels of norepinephrine becomes evident in patients with {…}, an endocrine tumor of the adrenal medulla that secretes excessive amounts of epinephrine and norepinephrine.
Pheochromocytoma
This type of adipose tissue is located in the Subcutaneous layer, mammary gland, greater omentum, mesenteries, retroperitoneal space, visceral pericardium, orbits (eye sockets), and bone marrow cavity.
What is white adipose?
This adipose tissue is found in large amounts in newborns and in remnants in adults at the retroperitoneal space, deep cervical and supraclavicular regions of the neck, interscapular, paravertebral regions of the back, and the mediastinum.
What is brown adipose?
List 5 functions of white adipose.
1) Metabolic energy storage
2) Insulation
3) Cushioning
4) Hormone production (adipokines)
5) Metabolic water source
List 2 functions of brown adipose.
1) Heat production (thermogenesis UCP-1 dependent)
2) Hormone production (batokines)
Clinical term for RBC.
What is an erythrocyte?
Clinical term for WBC.
What is a leukocyte?
Clinical term for platelets.
What is a thrombocyte?
What are the 2 key components of blood?
Cells & plasma
The liquid extracellular material that imparts fluid properties to blood.
What is plasma?
The volume of packed erythrocytes in a sample of blood is called the {…} (HCT) or {…} (PCV).
1) Hematocrit
2) Packed cell volume
Normal HCT in men.
39-50%
Normal HCT in women.
35-45%
A condition characterized by low hematocrit values, often reflected in reduced numbers of circulating erythrocytes.
What is anemia?
These 2 blood cells constitute 1% of the blood volume.
What are WBCs and platelets?
The leukocytes and platelets are contained in a narrow, light-colored layer between the erythrocytes and plasma called this.
What is the buffy coat?
Approximately {…}% of plasma by weight is water, which serves as the solvent for a variety of {…}, including proteins, dissolved gases, electrolytes, nutrients, regulatory substances, and waste materials. The solutes in the plasma help maintain {…}, a steady state that provides optimal pH and osmolarity for cellular metabolism.
1) 92
2) Solutes
3) Homeostasis
The main protein constituent of plasma, accounting for approximately one-half of the total plasma proteins. It is the smallest plasma protein (about 70 kDa) and is made in the liver.
What is albumin?
What is the purpose of albumin?
Exerting the concentration gradient between blood and extracellular tissue fluid
This major osmotic pressure on the blood vessel wall, called the {…} osmotic pressure, maintains the correct proportion of blood to tissue fluid volume.
Colloid
List the 2 types of globulins and their associated sub-globulins.
Immunoglobulins - γ-globulins
Nonimmune globulins - α-globulin and β-globulin
Are immunoglobulins or nonimmune globulins the largest component of the globulin fraction?
Immunoglobulins
Nonimmune globulins are secreted by the {…}. They help maintain the osmotic pressure within the vascular system and also serve as carrier proteins for various substances, such as copper (by ceruloplasmin), iron (by transferrin), and the protein {…} (by haptoglobin).
1) Liver
2) Hemoglobin
The largest plasma protein (340 kDa) made in the liver.
What is fibrinogen?
In a series of cascade reactions with other coagulation factors, soluble fibrinogen is transformed into this insoluble protein.
What is fibrin?
A procedure in which samples of blood are drawn from a vein.
What is venipuncture?
A blood {…} consists mostly of erythrocytes entangled in a network of fine fibers composed of fibrin. To prevent clotting of a blood sample, an {…} such as citrate or heparin is added to the blood specimen as it is obtained.
1) Clot
2) Anticoagulant
What is serum?
Plasma minus clotting factors
The fluid that surrounds tissue cells, called {…} fluid, has an electrolyte composition that reflects that of blood plasma, from which it is derived.
Interstitial
This is the preparation method that best displays the cell types of peripheral blood.
What is a blood smear?
On the basis of their appearance after staining, leukocytes are traditionally divided into {…} (neutrophils, eosinophils, and basophils) and {…} (lymphocytes and monocytes).
1) Granulocytes
2) Agranulocytes
Anucleate, biconcave discs devoid of typical organelles.
What are RBCs?
Is this the typical diameter of an RBC?
7.8 𝛍m
What is the typical lifespan of an RBC?
120 days
Why are RBCs referred to as the HISTOLOGIC RULER?
Their size is consistent in fixed tissue, so they are used to estimate the size of other cells and structures in tissue sections
