Cell and Tissue Biology

CTB I Comphrehensive Final Exam

Study Questions by Subject Area

Formed Elements of Blood

  • List basic functions of blood.
  • Know the RELATIVE abundance (approximate percentages) of the different types of leukocytes.
  • Know the basic structure/function of the erythrocyte.
    • What is the membrane skeleton? What does it do? What molecular defect leads to Hereditary Spherocytosis?
    • What is the molecular basis of sickle cell disease? How does this lead to the clinical symptoms seen in patients?
  • Make a table of leukocytes with columns: size, basic function (including any key molecular effectors, mophological description (i.e. how do you recognize this cell in a blood smear?)
  • What is diapedesis? Which adhesion molecules are involved?
  • What are the basic functions of platelets? Where do platelets come from?

Cells & Organelles I & II

  • Plasma membrane
    • Basic structure: understand fluid mosaic model, various types of membrane proteins & glycocalyx
    • Learn the basic functions of: membranes, different types of membrane proteins & the glycocalyx.
    • What are "membrane domains" & what role do occluding junctions play in their maintainance?
    • Can you explain how is glucose transported across the gut epithelium?
    • Cell signaling: Understand how heterotrimeric G proteins work (lecture notes, cells & organelles I).
  • Membrane-bound organelles
    • Understand endocytosis (and phagocytosis)
      • Can you describe receptor mediated endocytosis via clathrin coated pits?
      • How might a defect in receptor-mediated endocytosis be related to high levels of LDL in the blood and early death from atherosclerosis?
    • Mitochondria structure & function
      • What is the role of the inner membrane?
      • What happens in the matrix space?
      • Mitochondrial genome - understand the maternal inheritance of mitochondrial diseases.
      • How are new mitochondria produced and how does this relate to their evolutionary origin?
      • Where are mitochondria usually located in cells? Why? Can you provide a few examples?
      • Where are most mitochondrial proteins encoded? Where are most mitochondrial proteins translated?
    • Rough endoplasmic reticulum
      • Understand the signal hypothesis.
      • What is the signal recognition particle (SRP) and how does it work?
      • What are the major functions of the RER?
    • Golgi apparatus
      • Understand the major functions: review textbook page 52 figure 2.35, and lecture notes, cells & organelles II.
      • What are Cop I and Cop II coated vesicles?
      • What are the major functions of the RER?
    • Lysosomes
      • What are primary and secondary lysosomes?
      • What is the role of pH in lysososme function?
      • What are autophagosomes? How can you distinguish them from lysosomes in the TEM?
      • Clinical correlation:
        • Understand the concept of lysosomal storage diseases.
        • Recognize the names of the following lysosomal storage diseases: Hurler, Tay-Sachs, Gaucher, I-cell disease
    • Peroxisomes
      • Understand their basic structure and function.
      • How are new proteins targeted to the peroxisome?
  • Proteosomes - what are they and what do they do?

Cells & Organelles III

  • What are the three major filament types of the cytoskeleton, and which of them are polor?
  • For polar filaments, what is the meaning of "+" and "-" end?
  • What are the names of the various "motor" proteins that move along cytoskeletal filaments? What filament does each motor move on? What direction does each motor go?
  • Why don't mictotubules and actin filaments spontaneously assemble in uncontrolled fashion within the cytoplasm?
  • How does the cell control the location (and orientation) of new actin filaments or microtubules?
  • What does "dynamic instability" mean?
  • Understand how the following drugs work on microtubules: Taxol, Colchicine, Vinblastine & Vincristine.
  • Can you describe serveral different types of actin binding proteins?
  • Clinical correlation: Kartegener's syndrome - what is the molecular basis of this disease and why does it cause male sterility and respiratory infections?
  • Understand basic axoneme structure and function.
  • What is a basal body? How would you recognize it in the TEM?
  • What is a centriole? What is a centrosome? What is gamma-tubulin and what does it do?
  • Can you describe the mitotic spindle including the orientation of microtubules and the position and roles of the motor proteins kinesin and dynein?
  • What is the Arp2/3 complex? How does it relate to actin filaments and the motility of neutrophils? Can you describe how a neutrophil "chases" down a bacterium and engulfs it? How does signaling control the actin-based cytoskeleton?
  • How did intermediate filaments get their name? Are they polar? Do they have associated motors?
  • What is the molecular basis of epidermolysis bullosa symplex? Explain how this causes the symptoms seen in patients.

Cells & Organelles IV

  • Can you describe the basic structure of the eucaryotic cell nucleus including the nuclear envelope, heterochromatin, euchromatin, nuclear lamina, nuclear pores, nucleolus?
  • How is DNA organized in chromatin? What is a nucleosome? What are chromosomal scaffolding proteins?
  • What is a Barr body?
  • What happens in the nucleolus?
  • What does a nuclear pore do? What does a nuclear pore look like? Are nuclear pores involved in energy-dependent transport - i.e. moving things against a concentration gradient?
  • Understand the basic stages in the cell cycle - what happens in each stage.
  • Can you name some of the major "check points" in the cell cycle?
  • What are the stages of normal mitosis? - review textbook section on cell division.
  • What is a centromere?
  • Compare and contrast necrotic and apoptotic cell death.

Epithelia (Introduction to Tissue Types)

  • What are the basic propterties of epithelia?
  • What are the basic functions of epithelia? Can you provide examples?
  • What are the basic types of epithelia? Can you describe each of them? How do you distinguish one from another based on morphology? What functions do the different types perform? How is form related to function?
  • Apical specializations: do you know the difference between microvilli and cilia? How would you distinguish them in the TEM?
  • Make a table of all cell-cell junctions with columns: location, molecular components in the membrane, associated cytoskeletal filaments, basic functions. It should look like the table on page 135 of the text (Table 5.4). THIS IS VERY IMPORTANT.
  • What is the basal lamina? What is the major structural protein of the basal lamina and how is it organized?
  • Understand the epthelial origin of exocrine and endocrine glands.
  • What are myoepithelial cells? Where would you find them? What do they do? Which proteins do they use to perform this function?
  • How do merocrine, apocrine and holocrine secretion differ?

Connective Tissue

  1. Understand difference between dense and loose connective tissue.
  2. Know all the major cell types found in dense and loose connective tissue as well as their major functions - cell types are listed in text page 178.
    A few examples:
    • Fibroblast - makes collagen fibers, elastic fibers, and ground substance.
    • Plasma cell - functions in defense; differentitated B cell that secretes an antibody.
    • Macrophage - funtions in defense, phagocyte and professional antigen presenting cell; precursor = monocyte in circulation
    • Mast cell -
      • Functions in defense
      • Stores primary inflammatory mediators (e.g, histamine and eosinophil chemotactic factor, etc.) in secretory granules.
      • Becomes activated when IgE held in surface Fc receptors are cross linked by binding antigen. Activation causes:
        • Release of granule contents = primary (i.e. stored) inflammatory mediators; can you name several examples?
        • Synthesis of secondary (made upon activation) inflammatory mediators - leukotrienes, prostaglandins.
  3. Know major types of extracellular fibers in connective tissue. What are their functions?
  4. Undertand the steps in type I collagen synthesis as presented in figure 6.8, page 167 of the textbook: what is the purpose of each step?
  5. Know that Ehlers-Danlos is caused by defects in collagen synthesis. Know major symptoms.
  6. Understand that Marfan's is caused by mutations in fibrilin gene and that this leads to defective elastic fibers. What are the clinical consequences?
  7. Understand the differences between types I, II, III and IV collagen. What structures do these different collagens make? Where are they found? Do they all make filaments? (Table 6.2 page 165 of textbook)
  8. Understand the basic difference between glycoproteins (e.g laminin, fibronectin) and proteoglycans (e.g. aggecan), and understand their general functions.
  9. Understand how cells use integrin to bind to the extracellular matrix, thus linking the extracellular matrix to the actin cytoskeleton (page 135, Table 5.4).

Adipose Tissue

  1. Know the major functional and structural differences between unilocular and mulitlocular apipose tissue.
  2. What are the major functions of unilocular fat cells (i.e., energy storage, insulation, cushioning/shock absorbers).
  3. What is the major function of multilocular fat? Why is multilocular fat brown in color? What is the function of thermogenin and why is it in the mitochondria of brown fat?

Muscle

  1. Make a table listing the similarites/differences for the three major types of muscle: skeletal, cardiac, and smooth.
    For example:
    • Which have strations?
    • Are there differences in how contraction is regulated, and if so, what are the differences?
    • Which types of muscle fibers are formed by the fusion of myoblasts?
    • Which types of muscle cells have T-tubules and triads? What do these structure do? Where are they located (i.e., at what level of the sarcomere)?
    • Which have a sarcoplasmic reticulum?
    • Where are the nuclei located within the cells?
    • Do all three types have dense bodies (what are dense bodies)?
    • Do all three types have intercalated discs? What are intercalted discs? What are the major components/functions of the transverse and longitudinal subdomains of the intercalated disc?
    • Which type of muscle cell can produce collagen fibers and ground substance, functions in common with fibroblasts?
  2. Understand sacromere structure as it relates to function:
    For example:
    • CAN YOU DIAGRAM A SACROMERE FROM MEMORY? CAN YOU EXPLAIN THE SLIDING FILAMENT MODEL OF MUSCLE CONTRACTION?
    • Which of the "bands" within the sarcomere change dimension as muscle contracts or relaxes? Which don't change? Can you explain why in each case?
    • Which proteins would you expect to find in the sarcomere, and where would these proteins be located: actin, myosin, tropomyosin, troponin, alpha-actinin, nubulin, titin.
    • What would the arrangements of filaments be in TEM cross sections taken at different levels of the sarcomere? For example, what would you expect to see in a section though the H-zone? the I band?
  3. Know the basic differences (in form and function) between type I, type II, and intermediate skeletal muscle fibers. What determines fiber type, and what type of experiment demonstrates this?
  4. Understand the concept of the motor unit.
  5. Know the basic structure/fuction of muscle spindles. Why does the spindle have both afferent and efferent innervation?
  6. Understand the basic conduction system of the heart. What are Purkinje fibers, where are they located, what do they look like, and what do they do?
  7. What is "age pigment" and why is it often found in cardiac muscle cells?

Cardiovascular System

  1. Understand the basic architecture of blood vessels, i.e, the structure/function of each of the three tunics (learn the tunic names).
  2. How you would identify each of the following vessel types in the microscope (i.e. what are the critical mophological criteria that you would use)?
    Capillaries, arterioles, venules, small and large muscular arteries, veins, large elastic arteries, high endothelial cell postcapilary venules, lymphatic capillaries.
  3. What are the different types of capillaries? Can you give an example where each type is found in the body? Why are they found there (i.e. functional explanation)? For example, brain has continuous capillaries with well developed tight juctions. This helps maintain the blood-brain barrier.
  4. Understand the structure and function of Vasa Vasorem.
  5. Understand the structure and function of the nervous supply of blood vessels.

Lymphoid Tissue

  1. Differences between innate and adaptive immuninty. Which cells are involved?
  2. What is central lymphoid tissue? What are its functions?
  3. What is peripheral lymphoid tissue? What are its functions?
  4. What is a lymphoid nodule/follicle? Know all the places that they can be found - i.e. GALT, MALT, lymph nodes, spleen. What is a follicular dendritic cell?
  5. What is the role of the fibroblast-like reticular cells and the reticular fibers (type III collagen) that they produce within peripheral lymphoid tissue?
  6. Know the different "professional" antigen presenting cells. What key functions/properties do these cells have that permits them to play a central role in adaptive immune responses?
  7. What are the different "effector" T cells, i.e. what do CD8-expressing effector T cells do? What do CD4 effector T cells do (remember both classes of CD4 helper cells).
  8. How does a B cell become activated? Remember the role of CD4 helper T cells. How do lymph nodes promote the (appropriate) activation of B cells?
  9. What are the MHC class I and II proteins? What do they do? Which cells express MHC class I? Which cells express MHC Class II?
  10. How do most lymphocytes enter the lymph node? How do most lymphocytes exit the lymph node? How do activated dendritic cells enter the lymph node?
  11. Where are most B cells located in the lymph node? Where are most T cells located in the lymph node. What is a germinal center and how do you recognize it in a histological section?
  12. Understand the organization of the medulla of the lymph node: what are the cords and sinuses? WHAT CELL TYPES WOULD YOU EXPECT THERE? Where would you expect to find most of the plasma cells in a lymph node?
  13. Trace the route of a red blood cell as it flows through the spleen: trabecular artery, central artery, etc.
  14. What is the PALS?
  15. What is the organization of the splenic white pulp? What is the organization of the splenic red pulp? What kinds of cells are in the cords of the red pulp?
  16. What type of tissue composes the capsule and trabeculae of the spleen?
  17. Understand "thymic education" including the roles of both postive and negative selection. What happens to most T lymphocytes born in the thymus?
  18. Which cells first present "self" peptides (complexed with MHC class I) to T cells within the cortex of the thymus? What is the embryonic origin of these cells? Do you expect to find type III collagen fibers in the thymus?
  19. What is the blood thymus barrier (structure and function)? What does a Hassels corpuscle look like? Where would you find one?
  20. Where are B cells "educated"?
  21. Why is it so important the lymhoctyes constantly circulate thoughout the lymphoid tissues of the body - remember to consider the concept of clonal expansion in your explanation.

Skin and its Derivatives

  1. What are the major functions of skin?
  2. What are the epidemis, dermis and hypodermis (what type of tissue?)
  3. What are the different cell types that contribute to the epidermis? What is the function of each cell type?
  4. What are the names and basic structural features of the different layers of the epidermis?
  5. What is the difference between thick and thin skin and where is each type found?
  6. Where are new kerotinocytes produced? Within which layer of the epidermis would you expect to find mitotic figures?
  7. What are keratohyalin granules? What are keratinosomes?
  8. What are the lamellar bodies of keratinocytes? What do they look like? What to they contain? In what layer would you find them? What is their very important function?
  9. How does skin become pigmented? Which cells produce melanosomes? Which cells harbor the most melanosomes? Can you provide a brief overview of melanogenesis? Which types of defects lead to albanism?
  10. Describe the structure and function of the different layes of the dermis.
  11. Can you reconnize Pacinnian corpuscles? Which cell types contribute? What is their function?
  12. Can you diagram a hair follicle along with its associated structures including sebaceous glands and arrector pilli muscles?
  13. Can recognize a TEM showing a sebaceous gland?
  14. Can you diagram the histological feature of an eccrine sweat gland including clear cells, dark cells and myoepithelial cells?
  15. Which features of a mole suggest melanoma?

Respiratory System

  1. What are the major functions of the respiratory system? Can you describe the histological features that allow it to perform these functions?
  2. Can you describe how the verious features of the conducting portion of the respiratory system change from nasal fossae to terminal bronchioles? Consider epithelium, glands (including goblet cells), cartilage, smooth muscle and elastic fibers.
  3. Desribe the structure and function of respiratory epithelium. What are the cell types? What do they do? Be sure to consider apical specializations. Understand the significance of Kartegener's syndrome (immotile ciliary syndrome).
  4. Desribe the structure and function of olfactory epithelium. What are the cell types? What does each cell type do? What about associated glands? Be sure to consider apical specializations - - where are the odorant receptors located?
  5. Can you draw a histologic digaram of a bronchus?
  6. Can you draw a histologic digaram of a bronchiole, respiratory bronchiole, alvolar duct?
  7. Can diagram the blood-air barrier starting from air space in the alveolus to the plasma within the capillary lumen? Can you recognize each of the parts of the blood air barrier in a TEM?
  8. What are type I and type II pneumocytes? What do they look like? What do they do?
  9. What are Clara cells? What do they look like? What do they do?

Bone and Cartilage

  1. What are the three major types of cartilage and how to they differ?
  2. Can you describe perichondrium? What are its functions? What is appositional growth?
  3. What is the composition of the matrix of hyaline cartilage? What type of collagen? Can you describe an aggregan aggregate?
  4. What is articular cartilage and how is it different from regular hyaline cartilage?
  5. Compare and contrast cortical and cancellous bone.
  6. Can you draw an osteon? Can you define haversian canal? What are cannaliculi?
  7. What are the functions of osteoblasts, osteocytes, and osteoclasts? Can you reconize them in tissue sections?
  8. Explain how bone remodeling related to interstitial lamellae. Can you briefly describe how compact bone is remodeled?
  9. Describe the steps in endochondral bone fromation.
  10. How does parathyroid hormone increase levels of serum calcium?