Study Questions Exam 1
1. What are the 2 basic classes of hormones, & what are the molecules they are based on (precursor molecules)?
2. What is a second messenger system? How does this differ from the direct gene activation used by steroid hormones? What are the 2 second messenger systems used by hormones (& which molecules are the second messengers)?
3. How can a cell regulate its response to circulating hormones?
4. How does the body regulate hormone activity (distinguish between humoral, neural, & hormonal stimuli (positive regulation) and feedback inhibition (negative regulation))?
The Pituitary Gland (Hypophysis)
5. Where is the hypophysis located? Which 2 structures make up the neurohypophysis? What type of tissue is present in each lobe?
6. What hormones are stored in the posterior pituitary? Where are these hormones produced?
7. What is the hypophyseal portal system? How is it used to regulate the release of hormones synthesized in the anterior pituitary?
8. List the hormones synthesized by cells of the anterior pituitary. What are the gonadotropins?
9. What might be the effects of long-term homeostatic imbalance (oversecretion or undersecretion) of growth hormone?
10. What general mechanisms are often involved in hypersecretion (oversecretion) and hyposecretion (undersecretion) of hormones?
11. What types of molecules can lead to a reduction in Antidiuretic hormone (ADH) release? What are the effects of very high blood levels of ADH?
12. Where is the thyroid gland located?
13. Where is thyroid hormone produced within the gland? What are the 2 forms of thyroid hormone? Which one predominates?
14. What are the target organs of thyroid hormone?
15. Where is calcitonin produced within the gland? What are its target cells & function?
16. What are some effects of hyposecretion & hypersecretion of thyroid hormone?
17. How does parathyroid hormone act to increase calcium levels in the blood (what types of cells does it target)?
18. The adrenal cortex secretes 3 general forms of corticosteroids. In which cortical zone is each corticosteroid group produced?
19. Give an example of a positive and negative mechanism regulating release of the primary mineralocorticoid aldosterone.
20. What are some of the effects of excessive levels of glucocorticoids?
21. Distinguish between the effects of gonadocorticoids produced by the adrenal cortex and steroidal sex hormones produced by the gonads.
22. What subdivision of the autonomic nervous system regulates release of catecholamines produced by the adrenal medulla?
23. How does insulin lower blood glucose levels?
24. What disorder is related to hyposecretion of insulin? What are the three classic signs (symptoms) of this disorder?
25. Name the hormone(s) produced & function.
26. What type of tissue is blood? What are its major components?
27. What is a hematocrit?
28. What are some major differences between red blood cells and white blood cells?
29. What are the 3 major functions of blood?
30. What is the composition of plasma (what are some of its components)?
31. What are the formed elements of blood?
32. What is the function of red blood cells?
33. What are the components of hemoglobin?
34. What is hematopoiesis? Where does it occur? Describe the steps to the formation of a red blood cell from a myeloid stem cell.
35. What is erythropoietin & where/why is it produced?
36. How are old red blood cells removed from the body?
37. What are some causes of anemias?
38. What are the symptoms & possible causes of polycythemia?
39. Approximately what percent of total blood volume is occupied by white blood cells?
40. What is diapedesis & why is this important for leukocytes? What is positive chemotaxis?
41. What is leukocytosis? Can this be a normal condition?
42. Which leukocytes are most abundant in blood? (Remember: Never let monkeys eat bananas!)
43. Which of the leukocytes are granulocytes? Agranulocytes?
44. Know the basic functions of all leukocytes.
45. What is another name for neutrophils (helps to identify them in blood)?
46. Which of the leukocytes have phagocytic activities? Which is a precursor of a phagocytic cell?
47. Which of the leukocytes are involved in inflammatory responses? Which are involved in antibody production?
48. Leukopoiesis: Which leukocytes arise from myeloid stem cells? (Monoblasts & Myeloblasts?) Lymphoid stem cells?
49. What are the symptoms of leukemias? What are possible treatments?
Platelets & Clotting
50. How do platelets arise from megakaryocytes?
51. What are the 3 major components of the hemostasis response?
52. What are the 3 final phases of coagulation & what is the result of each?
53. What proteins are involved in fibrinolysis?
54. What is the function of heparin? Aspirin?
55. Bleeding disorders: give examples & causes for each.
56. What are agglutinins? What is Rh factor? Why are these important considerations in blood transfusions?
57. What are plasma expanders & when would they be important?
58. What are the 2 components of the lymphatic system & what are their primary functions?
59. What tissues lack lymph capillaries? Why?
60. Where are lacteals located?
61. What factors drive the flow of lymph in lymphatic vessels?
62. What are the 2 major types of lymphocytes? What is the function of each?
63. Where in the lymph node would you find follicles?
64. What are the basic functions of the spleen & the thymus?
65. What are the 4 forms of tonsils? Where is each located?
66. What are Peyerıs patches & where are they found?
Chapter 21: The Immune System: Innate & Adaptive Body Defenses
67. What are the components of the innate or nonspecific immune system?
68. Where are surface barriers or external body membranes located in the body?
69. How do surface barriers protect against infection? What are some of the protective chemicals produced?
70. What are the primary phagocytic cells of the innate immune system, & where is each located?
71. What is the function of natural killer cells? How does their function differ from that of lymphocytes (in terms of specificity)?
72. What are the 4 cardinal signs of acute inflammation?
73. What are the main inflammatory chemicals produced by cells of the immune system?
74. What are some benefits of local edema produced by exudate containing inflammatory chemicals & proteins?
75. What is the function of interferon in the immune system?
76. What are the results of the classical & alternative pathways of complement activation?
77. What is opsonization?
78. What causes fever & how might it be beneficial?
79. What cells are involved in the adaptive or specific immune system?
80. What is the difference between humoral immunity & cell-mediated immunity?
81. What is an antigen? What is an antigenic determinant?
82. What are self-antigens, & what types of cells express them?
83. What is the function of antigen-presenting cells? (APCs) What type of cells can function as APCs.
84. What is self-tolerance & what type of cells go through this process?
85. What is clonal selection, & what type of cells go through this process?
86. What is the difference between plasma cells & memory B cells? What is the primary function of each?
87. How does the secondary immune response differ from the primary immune response?
88. What is the difference between active & passive humoral immunity, & what are some examples of each?
89. Know the basic structure of an antibody.
90. What are the five major antibody classes, what is the function of each & where are they located on cells?
91. What are complement fixation & neutralization in terms of antibody activity?
92. What are CD8 & CD4 cells?
93. What is MHC restriction in T lymphocytes?
94. What are some of the costimulatory signals T cells need for proliferation?
95. What are some cytokines involved in T cell activity?
96. What are the 4 major types of grafts?
97. What are some forms of immunodeficiency & what are their causes?
98. What causes autoimmune diseases?
99. What is anaphylaxis and sensitization in immediate hypersensitivity?
Biology 211
Answers to Study Questions 1
Chapter 16: The Endocrine System
Hormone Chemistry
1. a. amino acid-based: amino acids, peptides & proteins
b. steroid: cholesterol
2. Second messenger system: response of cell to hormone is mediated by other molecule(s). Steroid hormone/receptor complexes directly activate responsive genes through binding to receptors on DNA.
Second messenger systems used by amino acid-based hormones:
a. cyclic AMP
b. PIP-Calcium: second messenger IP3
3. Blood hormone levels; hormone receptor up-regulation & down-regulation; hormone-receptor binding affinity
4. a. Positive control – hormone level increased by: blood levels of ions & organic nutrients (humoral stimuli); blood levels of releasing/activating hormones (hormonal stimuli); neural impulse/stimulation of endocrine glands (neural stimuli).
Negative control – hormone inhibited by rising blood levels of that hormone or a downstream target.
Major Endocrine Organs
The Pituitary Gland (Hypophysis)
5. Hypophysis location: sella turcica of sphenoid bone.
Neurohypophysis: posterior pituitary & infundibulum.
Anterior pituitary: glandular epithelial tissue
Posterior pituitary: nervous tissue (downgrowth of hypothalamic axons)
6. Oxytocin: secreted by paraventricular nuclei of hypothalamus
ADH: secreted by supraoptic nuclei of hypothalamus
7. Hypophyseal portal system: vascular connection between hypothalamus & anterior pituitary that allows delivery of releasing & inhibiting hormones controlling hormone release by anterior pituitary.
8. TSH, ACTH, FSH, LH, GH, & prolactin.
Gonadotropins: FSH & LH
9. GH hypersecretion: gigantism, acromegaly
GH hyposecretion: progeria, pituitary dwarfism
10.Hormone hypersecretion: endocrine gland/ectopic tumors
Hyposecretion: injury, trauma
11. ADH release inhibited by: water, alcohol consumption
High levels of ADH: vasoconstriction, increased blood pressure
The Thyroid Gland
12.Thyroid gland location: on trachea, inferior to larynx
13.Thyroid hormone produced in follicles
T3 & T4; primarily T4, which is converted to T3 at target cells
14.In adult, all except brain, spleen, testes, uterus & thyroid gland
15.Calcitonin produced by parafollicular cells
Target cells: bone cells, esp. osteoclasts (inhibitory)
16.Hyposecretion: growth retardation; decreased basal metabolic rate; low blood pressure
Hypersecretion: increased basal metabolic rate; high blood pressure
The Parathyroid Glands
17.Parathyroid hormone: stimulates osteoclasts to digest bone/release calcium to blood; enhances resorption of calcium by kidneys; stimulates activation of vitamin D (enhances intestinal absorption of calcium)
The Adrenal Glands
18.Mineralocorticoids: zona glomerulosa (outer cortex)
Glucocorticoids: zona fasciculata (middle cortex)
Gonadocorticoids: zona reticularis (inner cortex)
19.Mineralocorticoid regulation:
Positive: Renin-angiotensin mechanism; ACTH
Negative: ANP
20.Glucocorticoid hypersecretion: slows cartilage & bone formation; inhibits inflammation; depresses immune system
21.Gonadocorticoids: although function unclear probably important in onset of puberty; sex drive; estrogen production after menopause
Steroidal sex hormones produced by the gonads: secondary sex characteristics in males & females; normal functioning of testes in males & menstrual cycle in females.
22.Sympathetic nervous system
The Pancreas
23.Insulin: stimulates glucose oxidation in cellular respiration; stimulates glycogen formation from glucose; converts glucose to fat
24.Diabetes mellitus is related to hyposecretion of insulin. The three classic signs (symptoms) of this disorder: polydipsia, polyphagia, polyuria
The Pineal Gland & The Thymus
25.Pineal Gland: melatonin – function unclear may be involved in daily rhythms; Thymus: Thymosins & thymopoietins – important for normal T cell development
Chapter 17: The Cardiovascular System: Blood
Components & Function
26.Connective Tissue; composed of fluid called plasma & formed elements (erythrocytes, leukocytes & platelets)
27.hematocrit: % of total blood volume occupied by erythrocytes (normally between 42% and 47% ħ 5%)
28.red blood cells: anucleate, biconcave discs, function in gas transport; white blood cells: have nucleus & normal organelles, nucleus may be lobed, granules, involved in immune responses; protect the body from damage by bacteria, viruses, parasites, toxins & tumor cells
29.Blood Functions: transport & distribution of oxygen & nutrients, carbon dioxide & metabolic waste, and hormones,; regulation of body temperature, normal pH and fluid volume in cells & tissues; protection against blood loss (clotting) and infection (white blood cells)
30.Blood Plasma: mostly (~ 90%) water; also contains over 100 different dissolved solutes, including: proteins (albumin, globulins, clotting proteins, etc.), nutrients, electrolytes, respiratory gases
31.formed elements: erythrocytes, leukocytes & platelets
Erythrocytes
32.Red blood cells: function in respiratory gas (oxygen & carbon dioxide) transport to & from tissue cells
33.hemoglobin is composed of 4 globin polypeptide chains each bound to a heme group with an iron atom at its center
34.Red blood cell formation; occurs in red bone marrow; erythropoiesis (erythrocyte production): hemocytoblast -> myeloid stem cell -> proerythroblast -> early erythroblast -> late erythroblast -> normoblast -> reticulocyte -> erythrocyte
35.erythropoietin: produced by the kidneys (responding to hypoxia (low oxygen levels in blood))
36.aged & damaged RBCs are broken down in small channels of the spleen, liver & marrow by macrophages
37.anemias may be caused by an insufficient number of RBCs (hemorrhagic, hemolytic & aplastic anemias), decreased hemoglobin content (iron-deficiency & athleteıs anemia) or abnormal hemoglobin (thalassemias & sickle cell anemia)
38.polycythemia: abnormal excess of RBCs; increases blood viscosity & can impair circulation; can be caused by: tissue hypoxia, dehydration, blood doping (infusion of red blood cells) or erythropoietin injection
Leukocytes
39.White blood cells occupy less than 1% of total blood volume
40.diapedesis: white blood cells can move out of capillaries & into tissues; positive chemotaxis: WBCs follow chemical trail of other WBCs to sites of infection
41.leukocytosis: condition of increased WBC count (a normal response to infection, but in rare cases may be a sign of a WBC disorder)
42.neutrophils are most abundant WBCs in blood
43.granulocytes: neutrophils, eosinophils, basophils; agranulocytes: monocytes, lymphocytes
44. neutrophils: phagocytize bacteria at sites of inflammation; eosinophils: kill parasitic worms; basophils: release histamine at sites of inflammation; monocytes: differentiate into macrophages; lymphocytes: T cells attack & destroy virus-infected cells & cancer cells & amplify immune response, B cells differentiate into plasma cells to produce antibodies
45.neutrophils are also known as PMNs (polymorphonuclear leukocytes)
46.neutrophils & eosinophils have phagocytic activity; monocytes differentiate into phagocytic macrophages
47.all WBCs may be involved in inflammatory response; B lymphocytes are involved in antibody production
48.neutrophils, eosinophils, basophils & monocytes arise from myeloid stem cells; lymphocytes arise from lymphoid stem cells
49.leukemias are characterized by abnormal production & accumulation of immature leukocytes (acute leukemias) or mature leukocytes (chronic leukemias); leukemias may be treated by bone marrow transplants with radiation &/or chemotherapy
Platelets & Clotting
50.extensions of megakaryocyte in bloodstream rupture to form platelets
51.vascular spasms, platelet plug formation & coagulation
52.activation of prothrombinase ( prothrombin activator) by clotting factors, activation of thrombin from prothrombin & activation pf fibrin from fibrinogen
53.Tissue plasminogen activator (tPA) activates plasma plasminogen, which is converted to plasmin, plasmin is an enzyme that digests fibrin, breaking down clot
54.heparin & aspirin function as anticoagulants; heparin helps in blocking thrombin; aspirin inhibits vasoconstriction & platelet aggregation
55.hemophilia: caused by inherited deficiency in clotting factors; thrombocytopenia: caused by deficiency in platelets due to spleen &/or liver malfunction, infection or inherited disorders affecting platelet production
56.individuals make antibodies (agglutinins) against the antigen(s) not present on their red blood cells; Rh factors are antigens that also may be present on the surface of red blood cells; following infusion of mismatched blood, agglutination occurs as antibodies complex with the foreign blood group antigens - this blocks blood vessels & hinders blood flow; reduces oxygen availability to tissues, as the RBCs are lysed, hemoglobin escapes & may precipitate in kidney tubules leading to renal failure
57.plasma can be temporarily used to replace some blood volume when properly typed blood is not immediately available
Chapter 20: The Lymphatic System
58.lymphatic vessels: drain excess fluid from tissue spaces & return it to the blood; lymphoid organs & tissues: house phagocytes & lymphocytes, which initiate specific immune responses to microbes or abnormal cells
59.lymph capillaries: occur almost everywhere blood capillaries occur except bones & teeth, bone marrow, & central nervous system (uses CSF to collect fluid); avascular tissue such as cartilage, epidermis & the cornea of the eye also lack lymphatic capillaries
60.lacteals are specialized lymphatic capillaries in the intestinal mucosa
61.lymph is not pumped, but flows by smooth muscle contraction in the walls of the vessels, pressure changes in the thorax during breathing & valves to prevent backflow
62.T cells direct the immune response against virally-infected cells & cancer cells; B cells produce plasma cells that synthesize antibodies
63.follicles are located within the cortex of a lymph node
64.spleen removes aged & defective blood cells from circulation & contains macrophages to cleanse blood of foreign matter, stores breakdown products of red blood cells for later use produces erythrocytes in the fetus & stores blood platelets; thymus functions in maturation of T cells
65.palatine tonsils: paired at posterior end or oral cavity; pharyngeal tonsil: at superior aspect of nasopharynx; lingual tonsils: at base of tongue; tubal tonsils: at openings of auditory tubes into pharynx
66.Peyerıs Patches: Mucosa-associated Lymphatic tissue (MALT) in ileum of small intestine
Chapter 21: The Immune System: Innate & Adaptive Body Defenses
Innate Defenses
67.surface barriers: skin & mucous membranes; internal defenses: cells (macrophages & other phagocytes; NK cells) & chemicals (acidic secretions & anti-microbial proteins (lysozyme, interferons & complement)
68.keratinized epithelial cells of skin & epithelial mucosae of respiratory & digestive tracts
69.bacterial growth inhibited by acidic secretions (HCl in stomach; sebum) & microbes inhibited or killed by anti-microbial proteins (lysozyme, interferons & complement)
70.free macrophages in tissues: alveolar macrophages of lungs, dendritic cells of epidermis (Langerhansı cells); fixed macrophages: Kupffer cells of liver, microglia of brain; also, neutrophils & eosinophils in blood
71.Natural Killer (NK) Cells: large granular lymphocytes present in blood & lymph that kill cancer cells & virus-infected cells; unlike T cells, NK cells are not specific for a specific virus or cancer cell type
72.4 signs of inflammation: redness, heat, swelling & pain
73.histamine, kinins, prostaglandins, complement & cytokines
74.swelling (edema) dilutes toxic chemicals from pathogens & speeds delivery of repair materials
75.Interferon (IFN): proteins released by virus-infected cells that prevent viral replication in neighboring cells
76.classical pathway: complement proteins bind to antibody-antigen complex to begin lysis; alternative pathway: complement factors B, D, & P bind to surface polysaccharides of microbe to begin lysis
77.opsonization: foreign antigen is coated with complement & antibodies to enhance adhesion to macrophages
78.fever: caused by chemicals called pyrogens secreted by leukocytes & macrophages exposed to bacteria & antigens; fever intensifies effects of cytokines, inhibits growth of some bacteria & speeds up tissue repair
Adaptive Defenses
79.B lymphocytes & T lymphocytes
80.humoral immunity (antibody-mediated immunity): mediated by antibodies produced by B cells & plasma cells in the bodyıs ³humors² or fluids (blood, lymph, etc.); cellular immunity (cell-mediated immunity): mediated directly by T cells
81.antigens: substances that can provoke an immune response; antigenic determinants: immunogenic regions of antigen
82.self antigens: antigens that are not immunogenic to an individual but strongly immunogenic to others (MHC or HLA antigens on our own cells); expressed by antigen-presenting cells (APCs), primarily professional APCs (dendritic cells, macrophages & activated B cells), but most cell types can function as APCs
83.antigen-presenting cells: one of several cell types that engulfs & digests antigens & presents part of them on its plasma membrane bound to MHC molecules for recognition by T cell receptors; professional APCs are dendritic cells, macrophages & activated B cells, but most cell types can function as APCs
84.Self-tolerance: T cells that strongly bind self-antigens or are not immunocompetent are weeded out & destroyed (negative selection), while T cells that weakly bind self antigens continue to develop (positive selection)
85.Clonal selection of B cells: immunocompetent but naïve lymphocyte is activated by antigen binding its receptor, & forms a clone (population of identical cells); B cells & T cells
86.plasma cells, which secrete antibodies; memory B cells can mount an immediate response to another encounter with the same antigen
87.Primary immune response: clonal selection & differentiation of B cells, takes approximately 3-6 days to start antibody production; Secondary immune response: rapid & enhanced response to subsequent exposure to same antigen, within 2-3 days
88.Active immunity: response by our own B cells to antigen(s)
Naturally acquired: antigens from bacteria & viral infections
Artificially acquired: antigens from vaccines
Passive immunity: antibodies harvested from human/animal immune serum
Naturally acquired: antibodies pass from mother to child via placenta
Artificially acquired: antibodies acquired from injection of immune serum
89.Y-shaped proteins produced by activated B cells & plasma cells; composed of 2 identical heavy (H) chains & 2 identical light (L) chains; each chain has a variable (V) region & constant (C) region
90.IgD: B cell antigen receptor; IgM: monomer & pentamer forms (monomer – B cell antigen receptor; pentamer – circulates in blood plasma; first Ig class secreted); IgG: most abundant circulating antibody; protects against bacteria, viruses & toxins; fixes complement; IgA: monomer & dimer forms (monomer: small amounts in plasma; dimer: found in secretions (mucus, saliva, sweat intestinal juice, milk), helps to prevent pathogens from entering body); IgE: binds to mast cells & basophils & causes release of histamine & other mediators of inflammation
91.complement fixation: complement binding site of antibody binds complement, which triggers cell lysis; neutralization: antibody binds to active site of toxin (from virus or bacteria) & inactivates it
92.CD4 & CD8 cells are lymphocytes carrying cell surface proteins named CD4 & CD8, respectively; CD4 cells are primarily helper T cells; CD8 cells are cytotoxic T cells
93.MHC restriction: T cell receptors recognize & bind to antigen-MHC protein complex on cell surface of APC; cytotoxic T cells are restricted to binding to Class I MHC-antigen complexes; helper T cells are restricted to binding to Class II MHC- antigen complexes
94.costimulatory signal can be binding to additional receptor on APC surface (B7 on macrophages binds CD28 on T cell) or cytokine (interleukin) stimulation (from helper T cells)
95.cytokines include interleukins (IL-1 & IL-2), as well as cell toxins (perforin), & inflammatory factors
96.4 types of grafts (tissue transplants): autograft, isograft, allograft & xenograft
97.severe combined immunodeficiency syndrome (SCID): congenital (present from birth) condition resulting from deficits in both T and B cells; acquired immunodeficiency syndrome (AIDS): infection with human immunodeficiency virus (HIV) destroys helper T cells
98.autoimmune diseases: caused by antibodies & activated cytotoxic T cells that target & destroy (self) body tissues
99.anaphylaxis: first contact with allergen sensitizes individual; second contact results in immediate symptoms