MCB 135E Final Review

1. MCB 135EFinal Review Fall 2005 GSI: Jason Lowry

2. Exam Information • Monday, Dec. 19th • 22 Warren • 5-8 pm • Multiple Choice (50pts) • True / False (50 pts) • Short Answer (100 pts) • Comprehensive exam • Majority will come from material since last midterm

3. Immune System Adolescence and Puberty Factors Affecting Sexual Behavior Muscle Growth and Plasticity Nutrition Eating Disorders Homeostasis Hormesis New Material

4. Immune System • Function of System • Tissues and Organs Involved • Cells Involved • Viral vs. Bacterial Response • Developmental Aspects • Ig Classes

5. Cell Types • Lymphocytes: derived in bone marrow from stem cells 10^12 • A) T cells: stored & mature in thymus-migrate throughout the body • -Killer Cells • Perform lysis (infected cells) • Cell mediated immune response -Helper Cells Enhance T killer or B cell activity -Supressor Cells Reduce/suppress immune activity May help prevent auto immune disease

6. Lymphocytes (cont.) • B-Cells: stored and mature in spleen • secrete highly specific Ab to bind foreign substance (antigen: Ag), form Ab-Ag complex • responsible for humoral response • perform antigen processing and presentation • differentiate into plasma cells (large Ab secretion)

7. Neutrophils- found throughout body, in blood -phagocytosis of Ab-Ag CX Macrophages- throughout body, blood, lymphatics -phagocytose non-specifically (non Ab coated Ag) -phagocytose specifically Ab-Ag CX -have large number of lysosomes (degradative enzyme) -perform Ag processing and presentation -present Ag to T helper cell -secrete lymphokines/ cytokines to stimulate T helper cells and immune activity 4. Natural Killer Cells-in blood throughout body -destroy cancer cells -stimulated by interferons

8. Macrophage Bacteria Bacterial Infection

9. Complement Series of enzymes which are sequentially activated and result in lysis of cell membrane of infected cell at bacterium Permeablizes membrane leaky Complement binding and activation ~35 enzymes and factors involved in cascade

10. Viral Infection

11. Immune System • Antibodies • Types • Characteristics • Specificity • In Newborns • Development of the Immune System

12. 5 classes of Ig IgG: 150,000 m.w. most abundant in blood, cross placental barrier, fix complement, induce macrophage engulfment IgA: associated with mucus and secretory glands, respiratory tract, intestines, saliva, tears, milk variable size IgM: 900,000 m.w. 2nd most abundant , fix complement, induce macrophage engulfment, primary immune response

13. 5 Classes of Ig IgD: Low level in blood, surface receptor on B- cell IgE: Binds receptor on mast cells (basophils) secretes histamine, role in allergic reactions Increased histamine leads to vasodilation, which leads to increase blood vessel permeability. This induces lymphocyte immigration swelling and redness.

14. Thymus Involution

15. ORGAN AND T-CELL DEVELOPMENT • YOLK SAC • LIVER • (4 Weeks) • BONE MARROW • (4-5 Weeks ) • THYMUS • (7-10 Weeks) • BLOOD LYMPH • (14 Weeks) • SPLEEN • (16 Weeks) • T-cells migrate and appear in tissues with development and increase in number throughout Gestation

16. B-CELLS • FIRST appear in immature state - Liver at 7 weeks • LATER –appear mature by 14-20 weeks • CAN DIFFERENTIATE INTO IMMUNOLOGICALLY COMPETENT ANTIBODY-PRODUCING PLASMA CELLS

17. NATURAL KILLER CELLS • FIRST APPEAR IN FETAL BONE MARROW AROUND 13 WEEKS GESTATION • FIRST APPEAR IN FETAL BONE MARROW AROUND 13 WEEKS GESTATION • FOUND THROUGHOUT BODY • NK CELLS HAVE DIMINISHED ACTIVITY BEFORE BIRTH COMPARED TO ADULT • STIMULATED BY INTERFERON AFTER 27 WEEKS

18. COMPLEMENT PROTEINS • ARISE FROM LIVER • FIRST DETECTED 5-6 WEEKS GESTATION • INCREASE GRADUALLY IN CONCENTRATION • AT ABOUT 28 WEEKS COMPLEMENT PROTEINS ARE AROUND 2/3 THAT OF ADULT CONCENTRATIONS • INDIVIDUAL VARIATION

19. Adolescence and Puberty • Functional Changes During Adolescence • Male Reproductive System Maturation • Female Reproductive System Maturation

20. Adolescence and Puberty • Adolescence • Period between onset of reproductive function and adulthood (maturation of functions) • Puberty • Maturation of reproductive function • One of many physiologic changes occurring during adolescence

21. Puberty • Gonadal Function in Children Characterized by: • Very low levels of sex hormones • Very low levels of GnRH and FSH/LH • Testis and Ovary are differentiated • Indicates negative feedback is not functioning correctly

22. CNS Development and Sexual Maturation • CNS Matures progressively from birth to late childhood by: • Dendritic branching and number of synapses • Glial Cell Number • These lead to better communication, better metabolism, more efficient neurotransmissions • Due to a decreased threshold, neurons are responsive to lower stimuli levels

23. Experimental Evidence of Limbic System Immaturity • Immature gonads transplanted into an adult animal will mature immediately and demonstrate normal reproductive function • The pituitary taken from a prepubertal animal and transplanted into an adult will regulate normal reproductive function • Trauma to the hypothalamus will prevent the prepubertal animal from developing normal reproductive function

24. Functional Changes • Adult Reproductive function is established during adolescence • Female – Cyclic • Male – Tonic • Puberty Age • Female – 8-13 • Male – 9-14

25. Factors Influencing the Onset of Puberty • Hormonal • Nervous • Somatic (peak of accelerated growth/menarche) • Environmental • Social • Genetic

26. Precocious or Delayed Puberty True precocious puberty constitutional, cerebral Pseudoprecocious puberty secondary sex characteristics but no spermatogenesis/oogenesis Adrenal (hyperplasia tumor) Gonadal (tumor of Leydig cells or granulosa cells) Delayed Puberty Difficult to establish When menarche fails to occur by 17 years or testicular development by 20 years XO, XXY, panhypopituiarism

27. Male Genital Penis increases length and width Scrotum becomes pigmented and rugose Seminal Vesicles enlarge Prostate enlarges and secretes Extragenital Voice - Deepens Hair - Increased Behavior – More aggressive, sexual interest Skin - Acne Body Conformation Females Genital Vagina and uterus increase in size and thickness Menarche Major and Minor Labia enlarge and become pigmented Extragenital Voice – Remains high Hair - Increased Behavior – Interest in opposite sex Skin – Some Acne Body Conformation Hips Broader, Fat Deposition in breast/buttocks Changes at Puberty

28. Blood Pressure and Pulse Rate in Girls before and after menarche Systolic blood pressure Diastolic blood pressure Pulse Pressure Pulse rate

29. H-P-G Axis

30. Major Male Androgen Testosterone Develop and maintain male secondary sex characteristics Exert important protein, anabolic action, and growth promoting effects To exert inhibitory feedback on Pit LH secretion Female Ovarian Hormones Estrogen Stimulates growth and maintenance of secondary sex organs and characteristics Stimulates ovary and follicle growth Stimulates growth of smooth muscle and epithelial linings of reproductive tract Stimulates bone growth and epiphyses closure Protection against osteoporosis Progesterone Stimulation of uterine gland secretions Decrease contractility of uterine muscle Feedback on hypothalamus and pituitary Sex Hormones

31. Days 1-5: E/P levels low Endometrial epithelium sloughs FSH and LH increase (due to loss of P inhibition) Follicles start to enlarge Days 6-7 Dominant follicle selected Days 7-12 Plasma E levels rise and endometrium proliferates Days 12-13 High E induces LH secretion (positive feedback from E) Oocyte undergoes first meiotic division and undergoes cytoplasm maturation Follicle is stimulated to secrete lytic enzymes and prostaglandins Day 14 Ovulation Female Menstrual Cycle

32. Days 15-25 Corpus luteum forms and secretes E/P Secretory endometrium develops Secretion of FSH and LH is inhibited (negative FB) New follicles do not develop Days 25-28 Corpus Luteum degenerates Plasma levels of E/P decrease Endometrium Sloughs Return to Day 1 for a new cycle Menstrual Cont.

33. Sexualization • Muscle Growth and Plasticity • Nutrition • Eating Disorders • Homeostasis • Hormesis

34. Allows: Perpetuation of species Genetic adaptation Two sexes with a common goal Successful Pregnancy: Requires Mother’s Health Delivery of health child Safe environment to raise child Shared responsibility by mother, father, family, and society Choosing of a mate Physical Attraction Behavior Chemical Attractants Cultural Influences Sexual Orientation Theories about homosexuality Genes Sensitivity to alteration of prenatal testosterone Sexualization

35. Embryology • All muscles derive from the MESODERM of the GASTRULA Remember? Morula then Blastula then Gastrula • From its mesoderm layer: A) striated or voluntary muscles B) cardiac muscle or scalariform C) smooth muscle (of GI tract, Urinary, etc)

37. Importance of the Nervous System • Autonomic nervous system controls smooth and cardiac muscles • Central nervous system controls the voluntary muscles

38. Histology Each fiber being a multinucleated cell consists of myofibrils in bundles with a large number of mitochondria and a myoglobin (pigmented protein)

39. Contractility Secondary to the sliding characteristic of the 2 main proteins of the myofibrils: MYOSIN ACTIN (thinner)

40. TYPES of FIBERS Type 1: reddish Slow Oxidative (SO) Type 2: pale and divided into Fast Oxidative Glycolytic (FOG) Fast Glycolytic (FG)

41. Myoplasticity: Concept Ability of the muscle to alter the quantity and the type of its proteins in response to stimulations Modalities of stimulations: 1) Physical activities leading to an increase in its cross-sectional area 2) Increase in the muscular mass with changes in the myosin type Muscle plasticity may involve: • Change in the amount of protein • Change in the type of protein • Combination of both

42. Myoplasticity Due to Exercise • Endurance exercise increases the oxidative metabolism of the muscle • Resistance training increases the cross-sectional area due to true hypertrophy of the single cells • Inactivity induces rapid regression

43. Muscle Fiber Number Virtually Fixed at Birth • The increase in mass (hypertrophy, sometimes as much as 50%) is due to increase in length and in the cross-sectional area of the muscle fibers. This is due to an increase in the number of myofibrils (from 75 to over 1000) • The capacity for regeneration and plasticity is a response to neural, hormonal and nutritional differences

44. The Macronutrients: Lipids • Saturated, no double bonds, usually solid • Trans-fats, from liquid to solid format (usually commercial only) • Mono-unsaturated, like olive oil • Poly-unsaturated, like most other oils • OMEGA 3, fatty acids, like many fish oils

47. The Micronutrients • Salt, Na+ (<5 mg/day) and K+ (deficits, excesses, need) • Ca+ (1800 mg/day), P and Fl (bone metabolism) • Fe++ (deficit and excess), Cu, Mn, and Mg • Other metals: Cr, Se, Zn and the Metalloid I • Memo the hidden aspects of hypothyroidism

48. Body Mass Index • Weight in kg divided by height in m2 • NORMAL BMI : 18 to 24 years of age BMI < 18 : suspect malnutrition BMI 24 to 30 : overweight BMI 30 to 40 : obesity BMI above 40 = morbid obesity

49. Be familiar with: • Eating disorders • Causes, Symptoms, Treatments • Obesity • Types of obesity • Implication on health • The female athlete triad

50. Increased blood pressure Increased heart rate Increased force of heart contraction Increased heart conduction velocity Shift of blood flow distribution Contraction of spleen capsule Increased depth and rate of respiration Mobilization of liver glycogen to glucose (glycogenolysis) Mobilization of free fatty acids from adipose tissue (lipolysis) Mydriasis (widening of pupil) Accommodation for far vision (relaxation of ciliary muscle) Widening of palpebral fissure (eyelids wide open) Piloerection Inhibition of gastrointestinal motility and secretion, contraction of sphincters Sweating (cold sweats as skin blood vessels are constricted). Stress Stress induces defense mechanisms for maintenance of homeostasis in response to environmental challenges Types of stress known to stimulate the HPA axis*: Physical Stress:hypoglycemia, trauma, exposure to extreme temperatures, infections, heavy exercise Psychological Stress: Acute anxiety, Anticipation of stressful situations, Novel situations, Chronic anxiety Exposure to stress generates: Specific responses: varying with the stimulus and generating different responses with each stimulus Non-Specific responses:always the same, regardless of the stimulus and mediated through stimulation of neural, endocrine & immune axes *HPA axis = hypothalamo-pituitary-adrenal axis