IPHY 4440 1st EditionFinal Exam study guide Old materialIdentify if a bioregulator is a hormone, a neurocrine (which type), cytocrine (which type),or semiochemical (which type) based on its actions.- A bioregulator is a hormone if released directly into the blood - Neurocrines: secreted by neurons 3 Types1) Neurotransmitters (ex. aCh) released to synapse to induce an electrical charge aka actionpotential2) Neuromodulators released to synapse cause a direct effect on target cell therefore NO action potential is generated but alters the activity of other neuron ex: acupuncture releases Enkephalin 3) Neurohormones released directly into the blood (no synapse) aka neurosecretory hormones, which trigger a wide range of effects throughout the body and very close to the synaptic terminal and blood vessel ex. AdrenalineCartoon depiction: two cells exchanging a holiday card (aka the synapse)- Cytocrines (“cyto”=cell)2 types: Secreted by ALL cells are local messengers released into the ECF (no synapse) 1) Paracrines: affect other cell types ex. Epithelial cells communicate to connective tissue tobuild collagen or epithelial cell “talking” to another epithelial cellsCartoon depiction: cards spread everywhere (communication to any neighboring cells) 2) Autocrines: “self-stimulating” affect the same cell. Monitoring its own physiology and produce their own responses ex. Cancer cellsCartoon depiction: “Note to self” - SemiochemicalsTwo types: secreted by the organism and secreted outside the animal and signals between organisms 1) Pheromones: affect the same species. Ex: reproductive behavior or menstrual cycles2) Allelomones: affect different species. Ex. Different forms of one gene= “allele”Know the defining chemical features (C18, C19, or C21; Δ4 or Δ5; aromatic A ring) ofthe following steroids:a. Pregnenolone : Delta 5 pathway and delta 4 pathwayb. Progesterone  C21c. Testosterone  C19d. DHT  C19e. Glucocorticoids (cortisol and corticosterone)  C21f. Aldosterone  C21g. 17β-estradiol  C18, has aromatic A ring Know the function of following enzymes in steroid synthesis pathways.a. P450sccb. P450c11c. 3β-HSDd. 5α-reductasee. P450arof. P450aldoKnow general patterns, key enzymes, and products of Δ4 and Δ5 steroid synthesispathwaysKnow components of the HPT, HPA, and HPG axes. Know how negative and positivefeedbacks (if any) operate within each axis.Know how the following signal transduction pathways work:a. cAMPb. phosphotidylinositolc. MAPKKnow the anatomical relationship among the hypothalamus, neurohypophysis, andadenohypophysis.Know the function and production site of the following pituitary hormones: GH, PRL,LH, FSH, TSH, ACTH, MSH, OXY, AVP.Know the function of thyroid hormones.10. Know the three zones of adrenal cortex and the hormones they produce.11. Know the function of aldosterone and glucocorticoids.New Material Development of the Reproductive System Explain how sex is determined by genes Male is heterogametic (XY) Maleness is defined by testes, produces  sperm (small gamete)Female is homogametic (XX) Femaleness is defined by one having ovaries, produces  eggs (large gamete)SRY gene: on Y chromosome, genetic basis for sex determination (only in male determination)- (XY) SRY  testis determining factor  testis- (XX) No SRY  by default  ovary forms What are the two features that distinguish sex differentiation? And what is sex differentiation driven by?1) Reproductive tract 2) External genitalia - Sex differentiation is actually driven by hormones not by genes - Differentiation of sex reproductive tract1) Wolffian duct: allow to grow and mature into male reproductive tract include: vas deferens, seminal vesicle, epididymis 2) Mullerian duct: allow to grow and mature into female reproductive tractwhich includes: oviduct, uterus, vagina3) If fetus is male: Testis  T & Mullerian Inhibiting Substance (MIS)  wolffian duct maintained and Mullerian duct degenerates4) If fetus is a female: No testis  No testosterone & No MIS  wolffian duct degenerates and Mullerian duct maintained Explain the 3 types of Pseudohermaphroditism1) ``````````Testicular feminization syndrome(androgen-insensitivity syndrome) No functional androgen receptor- so chromosome: XY, Gonad: testis, Duct: none, Genitalia: female, Phenotype: female2) 5a-reductase deficiency (Guevedoces)-Dominican Republic Lacks 5a-reductase- Genitalia: female first (no DHT) then male at puberty (increase T) - Phenotype: female first (no DHT) then male at puberty (increase T)Facial hair, grow a penis 3) Congenital adrenal hyperplasia - Most common pseudohermaphroditism (50%)- androgen immediately before ® after birthDescribe the testicular structure and include seminiferous tubules, leydig cells, sertoli cells, and germ cells.- Seminiferous tubule  Spermatogenesis takes place, surround by connective tissue layer that has no blood vessels that penetrate the tubules - Leydig cells steroidogenic, primary job has to do with spermogenesis- Sertoli cells  support spermatogenesis. Sertoli cells aka Sustentacular cells nurture the sperm by tight junctions that make the blood-testis barrier- Lumen of seminiferous tubule contains germ cells (sperm)- Germ cells: Spermatogonia (diploid stage) undergoes spermatogenesis (mitosis and meiosis)  Spermatid (haploid stage) undergoes spermiogenesis (differentiation and elongation) spermatozoa (sperm) (haploid stage) Why is the blood-testis barrier important?- Important because immune cells will never seen sperm so may launch attack on sperm -autoimmune if they see a sperm cell as foreignWhat is the role of LH and FSH in terms of testis regulation function?- LH: increases synthesis of testosterone, increases spermiation= release of sperm into lumen- not ejaculation - LH doesn’t directly increase spermiation but must increase Testosterone first and must have LH to have testosterone- Rely on instructions coming from the pituitary - FSH: stimulates spermatogonial proliferation (mitosis) but no FSH receptors on gonia instead FSH directly stimulates Sertoli cells (have FSH receptor), secrete paracrine factors to increase spermatogonia- Stimulates the synthesis of aromatase synthesis of E2 by the leydig and sertoli cells- Stimulates synthesis of cytoskeletal elements- Stimulates the synthesis of STP= Steroidogenesis-stimulating protein that increases LH sensitivity of leydig cells and increase steroid production -