BIOH 370 1st edition Lecture 31Outline of Last Lecture Fluid, Electrolyte and Acid-Base Balance Lecture Day 2I. Treatment for Water Intoxication and DehydrationII. EdemaIII. Electrolyte ConcentrationIV. Extracellular vs. Intracellular FluidsV. Blood Electrolyte Imbalances ChartsVI. Acid-Base Balancea. Chart of Mechanisms to Maintain pH of Body Fluidsb. Buffer systems:i. Bicarbonate Buffer Systemii. Phosphate Buffer Systemiii. Protein Buffer Systemc. Physiological Buffering: Exhalation of CO2d. Renal Mechanisms i. Type A intercalated Cellsii. Type B intercalated Cellse. Acidosis Vs. AlkalosisOutline of Current Lecture These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Fluid, Electrolyte and Acid-Base Balance Lecture Day 3, Reproductive System LectureI. Summary of Acidosis and AlkalosisII. Electrolyte Developmental Aspectsa. Infantsb. At Pubertyc. ElderlyIII. Reproductive Systema. Primary Sex Organsb. Accessory Reproductive Organsc. Sex HormonesIV. Male Reproductive Systema. Male Reproductive Organsi. Testesii. Spermiii. Accessory sex glandsiv. Scrotumv. Testesb. Spermatogenesisi. Sustentacular Cellsii. Meiosis Gametesiii. Steps in Spermatogenesisc. Hypothalamic-pituitary-gonadal (HPG) AxisCurrent LectureFluid, Electrolyte and Acid-Base Balance Lecture Day 3, Reproductive System LectureI. Summary of Acidosis and AlkalosisII. Electrolyte Developmental Aspectsa. Infants- Infants have proportionately more ECF than adults until about 2 years of age- Problems with fluid, electrolyte, and acid-base balance are most common in infancy, reflectingo Low residual lung volumeo High rate of fluid intake and outputo High metabolic rate, yielding more metabolic wasteso High rate of insensible water losso Inefficiency of kidneys, especially during the first month- Babys born bloated then lose 10% of body weight throughout first week (mostly water weight lost)= why need to change newborn’s diapers 10-12 times/dayb. At Puberty- At puberty, sexual differences in body water content arise as males develop greater muscle massc. Elderly- In old age, total body water often decreases- Homeostatic mechanisms slow down with age- Elders may be unresponsive to thirst clues and are at risk of dehydrationIII. Reproductive Systema. Primary Sex Organs (gonads)- Testes and ovarieso Produce sex cells (gametes)o Secrete steroid sex hormonesi. Androgens (males) ii. Estrogens and progesterone (females)b. Accessory Reproductive Organs- Ducts, glands, and external genitaliac. Sex Hormones- Development and function of the reproductive organs- Sexual behavior and drives- Growth and development of many other organs and tissuesIV. Male Reproductive Systema. Male Reproductive Organsi. Testes: within the scrotum- produce spermii. Sperm: delivered to the exterior through a system of ducts- Epididymis, ductus deferens, ejaculatory duct, and the urethraiii. Accessory sex glands= seminal vesicles, prostate, bulbourethral glands- Empties secretions into the ducts during ejaculationiv. Scrotum: sac of skin and superficial fascia- Hangs outside the abdominalpelvic cavity- Contains paired testes= 3 degrees C lower than core body temp= necessary for sperm prod.- Temp kept constant by two sets of muscles: o Smooth muscles that wrinkle scrotal skin (dartos muscle)o Bands of skeletal muscles that elevate the testes (cremaster muscles)- used when go into cold waterv. Testes:- Each is surrounded by two tunics o Tunica vaginalis, derived from peritoneumo Tunica albuginea, the fibrous capsule- Septa divide the testis into 250–300 lobules, each containing 1–4 seminiferous tubules (site of sperm production)- Blood supply comes from the testicular arteries and testicular veins - Spermatic cord encloses nerve fibers, blood vessels, and lymphatics that supply the testes- Sperm are conveyed througho Seminiferous tubuleso Tubulus rectuso Rete testiso Efferent ductuleso Epididymisb. Spermatogenesis:- Sequence of events that produces sperm in the seminiferous tubules of the testes - Most body cells are diploid (2n) and containo Two sets of chromosomes (one maternal, one paternal) o 23 pairs of homologous chromosomes- Gametes are haploid (n) and contain- 23 chromosomes - Gamete formation involves meiosiso Nuclear division in the gonads in which the number of chromosomes is halved (from 2n to n)o Two consecutive cell divisions (meiosis I and II) following one round of DNA replicationo Produces four daughter cellso Introduces genetic variationi. Sustentacular Cells:- Large supporting cells (Sertoli cells)- Extend through the wall of the tubule and surround developing cells- Provide nutrients and signals to dividing cells - Dispose of excess cytoplasm sloughed off during spermiogenesis- Secrete testicular fluid into lumen for transport of sperm- Tight junctions form a blood-testis barrier= why we call the testes immonuprivelaged o Prevents sperm antigens from escaping into the blood where they would activate the immune system- Because sperm are not formed until puberty, they are absent during immune system development, and would not be recognized as “self”ii. Meiosis Gametes- gametes produced by meiosisiii.Mother cell (before chromosome replication) Chromosome replication Chromosome replication 2n = 4 MITOSI S Replicated chromosome P rophas e Chromosomes align at the metaphase plate Sister chromatids separate during anaphase 2n 2n Metaphas e Daughter cells of mitosis Tetrad formed by synapsis of replicated homologous chromosomes Tetrads align at the metaphase plate Homologous chromosomes separate but sister chromatids remain together during anaphase I No further chromosomal replication; sister chromatids separate during anaphase II Daughter cells of meios is I I (usually gametes) n n n n Prophas e I Metaphas e I Daughter cells of meios is I Meios is I I MEIOSIS iv. Steps in Spermatogenesis: spermatic cells give rise to sperm- Mitosis (2n)o Spermatogonia form spermatocytes- Meiosis (n)o Spermatocytes form spermatids - Spermiogenesiso Spermatids become spermc. Hypothalamic-pituitary-gonadal (HPG) Axisi. Hypothalamus releases gonadotropin-releasing hormone (GnRH) ii. GnRH stimulates the anterior pituitary to secrete FSH and LHiii. FSH causes sustentacular cells to release androgen-binding protein (ABP), which makes spermatogenic cell receptive to testosteroneiv. LH stimulates