anatomy and physiology test 4

Regulation of GFR

Glomerular blood flow depends on systemic BP and diameter of afferent and efferent arterioles - 3 mechanism Renal Autoregulation of GFR - blood flow autoadjustment Myogenic Mechanism - Smooth muscle contracts when stretched reduces blood flow which reduces pressure downstream. Tubuloglomerular feedback - negative feedback mechanism using the juxtaglomerular apparatus [respond to NaCl concentration]

Net Filtration Pressure

Glomerulus blood filtering depends on 3 main pressures -1 promotes, 2 oppose 1- Blood Hydrostatic Pressure [HPG] - about 60 torr - forces fluid out of capillaries 2- Capsular Hydrostatic Pressure [HPC] - about -18 torr - opposes -from fluid already in capsular space 3 - Colloidal Osmotic Pressure of blood [OPC] about -32 torr - opposes NFP = HPG - [HPC + OPC] = 55 - 15- 30]] = about 10 torr outward This positive pressure moves fluid out of the glomerulus into Bowman's capsule. Pressure remains high enough throughout length that filtration continues - not like other capillaries. Especially sensitive to hypertension

Spermatozoa

Head - contains genetic material and acrosome [structure containing special enzymes for egg penetration] Tail Midpiece - helically arranged mitochondria energy Tail - flagellum Seminiferous tubules contain Sertoli cells [sustenacular cells], joined by tight junctions that form the blood-testis barrier

Metabolic Alkalosis

High bicarbonate, high pH Caused by loss of acid or intake of alkaline drugs [vomiting is the most common cause] Compensation - respiratory - hypoventilation [slow, shallow]. PCO2 rises. Treatment - electrolyte/fluid therapy

Phosphate buffer system

Important in cytosol and kidneys OH- + H2PO4- ⇌ H2O + HPO42- H+ + HPO42- ⇌ H2PO4-

Renin-angiotensin II pathway regulation of GFR

Juxtaglomerular cells release renin in response to 1 - decreased delivery of fluid and NaCl to macula densa 2 - decreased stretching of juxtaglomerular cells 3 - increased rate of stimulation by renal sympathetic nerves Renin + angiotensinogen angiotensin I lungs angiotensin II adrenal cortex aldosterone Angiotensin II is the active hormone that a. produces constriction of arterioles to increase GBHP and raise GFR b. stimulates secretion of aldosterone, which enhances reabsorption of Na+ [and water] by principal cells in collecting ducts c. stimulates the thirst center of the hypothalamus d. stimulates release of ADH which increases water reabsorption increase in blood volume higher BP

types of nephrons

Juxtamedullary - long loop penetrates deeply into medulla - 15% of nephrons Cortical - short loop - penetrates only slightly into medulla - 85%

Renal Control of pH

Kidneys can expel H's by secretion - neutralize it in tubules with bicarb, phosphate, etc. Only way to remove non-carbonic acid H+ [phosphoric uric, lactic acid, ketone bodies] Also only way to regulate alkaline substances - can break down bicarb to CO2 and reabsorb that

Testes

Lobules -composed of seminiferous tubules [where sperm are formed] a. contain spermatogenic cells [in different stages of spermatogenesis] b. protected by sustenacular cells [Sertoli cells] which form blood testes barrier &also secrete inhibin 4. Leydig cells [interstitial cells] between seminiferous tubules secrete testosterone. 5. once formed sperm move into rete testis in capsule to begin maturation 6. The B-T barrier protects sperm from substances in blood and prevents the immune system from attacking the sperm as "foreign"

Scrotum

Loose skin and fascia 2. Scrotal median septum 2 bags 3. Spermatic cord contains ductus deferens, blood vessels & nerves - passes through inguinal canal into abdomen 4. For normal functional sperm, the temperature needs to be 2-3 degrees below core body temperature; Testes therefore are outside to keep the sperm cool 2 groups of muscles Cremasters - skeletal - from internal obliques b. Dartos - smooth - in septum and subcutaneous layer c. Function - suspend and support testes and help maintain appropriate temperature. d. when it is cold, the cremasters contract and pull the testes up and closer to the body for warmth, and the Dartos contract and cause wrinkling the scrotum. With heat, these processes reverse. 6. Pampiniform plexus - net of veins testicular vein returning to body acts as a heat exchanger keeping arterial bold heat from inhibiting sperm

Respiratory Alkalosis

Low pCO2, high pH Caused by hyperventilation [e.g. From oxygen deficiency] Compensation - renal - decrease H+ secretion, bicarbonate elimination Treatment - breathe into a bag

Metabolic Acidosis

Low systemic and arterial bicarbonate, low pH Caused by loss of bicarbonate, accumulation of another acid, ketosis, or kidney failure Compensation - respiratory hyperventilation [increased rate and depth]. PCO2 falls. Treatment - NaHCO3 IV

Mammary Glands

Modified sudoriferous glands which produce milk Areola - pigmented area around nipple - contains modified oil glands Function - lactation - control - prolactin [synthesis] and oxytocin [ejection] 15-20 lobes separated by adipose tissue Subdivided into lobules with clusters of alveoli = milk secreting glands Produce milk passes to lactiferous ducts to nipple.

Vulva (external male genetalia

Mons pubis = skin + adipose cushion of pubic symphysis Labia majora - 2 folds of skin with sebaceous and sudoriferous glands Labia minora - 2 folds medial to majora - contain mostly sebaceous gland Clitoris - small mass of erectile tissue and nerves with prepuce and a glans [analogous to penis] Vestibule - cleft between labia minora - contains vaginal orifice, urethral orifice and duct openings. Paraurethral glands [equiv. To prostate] secrete mucus Greater vestibular glands [equiv. To Cowper's] produce mucus for lubrication

Tubular Reapsorption in the Proximal Convoluted Tubules

Most reabsorption occurs - transcellular or paracellular routes through ells or through cell junctions --> intracellular fluid --> peritubular capillaries Na+ reabsorption - via facilitated diffusion and symporters and antiporters [Na+K+] Reabsorption in PCT 100% of filtered glucose, lactate and amino acids 90% of bicarbonate ions 65% of Na+ and water 50% of Cl- and K+

Gonorrhea

Neisseria gonorrhoeae; causes PID, neonatal blindness

Neural Regulation of GFR

Norepinephrine causes vasoconstriction Affects smooth muscles of vessels - low input dilation, high constriction

phosphate

Nucleic acids, ATP, phospholipids, bone, etc. Control: Kidneys reabsorb if levels drop, Parathyroid hormone stimulates excretion

Seminal Vesicles

Paired posterior to urinary bladder Constitutes about 60% of semen

Uterus

Pathway for sperm, Site of menstruation, Site of implantation, Site of fetal development Parts Fundus Body - uterine cavity Isthmus Cervix - cervical canal External os Secretory cells of the cervical mucosa lining produce cervical mucus

Uterine Wall

Perimetrium - part of visceral peritoneum Myometrium - 3 layers of smooth muscles - stimulated by oxytocin during labor] Endometrium - highly vascularized Simple ciliated columnar epithelium + secretory cells 2 layers: Stratum functionalis - closest to uterine cavity - shed during menstruation Stratum basalis - permanent layer which repeatedly gives rise to stratum functionalis Blood supply - uterine arteries arcuate arteries radial arteries straight arterioles or spiral arteries Straight arterioles terminate in s. basalis and supply materials needed to regenerate s. functionalis Spiral arterioles penetrate into s. functionalis and change markedly during menstrual cycle Held in place by 4 ligaments [broad, uterosacral, cardinal, round]

oogenesis

Primordial germ cell from yolk sac migrates to ovary during development Mitosis a primary oocyte [2N]; Primary oocyte enters meiosis I, stops [primary follicle] At puberty LH levels rise, oocyte completes meiosis I = Secondary oocyte + polar body. In monthly cycles, one or more secondary oocytes enter meiosis II, stop at metaphase II If fertilization occurs completes meiosis II = ovum Ovum nucleus fuses with sperm zygote; if no fertilization, ovum degenerates

Spermatogenesis

Primordial spermatogonia are derived from the embryonic yolk sac. They migrate to the developing gonads in the fetus, where they divide to form multiple diploid cells. Spermatogenesis begins when a spermatogonia divides by mitosis one cell replaces the original, the other forms the primary spermatocyte The primary spermatocyte [still 2N] enters meiosis I 2 secondary spermatocytes [1N] Meiosis II 4 spermatids spermiogenesis [maturation] 4 sperm Takes ~ 74 days for whole process. Make about 400 million per day

Renal Tubule

Proximal Convoluted Tubule - in cortex Cuboidal epithelium with microvilli [brush border] - does lots of absorption Loop Of Henle [nephron loop] - in medulla Descending limb [thin] simple squamous epithelium - permeable to water [out], urea [in]; thick walls Ascending limb [thick] - cuboidal to low columnar epithelium; thick at top, then thin Distal Convoluted Tubule - in cortex Cuboidal epithelium - only a few microvilli Collecting Ducts - drains several DCT's Combine to form papillary ducts calyces Cuboidal epithelium, then columnar

Tubular Reabsorption of the Loop of Henle (Nephron Loop)

Reabsorption 25% K+ and Na+ & Cl- 15% of water

Prostate Gland

Single gland surrounding urethra like a donut. Contributes about one third of semen

how do birth control pills work

Specifically, synthetic estrogen in the pill works to: Stop the pituitary gland from producing follicle stimulating hormone (FSH) and luteinizing hormone (LH) in order to prevent ovulation. Support the uterine lining (endometrium) to prevent breakthrough bleeding mid-cycle. Meanwhile, synthetic progestin works to: Stop the pituitary gland from producing LH in order to prevent egg release. Make the uterine lining inhospitable to a fertilized egg. Partially limit the sperm's ability to fertilize the egg. Thicken the cervical mucus to hinder sperm movement (although this effect may not be key to preventing pregnancy

Epiddidymis

Tightly coiled tube - about 18 ft long Lined with pseudostratified columnar epithelium Layers of smooth muscle for peristalsis Functions - sperm maturation [up to 20 days] Sperm motility increases and sperm become fertile Store up to 6 wks - then degenerate and reabsorb Convey sperm to Vas deferen

Fallopian Tubes

Transport channels for ova Usually site of fertilization zygote reaches uterus in about 7 days Layers - mucosa, smooth muscles and serosa Mucosa - continuous with vagina and uterine

Syphilis

Treponema pallidum; spirochete, passed to infants. Tertiary form causes insanity

what determines the type of nephron

Where the loop of Henle reaches to

Testosterone

aids in FSH in beginning spermatogensis produced in the Sustenacular cells (in the testes) and Leydig (Interstitial) Cells (adjacent to the seminiferous tubules in the testicle)

sodium regulated by

aldosterone - renin-angiotensin system - [increases reabsorption of Na+ and excretion of K+], ascending loop, DCT & collecting ducts ADH [increases water reabsorption in response to increases in Na], ANP [increases Na+ excretion by kidneys by inhibing ADH & aldosterone] Estrogens - enhances Na reabsortion and water retention Progesterone may decrease Na+ reabsorption by blocking aldosterone. Glucocorticoids - can cause edema

potassium regulated by

aldosterone [hi K+ increases aldosterone which stimulates principal cells to secrete K+]

Menstrual Cycle

build up, breakdown and disposal of endometrium monthly. 1. General: 4 phases involve hormonal changes [brain, pituitary, ovaries, uterus], cyclic changes in breast and cervical tissue - Average cycle - 28 days [24-35 range] 2. Proliferative phase - days 6-14 Estrogen stimulates replacement of stratum functionalis via mitosis in stratum basalis increases endometrium thickness; Estrogen also stimulates formation of progesterone receptors 3. Secretory phase - days 15-28 Progesterone stimulates increased proliferation of endometrial glands and stimulates release of glycogen from them. Progesterone also stimulates vascularization and thickening of the stratum functionalis and an increase in tissue fluid 4. Premenstrual phase If fertilization does not occur corpus luteum degenerates to Corpus albicans and get low Progesterone and Estrogen levels constriction of spiral arterioles ischemic phase necrosis, degeneration 5. Menstrual phase - first 1-5 days Cells supplied by spiral arterioles slough off - results in total loss of stratum functionalis [50-150 mL blood, tissue and fluid]

Luteinizing Hormone

causes secretion of testosterone and other androgens by the interstitial cells (located in between the seminiferous tubules in the testies

Ejaculatory Duct

connects vas Deferens to urethra

Vas Deferens

continuous with epididymis About 45 cm long Ascends into pelvic cavity, loops around side and down back of bladder and empties into ampulla ejaculatory duct urethra 3 layers of smooth muscles Function -store sperm [external part only - internal T is too high to remain viable

Fimbriae

finger-like projections from infundibulum Sweep- push ova into tube

Ovaries

from endodermal tissue Produce secondary oocytes during oogenesis and hormones Held by 3 ligaments - broad [part of parietal peritoneum], ovarian [to uterus] and suspensory [to pelvic wall

HSV -II

genital herpes - viral; incurable at present.

HPV

genital warts, cervical cancer.

where and when does implantation occur

high on the uterine wall, 7 days after fertilization

Protein Buffer System

in cells and plasma [most important buffer - does ¾ of all] Proteins are amphoteric - change charge with pH The acid group [COOH] can give up and H+ to neutralize a base [lowers pH] The amine group can accept an H+, raising pH

where does fertilization normally occur

in the Fallopian tube

Inhibin

inhibits FSH. [FSH initiates spermatogenesis] increased release when sperm count is high located in the Sustenacular cells

Follicle Stimulating Hormone

initiates spermatogenesis produced in the anterior pituitary

Juxtaglomerular Apparatus

juxtaglomerular cells - smooth muscle fibers of afferent arterioles - mechanoreceptors - dilate or constrict with pressure change & secrete renin. macula densa- chemoreceptors - at end of ascending limb tall crowded cells that monitor Na+ and Cl- concentration

chloride

more abundant in intracellular cation Major extracellular anion Functions in OP regulation, HCl formation[GI] Levels regulated by Na+ movements [follows Na+]

Chlamydia

most common STD; causes 'silent' PID - sterility

what is the functional unit of the kidney

nephron

Normal Blood Values

pH 7.35 - 7.45 PCO2 35 - 45 mm Hg HCO3- 22 - 26 mEq/L

Blood Acidosis

pH below 7.35 depression of CNS coma

most abundant electrolyte for ICF

potassium Most abundant intracellular cation Functions in impulse conduction, OP regulation, protein synthesis, Na/K pump and pH

most abundant electrolyte for ECF

sodium 90% of ECF cations important in impulse transmission contributes to osmotic pressure - most important solute in determining water distribution Adult need 0.5 g/day - in America always have EXCESS - problem is getting rid of it Concentrations are maintained by maintaining water levels - "water follows salt"

Gonadotropin Releasing Hormone

stimulates the pituitary gland to produce two hormones, follicle-stimulating hormone (FSH) and luteinizing hormone (LH)

electrolyte

substance that dissociates into + [cations] and - [anions] in water solution and conducts electricity in solution

Tubulae Reabsorption of the Distal Convoluted Tubule and Collecting Duct

variable absorption based on need - 2 cell types Principal cells - have infolding of basement membrane - maintain water and Na balance. Sensitive to ADH and aldosterone Intercalated Cells - very few - lots of mitochondria - can reabsorb K+ and secrete H+ to rid body of excess acid

Calcium

Ca Most abundant mineral in body Abundant extracellular cation Functions: bone, teeth, blood clotting, impulse conduction, muscle, contraction Levels controlled by PTH - stimulates osteoclast release of Ca from bone, stimulates formation of calcitrol from Vit. D - enhances intestinal uptake, stimulates kidney reabsorption. Calcitonin - stimulates Ca incorporation into bone [mostly in children].

formation of concentrated urine

Concentrated urine is hypertonic to blood plasma Occurs during time of low water intake ADH is present - water channels [aquaporins] form in principal cell membranes [increase water reabsorption] More complex than dilution - depends on high concentration of solutes in interstitial fluid in medulla Solute concentration is maintained by a counter current mechanism

Female Sexual Cycle

Control: hypothalamus --> pituitary --> ovaries --> uterus Ovarian cycle - 2 phases - follicular & luteal Follicular Phase - preantral - before birth, & antral phases Primordial follicle - develops 12-16 wks gestation - oocyte in early meiosis + single layer of follicular cells Primary follicle - pre-birth - follicular cells thicken and ad layers -- > zona pellucida [glycoprotein gel] Secondary antral follicle - develops from primary to Graafian - several develop each month. Dominant follicle - The one that wins the race to develop first undergoes ovulation - expulsion from Graafian follicle into body cavity The time BEFORE ovulation is the pre-ovulatory period Ovulation - rupture of follicle - [omit mechanism] The Luteal phase then begins - the corpus luteum develops from the remnants of the Graafian follicle & secretes Es & P [increases 10X] No pregnancy --> stops secretion and becomes corpus albicans

formation of dilute urine

Controlled by ADH To produce dilute urine - just don't remove any water after ascending loop of Henle Dilution occurs in the absence of ADH - makes principal cells impermeable to water reabsorption

Respiratory Acidosis

Elevated pCO2, low pH Caused by hypoventilation, decreased external respiration [ex. Pulmonary edema, emphysema] Compensation - renal H+ secretion, increased bicarbonate reabsorption Treatment - respiratory and IV bicarbonate

structure of the filtration membrane

Endothelium of glomerulus - open pores [fenestrations] - 70-90 nm diameter everything but cells and platelets pass through Basal lamina [basement membrane] of glomerulus - serves as dialysis membrane -blocks large plasma proteins Filtration slits - Endothelium of visceral layer of glomerular capsule - podocytes form filtration slits [spaces between pedicels] - negatively charged - repel anions - 30 nm slit width

Semen

= sperm + secretions from accessory sex glands Volume per ejaculation = 2 - 5 mL Sperm count - 50 - 120 million/mL [<20-25 million --> sterility] Prostate gland Secretes milky slightly acidic fluid containing citric acid and several enzymes. Seminal vesicles Secrete alkaline viscous fluid containing fructose [for sperm ATP production], prostaglandin [to enhance sperm motility] Alkaline pH neutralizes acid in male urethra and female reproductive tract. Final properties - Slightly alkaline [pH 7.2-7.6] Provides sperm a transport medium, contains enzymes to activate sperm, contains seminal plasmin [an antibiotic], contains coagulation [seminogelin]and decoagulation chemicals to form and dissolve plug [gels for 5-20 min]

Glomerular Filtration Rate

Amount of filtrate formed in all areas of the renal corpuscles of both kidneys every minute Directly related to pressures that determine NFP Adult rate is about 125 mL/min - 180L/day [males]

what constitutes normal urine

Appearance - clear, colorless to amber Odor - slight - increases with standing due to bacterial ammonia production Specific gravity - 1.001 - 1.028 [water is 1.000] Osmolarity - 50 - 1200 mOsm/L pH - 4.5 - 8.2 Composition - 95 water

Counter Current Mechanism

Based on anatomic arrangement of juxtamedullary nephrons and the vasa recta Get salinity gradient produced in ECF - very high at base. Countercurrent Multiplier - loop of Henle - recaptures Na+ and returns it to deep medullary tissues keeping the gradient in place. Descending - water leaves, Na+ and Cl- stay Ascending water enters, NaCl leaves Recycling of urea in renal medulla - gets concentrated in tubules diffuses out at collecting duct into medulla into tubular fluid in ascending loop - repeats Countercurrent exchanger - VR Vasa Recta - Blood flows in opposite direction from loop - Maintains a gradient - keep removing water and adding salt.

Bulburethral gland

Beneath prostate - empties into spongy urethra Secretes alkaline substance and mucus to lubricate urethral lining and penis during intercourse. Contributes about 5% of semen

Renal Corpuscle

Bowman's Capsule - in cortex Parietal layer - wall of simple squamous epithelium Capsular space Visceral Layer - wall with specialized epithelial Podocytes with foot processes [wrap around capillary of glomerulus] Functions - pressure filtration of blood - water and small solutes leave blood vascular pole - blood in - urinary pole -urine out

buffers

Buffers resist changes in pH when strong acid or strong base are added. Buffer system "physiological buffers" - remove or add H or base as needed - urinary system [slow] & respiratory system [fast] Chemical buffer - Weak acid and salt of that acid Work by converting strong acids/bases to weak ones that don't dissociate as much to give operative ions [H+, OH-]

Vagina (Birth Canal)

Functions- Passage for menstrual flow, Passage for sperm, Passage for childbirth Tubular fibromuscular organ with mucus membrane of stratified squamous epithelium. Mucus has large amounts of glycogen which decomposes to produce acids. The low pH retards microbial growth, but is harmful to sperm

renal failure values

GFR: <60 mL/min/1.73 m2 for 3 months Higher levels of creatinine urinalysis: shows that the kidney is allowing the loss of protein or red blood cells into the urine BUN: level rises

Histology of Ovary

Germinal epithelium of simple squamous to cuboidal epithelium - on outer surface Tunica albuginea - deep to germinal layer Cortex - contains ovarian follicles and dense CT Medulla - loose CT, vessels, nerves Ovarian follicle = oocyte + surrounding follicle cells - In cortex [see figure 28.2, p. 1067] Follicle epithelial layers progressively become more numerous, and fluid is secreted into space with oocyte Graafian [mature] follicle - large, fluid filled - contains secondary oocyte ready for ovulation Secretes estrogens Corpus luteum - remnants of follicle after ovulation Secretes progesterone, estrogens, relaxin and inhibin Degenerates into corpus albicans Ligaments - ovarian, suspensory & mesovarian

histology of the nephron

2 parts Renal Corpuscle = glomerulus + Bowman's capsule Renal Tubule = proximal convoluted tubule, loop of Henle, distal convoluted tubule [proximal and distal relate to position re glomerular capsule

Penis

3 regions Root = attached internal portion[about 1/2 of length] Body - 3 cylindrical masses of tissue - function in erection 2 = corpora cavernosa [lateral] 1 = corpora spongiosum [ventral, contains urethra] All three contain erectile tissue permeated by blood sinuses Glans Penis = distal end Enlarged portion - has external urethral orifice Covered by prepuce or foreskin - with glans produces smegma

Bicarbonate/Carbonic Acid System

- only important ECF buffer. Important in blood Carbonic acid and sodium bicarbonate - H+ + HCO3- ⇌ H2CO3 ⇌H2O + CO2

Urethra

- terminal duct for reproductive and urinary systems Passes through prostate gland, urogenital diaphragm and penis 3 regions prostatic - passes through prostate membranous - going through urogenital diaphragm spongy - enters penis and ends at external urethral orifice

what hormones does the uterus produce

Estrogen: In pregnancy, estrogen stimulates the growth of the uterus and improves blood flow between the uterus and placenta. It also preps the breasts to prepare for milk production by enlarging a woman's milk ducts. Peak estrogen secretion happens right before birth. Progesterone: This hormone helps maintain the inner layer of the uterus to provide support for the developing embryo. It also serves the very important role of quieting the uterine muscle, so the blastocyst can have a safe landing while implanting. Human Placental Lactogen: Besides helping with milk preparation, this hormone also increases a mom's metabolism during pregnancy (she needs more energy caring for another human, after all). Human Chorionic Gonadotropin: This hormone stimulates the corpus luteum (the part of the follicle left behind in the ovary) to produce estrogen and progesterone in the first 10 weeks after conception, until the placental cells can do so by themselves. (For this reason, it is also the hormone we check in your urine or blood to determine whether you're pregnant.) Levels of hCG, which have been associated with morning sickness, typically peak toward the end of the first trimester, then decline and level off for the rest of the pregnancy.

Respiratory Control of pH

Exhalation of CO2 lowers H+ by lowering carbonic acid With alkalosis - get shallow slow breathing to help ACCUMULATE CO2

Direction of flow through the nephron

Filtered out of glomerulus capillaries through Bowman's capsule proximal convoluted tubule loop of Henle distal convoluted tubule Several distal convoluted tubules flow into a collecting duct papillary duct Filtered out of glomerulus capillaries through Bowman's capsule proximal convoluted tubule loop of Henle distal convoluted tubule Several distal convoluted tubules flow into a collecting duct papillary duct