SORRY

1
SORRY!

• Lecture exams will be done by Friday morning (I
  hope).
• Friday afternoon the latest Thursday night
  earliest.
• Wednesday lab
• Turn in your extra credit right after lecture
  today.
• Thanks.

2
The Urinary System

• Lecture 19
• Wednesday, November 10

3
Urinary System Fuctions

• Plasma concentrations of Na, K, Cl, Ca are
  regulated (solute composition concentration of
  blood)
• Blood volume and blood pressure regulated
  erythropoietin and renin released water volume
  lost is adjusted
• Blood pH stabilization
• Not excrete nutrients
• Eliminate urea, uric acid, toxic stuff, drugs
• Makes calcitrol (from Vit D3 stim Ca2
  absorption by intestinal epithelium)
• Assists liver in detoxification of poisons

4
Urinary System

• Kidneys make urine (water, ions, small soluble
  compounds)
• Ureters
• Urinary bladder (storage)
• Urination or micturation through
• Urethra

Fig 26.1 a
5
Kidneys

• Post abdominal wall retroperitoneal
• Right covered by liver, duodenum, right colic
  flexure
• Left covered by spleen, pancreas, stomach,
  jejunum, left colic flexure
• Each superiorly covered by adrenal gland
• Kidney bean shape
• 10 cm X 5.5 cm X 3 cm
• Hilus medial indentation
• Renal artery, vein ureter

6
Kidney Sectional Anatomy

• Cortex
• Nephrons
• Medulla
• Renal pyramid
• Renal papilla (empties into renal sinus)
• Minor calyx
• Major calyx
• Renal pelvis (connected to ureter)

7
Fig 26.3
8
Kidney Blood Supply
Fig 26.4 a

• Receives 20-25 total cardiac output
• Renal artery
• Branches until afferent arterioles to nephrons
• GLOMERULI capillaries
• Venules ? ? ? renal vein

9
Nephron

• Renal corpuscle
• Bowmans capsule and glomerulus
• Proximal thick segment
• Proximal convoluted tubule and proximal straight
  tubule
• Thin segment
• Thin limb of loop of Henle
• Distal thick segment
• Distal convoluted tubule and ascending limb

Proximal straight tubule
Thin Ascending Limb
Fig 26.7
10
Fig 26.6
11
Types of Nephrons

• Cortical (85)
• Most of reabsorption and secretion
• Juxtamedullary (15)
• Create conditions for making concentrated urine

12
Renal Corpuscle

• Glomerulus
• Endothelium, fenestrated
• Bowmans capsule
• Visceral layer podocytes
• Parietal layer simple squamous epithelium
• Capsular space (fluid and dissolved solutes)
• Vascular pole afferent efferent aa
• Tubular pole proximal convoluted tubule
• Mesangial cells
• Regulate blood flow, make ECM
• FILTRATE protein-free solution glucose, free
  fatty acids, amino acids, vitamins (need to be
  reabsorbed!)

13
Renal Corpuscle
Bowmans Capsule
Fig 26.6
Fig 26.8 c
14
Terms

• Fluid transfer across caps BP (fluid out cap) is
  much higher than oncotic/osmotic P (fluid into
  cap)
• Glomeruli pressure net filtration with fluid
  into BCfiltrate
• Filtration fluid transfer across glom walls into
  space
• Filtrate fluid from blood-bld cells (into
  tubules)
• Cause high pressure in glomeruli, glomeruli caps
  more permeable than others in body
• Reabsorption substances w/drawn from fluid and
  returned to caps to the body
• Secretion substances removed from blood and
  added to tubular fluids
• Peritubular caps/vasa recta BP is low? fluid
  reabsorption b/c osmotic pressure of plasma
  proteins

15
Filtration in Renal Corpuscle

• Capillary Endothelium
• Fenestrated no RBC passage, but allow proteins
  out, size of plasma proteins
• Basement Membrane
• Much thicker than typical basement membrane
• Lamina densa restricts larger protein passage,
  but allows smaller plasma proteins, nutrients,
  ions
• Mesangial cells physical support engulf what
  could clog the lamina densa regulate capillary
  diameters
• Bowmans Capsule Visceral Epithelium
• Podocytes w/narrow gaps or slits
• Water w/dissolved ions, small organic molecules

16
Capillary Endothelium
Basement Membrane
Glomerular Epithelium
Podocytes
Fig 26.8 d
17
Juxtaglomerular Apparatus

• Macula densa specialized cells in distal
  convoluted tubule
• When dehydrated sense Na in IF, signal to
  juxtaglomerular cells
• Juxtaglomerular cells modified SM cells of
  afferent arteriole
• Renin produced and into blood angiotensin
  system SM contraction and change flow/filtration
• Extraglomerular mesangial cells
• SO, renal blood pressure, blood flow or local
  oxygen levels decrease elevate blood volume
  levels, hemoglobin levels, blood pressure

18
Fig 26.8
19
Proximal Convoluted Straight Tubule

• Entrance at tubular pole
• Cuboidal epithelium w/microvilli inc SA for
  reabsorption
• Organic nutrients, Na Cl ions, plasma proteins,
  water, glucose
• Active absorption of K, Ca, Mg, bicarbonate,
  phosphate, sulfate ions, glucose
• As solutes absorbed, osmotic forces pull water
  into IF

Fig 26.6
20
P(C)T

• 120 mL of protein-free plasma filtered/min
• Reduce filtrate volume, reabsorb essentials
• By end 2/3 water and all nutrients reabsorbed
• Na/K pump to interstitial space then diffuse into
  peritubular cap. (? Na reabsorbed)
• Creates osmotic gradient for water reabsorption
• Water now in IF high oncotic P in caps (absorb
  water)
• This water loss from tubule s solutes
  remaining
• Glucose transported inside PT cell into blood
• Secretory of Ca, Mg, P (imp for drugs)

21
Loop of Henle Thin Segment

• Simple squamous
• Descending permeable to H2O and Na
• Ascending H2O impermeable (to DT) permeable to
  Na
• Pumps Na w/o allowing water to follow
• Active transport Na into IF (so DT always
  hypotonic)
• Hypertonic IF (in deep medulla)
• CDs pass through allow water be w/drawn by
  osmosis into IF
• SO IF hypertonic in medulla

22
Distal Convoluted Straight Tubules

• Simple cuboidal epithelium
• Ascending straight impermeable to water
• Responds to aldosterone
• Reabsorption Na, bicarbonate
• Secrete K, H
• Convert ammonia to ammonium ion

23
Collecting Tubules Ducts

• BOTH simple cuboidal
• Regulate water and solute balance responsive to
  ADH and aldosterone
• Well only consider ADH

24
Normal (or no ADH)
NaCl
hypotonic
Water
Hypotonic urine
Physiology Coloring Book. Kapit, Macey, Meisami.
HyperCollins Publishers. 1987

• No ADH DT CD impermeable to water
• More hypotonic as salts are reabsorbed

hypotonic

• H2O intoxication high vol, dilute urine

• Ascending loop of Henle actively reabsorb NaCl
• but prevent concomitant reabsorption of H2O
• (b/c are impermeable)

• So fluid to DT is hypotonic (Normal)
• This creates hypertonic IF in medulla
• (CDs pass thru)

hypertonic

• Hypotonic urine from DT to CD now even more
  hypotonic when leave CD b/c salts are reabsorbed
  w/o water following

25
NaCl
If ADH present
Water
Hypertonic urine

• Rise in osmolarity of interstitial fluid
• Hypothalamus inc ADH from post pituitary

• The latter DT and CD are H2O permeable.
• Water equilibrates w/IF so fluid leaving CD
• has same hypertonic as lower medulla

SO more hypertonic urine relieves a rise in
osmolarity of IF

• In other words, as fluid goes thru CD into
  medulla more and more hypertonic until urineIF

hypertonic

• Also last part of CD permeable to urea (into IF)
  
• Increases osmolarity in IF.

• H2O deprived conserve H2O
• low vol, d urine

26
Ureters

• Transitional epithelium
• Able to stretch during distension
• Continuation of renal pelvis
• End in post wall of bladder (trigone) as slits
• Takes a diagonal course

Bladder lumen
Fig 26.1
27
Urinary Bladder

• Hollow muscular organ storage
• Male base b/n rectum and symphysis pubis
• Female base b/n inf to uterus, ant to vagina
• Full 1 liter
• Trigone triangle of ureters to urethra

Fig 26.10
28
Urethra

• Neck of bladder to exterior
• Female
• Short 1-1.5 in
• UTI (bacteria or fungus)
• External urethral orifice very close to vaginal
  orifice
• Male
• Long 7-8 in
• Prosthatic, membranous, penile
• Urogenital diaphragm external urethral sphincter
  (skeletal muscle)
• resting to urinate

Fig 26.10
29
Male Reproductive System

• Chapter 27

30
Functions and Organs

• Makes,
• Stores,
• Nourishes,
• Transports
• Viable gametes (sperm)

• Organs makes gametes and hormones
• Reproductive tract ducts for receiving, storing
  and transporting gametes
• Accessory glands and organs secrete fluids into
  ducts
• External genitalia

31
Anatomy

• Testes (w/n scrotum)
• Epididymis
• Ductus (vas) deferens
• Urethra
• Penis
• Accessory glands
• Seminal vesicles
• Prostate gland
• Bulbourethral glands

Bladder
Fig 27.8 a
Fig 27.1
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Testes, Scrotum

• Testes (Sing. testis) oval shape
• Hang w/n scrotum (skin suspended inf to perimeum
  and ant to anus)
• Tunica vaginalis serous membrane on outside
  (reduces friction w/scrotum)
• Tunica albuginea dense fibrous layer under T.
  vaginalis (form septa w/n testes)
  albugineawhite
• Scrotum
• Cremaster muscle skeletal, tenses scrotum and
  pulls testes closer to body
• During sexual arousal and temp change
• Sperm development 2F below body temp

Fig 27.3
33
Testes Histology

• Septa form lobules filled with (800)
  seminiferous tubules (31 in each!)
• Where spermatogenesis occurs (make sperm)
• Connect to straight tubule to rete testis to
  efferent ductules to epididymus
• To ductus deferens

Fig 27.4
34
Testes Histology

• Around seminiferous tubules interstitial cells
  or Leydig cells
• Make testosterone in response to LH
• Stimulate spermatogenesis
• Promote physical and functional maturation of
  spermatozoa
• Maintain accessory organs
• 2 sex characteristics
• Growth and metabolism
• Brain development
• Sertoli Cells

Sertoli Cells
Leydig Cells
35
Testosterone directly stimulates spermatogenesis
Puberty begin
Cytoplasmic bridges!!
Seminiferus Tubule Lumen
Sertoli Cells
Leydig Cells
Fig 27.5
36
Spermiogenesis

• Each spermatid ? spermatozoan
• Lose ER, Golgi, lysosomes, peroxisomes, etc
• Form acrosome vesicle
• cap over nucleus
• Form a flagellum
• Create residual bodies (cytoplasmic bridges)
• Mature sperm
• Head DNA
• Acrosome hyaluronidase, proteinases (2 oocyte)
• Midpiece mitochondria for locomotion
• Tail flagellum

Fig 27.6
37
Sertoli Cells

• Blood-testis barrier
• Tight junctions lumen from IF
• Lumen lots of androgens, estrogens, K, AAs
• Developing spermatozoa have sperm-specific
  antigens
• Be attacked if not have this barrier!
• Create FSH and testosterone for spermatogenesis
• Needed for spermiogenesis (support)
• Phagocytose residual bodies from spermiogenesis