ACCESSORY DIGESTIVE GLANDS

PANCREAS1) EXOCRINE PORTION

- COMPOUND ACINOUS GLAND

- EACH ACINI CONSIST OF 5-8 PYRAMIDAL CELLS THAT SIT ON A BASAL LAMINA AND SURROUND A CENTRAL LUMEN

ACINAR CELLS

- BASALLY LOCATED NUCLEI & RER

- SUPRANUCLEAR GOLGI ZONE

- ZYMOGENIC GRANULES CONTAINING DIGESTIVE ENZYMES IN APICAL REGION

CENTROACINAR CELLS- LINE LUMEN OF ACINUS

- SECRETE LARGE AMOUNTS OF BICARBONATE

ACCESSORY DIGESTIVE GLANDS

PANCREAS1) EXOCRINE PORTION

INTERCALATED DUCTSPANCREAS H&E

ACCESSORY DIGESTIVE GLANDS

PANCREAS2) ENDOCRINE PORTION

ACCESSORY DIGESTIVE GLANDS

LIVER

PORTA HEPATIS

PORTAL TRIAD

ACCESSORY DIGESTIVE GLANDS

LIVER

CLASSIC LOBULE PORTAL LOBULE LIVER ACINUS

- central vein at center

- hexagonal in shape

- portal triad at corners

- portal triad at center

- triangular in shape

- central vein at corners

- short axis: branches of portal triad between 2 classic lobules

- long axis: between 2 central veins

LIVER

ACCESSORY DIGESTIVE GLANDS

LIVER

ACCESSORY DIGESTIVE GLANDS

GALLBLADDER

ROUTE OF BILE

HEPATOCYTE

BILE CANALICULI

RT & LT HEPATIC DUCTS

COMMON BILE DUCT

FILLING OF GALLBLADDER

- LOCATION FOR CONCENTRATION AND STORAGE OF BILE

URINARY SYSTEM: I

TO IDENTIFY THE COMPONENTS OF THE URINARY SYSTEM

TO EXAMINE THE HISTOLOGICAL STRUCTURE OF THE NEPHRON AND THE COLLECTING DUCTS

TO CORRELATE STRUCTURE OF VARIOUS COMPONENTS WITH FUNCTION

URINARY SYSTEM: I

TO CHARACTERIZE THE GENERAL ORGANIZATION OF THE KIDNEY

URINARY SYSTEM

KIDNEY

ANATOMICAL STRUCTURE AND BLOOD SUPPLY

URETER

BLADDER

URETHRA

- highly vascular (25% cardiac output)- produces urine (water and elctrolytes,

urea, uric acid, creatinine), initially an ultrafiltrate of the blood

URINARY SYSTEM

KIDNEY

1) EXOCRINE PORTION

2) ENDOCRINE PORTION

- synthesis and secretion of erythropoietin (regulation of red blood cell formation)

- synthesis and secretion of renin (hormone necessary for control of blood pressure and blood volume)

URINARY SYSTEM

KIDNEY (ORGANIZATION)

- RENAL HILUM, PELVIS, AND SINUS

- RENAL CAPSULE

GROSS STRUCTURE:

- RENAL CORTEX

- RENAL MEDULLA

M

C

URINARY SYSTEM

KIDNEY (ORGANIZATION)

CORTEX

MEDULLA

- region immediately beneath renal capsule- composed of two distinct regions:

(1) CORTICAL LABYRINTH

(2) MEDULLARY RAY

- located immediately beneath renal cortex

- consists of triangular blocks of tissue called the PYRAMIDS

- RENAL COLUMNS are strands of cortical tissue that extend down between adjacent pyramids

RC

P

PP

P

P

PP

URINARY SYSTEM

KIDNEY (ORGANIZATION)

P

PP

P

P

PP

RENAL LOBE- a single pyramid with its associated

overlying cortex

RENAL LOBULE- defined within cortex and involves a

single medullary ray (central axis of lobule) with adjacent adjacent cortical labyrinth

- defined as a functional unit that consists of a collecting duct and all the nephrons that it drains

Cortical Labyrinth with interdigitating Medullary Rays

URINARY SYSTEM

THE NEPHRON & COLLECTING DUCTS

URINARY SYSTEM

THE NEPHRON & COLLECTING DUCTS

1) THE NEPHRON

2) COLLECTING DUCTS

a) RENAL CORPUSCLE

- distributed throughout cortex and various zones of medulla

BOWMAN’S CAPSULE + GLOMERULUS

b) PROXIMAL TUBULECONVOLUTED AND STRAIGHT PORTIONS

c) HENLE’S LOOPTHICK AND THIN PORTIONS

d) DISTAL TUBULESTRAIGHT AND CONVOLUTED PORTIONS

URINARY SYSTEM

THE NEPHRON & COLLECTING DUCTS

CORTICAL LABYRINTH

1- RENAL CORPUSCLES2- PROXIMAL CONVOLUTED TUBULES3- DISTAL CONVOLUTED TUBULES

MEDULLARY RAY

1- STRAIGHT PORTIONS OF PROXIMAL TUBULE (THICK DESCENDING)

2- STRAIGHT PORTIONS OF DISTAL TUBULE (THICK ASCENDING)

3- COLLECTING DUCTS

CORTEX:

URINARY SYSTEM

THE NEPHRON & COLLECTING DUCTS

OUTER ZONE

INNER ZONE

MEDULLA:

1- STRAIGHT PORTIONS OF PROXIMAL TUBULE (THICK DESCENDING)

2- STRAIGHT PORTIONS OF DISTAL TUBULE (THICK ASCENDING)

4- COLLECTING DUCTS

3- THIN SEGMENTS OF LOOP OF HENLE (DESCENDING & ASCENDING)

2- COLLECTING DUCTS

1- THIN SEGMENTS OF LOOP OF HENLE (DESCENDING & ASCENDING)

URINARY SYSTEM

BLOOD FLOW (KIDNEY)AORTA

RENAL ARTERY

INTERLOBAR ARTERIES

INTERLOBULAR ARTERIES

ARCUATE ARTERIES

AFFERENT ARTERIOLES

GLOMERULAR CAPILLARY BED

EFFERENT ARTERIOLES

RENAL LOBULE

- run between lobes in medulla

- run parallel to bases of pyramids at the corticomedullary junction

- delineate lateral limits of renal lobules

- supply blood to glomerulus

- drain blood from glomerulus and form either peritubular capillary plexus (cortex) or vasa recta system (medulla)

URINARY SYSTEM

BLOOD FLOW (KIDNEY)

VENA CAVA

RENAL VEIN

INTERLOBAR VEINS

INTERLOBULAR VEINS

ARCUATE VEINS

RENAL LOBULE

- run between lobes in medulla

- run parallel to bases of pyramids at the corticomedullary junction

- delineate lateral limits of renal lobules

PERITUBULAR CAPILLARY PLEXUS

VASA RECTA SYSTEM

URINARY SYSTEM

Gaa

ea

IA

G

G

BLOOD FLOW (KIDNEY)

URINARY SYSTEM

THE NEPHRON & COLLECTING DUCTS

1) THE NEPHRON

2) COLLECTING DUCTS

a) RENAL CORPUSCLE

- distributed throughout cortex and various zones of medulla

BOWMAN’S CAPSULE + GLOMERULUS

b) PROXIMAL TUBULECONVOLUTED AND STRAIGHT PORTIONS

c) HENLE’S LOOPTHICK AND THIN PORTIONS

d) DISTAL TUBULESTRAIGHT AND CONVOLUTED PORTIONS

HISTOLOGICAL STRUCTURE AND FUNCTION

URINARY SYSTEM

THE NEPHRON & COLLECTING DUCTS

1) THE NEPHRON

2) COLLECTING DUCTS

a) RENAL CORPUSCLE

- distributed throughout cortex and various zones of medulla

BOWMAN’S CAPSULE + GLOMERULUS

b) PROXIMAL TUBULECONVOLUTED AND STRAIGHT PORTIONS

c) HENLE’S LOOPTHICK AND THIN PORTIONS

d) DISTAL TUBULESTRAIGHT AND CONVOLUTED PORTIONS

HISTOLOGICAL STRUCTURE AND FUNCTION

URINARY SYSTEM

RENAL CORPUSCLEBOWMAN’S CAPSULE + GLOMERULUS

1. BOWMAN’S CAPSULE:

- the beginning of the nephron that consists of a blind sac lined with simple squamous epithelium that is continuous with the PCT

- parietal layer & visceral layer (specialized)

2. GLOMERULUS:

- specialized tuft of capillaries which housed in the capsular space (10-20 capillary loops)

- blood flowing through glomerulus capillaries undergoes a filtration process to produce the initial urine filtrate

FILTRATION APPARATUS OF KIDNEY

URINARY SYSTEM

RENAL CORPUSCLEBOWMAN’S CAPSULE + GLOMERULUSFILTRATION APPARATUS OF KIDNEY

VASCULAR POLE

URINARY POLE

GLOMERULUS (FILTRATION MEMBRANE):

1- fenestrated capillaries; discontinuous endothelium; fenestrae have a diameter of 500-1000Å and lack a diaphragm

2- continuous basal lamina

3- podocytes of visceral layer; processes contact basal lamina and are separated by slits measuring approximately 250Å

URINARY SYSTEM

RENAL CORPUSCLEBOWMAN’S CAPSULE + GLOMERULUSFILTRATION APPARATUS OF KIDNEY

GLOMERULUS (FILTRATION MEMBRANE):

prevents RBC’s and large MW proteins from leaving circulation, while most other blood constituents pass easily into the capsular space

MESANGIAL CELLS

- phagocytic cells with a surrounding matrix that lend structural support to the glomerulus

URINARY SYSTEM

RENAL CORPUSCLEBOWMAN’S CAPSULE + GLOMERULUSFILTRATION APPARATUS OF KIDNEY

GLOMERULUS (FILTRATION MEMBRANE):

1- fenestrated capillaries

2- continuous basal lamina

3- podocytes

PODOCYTE

1° process

2°pedicels