ANNOUNCEMENTS LAB PRACTICAL RESCHEDULED: April 28, 29 Material Covered: Urinary, Exocrine, & Endocrine Systems, Digestive System & Accessory Organs, and Lymphatic System and Reproductive Systems. SECOND EXAM RESCHEDULED: April 22nd Material Covered: Bone, Muscle, Nerve & Circulatory, Lymphatic, & Urinary Systems Conflicts? Exam by appointment: 4/21, 4/23 ** Appointments must be made by 4/17.** REVIEW SESSION HERE THIS FRIDAY 12:20 Final Exam: May 18th 1:30 PM in Morrill 203

The Lab Project GOAL: To work as a team to analyze an organ with embedding & sectioning & immunohistochemistry. To prepare: Identify your group members. Identify 3 organs you would like to work on. Possible organs are: liver, brain, bladder, lung, pancreas (?), skeletal muscle, stomach, intestine, kidney, uterus. Choose 2 antibodies to stain frozen sections. All sections will be stained with DAPI, a marker of cell nuclei. Choose 2 other markers from the list under Review Materials. Label one with a red fluorochrome and one with a green fluorochrome.

LAB SCHEDULE Week of April 13: Learn to frozen section organs. Week of April 20: Complete frozen sections. Week of April 27: Lab Practical and learn to section embedded material. Week of May 4: Immunohistochemistry. Complete sectioning & staining of embedded material. In class, May 11: Share results, discuss interpretation. Each student writes own report according to the guidelines provided on the Review Materials page. May 18: Lab Project report due at Final Exam.

***EXTRA CREDIT***

*BIOLOGY SENIORS* Join us for lunch! 12 Noon Wednesday, May 13th Lawn, Durfee Conservatory

NEPHRON Glomerulus - initial blood filtration Glomerular Filtration Rate - fluid volume filtered from glomerular capillaries into Bowman's capsule/unit time. Filtrate Secretion Reabsorption Creatinine, acids, bases water, sodium, glucose Excretion

Reabsorption Across proximal tubules, most salt and water are reabsorbed as well as glucose and amino acids.

Proximal Convoluted Tubules Specialized for reabsorption -cuboidal to columnar -apical microvilli/brush border -junctional complex -basal striations -larger diameter -star shaped lumen

PROXIMAL TUBULES

Proximal tubule ~65% of H 2 O, Na, Cl, PO4, glucose, amino acids reabsorbed 1. Na actively pumped out basolateral membrane 2. Na crosses apical membrane via facilitated diffusion 3. Cl and water follow Aquaporin water channels Glucose, amino acids cotransport with Na across apical membrane Proximal Tubule-->Intercellular space-->Peritubular capillaries people.eku.edu/ritchisong/bird_excretion.htm

Loop of Henle Descending & Ascending limbs thin and thick segments Varies in epithelium descending thick -->simple cuboidal descending thin -->simple squamous ascending thin -->simple squamous ascending thick -->simple cuboidal Varies in permeability & molecular composition descending thin --> highly permeable to water ascending thin --> impermeable to water Countercurrent multiplier

Countercurrent multiplier: Flow of blood and filtrate are in opposite directions Osmotic gradient along loop of Henle Descending limb: Permeable to water  water leaves filtrate  Water enters Vasa recta Ascending limb: Impermeable to water Active extrusion of Na => increased osmotic pressure in interstitial fluid

Countercurrent multiplier: Flow of blood and filtrate in opposite directions vacularizes kidney while maintaining osmotic gradient and removing water

Distal convoluted tubule cuboidal, extensive basal and lateral invaginations Na reabsorption K secretion Regulated by ALDOSTERONE Collecting Tubule: Clear cell boundaries, large diameter, more nuclei than proximal Thin Tubule: Simple squamous

Collecting ducts Permeability to water controlled by Antidiuretic Hormone (ADH), secreted by posterior pituitary gland => insert of aquaporin channels in apical membrane No ADH, water excretion ADH, water reabsorption

Collecting Ducts Clear cell boundaries, large diameter, more nuclei than proximal

Diabetes Insipidus Inability of kidneys to conserve water results in frequent urination and pronounced thirst What are the possible causes?

Renal Pelvis ----> Ureter -----> Bladder Mucosa: Transitional epithelium - lamina propria Muscularis: Smooth muscle Longitudinal inner layer Circular outer layer Adventitia

URETER 25.

URETER

BLADDER

Urethra Epithelium: Female: Transitional----> Stratified Squamous Male: Transitional----> Stratified or Pseudostratified Columnar Stratified Squamous

Treatment of Kidney Failure: Dialysis

Kidney Stones Form in kidney or ureter Types of stones include: Calcium stones: most common,appear between ages Cystine stones Struvite stones: in women with urinary tract infections Uric acid stones

Kidney Stones Lithotripsy procedure: shock wave lithotripsy (ESWL) is used to shatter simple stones in the kidney or upper urinary tract. Ultrasonic waves are passed through the body until they strike and pulverize the dense stones. (NIH Medline)