ANNOUNCEMENTS

LAB PRACTICAL RESCHEDULED: April 28, 29Material Covered: Urinary, Exocrine, & Endocrine Systems, Digestive System & Accessory Organs, and Lymphatic System and Reproductive Systems.

SECOND EXAM RESCHEDULED: April 22ndMaterial 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

NEPHRONGlomerulus- initial blood filtration

Glomerular Filtration Rate- fluid volume filtered from glomerular capillaries into Bowman's capsule/unit time.

Filtrate

Secretion ReabsorptionCreatinine, 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 TubulesSpecialized for reabsorption

-cuboidal to columnar-apical microvilli/brush border-junctional complex-basal striations-larger diameter-star shaped lumen

PROXIMAL TUBULES

Proximal tubule

~65% of H2O, 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 epitheliumdescending thick -->simple cuboidaldescending thin -->simple squamousascending thin -->simple squamousascending thick -->simple cuboidal

Varies in permeability & molecular compositiondescending thin --> highly permeable to waterascending 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 waterActive extrusion of Na=> increased osmotic pressure in interstitial fluid

www.nature.com/.../v21/n1/full/ng0199_67.html

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

www.uic.edu/.../bios100/lecturesf04am/lect21.htm

Collecting DuctsClear cell boundaries, large diameter, more nuclei than proximal

Diabetes Insipidus

Inability of kidneys to conserve waterresults 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 layerCircular outer layer

Adventitia

URETER

25.

URETER

BLADDER

http://www.visualsunlimited.com/browse/vu306/vu306638.html

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 20 - 30. Cystine stones

Struvite stones: in women with urinary tract infections

Uric acid stones

Kidney StonesLithotripsy 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)