This discussion assesses your ability to clarify the role of each legally mandated attendee on the Individualized Education Program team. This assessment also supports your achievement of Course Learning Outcome….
Describe the histology and anatomy of a nephron.
I have two quizzes that I really need to get an a on them. Each quiz is ten questions and I will provide all the information. I will also provide login information to who ever I pick.
WEEK 13 Folder: Quiz 10
The Urinary System
Textbook chapter: 25.
1. Describe the general functions of the urinary system.
2. Describe the gross anatomy of the organs of the urinary system, and their functions.
3. Trace the flow of urine through the nephron and larger organs until it is released from the body..
4. Describe the histology and anatomy of a nephron.
5. List the general functions of the nephron. Distinguish between the functions of filtration, reabsorption, and secretion.
6. Name the three layers of the urinary bladder, including the tissues of each, and their functions.
Be able to recognize the following structures.
|calyces||renal pelvis||ureter||urniary bladder|
|urethra||urinary mucosa||muscularis||renal artery|
|afferent arteriole||glomerular capillaries||efferent arteriole||glomerular capsule|
|PCT||loop of nephron||DCT|
The Urinary System
Textbook chapter: 25.
Use these web resources to supplement your studies of lecture notes and objectives.
Textbook (sample quizzes, labeling)-select a chapter number in pull down menu.
I Functions of system
1) Maintains normal blood fluid volume and therefore blood pressure
2 ) Helps regulate normal blood hydrogen and bicarbonate ion levels and therefore blood pH.
3) regulates blood calcium, sodium and potassium levels
4) removes urea and ammonia
II. Kidneys: the major excretory organs
A. External Anatomy:
1) renal capsule – adheres directly to the kidney s surface
– dense irregular connective tissue |
– helps prevent infection
2). Renal Hilus; on the medial, concave surface
– leads into the renal sinus
– the ureters, blood vessels, lymphatics, and nerves enter or exit here
B. Internal Anatomy:
1. renal cortex – the outer region
a) contains the nephron ( glomerular corpuscle, proximal convoluted tubule, loop, distal convoluted ducts, collecting duct) which are the functional units of a kidney)
2. Renal medulla (inner region)
pyramids – cone-shaped tissue masses of the medulla containing ducts
renal pelvis-open area
3. Blood flow
Blood originates at renal Artery, distributed throughout the kidney via a variety of arteries into the cortex where blood flows into the “afferent:” arterioles that regulate flow into the glomerular capillaries (where water and smaller substances are filtered into the glomerular capsule.). Non-filtered blood exits glomerular capillaries into “efferent” arteriole which regulates flow into the “vasa recta” capillaries. From there blood is drained via a variety of veins into the renal vein.
C. Microscopic Anatomy: Nephron
1) Glomerular capsule (Bowman s capsule) receives filtered blood from the very leaky glomerular capillaries (allowing filtration of blood components into nephron).
2) nephron tubules (includes proximal convoluted tubule, loop of nephron, distal convoluted tubule, collecting duct)- filtrate meanders through the tubules allowing tubular reabsorption (movement of substance back into blood supply) and tubular secretion (movement of substance from blood supply into urine).
D. Nephrons are the functional units of kidneys.
– functions blood by filtration (red blood cells, white blood cells, platelets and large proteins are prevented from being filtered into urine so are conserved by the body. Some filtered substances are then secreted (removing materials from blood into urine) or reabsorbed (reclaiming materials from urine into blood).
Glomerular capillaries allow filtration
Vasa recta capillaries allow reabsorption and secretion.
E. Filtrate/Urine flow in kidney
(microscopic:) glomerular capsule to PCT to Loop to DCT to collecting ducts to papillary ducts to (gross:) calyces to renal pelvis
– convey urine from the renal pelvis in kidneys to the urinary bladder
– enter the posterior wall of the urinary bladder
1. Mucosa; transitional epithelium
2. Muscularis; smooth muscle
3. Adventitia; outer layer, fibrous connective tissue
IV. Urinary Bladder:
Function – holds urine and ejects urine (micturition)
Filled by the paired ureters and ejects urine through opening of the urethra.
1. Mucosa; transitional epithelium allows stretch to store urine.folded into rugae for even more stretch.
2. Muscularis; smooth muscle to eject urine.
3. Adventitia; outer layer, fibrous connective tissue or serosa (visceral peritoneum)
– drains urine from the urinary bladder and carries it outside of the body
A. Sphincters: two that control the release of urine
1) internal – involuntary
2) external urethral sphincter – voluntary
– surrounds the urethra as it passes through the pelvic floor
– skeletal muscle
Entire system Urine flow
Blood>Filtrate in glomerular capsule of nephron>nephron tubules>pyramidal ducts>calyces>renal pelvis>ureter>urinary bladder>urethra
VI. Urinary hormones
Hypothalamus and Posterior Pituitary – releases ADH
– known as the neurohypophysis
– sits in the sella turcica or sphenoid bone
ADH causes the collecting ducts of the kidneys to reabsorb water more, thereby increasing blood volume and blood pressure. It decreases urine output.
Adrenal cortex-produces Aldosterone
Adosterone promotes Na reabsorption and K secretion at the collecting ducts.So Na is reclaimed and K is lost into the urine