URINARY SYSTEM & FLUID BALANCE

Lecture

major excretory system; controls the composition & volume of body fluids

Urinary System

What are the functions of Urinary System?

Excretion of waste products, Regulation of blood volume and pressure, Regulation of the concentration of solutes in the blood, Regulation of extracellular fluid pH, Regulation of red blood cell synthesis, Regulation of vitamin D synthesis

bean-shaped organs located retroperitoneally & on each side of the vertebral column; the major excretory organ of urinary system

Kidney

What are the two regions of Kidney?

outer cortex & inner medulla

layer of connective tissue that surrounds each kidney; around is a thick layer of adipose tissue that protects the kidney from mechanical shock

Renal Capsule

medial area where renal artery & nerves enter & renal veins, ureter, & lymphatic vessels exit the kidney

Hilum

cavity which contains blood vessels part of system for collecting urine, & adipose tissue

Renal Sinus

cone-shaped; bases are located at boundary between two regions & the tips project towards the center of kidney

Renal Pyramids

funnel-shaped structure that surrounds the tip of each pyramid

Calyx

a larger funnel formed from joining of all the calyces

Renal Pelvis

a small tube from narrowed renal pelvis which exits the kidney & connects to urinary bladder

Ureter

Urine Flow:

tips of renal pyramid > calyces > renal pelvis > ureter > urinary bladder

A patient has kidney disease that damages the microscopic structures responsible for filtering blood and producing urine. Which functional unit of the kidney is affected?

Nephron

A patient has damage to the part of the nephron where blood filtration begins. Which kidney structure is primarily affected?

Renal Corpuscle

During the first stage of urine formation, blood is filtered through the glomerulus and the resulting filtrate is collected before entering the renal tubule. Which structure collects this filtrate?

Bowman's Capsule

During urine formation, blood passes through a network of capillaries where plasma is filtered into Bowman's capsule. What structure performs this filtration?

Glomerulus

supplies the blood for filtration

Afferent Arteriole

transports the filtered blood away from glomerulus

Efferent Arteriole

a vital regulatory structure located next to glomerulus; responsible for the secretion of enzyme renin

Juxtaglomerular Apparatus

cuff of specialized smooth muscle cells at the point where the afferent arteriole enters the renal corpuscle

Juxtaglomerular Cells

group of specialized cells at the part of distal convoluted tubule that lies between the afferent & efferent arterioles

Macula Densa

primary site for reabsorption of solutes & water

Proximal Convoluted Tubule

A patient has a kidney disorder affecting the part of the nephron responsible for concentrating urine and reabsorbing water and salts. Which structure is affected?

Loop of Henle

extends toward the renal sinus; critical site for water reabsorption by osmosis

Descending Limb

extends toward the cortex; the filtered fluid flows going to distal convoluted tubule

Ascending Limb

empties fluid into a single collecting duct, in which multiple ducts empty into a single papillary duct

Distal Convoluted Tubule

It is a type of nephrons that is next to medulla that is approximately 15% of nephrons

Juxtamedullary Nephrons

Type of nephrons that do not extend deep into medulla

Cortical Nephrons

movement of materials across the filtration membrane into the Bowman capsule to form filtrate

Filtration

A pressure gradient which forces the fluid from glomerular capillary across filtration membrane into the Bowman capsule to form filtrate