Urine Flashcards
What is Waste Excretion?
Chemical reactions in the body result in waste products that may be potentially harmful, therefore must be eliminated
What are examples of Metabolic Waste Products?
- carbon dioxide
- urea
- salts
What are Methods of Elimination?
- respiratory system
- urinary system
- digestive system
- sweat
What are the parts of the Urinary System?
- 2 kidneys
- 2 ureters
- urinary bladder
- urethra
Kidneys
-2 -make urine and carry out other vital functions
Ureters
-2 -carry urine to the urinary bladder
Urinary Bladder
Collects, stores and releases urine
Urethra
Carries urine from the body to the external environment
Nephro/Reno
Kidney
Nephrology
Study of the kidney
Diuresis
Producing and passing large amounts of urine
Oliguria
Passing small amounts of urine
Anuria
No urine is passed from the body
Dysuria
Difficult urination
Hematuria
Blood in urine
Polyuria
Increased urine volume
What are the functions of the Kidneys?
- maintain homeostasis
- blood filtration, reabsorption and secretion
- fluid balance regulation
- acid-base regulation
- electrolyte regulation
- hormone production
Blood Filtration, Reabsorption and Secretion
- blood is flitered
- useful substances are returned to circulation
- waste product is secreted
Fluid Balance Regulation
makes sure body has enough water to maintain a healthy environment
Acid Base Regulation
ability to remove hydrogen and bicarbonate ions from blood
Electrolyte Regulation
- Na+, K+, Cl-
- can be fatal outside of normal levels
Hormone Production
- kidneys produce erythropoietin (necessary for RBC production)
- produce some prostoglandins
- influenced by antidiuretic hormone (posterior pituitary and Aldosterone (adrenal cortex)
Where are the Kidneys located?
- dorsal part of abdomen
- ventral to and on either side of first few lumbaar vertebrae
- retroperitoneal to abdominal cavity
- considered to be outside the body
- somewhat move
-
What is Perirenal Fat?
-surrounds and helps protect from exertion from other organs
What does the Kidney look like?
- bean shaped
- covered in fibrous connective capsule
- reddish brown
- smooth surface
Which animal has a multi lobed kidney?
cattle
What is the Hilius?
- indented area on medial side of kidney
- ureters, nerves, blood, and lymph vessels enter/leave kidney here
What is the Renal Pelvis?
- funnel shaped area inside hilus
- forms beginning of ureter
- lined with strechy transitional epithelium
What animal doesn’t have a Renal Pelvis?
cattle
What is the Cortex?
- outer portion of kidney
- rough granular appearance
- reddish brown
What is the Medulla?
- inner portion around renal pelvis
- smooth
- dark purple outer area
- grey/red inner area
- varie with species : can be multipyramidal (multilobar)or unipyramidal (unilobar)
What is the Calyx?
- funnel like extension of renal pelvis
- medullary pyramids drain here
- calyces funnel flluid into renal pelvis
What is the Nephron?
- basic functional unit of kidney
- job is to filter, reabsorb and secrete
- smallest part of kidney
- number varies per kidney and species
How many Nephron do humans, sheep and pigs have?
1 million
How many Nephrons do cats have?
200,000
What is a Nephron composed of?
- renal corpuscle: Bowman’s capsule and glomerulus
- Proximal Convoluted Tubule (PCT)
- Loop of Henle
- Distal Convoluted Tubule (DCT)
What is the Renal Corpuscle?
- located in cortex of kidney
- function: filter blood in first stage of urine production
- made up of Glmoeruls and Bowman’s capsule
What is Glomerular Filtrate?
first stage of urine production
What is the Glomerulus?
tuft of glomerular capillaries
What is the Bowman’s Capsule?
double walled capsule that surrounds the glomerulus
What are the layers of the Bowman’s Capsule?
- inner visceral layer
- outer parietal layer
What is the Capsular Space?
- space between the 2 layers of bowman’s capsule
- continuous with the proximal convoluted tube
What is the Proximal Convoluted Tube (PCT)?
- contiuation of the capsular space of the Bowman’s capsule
- longest part of the tubular system of the nephron
- glomerular filtrate becomes tubular filtrate (primitive urine)
What cells make up the PCT?
- cuboidal
- have brush border on lumen side
What is the Loop of Henle?
- continued from PCT
- descends into medulla of kidney
- ascends back into cortex
What is the Descending Portion of the Loop of Henle?
epithelial cells like PCT and brush border
What happens at the bottom of the Loop of Henle?
- epithelium flatten to simple squamous
- loses brush border
What happes at the Ascending Portion of the Loop of Henle?
- wall becomes thicker again
- no brush border
What is the Distal Convoluted Tube (DCT)?
-contiuation of ascending portion of Loop of Henle
Where do all the DCT’s from all Nephrons empty?
- series of collecting ducts which carry tubular filtrate through medulla
- enventually empty it into renal pelvis that becomes ureter
The DCT and Collecting Ducts are the sites of action for:
- antidiuretic hormone (ADH)
- regulation of K+
- Acid-base balance
What supplies the Nerve Supply to the Kidneys?
- sympathetic portion of autonomic nervous system
- sympathetic stimulation decreases the diameter of blood vessels leading to kidneys
Where does the Nerve Supply to the Kidneys controls blood flow to?
-through the glomerular capillaries
Why do transplanted kidneys work?
nerve supply is not essential to kidney function
How long does it take blood to circulate through the kidneys?
4-5 minutes
What structures make up the Blood Supply to the Kidneys?
- Renal Artery
- Afferent Glomerular Arterioles
- Glomerular Capillaries
- Efferent Glomerular Arterioles
- Peritubular Capillaries
- Renal Vein
What are the Renal Arteries?
- branch off aorta and enter kidneys at Hilus
- divides smaller and smaller until it becomes Afferent Glomerular Arterioles
What are the Afferent Golmerular Arterioles?
carry blood into the Glomerular Capillaries of the Renal Corpuscle
What are the Glomerular Capillaries?
- continuation of Afferent Glomerular Arterioles
- fliter plasma from blood into capsular space (Glomerular filtrate)
- only place in body where blood that enters and leaves capillaries is still oxygenated!
What are Efferent Glomerular Arterioles?
- recieve (arterial) blood from Glomerular Capillaries
- divide into Peritubular Capillaries
What are Peritubular Capillaries?
- surround Nephron and converge to form venules to become renal vein
- oxygen transfer occurs here
- usuable substances are removed from Tubular Filtrate and reabsorbed
- other waste substances are secreted into filtrate here as well
What is the Renal Vein?
- leaves kidney at Hilus and joins abdominal portion of the Caudal Vena Cava
- Purest Blood In The Body!
