Kidney Structure Flashcards
What is the primary function of our kidney’s?
Maintain our internal fluid homeostasis
What is the basic functional unit of the kidney?
Nephron
Which structure is the primary site of blood filtration?
Renal corpuscle
Which of the following is the primary force that drives glomerular filtration?
Glomerular hydrostatic pressure
What substance is typically measured to give an indication of the glomerular filtration rate?
Creatinine
What diseases does oral health impact?
Cardiovascular disease
Rheumatoid arthritis
Respiratory diseases
Diabetes
Kidney disease
What two ways can oral health impact the rest of the body?
pathogens can disseminate from the mouth to the body
chronic inflammation
What are the two roles of the kidney?
Process blood and rid the body of the waste products of metabolism via urine
Maintain internal homeostasis of fluid
What two components of blood affect B.P?
fluid
electrolytes
What other components in blood do the kidney’s maintain?
Acid/base
Calcium/vitamin D metabolism
Erythropoietin
What are the components of the urinary system?
kidneys
ureters
bladder
urethra
Where do the kidneys lie?
Lie behind peritoneal cavity (retroperitoneal)
What are the kidney’s surrounded by?
fatty tissue called the renal fat pad
What are the 3 parts of the kidney?
cortex, medulla, pelvis
What does the cortex do?
contains 85% of all kidney tubules (nephrons).
What does the medulla do?
the site where urine is concentrated
prevents excessive water loss.
What does the pelvis do?
collection area for urine which is funnelled into the ureter.
What are the kidney’s encased by?
fibrous capsule
What % of cardiac output do the kidneys receive?
20%
What are the vessels of the kidneys?
afferent arterioles > glomerular capillaries (glomerulus) > efferent arterioles > peritubular capillaries (vasa recta)
What is the difference between cortical nephrons and juxtamedullary nephrons?
Juxtamedullary nephrons have very long loops of henle, which help concentrate urine and preserve water
Juxtamedullary - next to medulla
What composes the renal corpuscle?
Glomerulus
Bowman’s capsule
What is the primary site of reabsorption and secretion?
Renal tubule
What composes the renal tubule?
Proximal convoluted tubule
Loop of Henle
Distal convoluted tubule
Collecting duct
What is the network of fine capillaries in the glomerulus surrounded by?
bowman’s capsule
What are the characteristics of the capillaries?
Network of fine capillaries
Single layer of endothelial cells resting on a basement membrane
Fenestrated
What feature in capillaries allows enables rapid filtration of blood plasma?
Fenestrated
What shape is the bowman’s capsule?
cuplike
What is the structure of the bowman’s capsule?
Two layers with a space in-between called the bowman’s space where filtered fluid is collected from the nephron
What are the layers in bowman’s capsule?
Partial outer layer of simple squamous epithelium
Visceral inner layer of specialised epithelium (podcytes)
What wraps around the glomerular capillaries?
The long branched processes (pedicels) of podocytes
What forms the filtration barrier?
glomerular endothelium
basement membrane
pedicels
What do pedicels share a basement membrane with?
fenestrated endothelium
What can pass through the filtration barrier and what cannot?
Freely permeable to water and small molecules
NOT large proteins or cells
Where does unfiltered blood arrive at?
glomerulus via the afferent arteriole
Where does the filtered blood exit?
glomerulus via the efferent arteriole
Where is there high pressure and what type of pressure is it?
High hydrostatic pressure in capillaries
What are examples of waste products?
Urea and creatinine
What substances are filtered?
Water
Glucose
Amino acids
Urea
Creatinine
Sodium
Chloride
Calcium
Phosphate
Potassium
Bicarbonate
What substances cannot be filtered?
Cells
Large proteins (Haemoglobin)
Negatively charged proteins (albumin)
What is the Glomerular Filtration Rate (GFR)?
The rate at which blood is filtered through the glomerulus into the Bowman’s capsule
What pressures counteract the glomerular hydrostatic pressure?
hydrostatic pressure in the bowman’s capsule
glomerular osmotic pressure
What dictates the GFR?
sum of forces
What factors influences the GFR?
Hydrostatic pressure
Osmotic pressure
Systemic blood pressure
Renin-angiotensin system
Disease
What is the normal GFR per min?
125ml/min
What disease reduces GFR?
CKD
What does reduced GFR mean?
inefficient blood clearance and waste removal
waste products accumulate in blood
What stage is CKD usually diagnosed at?
stage 3
What % of water is reabsorbed?
99%
What is an indicator of infection if found in urine?
proteins
RBCs and WBCs
