(Slides 1-7) Kidney Anatomy, blood flow, and function.

What are the components of the urinary system?

• Kidneys

• Ureters

• Urinary bladder

• Urethra

The urinary system maintains?

Homeostasis by managing the volume and composition of fluid reservoirs, primarily blood.

What are the functions of the urinary system?

• The kidneys regulate blood volume and composition, help regulate blood pressure, synthesize glucose, release erythropoietin, participate in vitamin D synthesis, and excrete wastes in the urine.

• The ureters transport urine from the kidneys to the urinary bladder.

• The urinary bladder stores urine.

• The urethra discharges urine from the body.

What do the kidneys regulate?

Blood volume and composition.

How do the kidneys help regulate blood pressure?

Through their physiological functions

• Renin

What metabolic process can the kidneys perform related to glucose?

They synthesize glucose

• Gluconeogenesis

  • making glucose out of non-carb substances

  • also done in the liver

What hormone do the kidneys release to influence red blood cell production?

Erythropoietin.

• increases blood cell production

What vitamin do the kidneys help synthesize?

Calcitrol

• Active form of Vitamin D

What do the kidneys excrete?

Wastes in the urine

• Metabolic Waste

• Foreign Substance (drugs or toxins)

What is the function of the ureters?

They transport urine from the kidneys to the urinary bladder.

What is the function of the urinary bladder?

It stores urine.

What is the function of the urethra?

It discharges urine from the body.

What are the homeostatic kidney functions?

• Regulation of blood ionic composition ( e.g. Na+, K+, Cl–, Ca+2 , PO43)

• Regulation of blood pH

• Regulation of blood volume and blood pressure (Renin enzyme)

• Regulation of Maintenance of blood osmolarity

• Production of hormones

• Excretion of metabolic wastes and foreign substances (drugs or toxins)

• Regulation of blood glucose level

What ions are regulated by the kidneys?

Na⁺, K⁺, Cl⁻, Ca²⁺, PO₄³⁻.

What two substances are involved in kidney regulation of blood pH?

H⁺ and HCO₃⁻.

How do the kidneys help regulate pH?

By controlling levels of H⁺ and HCO₃⁻ in the blood.

How do the kidneys regulate blood volume?

By adjusting water levels in the blood.

What two hormones are produced by the kidneys?

Calcitriol (vitamin D) and erythropoietin.

What is the total number of dissolved particles per liter of solution?

Osmolarity

What do the kidneys maintain regarding osmolarity?

Regulation and maintenance of blood osmolarity.

What is the position of the kidneys relative to the peritoneal cavity?

Retroperitoneal

• behind the peritoneal cavity.

The kidneys are slightly protected by?

The lower ribs and are surrounded by fat for protection.

What are the three protective coverings (external layers or connective tissue) of the kidneys from superficial to deep?

• Renal Capsule

• Adipose Tissue

• Renal Fascia

What is the innermost protective covering of the kidney?

Renal capsule (Fibrous Capsule)

• anchors to other structures

What is the intermediate protective covering of the kidney?

Adipose tissue (Renal Fat Pad or Perinephric Fat)

• protect and anchors

What is the outermost protective covering of the kidney?

Renal fascia

• continous with ureter

What is another name for the adipose tissue surrounding the kidney?

Perinephric fat (renal fat pad).

What does our internal renal anatomy consist of?

• Cortex

• Medulla

• Renal Pelvis

• Renal Sinus

• Nephron

What is the outer region of the kidney called?

Renal cortex

What is the inner region of the kidney called?

Renal Medulla

What structures are found in the renal medulla?

• Pyramids

• Renal columns

What are extensions of the renal cortex?

• Extensions of the cortex between the pyramids

Renal columns

What is the renal pelvis?

The funnel‑shaped structure that collects urine.

What structures drain into the renal pelvis?

Minor and major calyces.

What are the structural and functional unit of the kidney?

Nephrons

• ~1 million in a single kidney

What percentage of total body mass do the kidneys make up?

Less than 0.5% of total body mass.

What percentage of resting cardiac output do the kidneys receive?

• How much blood flows through the kidneys each minute

20–25% of resting cardiac output.

• blood that goes straight to the kidneys

• ~1100 mL per minute.

What type of innervation do the renal nerves primarily carry?

Sympathetic outflow.

What do the renal nerves regulate?

Blood flow through the kidneys.

Nerve supply means?

Sympathetic Innervation

What vessel brings blood into the kidney?

Renal artery.

What arteries branch from the renal artery?

Segmental arteries.

What arteries run between the renal pyramids?

Interlobar arteries

What arteries arch over the base of the pyramids?

Arcuate arteries

What arteries extend into the cortex?

Cortical radiate arteries

• Interlobular arteries.

What vessel brings blood into the glomerulus?

Afferent arteriole.

What is the capillary bed inside the renal corpuscle?

Glomerulus.

What vessel carries blood away from the glomerulus?

Efferent arteriole.

What capillaries surround the PCT and DCT?

Peritubular capillaries.

What capillaries surround the loop of Henle?

Vasa recta.

What veins drain the cortex?

Cortical radiate veins.

• Interlobular veins

What veins arch over the base of the pyramids?

Arcuate veins

What veins run between the pyramids?

Interlobar veins

What vein exits the kidney?

Renal vein.

What do the arteries of the kidney have that the veins don’t?

Arteries have segemental arteries while veins dont have segmental anything

The efferent arteriole is the connecting vessel between the?

• Glomerulus

• Peritubular capillaries

• Vasa recta.

Trace the pathway of blood form the renal artery to the renal vein?

• Aorta

• Renal Artery

• Segmental Artery

• Interlobar Artery

• Arcuate Artery

• Cortical Radiate Artery (Interlobular)

• Afferent Arteriole

• Glomerulus

• Efferent Arteriole

• Peritubular capillaries/Vasa rRcta

• Cortical Radiate vein (Interlobular)

• Arcuate Vein

• Interlobar Vein

• Renal Vein

• Inferior Vena Cava