Contains glomerulus, renal corpuscle, proximal and distal convoluted tubules, proximal collecting ducts
Medulla
Inner layer of kidney
Divided into 10 to 18 pyramidal blocks of tissue: medullary pyramids
Contains thick and thin limbs of loops of Henle, distal parts of proximal and distal convoluted tubules, distal collecting ducts
Renal fascia
Separates, but encloses kidneys and suprarenal glands with surrounding perirenal fat
Continuous superiorly with fascia of diaphragm
Helps to hold kidney in relatively fixed position
Perirenal fat
Continuous at hilum with fat in the renal sinus
Surrounds kidney and suprarenal gland
Cushions and helps to hold kidney in relatively fixed position
Pararenal fat
External to perirenal fat and renal fascia
Most obvious posteriorly
Cushions and helps to hold kidney in relatively fixed position
Vascular supply
Right and left renal arteries
Branches of aorta (at L1/2), with the right passing posterior to the inferior vena cava (IVC)
Lie anterior to renal pelvis
Each artery divides into five segmental end arteries; four anterior segmental arteries and one posterior segmental artery
Right and left renal veins
Anterior to renal arteries
Left passes anterior to the aorta and posterior to descending superior mesenteric artery (SMA) = so-called nutcracker
Lymphatics
Follow the renal veins
Drain into the lumbar (aortic) lymph nodes
Nerves (Section 4-7: Abdomen-Innervation)
From renal plexus
Parasympathetic fibers from the vagus nerve
Sympathetic fibers from the thoracic splanchnic nervesUreters
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Retroperitoneal, muscular ducts from renal pelvis to urinary bladder
Constricted at three sites along course:
Junction of ureter and renal pelvis
As they cross the pelvic brim
In wall of urinary bladder
Potential sites of obstruction of urinary calculi
Vascular supply:
Arteries are branches from
Renal arteries
Gonadal arteries
Aorta
Can divide into ascending and descending branches
Freely anatomise
Veins drain into the renal and gonadal veins
Lymphatics
Join the renal lymphatic vessels
Or pass directly to lumbar (aortic) and common iliac nodes
Nervous supply
From the renal, aortic, superior, and inferior hypogastric plexuses
Visceral afferent fibers (pain) follow sympathetic fibers to T11-L2 spinal cord segmentsSuprarenal (adrenal) glands
Endocrine glands concerned with metabolism
Have different shapes
Triangular right gland
Semilunar left gland
Located between upper pole of kidney and diaphragm
Surrounded by perinephric fat, inside the renal fascia
Anatomic relations:
Right gland
Anterior to diaphragm
Contacts IVC and liver
Left gland related to spleen, stomach, and left crus of diaphragm
Parts
Cortex and medulla
Have different embryologic origins and functions
Cortex
Derived from mesoderm
Secretes
Glucocorticoids