[MOD11 - ANATOMY] Gross Anatomy of the Retroperitoneum and Renal System_2028

What are the two main body cavities?

Dorsal and ventral body cavities

What does the cranial cavity house?

Brain

What does the spinal cavity house?

Spinal cord

What does the thoracic cavity house?

Lungs and heart

What does the abdominal cavity house?

The GI tract

What does the abdominopelvic cavity house?

Male and female reproductive organs

What is the peritoneum?

A membrane that lines the abdominopelvic cavity and invests the viscera

What are the two layers of the peritoneum?

Parietal and visceral peritoneum

What is the space between the parietal and visceral peritoneum called?

Peritoneal cavity

What is the main function of the peritoneal cavity?

To allow movement of the abdominal organs with minimal friction

What type of pain is the parietal peritoneum sensitive to?

Pressure, pain, heat, cold, and laceration (well-localized pain)

What type of pain is the visceral peritoneum sensitive to?

Stretching and chemical irritation (poorly localized pain)

Where is pain from the foregut felt?

Epigastric region

Where is pain from the midgut felt?

Umbilical region

Where is pain from the hindgut felt?

Hypogastric region

Why does diarrhea cause localized pain?

Due to stretching and chemical irritation of the visceral peritoneum

Why are stab wounds to the abdomen well-localized?

Because the parietal peritoneum shares the same blood and nerve supply as the abdominal wall

What is the initial presentation of appendicitis?

Periumbilical pain due to visceral peritoneum irritation

What happens when appendicitis progresses?

Pain localizes to the right lower quadrant as the parietal peritoneum becomes inflamed

Are organs inside the peritoneal cavity?

No, they are only covered by the peritoneum.

What is an intraperitoneal organ?

An organ that is covered by visceral peritoneum (e.g., stomach, intestines)

What is a retroperitoneal organ?

An organ located behind the peritoneum (e.g., kidneys)

What is a subperitoneal organ?

An organ located inferior to the peritoneum (e.g., urinary bladder)

What is the retroperitoneum?

An anatomical space in the abdominal cavity behind the peritoneum

What are the boundaries of the retroperitoneum?

Anterior: Parietal peritoneum; Posterior: Posterior abdominal wall

What are the five retroperitoneal spaces?

Anterior Pararenal Space (APS), Perirenal Space (PS), Posterior Pararenal Space (PPS), Retromesenteric Space (RMP), Retrorenal Space (RRS)

What retroperitoneal space contains the pancreas, ascending & descending colon, and duodenum?

APS

What retroperitoneal space contains kidneys, renal vessels, ureters, perirenal fat, adrenal glands?

PS

What retroperitoneal space contains fat?

PPS

What retroperitoneal space separates APS from PS?

RMP

What retroperitoneal space separates PS from PPS?

RRS

What are the retroperitoneal organs? Use the mnemonic.

Mnemonic: SAD PUCKER; Suprarenal (adrenal glands, Aorta/IVC, Duodenum (2nd-4th parts), Pancreas (except tail), Ureters, Colon (ascending & descending), Kidneys, Esophagus (abdominal part), Rectum (upper 1/3)

What is the difference between primary and secondary retroperitoneal organs?

Primary - organs are already located retroperitoneally at the beginning of development; Secondary - embyrologically located intraperitoneally but are pushed retroperitoneally as they developed

What are the secondary retroperitoneal organs? Use the mnemonic

Mnemonic: Pussy Cat Dolls; Pancreas (except tail), Colon (ascending & descending), Duodenum (2nd-4th part)

What structures form the posterior border of the retroperitoneum?

Bones, muscles, and blood vessels

What are the bones of the posterior abdominal wall?

Floating ribs (11 & 12), iliac crest, and lumbar vertebrae

What are the muscles of the posterior abdominal wall?

Diaphragm, iliacus, psoas major & minor, quadratus lumborum

What is the function of the psoas major and minor muscles?

Primary muscles for hip flexion

What are the major blood vessels found in the posterior abdominal wall?

Aorta and Inferior Vena Cava (IVC)

What spinal nerve roots contribute to the lumbar plexus?

L1 to L4 (sometimes T12 contributes)

How does the lumbar plexus differ from the brachial plexus?

The lumbar plexus has a simpler structure without trunks, divisions, or cords—it terminates as branches.

What is the function of the iliohypogastric nerve (L1)?

Sensation to the hypogastric and inguinal area, motor supply to the internal oblique and transversus abdominis muscles

What is the function of the ilioinguinal nerve (L1)?

Sensation to the hypogastric and inguinal area

What does the genitofemoral nerve (L1-L2) innervate?

Sensation to the anterior thigh and genital area (scrotum in males, labia in females)

What nerve provides sensory innervation to the lateral thigh?

Lateral femoral cutaneous nerve (L2-L3)

What condition results from impingement of the lateral femoral cutaneous nerve?

Meralgia Paresthetica

What is the function of the femoral nerve (L2-L4)?

Supplies the hip flexors

What is the function of the obturator nerve (L2-L4)?

Supplies the adductor muscles of the thigh

Where are the kidneys located?

Retroperitoneally at T12 to L3

What is the function of Gerota's fascia?

Encloses the kidneys, adrenal glands, and surrounding fat

What is Brodel's Line?

A less vascular area on the posterior kidney used for surgical access

What is the renal sinus?

The central cavity of the kidney containing the renal pelvis, blood vessels, and fat

What does the anterior surface of the kidney face?

Peritoneum

What does the posterior surface of the kidney face?

Posterior abdominal wall

What is the medial margin of the kidney, and what is its function?

t is concave and serves as the entry and exit point for vascular structures via the hilum.

What is the shape of the lateral margin of the kidney?

Convex

What structure is accommodated by the superior pole of the kidney?

Adrenal (suprarenal) glands

What separates the adrenal gland from the kidney?

A weak fascial septum

What is the primary attachment of the adrenal gland?

Diaphragm

What surface landmark is used to locate the inferior pole of the kidney?

It is about a finger breadth superior to the iliac crest.

What structure surrounds the kidney for protection and support?

Perirenal (perinephric) fat

What fascia blends with the fascia covering the great vessels?

Anterior renal fascia

What fascia blends with the fascia of the psoas muscle?

Posterior renal (Zuckerkandl's) fascia

What is the periureteric fascia?

An inferomedial continuation of the renal fascia that covers the ureter

How do the surrounding structures of the kidney function during movement?

They hold the kidney in position while allowing slight movement during respiration or postural changes.

At what level does the renal artery branch from the abdominal aorta?

L1-L2

What are the segmental branches of the renal artery?

Anterior: Superior (Apical), Anterosuperior, Anteroinferior, Inferior (Basal); Posterior: Posterior branch

What vein emerges from the hilum of the kidney and drains into the IVC?

Renal Vein

What is the arrangement of the renal hilum structures (anterior to posterior)?

VAU - Vein, Artery, Ureter

Compare the renal artery from the left and right sides of the kidney.

Right renal artery: Longer and lower; Left renal artery: shorter and higher

Compare the renal vein from the left and right sides of the kidney.

Right renal vein: Shorter and drains directly into IVC; Left renal vein: Longer and has 3 tributaries before IVC

What is the mnemonic for tributaries of the left renal vein?

SUPR GOLUM - SUPRarenal vein, GOnadal vein, LUMbar vein

Explain the renal blood flow

Renal artery → segmental artery → interlobar artery → arcuate artery → cortical radiate artery (interlobular) → afferent arteriole → glomerular capillaries → efferent arteriole → interlobular vein → arcuate vein → interlobar vein → renal vein

What covers the kidney up to its sinus?

Fibrous capsule

Outer part of the kidney

Cortex

Inner part of the kidney

Medulla

Located between renal pyramids in the medulla

Renal columns of Bertin

Cavity within the center of the kidney occupied by the renal pelvis, blood vessels, and fat

Renal sinus

What are the three constriction sites of the ureter and their locations?

Ureteropelvic junction - near the hilum; Pelvic brim - crosses the iliac artery; Vescioureteric junction - enters the urinary bladder

What structures will the ureter pass over after exiting the kidney?

Psoas muscle, pelvic brim, and common iliac arteries

Why are ureteric constriction sites clinically significant?

These are common sites for kidney stone obstruction.

What is nephrolithiasis?

The formation of kidney stones that can obstruct urine flow

What is ureterolithiasis?

The presence of stones in the ureter, leading to obstruction and pain

How does the nerve supply of the ureter relate to kidney stone pain?

The ureter is innervated by T11-L2, so pain radiates according to the level of obstruction

What is the typical pain pattern for a kidney stone lodged at the ureteropelvic junction?

Pain in the hypogastric region below the umbilicus or lumbar area

What is the typical pain pattern for a stone in the distal ureter?

Pain radiating to the groin area

What is the normal volume capacity of the urinary bladder?

400-600 mL

Where is the urinary bladder located?

Within the pelvic cavity (subperitoneal organ)

Why is the urinary bladder considered subperitoneal?

Because only its superior portion is covered by the peritoneum

What are the two main parts of the urinary bladder?

Body and neck

What is the function of the trigone in the urinary bladder?

It is a smooth triangular region where the ureters enter and the urethra exits

How does the bladder prevent urine reflux into the ureters?

The normal tone of the detrusor muscle compresses the ureters, preventing backflow

On which part of the urinary bladder is urine collected?

Body

What part of the urinary bladder connects with the urethra?

Neck

What forms the trigone of the urinary bladder?

Entry of left and right ureters and the proximal portion of the urethra near its neck