1. The abdomen

2. Anterior Abdominal Wall
Superior Border
Infrasternal notch
Costal Margins and Arch

3. Anterior Abdominal Wall
Inferior Borders

4. Inguinal Ligament What is it? Where does it attach?
What does it separate?
Inguinal fold

5. Surface Anatomy
Umbilicus
Level
Variety

6. Anterior Median line
Linea alba

7. Levels of Markers and Planes
Subcostal plane
Transtubercular plane
Midclavicular plane

8. Zones of the Abdomen Hypochondriac, Epigastric
Lumbar (Lateral), Umbilical
Iliac (Inguinal), Hypogastric

9. Fascia of the abdominal wall
Two layers

10. Superficial Fascia
Over most of body
In lower abdominal region

11. Deep Fascia

12. Nerves and blood vessels

13. Organization of the nervous system
Dorsal roots
Dorsal root ganglia
Ventral roots
Meninges
Dura mater
Arachnoid membrane
Pia mater

14. Filum terminale – extension of pia mater
Coccygeal ligament – filum terminale fuses with dura mater and attaches to coccyx

15. Organization of Nerves
As they exit the vertebral column, the dorsal and ventral roots join to form the spinal nerve (a mixed nerve)
The spinal nerve then divides into a posterior (dorsal) primary ramus and an anterior (ventral) primary ramus

16. Dorsal and Ventral Rami
The dorsal primary ramus innervates the skin and muscles around the spine
The ventral primary ramus innervates the skin and muscles for the rest of the body
Lateral and anterior trunk
Upper and lower extremities

17. Anterior Rami Nerve plexuses Cervical: C1-C4 Brachial: C5-T1
Lumbar: branch from T12, and L1-L4
Sacral: L4-S3
Pudendal: Parts of S2 and S3, and all of S4 – important for control of bowel, bladder and sexual function

18. Anterior Rami in the Thoracic Region
Do NOT form a nerve plexus
T1-T11: Intercostal nerves
Travel between ribs
T12: Subcostal nerve
Travels below 12th rib
L1: Follow similar direction as intercostal and subcostal nerves
Iliohypogastric nerve: lowest cut. nerve in abdomen
Ilioinguinal nerve

19. Branches of T1-L1 Motor branches to intercostal and abdominal muscles
Lateral cutaneous branch – sensory to skin
Anterior and posterior branches
Anterior cutaneous branch – sensory to skin

21. Walls of Inguinal Canal
Anterior wall
Part of aponeurosis of external oblique
Reinforced laterally by fibers of int. oblique and sometimes the transversus abdominis
Posterior wall
Fascia transversalis
Medially by fibers of conjoint tendon, the common tendon of int. oblique and transversus abdominis muscles

22. Superior wall (roof) Inferior wall (floor) Arching fibers of IO and TA
Superior surface of inguinal ligament
Lacunar ligament
Medial part of inguinal ligament that is reflected back and attaches to pectineal line

23. Superficial Inguinal Ring
Medial crus – pubic bone and pubic crest medial to pubic tubercle
Lateral crus – pubic tubercle
Center point of ring superior to pubic tubercle
Intercrural fibers

24. Deep inguinal ring Slit-like opening in fascia transversalis
Immediately superior to midpoint of inguinal ligament

25. Inguinal Canal
Male: spermatic cord
Female: Round ligament of uterus

26. Hernias More common in men
Indirect: hernia follows path from deep ring to canal to superficial ring
More common
Direct: hernia directly through weakness in abdominal wall

27. Linea alba and rectus sheath
See handout