Abdomen: Muscles of the abdomen Flashcards
Action: Compresses abdomen, flexes trunk, and is active in forced expiration
N: Intercostal nerves (T7-T11) and subcostal nerve (T12)
O: External surface of lower 8 ribs (ribs 5-12)
I: Ant. half of iliac crest, ant.-sup. iliac spine (ASIS), pubic tubercle, and linea alba
Name the muscle
External oblique m.
Action: Compresses abdomen, flexes trunk, and is active in forced expiration
N: Intercostal nerves (T7-T11), Subcostal n. (T12), iliohypogastric n. and ilioinguinal n. (L1)
O: lat. 2/3rds of inguinal ligament, iliac crest, and thoracolumbar fascia
I: Lower 4 costal cartilages, linea alba, pubic crest, and pectineal line
Name the muscle
Internal oblique m.
Action: Compresses abdomen and depresses ribs
N: Intercostal n. (T7-T11), subcostal n. (T12), iliohypogastric n. an ilioinguinal n. (L1)
O: Lat. 1/3rd of inguinal ligament, iliac crest, thoracoumbar fascia, and lower 6 costal cartilages
I: Linea alba, pubic crest, and pectineal line
Name the muscle
Transversus abdominis m.
Action: Depresses ribs and flexes trunk
N: Intercostal n. (T7-T11) and subcostal n. (T12)
O: Pubic crest and pubic symphisis
I: Xiphoid process and 5th-7th costal cartilages
Name the muscle
Rectus abdominis m.
Action: Tenses linea alba
N: Subcostal n. (T12)
O: Pubic body
I: Linea alba
Name the muscle
Pyramidalis (pyramidal) m.
Action: Retracts testis
N: Genitofemoral n.
O: Middle of inguinal ligament and lower margin of interal oblique muscle
I: Pubic tubercle and pubic crest
Name the muscle
Cremaster m.
All of these muscles attach to the linea alba EXCEPT:
A. Ext. oblique m.
B. Int. oblique m.
C. Transversus abdominis m.
D. Rectus abdominis m.
E. Pyramidal m.
F. Cremaster m.
G. D and F
H. None of the above all attach to linea alba
G. D and F
Rectus abdominis and Cremaster muscle do NOT attach to the linea alba at all, they do not originate from or insert into the linea alba.
Ext. oblique, int. oblique, transverus abdominis, and pyramidal insert into the linea alba.
