Structures of the Trunk Flashcards
what are the 4 cutaneous muscles?
- platysma (covers neck & face)
- draws lips caudally
- innervated by the facial nerve
- cutaneous trunci (covers side of the trunk)
- innervated by the lateral thoracic nerve
- cutaneous omobrachialis (continuation of the cutaneous trunci muscle over the shoulder)
- horses & ruminants
- preputial muscles
- carnivores, ruminants, & pigs
what is the difference between hypaxial and epaxial muscles? Know their general functions
hypaxial muscles:
- ventral to the transverse process of the vertebrae
- innervated by the ventral branches of the spinal nerve
- flexors of the spine
expaxial muscles:
- dorsal to the transverse process of the vertebrae
- innervated by the dorsal branches of the spinal nerve
- extensors of the spine
what are the structures that are involved in the epaxial musculature?
- Trapezius, cleidocephalicus
- Latissimus dorsi, rhomboideus
- Serratus ventralis, serratus dorsalis, splenius
- Iliocostalis, longissimus, semispinalis
- Multifidus, interspinales, inter-tranversarii
what epaxial musculatures are involved in respiration?
3rd layer
Cranial serratus dorsalis:
- Over dorsal part of ribs; pulls ribs cranially, involved in inspiration
Caudal serratus dorsalis:
- Over dorsal part of the caudal ribs; pulls ribs caudally, involved in expiration
how do the ribs and diaphragm move during inspiration and expiration?
inspiration: moves caudally
expiration: moves cranially
where is the location of the dorsal intercostal artery and intercostal nerves in relation to the rib?
dorsal intercostal artery:
- runs along the caudal aspect of ribs
- branch off the costocervical trunk (first few) or aorta (the remainder)
- joins the intercostal nerves
intercostal nerves:
- formed by the ventral branches of the spinal nerve
- runs along the caudal aspect of the ribs
what nerve (and cranial nerve) innervates the diaphragm?
phenric nerve
what are the three openings of the diaphragm and what passes through them?
- aortic hiatus (dorsal)
- Aorta, Azygous vein, Thoracic duct
- esophageal hiatus
- Esophagus, Dorsal/ventral vagal trunks
- caval foramen ( ventral)
- caudal vena cava
what are the the 4 abdominal muscles?
flat muscles:
1. external abdominal oblique
2. internal abdominal oblique
3. transversus abdominis
strap-like muscle:
4. rectus abdominis
which abdominal muscle includes the cremaster muscle?
internal abdominal oblique
- cremaster muscle: caudal slip = male reproductive tract
what is the holding layer when closing the abdominal wall during surgery?
linea alba:
- “white line” / fibrous cord
- ventral midline
-
name the structures that form the deep and superficial inguinal rings?
a slit in the aponeurosis of the external abdominal oblique muscle
- Internal abdominal oblique
- Rectus abdominis
- Inguinal ligament
what structures pass through the inguinal canal?
- External pudendal artery/vein
- Genitofemoral nerve
- Vaginal process (female)
- Spermatic cord (male)
- Cremaster muscle (male)
external abdominal oblique
- fibers orient caudal ventrally
- Extends from the ribs/thoracolumbar fascia to the ventral midline
- most superficial of the abdominal muscles
internal abdominal oblique
- fibers orient cranioventrally
- deep to the external abdomindal oblique
- Inserts on the last rib and the linea alba via an aponeurosis
- Cremaster muscle
(male reproductive tract)
