Rat: External Anatomy and Muscles Flashcards
Adductor muscles
Move the limb TOWARD the midline of the body
Abductor muscles
Moves the limb AWAY from the midline of the body
Masseter
Largest and most cranial muscle of the head (ventral side)
FUNCTION: Chewing
Digastric
Medial side of jaw; adjacent to masseter
FUNCTION: Depress the mandible; antagonistic to masseter
Sternohyoid
Origin: Cartilage of first rib
Insertion: basihyal
FUNCTION: Pulls tongue backward
Skeletal Muscle
Voluntary movement
All of the muscles we memorized in rat (which are part of axial and appendicular skeleton)
Origin
Less moveable location on a bone where muscle attaches
The place closest (PROXIMAL) to the main axis of the body where a muscle attaches, or else the attachment which moves the least when the muscle contracts
Insertion
More moveable attachment of muscle to bone/tendon
The opposite end of the muscle from the origin, farthest from (DISTAL to) the main axis of the body, or the attachment which moves the most with muscle contraction
Sternomastoid
Lateral to sternohyoid
Large muscle
FUNCTION: Turning the head
Cleidocervicalis and cleidobranchialis
FUNCTION: work together to pull forearm forward
Ceps
Latin for “head”
A muscle with several origins may have the word “ceps” in its name, e.g. triceps = three heads
Slips
If the origin or insertion is divided into a number of separate parts and the body of the muscle itself is composed of a number of parallel bands, it is said that the muscle “arises by a series of slips.” This is fequently the case with muscles associated with the ribs, each part attaching to a separate rib.
Belly
The fleshy, middle part of a muscle. This is where you want to cut a muscle if you are looking for deeper muscles
Fascia
The sheet of irregular dense white fibrous connective tissue surrounding a muscle
Aponeurosis
A sheet of connective tissue which serves as the tendon by whihc a sheet-like muscle arises or inserts; e/g/, the origin of the serratus dorsalis muscle from the thoracolumbar fascia, and the linea alba joining the muscles of the abdominal wall along the midline of the abdomen
