Cat Dissection: Muscles

Question 1

Sternocleidomastoid

Answer 1

Origin is sternum and clavicle.
Inserts on temporal bone.
Allows neck to flex and rotate.

Question 2

Frontalis

Answer 2

Inserts at skin of eyebrows.

Raises eyebrows.

Question 3

Orbicularis Oculi

Answer 3

Surrounds eye.

Allows you to squint and wink.

Question 4

Pectoralis Major

Answer 4

Fan shape that covers upper part of chest.
Origin is sternum, shoulder girdle and first 6 ribs.
Insertion is proximal end of humerus.
Adducts and flexes arm.

Question 5

Triceps

Answer 5

Origin is posterior humerus (proximal), and shoulder girdle.
Insertion is olecranon process of ulna.
Prime mover of elbow extension and antagonist to the biceps.
Another name is Boxer Muscle

Question 6

Latissimus Dorsi

Answer 6

Origin is lower spine and ilium.
Insertion is proximal end of humerus.
Adducts humerus(close to body) and extends humerus(straight down)

Question 7

Trapezius

Answer 7

Origin is occipatal bone down the vertebral column to the end of the thoraic vertebrae.
Flares laterally to the insert on the scapula and clavicle.
Extends the head and elevates, depresses, adducts and stabilizes the scapula.

Question 8

Deltoid

Answer 8

Insertion is proximal humerus.
Prime mover for arm abduction(away).
Why is this muscle important to nurses? Favorite injection site.

Question 9

Brachialis

Answer 9

Origin is distal humerus.
Insertion is proximal ulna.
It sits under the brachii and helps with elbow flexion.

Question 10

Biceps

Answer 10

Origin of two heads is the shoulder girdle.
Insertion is radial tuberosity.
Prime mover for flexion and supination.

Question 11

Rectus abdominus

Answer 11

Most superficial abdominal muscle.
Origin is the pubis.
Insertion is the rib cage.
It flexes the vertebrae and compresses the abdomen during childbirth.

Question 12

External Oblique

Answer 12

Superficial muscle that make up the lateral walls of the abdomen.
They run down and medially from the last eight ribs and then insert into the iliac crest.
They flex the vertebrae, rotate the trunk and bend laterally.

Question 13

Internal Oblique

Answer 13

Deep to the external oblique.
Origin is the iliac crest.
Insertion is the last three ribs.
What is the main difference between external and internal obliques? There fibers run at right angles to each other.

Question 14

Transverse abdominus

Answer 14

Deepest muscle.
Fibers run horizontally.
Origin is lower ribs and iliac crest.
Insertion is pubic bone.
It compresses the abdominal contents.

Question 15

Erector Spinae

Answer 15

Prime mover of back extension.
Its a deep muscle that has three columns that span the entire vertebral column.
These are the muscles that go into spasm and give us back pain.

Question 16

Hamstring

Answer 16

Is made up of semimembranosus, semitendinosus, and biceps femoris muscles.
It flexes the knee.

Question 17

Sartorius

Answer 17

Anterior iliac crest to medial side of tibia.

What does it do? Allows us to cross our legs.

Question 18

Gastrocemius

Answer 18

Origin is distal femur.
Insertion is calcaneus.
It allows for plantar flexion (pointing the foot) and flexes knee.

Question 19

Quadriceps

Answer 19

made up of the vastus lateralis, rectus fermoris, and vastus medialis.
Origin is the femur.
Insertion is tibial tuberosity via the patellar ligament.
It extends the knee.