What are the abdominal muscles and their functions

What are the layers of muscles

from the outside in of the abdominal

cavity.

They are the external abdominal oblique muscle,

internal abdominal oblique muscle

rectus abdominis muscle

transversus abdominis muscle

The left and right parts of each muscle come together

on the ventral midline at the linea alba (an aponeurosis

that extends from the xiphoid process (caudal end)

of the sternum to the cranial brim of the pubis

What are the oblique muscles?

Their fibers run in an oblique (slanting) direction to the long axis of the body and opposite to each other.   External abdominal oblique: fibers run in the opposite direction which is caudo(backword and downword) direction.

The internal abdominal oblique muscle fibers run in the opposite direction, which is cranioventral, or forward and downward.

The rectus abdominis muscle forms the floor (ventral portion) of the muscular abdominal wall. It consists of two straplike muscles on eihter side of the linea alba that run from the ribs and sternum back to the brim of the pubis

What is an attachment

The junction of a skeletal muscle to bone

What is aponeurosis

dense fibrous connective tissue much like

 the tendon but organized into a thin sheet of tissue

What is fleshy?

an apparent direct attachment of muscle to the bone: the muscle attaches to the periosteum of the bone by very short tendons.

What is the action of the muscle?

The body movement that a contraction

of the muscle will produce

Superficial pectoral

Origin: Cranial Sternum

Insertion: Greater Tubercle of humerus

Action: adducts thoracic limb

Deep Pectoral

Origin: Sternum

Insertion: Greater tubercle of humerus

Action: Adducts and pulls the limb caudally

Brachiocephalicas

Sounds like

brey-ke-o-spef-al-i-kus

Origin: Clavicular intersection

Insertion: Ulna, mastoid, dorsal neck

Action: Pulls limb forward, extends shoulder

Omotransversarius

Origin: Wing of atlas

Insertion: Spine and acomion of scapula

Action: Advances leg

Trapezius Muscle

 sounds like tra-pees-z-i-us

Origin: Dorsal aspect of neck

Insertion: Spine of scapula

Action: Elevates and abducts limb

Rhomboideus Muscle

sounds like rom-boy-d-us

Rhomboideus capitis, nuchal crest of the occipital bone

Rhomboideus cervicis, dedian fibrous tissue on the dorsal aspect of the neck

Rhomdoideus Thoracis, spinous process of the first 7 thoracic vertebrae

Origin: occipital bone of head

Insertion: Dorsal border of scapula

Action : Elevates forelimb

In horses and cows they only have 2 parts:thoracic and cervical

Latissimus Dorsi

sounds like : la-tiss-i-mas

Origin :Last 7 thoracic vertebrae and

spinous process of lumbar vertrae

Insertion : Teres Major tuberosity of humerus

Action: Draws limb caudally

Serratus ventralis

sounds like sir-a-tiss  / ven-tral-is

Origin : cervical vertebrae and ribs

Insertion : Dorsomedial scapula

Action: supports trunk

Sternocephalicus

sounds like sterno-sef-al-i-cus

Origin : Sternum

Insertion: Occipital bone

Action: Draws head to side

Platysma

sounds like pla-tiz-ma

Origin : Tendinous raphae on dorsal midline

Insertion: attach to muscles surrounding lips

Action : Draws commissures of lips caudally

Temporalis

sounds like temp-or-al-is

Origin : Parietal bone of skull

Insertion:  Coronoid process of mandible

Action: Closes mouth when chewing

Digastricus

sounds like : di-gas-tri-cus

Origin : Occipital and temporal bones

Insertion : Ventral mandible

Action: Opens mouth

Mylohyoideus

sounds like (my-low-hy-loid-i-us)

Origin : Medial mandible

Insertion: Median raphae between mandible

Action:  Raises floor of mouth

Umbilicus

sounds like (um-bill-i-kus)

It is a small scar that will be wither flat or slightly raised on the ventral midline of the abdomen about one third the distance from the xiphoid cartilage to the penis or vulva: the umbilicus serves as a landmark when abdominal surgery is preformed

Teats

Mammary papillae or mammae: number of mammae varies: Tomcats usally have 2, queens usally have 8 and dogs have 8 to 12. They are positioned in two rows on either side of the adbomen and are usally divided for discussion into thoracic, abdominal and inguinal.

Costal Arch

Caudal ventral border of the rib cage formed by the costal cartilages of the tenth, eleventh, and twelfth ribs: the thirteenth rib does not attach to the costal arch

Cutaneous trunci Muscle

sounds like( koo-tain-i-us)

This muscle covers the dorsal, lateral,

and ventral walls of the thorax and abdomen.

 What are the 8 extrinsic Thoracic Muscles

1. Superficial pectoral (transverse and descending)
2. Deep pectoral
3. Brachiocephalicus
4. Omotransversarius
5. Trapezius
6. Rhomboideus
7. Latissumus Dorsi
8. Serratus Ventralis

Superficial Pectoral Muscle

Origin: cranial sternum; the smaller descending pectoral originates on the first two sternebra. The larger transverse portion originates on the first two or three sternebra.

Insertion: the descending portion and the transverse portion insert on the greater tubercle of the humerus

Action: adducts the thoracic limb

Deep Pectoral Muscle

Origin: sternum

Insertion: crest of the greater tubercle in the cat but primarily the lesser tubercle of the humerus in the dog with some attachment to the greater tubercle.

Action: adducts the limb and pulls the llimb caudally 

Brachiocephalicus Muscle

sounds like bray-key-o-seph-cal-i-cus

A compound Y shaped muscle with 3 parts./ Runs from the arm to the head.

Origin: clavicular intersection

Insertion:

Cleidobrachialis, (sounds like: cly-dough-bray-key-al-is) ulna in the cat (in other animals it inserts on the cranial humerus)

Cleidomastoideus, mastoid process of temporal bone

Cleidocervicali, dorsal neck

Action: pulls the limb forward, extends the shoulder and depresses and pulls the head and neck laterally

Omotransversarius

Starts from the first cervical vertebra (the atlas) next to the back of the skull, dips beneath the other muscles of the neck, which extend to the sternum and arm, then attaches to the scapular spine near the acromion. Its obvious action is to draw the limb forward and rotate the bottom of the scapula forward while other muscles are trying to hold the rest of it in place.

Origin: Wing of the atlas

Insertion: spine and acromion of scapula

Action: advances the limb, and or pulls the head and neck to the side

What is an action

The body movement that a contraction of

the muscle will produce

Superficial cervical lymph

This lymph node is routinely palpapted during physical exams.

In the middle of the omotransversarius.

 Cephalic Vein

Located cranially on the leg. This is an

important structure becasue it is frequently used

 for intravenous injections in small animals

Muscles of the scapula and shoulder

lateral:                                Caudal Muscles of the Arm

Deltoideus (dell-toy-di-us)     Triceps brachii (brack-e)

Infraspinatus                          

Supraspinatus

Medial :                                  Cranial Muscles of the Arm:

Subscapularis                          Biceps brachii

Teres Major                             Brachialis (bray-ke-al-is)

(tear-ez)