Cat dissection Lab(s)

Cat dissection lab STARTING from week 6 of A&P I

Where is the biceps brachii located?

Located in the upper arm, between the shoulder and the elbow. It is responsible for flexing the elbow and rotating the forearm.

What are the two heads of the biceps brachii?

Medial and lateral heads

What is the main action of the biceps brachii?

The main action of the biceps brachii is to flex the elbow and supinate the forearm, allowing for movements like lifting and rotating.

Where does the long head of the biceps brachii originate?

The long head of the biceps brachii originates from the supraglenoid tubercle of the scapula.

Where does the short head of the biceps brachii originate?

The short head of the biceps brachii originates from the coracoid process of the scapula.

Define insertion

Refers to the point where a muscle attaches to the bone that it moves, typically the more mobile end during contraction.

Define origin

Refers to the point where a muscle attaches to the fixed or less movable bone, typically located proximal to the muscle's insertion.

Define agonist

A muscle that contracts to produce a particular movement, often working in opposition to an antagonist muscle.

Define antagonist

A muscle that opposes the action of an agonist, helping to regulate movement and ensure smooth motion.

Where is the triceps brachii located?

Located on the posterior aspect of the upper arm, extending from the shoulder to the elbow.

How many tricep brachii heads are there?

Three heads of the triceps brachii: the long head, lateral head, and medial head, each contributing to the muscle's function in elbow extension.

What is the main action of the triceps brachii?

The main action of the triceps brachii is to extend the elbow joint, allowing for straightening of the arm.

Where does the long head of the triceps brachii originate?

Originates from the infraglenoid tubercle of the scapula, contributing to shoulder stability and extension.

Where does the medial head of the triceps brachii originate?

Originates from the posterior surface of the humerus, between the radial and ulnar grooves, playing a role in elbow extension.

where does the lateral head of the triceps brachii originate?

Originates from the posterior surface of the humerus, above the radial groove, contributing to elbow extension.

Where is the epitrochlear muscle? Is it in humans? Cats? or both?

Located on the medial side of the arm, near the elbow, it assists in flexion and stabilization of the forearm. Is found in cats but is rare in humans.

What is the pectoantebrachialis muscle?

A superficial muscle in cats that extends from the sternum to the forelimb, aiding in adduction and flexion of the forelimb.

Where is the pectoralis major located? What is a characteristic to mention about it in cat muscles?

The pectoralis major is located on the anterior chest wall, covering a large area of the chest and extending from the manubrium and clavicle to the humerus. It is involved in adduction and rotation of the arm. In cats, the pectoralis major is either equal to or smaller than the pectoralis minor.

Where is the pectoralis minor?

The pectoralis minor is located beneath the pectoralis major on the anterior chest wall, extending from the ribs to the scapula.

What is the main action of the pectoralis minor?

The main action of the pectoralis minor is to stabilize and move the scapula, primarily aiding in its protraction and depression.

Where is the serratus anterior located?

It is superficial to the ribs, extending from the upper eight or nine ribs to the medial border of the scapula. It is responsible for protraction and stabilization of the scapula.

Where is the serratus ventralis located?

It is a fan-shaped muscle located on the side of the ribs and neck in cats. It helps connect the forelimbs to the trunk of the body.

What happens if the serratus anterior is weakened?

Weakness of the serratus anterior can lead to scapular winging, where the medial border of the scapula protrudes away from the rib cage, impairing shoulder stability and function.

What is the xiphihumeralis muscle? Where can it be found?

The xiphihumeralis muscle is a thin, flat muscle found in cats, located beneath the pectoralis major. It extends from the xiphoid process of the sternum to the humerus, aiding in the movement of the forelimbs.

Where is the clavotrapezius in a cat?

Superficial upper back and neck, runs from the skul/neck to the clavicle.

What does the clavotrapezius help do?

Moves clavicle and helps pull the forelimb forward

Where is the acromiotrapezius in a cat?

Across the upper back, connecting the midline of the neck/back to the acromion of the scapula

What does the acromiotrapezius do?

Moves the scapula and helps position the shoulder

Where is the spinotrapezius in a cat?

Located on the lower back, connecting the spine to the scapula.

What does the spinotrapezius do?

Pulls that scapula backward and helps move the shoulder blade

What is the human trapizius muscle?

A large superficial upper-back muscle extending from the neck and skull to the clavicle an the scapula

What are the three trapezius muscles in cats?

Clavotrapezius, acromiotrapezius, and spiotrapezius

What are the three deltoid muscle in cats?

The clavodeltoid, acromiodeltoid, and spinodeltoid.

Where is the clavodeltoid in a cat?

At the front of the shouldes, running from the clavicle region toward the humerus

Where is the acromideltoid in a cat?

Over the outer shoulder, running from the acromion toward the humerus

What does the clavodeltoid help do?

Flexes the shoulder, helping bring the forelimb forward

What does the acromiodeltoid do?

Abducts the shoulder, moving the forelimb away from the body

Where is the spinodeltoid in a cat?

Along the back of the shoulder, from the scapular spine towards the humerus

What does the spinodeltoid help do?

Helps flex the shoulder and move the forelimb

Where are the rhomboids in a cat?

Muscles deep to the trapezius and connects to the scapula via the vertebrae

What do the rhomboids do?

Pull the scapula toward the spine and helps stabilize it

Where are the major and minor rhomboids in humans?

Located between the scapula and the spine, with the major rhomboid beneath the minor rhomboid. Deep to the trapezius.

How do the human rhomboids differ from eachother?

Rhomboid major is lower and bigger. Rhomboid minor is higher and smaller

What does the latisimus dorsi do?

A broad muscle that pulls the arm backward and toward the body

Where is the latissimus dorsi?

Covers much of the lower and middle back, it attaches to the humerus

What is the external oblique?

The superficial side abdominal muscle. Its fibers run diagonally downward and forward

What does the external oblique do?

Compresses the abdomen and helps rotate or bend the trunk

What is the internal oblique?

Muscle deep to the external oblique

What does the internal oblique do?

Compresses the abdomen and helps bend and rotate the trunk

What is the transverse abdominis?

The innermost abdominal muscle, the fibers run horizontally.

What does the transverse abdominis do?

Compresses the abdominal contents and stabilizes the trunk

What is the rectus abdominis?

The paired, vertical abdominal muscle known for forming the ‘six-pack’ in humans

What does the rectus abdominis do?

Flexes the trunk and compresses the abdomen

What muscle is difficult to find in cats?

The rectus abdominis

Name this muscle

Transverse abdominis

Name these three muscles

Clavodeltiod, acromiodeltoid, and spinodeltoid

Name this muscle

Spinotrapezius

Name this muscle

Latissimus dorsi

Name this muscle

Clavotrapezius

Name this muscle

Rhomboids (minor and major)

Name this muscle

Acromiotrapezius

Name this muscle

Acromiotrapezius

Name this muscle

Internal oblique