Biology 223 - Lab 4: Axial Muscles

Reflect

The act of cutting a muscle and pulling it away to view deeper muscles.

Origin

End of a muscle that is fixed during contraction. (usually proximal for appendicular muscles)

Insertion

End of a muscle that undergoes movement during contraction ( usually distal for appendicular muscles).

Innervation

refers to nerve penetration of muscles

Agonist

The muscle that is responsible for performing the bulk of movement.

Antagonist

The muscle opposing the action of the agonist.

Synergist

The muscle that assists the agonist muscle perform particular movements.

Flexion

Type of movement that reduces the angle of a joint.

Extension

Type of movement that increases the angle of a joint.

Adduction

Movement towards the longitudinal axis of the body.

Abduction

Movement away from the longitudinal axis of the body.

Pronation

Rotating the forearm so that palms face posterior.

Supination

Rotating the forearm so that palms face anterior.

Frontal belly of occipitofrontalis

Superficial side, right on the forehead.

Occipital belly of occipitofrontalis

Superficial side, small, in the back

Epicranial aponeurosis

Gray matter, connects all occipitofrontalis

Temporoparietalis

Windmill-like, by ear, above temporalis

Corrugator supercilii

Deep side; where eyebrow would go. Eyebrow muscle under frontal belly of occipitofrontalis.

Orbicularis oculi

All around the eye; does not include eyelid.

Procerus

Vertical striations running between orbicularis oculi.

Nasalis

Horizontal striations across bridge of the nose.

Zygomaticus major

(Bottom) a slender band of muscle on each side of the face that arises from the zygomatic bone, inserts into the orbicularis oris and skin at the corner of the mouth, and acts to pull the corner of the mouth upward and backward when smiling or laughing.

*The structure is clipped on this model so you can only see s small piece of it*

Zygomaticus minor

(Top) a muscle of facial expression. It originates from zygomatic bone and continues with orbicularis oculi on the lateral face of the levator labii superioris and then inserts into the outer part of the upper lip.

Orbicularis oris

Around the mouth.

Levator labii superioris

Cheek, underneath eye (deep side) yellow nerve on it.

Depressor anguli oris (superficial)

Triangular muscle, helps frowning (lateral)

Depressor labii inferioris (superficial)

Facial muscle that helps lower the bottom lip; Outer surface of mandible along oblique line (medial)

Mentalis

where the chin is; right where mental protuberance is (skin patch on model)

Buccinator

(Deep side) muscle with a big orange dot on it on the model.

Platysma

Sheet muscle covering all neck muscles.

*No model for this structure, will either be shown on diagram for cadaver for practical*

Temporalis

Deep side, where temporal bone is.

Origin: Temporal Bone

Insertion: Coronoid Process of Mandible

Masseter

(Superficial side) helps chew, vertical striations under buccinator.

Origin: Zygomatic Arch

Insertion: Ramus of the Mandible

Medial pterygoid (deep side)

(bottom) vertical striations

Origin: Pterygoid Process

Insertion: Ramus of the Mandible

Lateral pterygoid (deep side)

(top) sits, above medial pterygoid, horizontal striations.

Origin: Pterygoid Process

Insertion: Ramus of the Mandible

Digastric, anterior belly

From hyoid to mental protuberance.

Origin: Mental Protuberance

Insertion: Hyoid Bone

Digastric, posterior belly

(lateral) from hyoid to mastoid process; back/below.

Origin: Mastoid Process

Insertion: Hyoid Bone

Stylohyoid (deep side)

Anterior to digastric posterior belly.

Origin: Styloid Process of Temporal Bone

Insertion: Hyoid Bone

Mylohyoid

Sheet muscle below anterior belly; has horizontal striations

Origin: Body of Mandible

Insertion: Hyoid Bone

Sternohyoid

(medial) running down the hyoid.

Origin: Manubrium and Clavicle

Insertion: Hyoid Bone

Omohyoid

(lateral) runs down the hyoid, "goes away to Omaha"

Origin: Superior Border of Scapula

Insertion: Hyoid bone

Sternocleidomastoid (SCM)

Huge muscle on side of neck (superficial side).

Origin: Manubrium and Clavicle

Insertion: Mastoid Process

Diaphragm

Under chest cavity, on model all of red portion on the bottom sheet muscle, vertical striations.

External intercostals (lateral; in between ribs)

More to the side; downward.

Internal intercostals (medial; in between ribs)

diagonal striations upward.

Rectus abdominis

a paired muscle running vertically on each side of the anterior wall of the human abdomen

External obliques

downward striations; greyish part on model

Internal obliques

below external obliques; upward striations; one layer down external oblique.

Transverse abdominis (inside view on model)

Below external oblique; horizontal striations.

Linea alba

fibrous structure that runs down the midline of the abdomen in humans and other vertebrates.

Tendinous inscriptions

separates 6 pack horizontally.

Pectoralis major

Chest muscle

Pectoralis minor

under pectoralis major; individually on ribs

Serratus anterior

muscle on your side; looks like bear claw, (grayish on model); also connects to ribs

Subclavius

Tiny muscle under clavicle

Levator scapulae

on the back; side of neck; small and triangular, by scapuli, small triangle on model

Rhomboid major (bottom)

bigger; muscle on the back that connects the scapula with the vertebrae of the spinal column.

Rhomboid minor (top)

smaller; muscle on the back that connects the scapula with the vertebrae of the spinal column.

Trapezius

Big muscle that looks like kite on back

Latissimus dorsi

lower back; sheet muscle.

Deltoid

Rounded, triangular muscle located on the uppermost part of the arm and the top of the shoulder.

Origin: Clavicle & Spine of Scapula

Insertion: Deltoid Tuberosity

Biceps brachii

Biceps brachii, short head:

Origin: Coracoid Process

Insertion: Radial Tuberosity

Biceps brachii, long head:

Origin: Glenoid Cavity

Insertion: Radial Tuberosity

triceps brachii

Triceps brachii, lateral head:

Origin: Proximal Humerus

Insertion: Olecranon

Triceps brachii, long head

Origin: Scapula

Insertion: Olecranon

Triceps brachii, medial head

Origin: Proximal Humerus

Insertion: Olecranon

Brachioradialis

Origin: Lateral Epicondyle of Humerus

Insertion: Styloid Process of Radius

Rectus femoris

Origin: Anterior Inferior Iliac Spine

Insertion: Tibial Tuberosity

Sartorius

Origin: Anterior Superior Iliac Spine

Insertion: Medial Condyle of Tibia

Gracilis

Origin: Inferior Pubic Ramus

Insertion: Medial Condyle of Tibia

Gluteus maximus

Origin: ilium & sacrum

Insertion: Iliotibial Tract & Proximal Femur

Gastrocnemius

Gastrocnemius, medial head:

Origin: Medial Condyle of Femur

Insertion: Calcaneus

Gastrocnemius, lateral head

Origin: Lateral Condyle of Femur

Insertion: Calcaneus

Tibialis anterior

Origin: Lateral condyle of tibia

Insertion: Metatarsal I