Vertebrate Muscle; Actions Flashcards
Contraction
Moving from relaxed elongate state to a short, fat state.
Striations
Tiny bands visible microscopically
Smooth Muscle Appearance
Non-striated, involuntary, small spindle shaped, each with a single nucleus.
Smooth Muscle Description
Smooth muscle causes motion associated with internal organs. (Example: Muscle contraction of the uterus, such as giving birth)
Skeletal Muscle Appearance
Striated, voluntary, large diameter, multi-nucleate cells
Skeletal Muscle Description
Drives motion of the skeleton & skin
Cardiac Muscle Appearance
Striated, involuntary, branches form connections between cells “Intercalated Discs” seen as very dark striations, single nucleus
Cardiac Muscle Description
Composes the muscle of the heart
Intercalated Discs
Facilitate coordinated contraction between the cells (appear as very dark striations)
Flexion
A movement that decreases the angle of a joint & lessons the distance between two bones. (Example: Bringing the knee towards your chest)
Extension
A movement that increases the angle of a joint & increases the distance between two bones (Example: Bending the elbow away from the chest)
Abduction
A movement of a limb away from the midline or medial plane of the body; generally in the frontal plane. (Example: Fanning of fingers or toes when they spread apart)
Adduction
A movement of a limb toward the mid-line or medial plane of the body, generally in the frontal plane. (Example: Opposite of abduction)
Calcaneal Tendon otherwise known as:
Achilles Tendon
Temporalis Muscle
Origin (sight that doesn’t move during contraction): Dorsal Cranium (back of head)
Insertion (sight that does move during contraction): Mandible (Jaw or jawbone)
Muscle Action: Elevation of the mouth (helps the mouth to close)
