18 Questions
What is the functional unit of muscle contraction?
Sarcomere
What type of muscle fiber has high endurance and low force?
Type I (slow-twitch)
What is the outermost layer of connective tissue surrounding the muscle?
Epimysium
What type of smooth muscle fiber functions as individual units?
Multi-unit smooth muscle
What is the cytoplasm of the muscle fiber composed of?
Myoglobin, glycogen, and mitochondria
What is the plasma membrane of the muscle fiber?
Sarcolemma
What type of muscle fiber has fast contraction, high force, and low endurance?
Type IIb (fast-twitch glycolytic)
What is the connective tissue surrounding a group of muscle fibers?
Perimysium
What is the total number of facial muscles in the human face?
43
Which muscle is responsible for smiling and raising the corners of the mouth?
Zygomaticus major
What is the function of the orbicularis oculi muscle?
Helping to close the eyelid
Which muscle helps to lower the jaw and pull the corners of the mouth down?
Platysma
What is the function of the masseter muscle?
Closing the jaw and elevating the mandible
What is one of the functions of the facial muscles?
Facilitating swallowing and preventing food from entering the airway
Which category of muscles includes the zygomaticus major?
Muscles of facial expression
What is the function of the frontalis muscle?
Raising the eyebrows and forehead
How many categories are the facial muscles divided into?
Two
What is the function of the buccinator muscle?
Compressing the cheeks and blowing air out of the mouth
Study Notes
Muscle Anatomy
Components of a Muscle
- Muscle fiber: the basic unit of contraction, composed of myofibrils, sarcoplasm, and sarcolemma
- Myofibrils: contractile elements of the muscle fiber, composed of sarcomeres
- Sarcomeres: functional units of muscle contraction, consisting of thin and thick filaments
- Sarcoplasm: cytoplasm of the muscle fiber, contains myoglobin, glycogen, and mitochondria
- Sarcolemma: plasma membrane of the muscle fiber
Muscle Fiber Types
-
Skeletal muscle fibers:
- Type I (slow-twitch): slow contraction, high endurance, low force
- Type IIa (fast-twitch oxidative): fast contraction, high force, moderate endurance
- Type IIb (fast-twitch glycolytic): fast contraction, high force, low endurance
-
Smooth muscle fibers:
- Single-unit smooth muscle: found in visceral smooth muscle, functions as a single unit
- Multi-unit smooth muscle: found in vascular smooth muscle, functions as individual units
-
Cardiac muscle fibers:
- Striated, branching fibers with intercalated discs for rapid conduction
Muscle Tissue Structure
- Epimysium: outermost layer of connective tissue surrounding the muscle
- Perimysium: connective tissue surrounding a group of muscle fibers
- Endomysium: connective tissue surrounding an individual muscle fiber
Test your knowledge of muscle anatomy, including muscle fibers, myofibrils, sarcomeres, and muscle tissue structure.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
