Muscle quiz Flashcards
What is myology?
The study of muscles
What are the 3 types of muscle?
Smooth, skeletal, and cardiac
How many skeletal muscles are there in the human body?
669
All skeletal muscles are attached to…
The skeleton
What 4 things does each skeletal muscle have?
- Own blood supply
- Own nerve supply
- Place where they start
- Place where they end
Skeletal muscle is also called…
Striated
Many nuclei are found below the sarcoplasm. So skeletal muscles are…
Multinucleated
What are the 6 functions of muscles?
- Movement
- Stability
- Control of body passages and openings
- Thermogenesis
- Hormone secretion
- Glycemic control
What is the movement function of muscles?
Muscles enable us to move from place to place and to move individual body parts.
They move body contents in the course of breathing, blood circulation, feeding and digestion, urination, and childbirth; and they serve various roles in communication – speech, writing, facial expression, and other body language.
What is the stability function of muscles?
Muscles maintain posture by preventing unwanted movements.
Some are called antigravity muscles because, at least part of the time, they resist the pull of gravity and prevent us from falling or slumping over. Many muscles also stabilize the joints by maintaining tension on tendons and bones.
What is the control of body passages and openings in muscles?
Muscles encircling the mouth serve not only for speech but also for food intake and retention of food while chewing. In the eyelid and pupil, they regulate the admission of light to the eye. Internal muscle rings control the movement of food, bile, blood, and other materials within the body. Muscles encircling the urethra and anus control the elimination of waste. (Some of these muscles are called sphincters, but not all).
What is the thermogenesis function of muscles?
The skeletal muscles produce 20% to 30% of the body’s heat at rest and up to 85% during exercise.
This body heat is vital to the functioning of enzymes and therefore to all metabolism. When it is lacking, people die of hypothermia.
What is the hormone secretion function of muscles?
Exercised muscles secrete hormones (myokines) that stimulate glucose synthesis by the liver and breakdown of visceral (body-cavity) fat.
What is the glycemic control function of muscles?
The regulation of blood glucose concentration within its normal range.
The skeletal muscles absorb, store, and use a large share of one’s glucose and play a highly significant role in stabilizing its blood concentration. In old age, in obesity, and when muscles become deconditioned and weakened, people suffer and increased risk of type 2 diabetes mellitus because of the decline in this glucose-buffering function.
What is peristalsis?
How food is moved through the body from the esophagus to the anus.
Peristalsis in the digestive tract begins in the esophagus. After food is swallowed, it is moved down the esophagus by peristalsis. The muscles in the stomach, small intestine, and large intestine continue the process. Food is further digested and broken down as it moves through the digestive tract, aided by digestive juices that are added along the way. Bile, which is an important part of the digestive process, is produced in the gallbladder and is moved from the gallbladder into the duodenum (a section of the small intestine) via peristalsis. At the end of its journey through the body via peristalsis, the digested food is excreted through the anus as stool.
What is the belly (body) of the muscle?
The “belly” of the muscle is typically the largest or thickest portion of the muscle.
What is the origin of the muscle?
The place where the muscle starts; usually stationary.
What is the insertion of the muscle?
The place where the muscle ends. Moves towards the origin when the muscle contracts; this is called actin.
What is actin? What does it do?
A contractile protein. It does the work of contraction along with myosin.
What is muscle electrical excitability?
Responsiveness; they respond to electrical signals.
What is muscle contractibility?
Muscle fibers shorten in length when contracted.
What is muscle extensibility?
Capable of being stretched between contractions.
What is muscle elasticity?
Muscle returns to its original rest length after being stretched.
What is epimysium?
A connective tissue that covers the entire skeletal muscle.
What is perimysium?
A connective tissue that bundles muscle fibers into fascicles.
What is endomysium?
A connective tissue that surrounds each muscle fiber.
What is a tendon?
A strip of collagenous tissue attaching muscle to bone.
What is a tendon sheath?
An elongated cylindrical bursa wrapped around a tendon; abundant in hand and foot
What is aponeurosis?
A broad, flat sheet of tendon-like material that anchors a muscle or connects it with the part that the muscle moves.
What is sarcolemma?
The plasma membrane of a muscle fiber.
What are myofibrils?
Rod-like long protein cords occupying ¾ of the sarcoplasm.
What drives muscle contraction and relaxation?
Myofibrils
What are myofibrils composed of?
Muscle filaments or myofilaments.
What is the glycogen component of muscle fiber?
Carbohydrate stored to provide energy for exercise.