Ch. 10.1 Intro and anatomy of skeletal muscle

Question 1

What are the five functions of skeletal muscle?

Answer 1

Movement
Body Posture
Protection and Support
Regulating elimination of material
Heat

Question 2

What’s another name for muscle cells?

Answer 2

Muscle fibers

Question 3

Epimysium

Answer 3

Layer of dense irregular connective tissue that surrounds the whole muscle.

Question 4

Perimysium

Answer 4

Layer of dense irregular connective tissue around each fascicle.

Question 5

Endomysium

Answer 5

Layer of areolar connective tissue which surrounds each muscle fiber. These electrically insulate each muscle fiber.

Question 6

What is a tendon made up of?

Answer 6

Epi, peri, and endomysium. Made of dense regular connective tissue. These are thick.

Question 7

Aponeurosis-

Answer 7

Thin flattened sheet of dense regular connective tissue.

Question 8

What is the function of tendons and aponeurosis?

Answer 8

Attaching muscle to skeletal component (bone or ligament) or to a fascia.

Question 9

Deep fascia- location and function

Answer 9

Expansive sheet of dense irregular connective tissue external to the epimysium.
Separates individual muscle bundles, binds together muscles of a similar function, contains nerves, blood vessels, and lymph vessels, fills space between muscles.

Question 10

Superficial fascia

Answer 10

Composed of areolar tissue and adipose connective

Separates muscle from skin.

Question 11

What layers do skeletal muscles’ vascular penetrate?

Answer 11

Epimysium and perimysium, but stop at the endomyseium where they become capillaries and are the sight of gas exchange, waste pick up, and nutrient deposition.

Question 12

Somatic motor neurons

Answer 12

Motor neurons that extend from the brain and spinal cord to control muscles.

Question 13

What layers do axons extend through?

Answer 13

Epi, peri, and endomysium and almost make contact with individual muscles fibers.

Question 14

Name of the gap between the somatic motor neuron axon and the muscle fiber

Answer 14

Neuromuscular junction

Question 15

Sarcoplasm

Answer 15

Cytoplasm that is inside skeletal muscle fibers.

Question 16

Myoblasts

Answer 16

Embryonic muscle cells that fuse together during development. This is the reason the skeletal muscle fibers are multinucleate.

Question 17

What are the steps of the sodium potassium pump?

Answer 17

1) 3 NA+ ions from inside the cell bond to NA+ pump in the cell wall.
2) ATP is broken into ADP and additional phosphate on the protein which provides energy to change the pump’s shape.
3) This releases NA+ to the outside of the cell. And pump shape changes so NA+ can’t bond to pump while it is facing outside the cell.
4) 2 K+ ions bond to activate pump that is still facing the outside. The protein then changes shape again and the K+ is released to the inside of the cell.

Question 18

What are the four properties of a muscle?

Answer 18

Excitability, conductivity, contractility, extensibility, elasticity

Question 19

What are the general functions of a muscle?

Answer 19

Movement, posture, protection, joint stabilization, and heat generation.

Question 20

What are satellite cells?

Answer 20

Adult stem cells that can help with muscle tissue repair if muscle is damaged.

Question 21

Sarcolema

Answer 21

Plasma membrane of a skeletal muscle fiber.

Question 22

Define t-tubules and their function.

Answer 22

Also called transversals tubules- these reach deep into the the skeletal muscle fiber to the sarcoplamic reticulum. Sarcoplasmis reticulum is the endoplasmic reticulum of the muscle cell.

Question 23

What is the order of organization of muscle from largest to smallest.

Answer 23

Skeletal muscle, fascicle, muscle fiber, myofibril, myofiliment.

Question 24

Sarcoplasmic reticulum

Answer 24

Internal membrane complex of the muscle. Segments of this fit around myofibrils like a sleeve. At either ends these sleeve segments are terminal cisternae.

Question 25

Terminal cisternae

Answer 25

Hem of the sleeve that is the sarcoplasmic reticulum wrap that goes around each myofibril. These are reservoirs for calcium ions are immediately adjacent to the t-tubules.

Question 26

Triad

Answer 26

Two terminal cisternae that sandwich a t-tubule. All of it together is the triad. T-tubules have voltage sensitive Ca2+ channels. Terminal cisternae have Ca2+ release channels. Electricity passes along the entire sarcoplasmic reticulum till it reaches the triad where it stimulates the release of Ca2+.

Question 27

Calmodulin and Calsequestrin

Answer 27

Proteins inside the sarcoplasmic reticulum were calcium is attached and stored.

Question 28

What are the two types of myofilaments?

Answer 28

Actin and myosin protein molecules.

Question 29

Myosin

Answer 29

The thick type of myofilament. Globular head and elongated tail. The head has a bindings site for the actin of the thin filaments. Also has a catalytic ATPase site where ATP where ATP attaches and is split into ADP and P

Question 30

What part of actin has the myosin binding site?

Answer 30

G-actin

Question 31

What protein has the binding site for Ca2+?

Answer 31

Troponin.