Muscle tissue

Question 1

Describe the function of Muscle tissue

Answer 1

to produce movement of body parts and changes in volume and shape of internal organs and vessels

Question 2

List and describe the two types of Myofilaments associated with cell contraction

Answer 2

Thick and thin filaments

Question 3

Thin Filaments

Answer 3

polymerized G-actin and associated proteins: Tropomyosin, tropomodulin, troponin

Question 4

Tropomodulin

Answer 4

capping protein which maintains & regulates length of the actin filaments

Question 5

Thick Filament

Answer 5

Myosin II
Motor protein aggregated tail to tail to form thick myosin filaments

Question 6

At a molecular level, How is a muscle contracted? 5 stages

Answer 6

Stage 1: attachment /reattachment of rigor configuration Myosin head tightly bound to actin. No ATP

Stage 2: Release: ATP binds to myosin head

Stage 3: Bending: ATP Hydrolysis induces conformation change and movement of myosin head which advances forward.

Stage 4: Force Generation: Myosin head binds weakly to new binding site on adjacent actin–> Results in a release of inorganic phosphate

Stage 5: power stroke: myosin head generates a force as it returns to original position. As Myosin head straightens, it forces movement of the thin filament

Question 7

Generally, what is happening as a muscle contracts?

Answer 7

There is a change in the overlap of thick and thin filaments. this allows for the contraction and relaxation of muscle fibers

Question 8

Describe the sarcomere as muscles contract

Answer 8

Sarcomere shortens and becomes thicker, but the myofilaments remain the same length.

A band remains constant
I band and H band both decrease in size
Z lines are drawn closer to the ends of the A bands

Question 9

Answer 9

Striated muscle

Question 10

Answer 10

Smooth muscle

Question 11

Types of Striated Muscle

Answer 11

Skeletal,Viceral ,cardiac

Question 12

Type of contraction for skeletal muscle?

Answer 12

Voluntary

Question 13

Location of Skeletal muscle?

Answer 13

Somatic/body wall

Question 14

Type of contraction for Visceral Muscle?

Answer 14

voluntary

Question 15

Location of Viceral Muscle

Answer 15

Soft tissue origin

Tongue, Pharynx, larynx, diaphragm and upper esophagus

Question 16

type of contraction for cardiac muscle

Answer 16

involuntary

Question 17

Location of cardiac muscle

Answer 17

Heart and roots of great veins that empty into the heart

Question 18

type of contraction for smooth muscle?

Answer 18

involuntary

Question 19

location of smooth muscle

Answer 19

Walls of visceral (internal) organs.

Stomach, gut tube, etc

Question 20

Answer 20

Epimysium-E

Dense connective tissue encasing multiple fascicles.

• contain major blood vessels and nerves
• continues with tendon to attach muscle at the myotendinous junction

Question 21

Answer 21

Perimysium-P

• Groups of skeletal myocytes/fibers form a fasicle
  
  • each fasicle is surrounded by a layer of connective tissue or perimysium
  • contains larger blood vessels and nerves

Question 22

Answer 22

Endomysiun- En

Delicate layer of reticular fibers that surround individual muscle fiber(myocyte)

• contains small blood vessels and very fine neuronal branches

Question 23

Answer 23

Cardiac muscle

Intercalated discs

centrally located nucleus

branched cells

striations

Question 24

Answer 24

Smooth muscle

Spindle shaped

centrally located nucleus