muscle structure n contraction

Question 1

muscles take — body mass and involved in —- as:
1- are high — demanding so it takes a lot of —
2- requires —-

Answer 1

• 20-40%
• hemostatic actions aș:
  – Chewing and swallowing food
  – Breathing
  – Generating heat
  – Regulating blood supply
• energy
• mitochondria
• nutrients and 02 and good blood supply

Question 2

types of muscles :
1- —- :
– Most abundant muscle, found
throughout the body
– Connected to bones to facilitate
movement, balance, posture
2- —- :
– Throughout the body, lining
organs such as blood vessels,
stomach and intestines
– Controls movement of contents
of the organ
3- — :
– Found in the heart
– Pumps blood around the body

Answer 2

• skeletal
• smooth
• cardiac

Question 3

2 classification systems of muscle types :
1- appearance as —
2- intervention as –

Answer 3

1- started or unstated
2- voluntary and involuntary
( check slide 6,7 plssss)

Question 4

skeletal muscles cells are surrounded by connective tissue sheath called —-
cells are grouped in — surrounded by —
fascicles are grouped together to form the — which is surrounded by —-

Answer 4

• endomysuim
• facile
• perminusm
• muscle
• epimysium ( outermost layer)
  ( check structure 9.10 plsss)

Question 5

-struture of skeletal muscle:
- skeletal muscle makes up — of the body weight
- cells are very large which is about —- microns in dimeter and several cm in length
- are —-
- each skeletal muscle fiber contains bundle of — called — running along the axis of the cell

Answer 5

• 40%
  -10-100
• mutlunculeated synytical struture
• filaments
• myofilments

Question 6

—– is the unit of a myofibril contained between two Z lines
- On either side of the Z line is —
- The area between two I bands within a sarcomere is the —
- A light area in the center of the sarcomere is called the—-
- A dark line called the — is evident in the center of the sarcomere

Answer 6

• sacromer
• light I band
• A band
• H band
• M line
  ( check structure 14,17 for this )

Question 7

accessory proteins:
* There are a number of proteins which maintain the
structure such as alpha-actinin which maintains the
actin lattice and dystrophin which anchors actin
filaments to the sarcolemma
- — which is largest protein known helps align the thick filament and adds an elastic element to the
sarcomere

Answer 7

• titin ( check slide 19)

Question 8

• muscle fiber cells contain:
• myofibril is composed of overlapping — and filamentous — along the accessory proteins

Answer 8

-myofibrils, mitochondria,
sarcoplasmic reticulum (modified smooth ER), and T-tubules
(inward extensions of the sarcolemma)
- myosin thick
-actin thin
( chrck slide 20 plsss)

Question 9

• In skeletal muscle, triads are located at the—– and — so we will have — tired per —

Answer 9

• junction of the A and I bands
• 2 traids
  ( check slide 22,23)

Question 10

1- —— molecules form an intertwined string with myosin binding site on the outer edge
2- —– protein which binds to actin and blocks the myosin binding site
3- — :
– Muscle relaxation: binds to Actin
and Tropomyosin to stabilise
interaction
– Muscle contraction: Binds to
calcium, displacing Tropomyosin
and allowing Actin and Myosin to
bind

Answer 10

• thin actin
• tropomyosin
• troponin

Question 11

thick filaments are made of —
1- several hundred molecules per thick filament
2- 1 myosin molecule contains – idnetntical subunit w inetwinded tails
3- — for flexibility
4- head region forms —- and has —-
5- oriented in — direction from —-

Answer 11

p myosin
- 2
- 2 hinge regions
- cross bridges
- actin binding sute and ATPase site
- opposite
- central M-line

Question 12

troponin binds — causing —- which moves — relative to — exposing sites on actin which — binds —

Answer 12

• ca++
• conformational changes
• troponysoin
• actin
• actin
  myosin head
  ( chrck slide 29)

Question 13

sliding filament hypothesis of Huxley :
1- —- by interdigitation of
actin and myosin
2-the scarome —-
3- I band —
4- H band —
5 - A band —

Answer 13

muscle shortens
shortens
shortens
shortnes
-a band stays constant in length

Question 14

—-form between myosin and
actin, with myosin pulling
actin into “H zone” and
shortening distance
between Z disks.

Answer 14

crossbirdge

Question 15

——occurs when actin and myosin, the major proteins of the thin and thick filaments, respectively, slide past each other in an ATP-driven enzymatic reaction

Answer 15

muscle contraction
( make sure to check the picture they are important especially 27 )