Muscular System

Question 1

Skeletal

Answer 1

Striated, one long continuous fibers and moves out skeleton

Question 2

Cardiac

Answer 2

Striated, darker lines called intercalated disks and has branches like a tree. Moves your heart

Question 3

Smooth

Answer 3

Non striated, GI tract, and intestines when you eat. One big tube of smooth muscle moving food.

Question 4

What is common between skeletal cardiac and smooth?

Answer 4

They move things and they generate heat to contract ATP from the mitochondria

Question 5

Metabolism

Answer 5

Signalling via Myokines and touching far distant tissues.

Question 6

Mature myocytes

Answer 6

Helps repair muscle after being torn

Question 7

Satellite cells

Answer 7

Used for repair

Question 8

Neurons

Answer 8

Messages from axons to contract

Question 9

Myocytes

Answer 9

Muscle fibers

Question 10

Schwann cells

Answer 10

Another type of neuronal cells for support and increase speed of signal

Question 11

Adipocytes

Answer 11

Fat cells in our muscles provides energy and cushion for protection for muscles to contract.

Question 12

Fibroblasts

Answer 12

Produce collagen and fiber in connective tissues

Question 13

Immune cells

Answer 13

Everywhere in the body, smooth muscle cells, vascularization from blood oxygen nutrition where blood vessel have smooth muscle layers

Question 14

Endothelial cells

Answer 14

Deeps layer is the epithelial. Forms a single cell layer that lines all blood vessels and regulates exchanges between the bloodstream and surrounding tissues

Question 15

Blood cells and hematopoietic stem cells

Answer 15

Are just pre blood cells and blood cells within that

Question 16

Fascicles

Answer 16

A bundle of structures such as nerve or muscles fibers covered by the perimysium

Question 17

Perimysium

Answer 17

The sheath of connective tissue surrounding bundles of muscle fibers to form the fascicles

Question 18

Endomysium layer

Answer 18

Surrounds the muscles fibers with a delicate layer. Provides nutrition and capillaries

Question 19

Epimysium

Answer 19

Connective tissue that Surrounds the entire muscle

Question 20

Sarcolemma

Answer 20

The fine transparent tubular sheath which envelops the fibers of skeletal muscles

Question 21

Sarcomeres

Answer 21

The smallest contractile unit of the skeletal striated muscle made from the myofibril of actin(thin) and myosin(thick). Also separated by zig zag lines. Two zlines is 1 sarcomere

Question 22

Fascia

Answer 22

Dense connective tissue layer around the muscles

Question 23

What is the order?

Answer 23

Epimysium->perimysium->fascicles->endomysium->myofibers-> myofibrils-> actin and myosin for contraction

Question 24

What is type 1 muscle fiber type?

Answer 24

Slow twitch: thinner and relies on oxidative metabolism energy system. Darker in color because hemoglobin has more iron in it and this carries more red blood cells. Has more mitochondria than type 2 since it builds off stability and lasting longer so needs more ATP.

Question 25

What is type x muscle fiber?

Answer 25

Crossover between 1 and 2: fast oxidative glycolytic

Question 26

What is type 2b muscle fiber?

Answer 26

Stronger and faster and EXPLOSIVE ENERGY. but gets more fatigued and lacks stability. It is lighter in color with less blood supply. Glycolytic energy system

Question 27

All of none principle

Answer 27

Motor neuron innervates those fibers, all contract/or none will contract within a motor unit.

Question 28

Pattern of motor unit recruitment

Answer 28

Recruit small or big, type 1 or type 2. There is a pattern

Question 29

What happens in muscle contraction?

Answer 29

1. Motor neuron stimulates skeletal muscle cell. 2. Calcium is released from the sarcoplasmic reticulum 3. Cross-Bridge cycling/contraction

Question 30

Shortened version of muscle contraction

Answer 30

-depolarization and calcium ion release -actin and myosin cross-bridge formation -sliding mechanism of actin and myosin filaments -sarcomere shortening (muscle contraction)

Question 31

7 steps of MC

Answer 31

1. Action potential generated which stimulates muscle 2. Ca2+ released 3. Ca2+ binds to troponin, shifts actin and exposes binding sites 4. Myosin cross bridges attach and detach, pulling actin filaments toward center (requires ATP) 5. Muscle contracts 6. Ca2+ removed, shifts actin filaments to original position, blocking binding sites 7. Muscle contraction stops

Question 32

Concentric

Answer 32

Velocity >0. Uses a lot more ATP like going up the stairs

Question 33

Isometric contraction

Answer 33

Velocity =0.

Question 34

Eccentric

Answer 34

Velocity<0 lengthens and no force produced

Question 35

T-tubules

Answer 35

Small tubules which run transversely through a striated muscle fiber and which electrical impulses are transmitted from the sarcoplasm to the fibers interior

Question 36

Summary of skeletal muscle contractions

Answer 36

1. Calcium is released from the sarcoplasmic reticulum close to the t-tubules. 2. Ca2+ binds for troponin -> troponin moves tropomyosin off myosin binding site of actin 3. Myosin head, ADP+P bounds and binds to actin 4. P and ADP falls off from power strokes 5. ATP head binding site revealed. 6. Myosin ATPase (enzyme) hydrolyzes ATP into ADP+P-> myosin head re-cocked and ready for TAKE OFF