Catos Test 2 Muscle (Ream)

Front 1

Fx of muscle (4)

Back 1

Movement, stability, storing and moving substances in the body, heat generation.

Front 2

Properties of Muscle Tissue (5)

Back 2

Electrical excitability (irritability) - respond to certain stimuli by producing electrical signals called action potentials (trigger-neurotransmitters)
Conductivity - propagate ax pot along PM due to voltage gated channels
Contractility - generates tension while pulling on attachment points
Extensibility - stretch w/o being damaged
Elasticity -returns to original length

Front 3

True or false Each skeletal muscle is considered an organ.

Back 3

True

Front 4

Muscle organ layers from out to in: (all are continuous with cx tiss that attaches muscle to other structures by forming a tendon)

Back 4

Epimysium-encircles whole muscle organ, vascular and nerve supply
Perimysium-surrounds 10-100 muscle fibers, separating them into fascicles (fx unit)
Endomysium-sep. muscle fibers w/ loose cx tissue of mostly reticular fibers, capillaries.
(each muscle fiber is surrounded by an external lamina)

Front 5

Dense irregular connective tissue w/ type 1 collagen(from fibroblasts)?

Back 5

Epimysium and perimysium

Front 6

Reticular Fibers

Back 6

cx tissue in endomysium to separate individual muscle fibers.

Front 7

How are muscle cells formed?

Back 7

Embryonically formed via fusion of myoblasts that form a postmitotic multinucleated myotube (a syncitium). This myotube matures into long muscle cells.

Front 8

The sarcolemma forms thousands of T-tubules. What are they?

Back 8

Invaginations that extend into the center of the fibers and are filled with interstitial fluid.

Front 9

Myofibrils

Back 9

Cylindrical units that extend the entire lenght of the fiber. The alignment of the myofibrils results in the banding pattern seen in skeletal and cardiac muscle.

Front 10

Sarcoplasm contains (2)

Back 10

β glycogen (a lot)
Myoglobin (red pigment found only in muscle)

Front 11

Contractile Proteins

Back 11

Actin and Myosin

Front 12

Myofibrils are held in place by what IF?

Back 12

Desmin. These filaments encircle the z disks of myofibrils, are attached to the z disks and other desmin filaments via PLECTIN filaments

Front 13

Bridging proteins btwn t-tubule and terminal cisternae are called:

Back 13

FEET - Ca release channels

Front 14

Ca pump

Back 14

(very quick) Most abundent protein in the SR of skeletal muscle. Transports two molecules of Ca into the lumen for every ATP hydrolyzed.

Front 15

Myofilaments

Back 15

Thin and thick filaments

Front 16

Every sarcomere has a relationship with two t-tubules. Explain

Back 16

Sarcomeres are from z disk to z disk, and the t-tubules run at the z disk (A I Jx) so each sarcomere has a t-tubule on each side.

Front 17

A bands

Back 17

Entire lenght of thick filament, so lenght of A band does not change with contraction, but thin filaments will be in this area as well.

Front 18

Thin filament regulatory proteins

Back 18

Troponin and tropomyosin
(no troponin in smooth muscle)

Front 19

Tropomyosin (Thin)

Back 19

Consists of two α-helical polypeptides twisted around each other. It covers the myosin binding site when the muscle is relaxed, and it gives strenght to the thin filament

Front 20

Troponin(Thin)

Back 20

"Tn C" possesses 4 binding sites for calcium
"Tn I" binds to actin inhibiting interaction of myosin and actin

Front 21

Bundles thin filaments into parallel arrays and anchors them to the Z disk

Back 21

α-Actinin (Thin)

Front 22

assist in achoring thin filaments to z disks, and acts as a template for determining the length of actin filaments.

Back 22

Nebulin (Thin)

Front 23

Cap Z (thin)
Tropomodulin

Back 23

binds to plus end of the thin filaments (capping protein)
Caps the minus end of the thin filament

Front 24

Titin (thin)

Back 24

From z disk to m line. Anchors the thick filaments to the z line like a spring. It is very elastic and is the largest protein in skeletal muscle.

Front 25

Types of muscle fibers (all 3 types are present in any 1 organ, however muscle fibers in any 1 motor unit are the same)

Back 25

Red (Slow Oxidative Fibers ie aerobic)
Intermediate
White (Fast Glycolytic Fibers ie anaerobic)
**When comparing red and white on page 748, think of the tortoise and the hare and it all is intuitive.)

Front 26

What bands decrease in length during contraction?

Back 26

I and H

Front 27

Depolarization and Ca release triggers..

Back 27

binding of actin and myosin and thus stimulates contraction.

Front 28

Initiation of contraction

Back 28

sarcolemma is depolarized at the myoneual jx, depolarization spreads of sarcolemma of muscle fiber and continues via membranes of t-tubules, voltage sensor proteins, DHP, in PM chg conformation and CRC open.

Front 29

What triggers the power stroke?

Back 29

The release of inorganic phosphate.

Front 30

Creatine

Back 30

waste product in blood plasma from muscle contractions. 100% is removed in urine
W/ Healthy Kidney Fx 1.5mg/dL

Front 31

How is skeletal muscle innervated?

Back 31

GSE in myoneural jx and two type of sensory nerve endings who fx in proprioception

Front 32

Myoneural Jx-motor nerve terminates on a skeletal muscle fiber.

Back 32

Axon terminal:
Lacks myelin, but has SC
Mito, synaptic vessels w/ Ach

Front 33

What is the muscle fiber part of the myoneural jx in the sarcolemma opposite the axon terminal?

Back 33

Motor End Plate
Has nicotinic receptors (ligand gated) for Ach and Na and K channels

Front 34

Cardiac Muscle Anatomy

Back 34

1(-2) large/oval/central N
Fibers branch
Atrial muscle has a lot of gap jx
A lot of myoglobin
Organelles congregate around N (golgi is nonstaining)

Front 35

Cardiac Muscle Structure

Back 35

T-tubules are wider/fewer
SR smaller/less organized, no highly developed terminal cisternae, low reserve of Ca because it enters extracellularly (both necessary)
More mito than skeletal
Intercalated disks-step like Jx end to end btwn cardiac muscle fibers
Atrial Granules
Purkinje Fibers
Cx tissue

Front 36

Cardiac Muscle Structure
Intercalated disks

Back 36

A. Intercalated disks
1.transverse
FA (αactinin and vinculin)
Desmosomes: where desmin and vimentin insert to mechanically hold the fibers together
2. Lateral Portions
Gap Jx to allow the cells to act as a syncitium

Front 37

Innervation of Heart

Back 37

Autonomic nervous system (GVE)

Front 38

Capeable of regeneration

Back 38

No

Front 39

Heart is from mesoderm. But it makes:

Back 39

Atrial Natriuretic Peptide (a diuretic) in granuals in the atrial cardiac muscle fibers

Front 40

Cardiac: Connective tissue

Back 40

Endomysium only

Front 41

Microscopic anatomy of smooth muscle:

Back 41

Nucleus: is oval and centrally located w/ 2+ nucleoli
Corkscrew appearance in longitudinal sections of contracted smooth muscle.
Cytoplams:looks homogenous
Organelles: Calveolae fluid and electrolyte transport (pinocytotic vessicles)
Dense bodies -contraction
Gap jx-excitation

Front 42

Smooth Muscle IF

Back 42

Desmin only in multiunit
Vimentin and desmin in visceral smooth muscle

Front 43

Contractile Filaments

Back 43

thin and thick but no troponin

Front 44

Smooth muscle innervation

Back 44

Autonomic
Sympathetic (noradrenergic)
Parasymp (cholinergic)

Front 45

Regeneration of smooth muscle

Back 45

Certain smooth muscle cells retain thier mitotic ability (ex uterus via estrogen)

Front 46

Tone-state of continued partial contraction

Back 46

In smooth and skeletal muscle, not in cardiac.

Front 47

Initiation of Contraction
1. Vascular smooth muscle
2. Visceral smooth muscle

Back 47

1. Nerve impulse
2. Stretching (myogenic)