Chapter 10 Flashcards

Question

Thousands of tiny invaginations of the sarcolemma ?

Answer 1

Transverse (T) tubules

Answer 2

Tunnel in from the surface towards the centre of each muscle fibre open to the outside of the fibre they are filled with interstitial fluid muscle action potentials travel along the sarcolemma and through the T tubules quickly spreading throughout the muscle fibre

Answer 3

Within the sarcolemma the cytoplasm of a muscle fibre includes a substantial amount of glycogen and includes a red coloured protein called myoglobin found only in muscle

Answer 4

A red coloured protein found only in muscle that binds oxygen molecules that diffuse into muscle fibres from interstitial fluid releases oxygen when it is needed by the mitochondria for ATP production

Answer 5

It small structures that appear in the sarcoplasm like it’s stuffed with little threads the contractile organelles of skeletal muscle extending the entire length of a muscle fibre giving it the striated look

Answer 6

A fluid filled system of membraneous sacs that in circles each myofibril similar to smooth endoplasmic reticulum and non-muscular cells

Answer 7

Dilated Sarco plasmic reticulum butt against the T tubule from both sides

Answer 8

Is formed by a transverse tubules and the two terminal cisterns on either side of it

Answer 9

Smaller structures within the myofibrils consisting of thin filaments and thick filaments Directly involved in the contract I’ll process Arranged in compartment called sacral mirrors

Answer 10

8nm in diameter and 1-2 um long, Composed of the protein Actin Too thin filaments for every thick filament in the region of filament overlap

Answer 11

16 nm in diameter and 1-2 um long, Composed of the protein myosin

Answer 12

Basic functional units of a myofibril

Answer 13

Are narrow plate shaped regions of dense protein material that separate one sarcomere from the next

Answer 14

A band - darker middle portion Zone of overlap - toward each end of the A band, where thick and thin filaments lie side by side I band - Lighter less dense area that contains the rest of the thin filaments but no thick filaments and a Z disc passes through the centre of each I band Alternating dark A bands and light I-band create the striation look H zone - narrow, centre of each A band contains thick filaments M line - supporting proteins that hold the thick filaments together at the centre of the H zone

Answer 15

1. Contractile proteins 2. Regulatory proteins 3. Structural proteins

Answer 16

Generate force during contraction Consists of myosin and actin proteins and other components of thick and thin filaments

Answer 17

Main component of thick filaments and functions as a motor proteins in all three types of muscle tissue

Answer 18

Pull various cellular structures to achieve movement by converting the chemical energy in ATP to the mechanical energy of motion which is the production of force Shaped like to golf clubs twisted together

Answer 19

Points toward the end line in the centre of the circle mirror tales of neighbouring myosin molecules lie parallel to one another forming the shaft of the thick filament

Answer 20

Two projections of each meion molecule that has two binding sites 1. active binding site 2. ATP binding site

Answer 21

Main component of thin filament individual actin molecules join to form an actin filament that is twisted into a helix on each actin molecule is a myosin binding site where a myosin head can attach

Answer 22

Part of the thin filament in smaller amounts than actin Tropomyosin blocks myosin from binding to actin in relaxed muscles tropomyosin strands are held in place by troponin molecules

Answer 23

Alignment, stability, elasticities, extensibility of myofibrils

Answer 24

A key structural protein the third most plentiful protein in skeletal muscle after actin and myosin and span half a sacromere from a Z disk to an M line help stabilize the position of thin filament

Answer 25

Titin Actin Myomesin Nebulin Dystrophin

Answer 26

As the thin filaments slide inward the I-band and H zones narrow and eventually disappear all together when the muscle is maximally contracted

Answer 27

The repeating sequence of events that causes the filament to slide

Answer 28

1. ATP hydrolysis 2. Attachment of myosin to actin 3. Power stroke 4. Detachment of myosin from actin

Answer 29

When a myosin head attaches to the Myosin binding site during the contraction cycle the Myosin head is referred to as a crossbridge

Answer 30

As the myosin head changes to its new position it pulls the thin filament past the thick filament toward the centre of the Sarcomere generating tension in the process

Answer 31

The sequence of events that links excitation (a muscle action potential) to contraction (sliding of the filaments)

Answer 32

Are located in the T tubule membrane they are arranged in clusters of four known as tetrad with the main role been excitation-contraction coupling the service voltage sensors, the trigger, opening of calcium release channels

Answer 33

Present in the terminal sisternal membrane of the SR when a skeletal muscle fibre is at rest the part of the calcium release channel that extends into the sarcoplasm is blocked by a given cluster of voltage gated calcium channels preventing calcium from leaving the SR

Answer 34

Found in the terminal cisternal membrane of the sarcoplasmic reticulum Use ATP to constantly transport calcium from the sarcoplasm into the SR

Answer 35

Molecules of a protein found inside the SR bind to calcium allowing even more calcium to be sequestered within the SR

Answer 36

Indicates how the forcefulness of muscle contraction depends on the length of the sarcomeres within a muscle before contraction begins

Answer 37

Stimulates skeletal muscle fibres to contract has a threadlike axon that extends from the brain or spinal cord to a group of skeletal muscle fibres

Answer 38

Where muscle action potential arises The synapse between a somatic motor neuron and a skeletal muscle fibre

Answer 39

A region where communication occurs between two neurons or between a neuron and a target cell in this case between a somatic motor neuron and a muscle fibre

Answer 40

A small gap at the synapse that separates the two cells because the cells are not touching the action potential cannot “jump the gap” from one cell to another

Answer 41

Used for cell communication due to the synaptic cleft

Answer 42

1. Release of acetylcholine 2. Activation of ACh receptors 3. Production of muscle action potential 4. Termination of ACh activity

Answer 43

A poison used by South American Indian on arrows and blow gun darts causes muscle paralysis by binding to and blocking ACh receptors in the presence of curare the ion channels do not open

Answer 44

1. From creatine phosphate 2. By anaerobic glycolysis 3. By aerobic respiration

Answer 45

An energy rich molecule that is found in muscle fibres synthesized from excess ATP that was produced when the muscle fibres were relaxed First form of energy when muscle contraction begins

Answer 46

Small amino acid like molecule does synthesized in the liver kidneys and pancreas and then transported to muscle fibres

Answer 47

Quickly breaks down each glucose molecule into two molecules of pyruvic acid occurs in the cytosol and produces a net gain of two molecules of ATP Does not require oxygen

Answer 48

The entire process by which the breakdown of glucose gives rise to lactic acid when oxygen is absent or at a low concentration

Answer 49

If sufficient oxygen is present the pyruvic acid formed by glycolysis enters mitochondria where it undergoes aerobic respiration a series of oxygen requiring reactions (the Krebs cycle and the electron transport chain) that produces ATP, carbon dioxide, water, and heat when oxygen is present glycolysis the Krebs cycle and electron transport chain occur

Answer 50

1. Oxygen that diffuses into muscle fibres from the blood 2. Oxygen released by myoglobin within muscle fibres

Answer 51

The inability of a muscle to maintain force of contraction after prolonged activity

Answer 52

Refers to the added oxygen over and above the resting oxygen consumption that is taken into the body after exercise

Answer 53

1. Convert lactic acid back into glycogen stores in the liver 2. To resynthesized creatine phosphate and ATP in muscle fibres 3. To replace the oxygen removed from myoglobin

Answer 54

Is a better term than oxygen debt for the elevated use of oxygen after exercise

Answer 55

Consists of a somatic motor neuron plus all of the skeletal muscle fibres it stimulates a single somatic motor neuron makes contact with an average of 150 skeletal muscle fibres in one motor unit contract in unison

Answer 56

Is the brief contraction of all muscle fibres in a motor unit in response to a single action potential in its motor neuron

Answer 57

The record of a muscle contraction

Answer 58

The brief delay that occurs between application of the stimulus in the beginning of the contraction

Answer 59

Calcium binds to troponin, myosin-binding sites on actin are exposed, and cross bridges form. peak tension develops in the muscle fibre

Answer 60

Is actively transported back into the sarcoplasmic reticulum, myosin binding sites are covered by a tropomyosin, myosin heads detach from actin, and tension in the muscle fibre decreases

Answer 61

The period of lost excitability and is a characteristic of all muscle and nerve cells

Answer 62

Stimuli arriving at different times causing larger contractions

Answer 63

Sustainable wavering contraction caused by partially relax muscles between stimuli

Answer 64

Is the stain contraction in which individual twitches cannot be detected caused by a stimulated muscle fibre that does not relax at all

Answer 65

The process in which the number of active motor unit increases

Answer 66

A small amount of tauntness or tension in the muscle due to week in voluntary contractions of its motor units muscle tone is established by neurons in the brain and spinal cord that excite the muscles motor neurons

Answer 67

When the motor neuron serving a skeletal muscle or damaged or cut the muscle becomes flaccid the state of lymph nodes in which muscle tone is lost

Answer 68

The tension developed in the muscle remains almost constant while the muscle changes in length isotonic contractions are used for body movements and for moving objects the two types of isotonic contractions are concentric and eccentric

Answer 69

If the tension generated is great enough to overcome the resistance of the object to be moved the muscle shortens and pulls on another structure such as a tendon to produce movement and to reduce the angle at a joint

Answer 70

When the length of a muscle increases during a contraction the tension exerted by the myosin cross bridges resist movement of a load process this type of contraction produce more muscle damage then concentric isotonic contractions

Answer 71

The tension generated is not enough to exceed the resistance of the object to be moved in the muscle does not change its length important for maintaining posture and for supporting objects in a fixed position even though the body is not moving energy is still expended

Answer 72

Skeletal muscle fibres that have a high myoglobin content and appear darker Contain more mitochondria in our supplied by more blood capillaries

Answer 73

Those that have a low content of myoglobin and appear lighter

Answer 74

1. Slow oxidative fibres 2. Fast oxidative glycolytic fibres 3. Fast glycolytic fibres

Answer 75

Appear dark red because they contain large amounts of myoglobin and many blood capillaries because they have large amounts of mitochondria SO fibres generate ATP mainly by aerobic respiration

Answer 76

Typically the largest fibres contain large amounts of myoglobin in many blood capillaries dark red appearance generate considerable ATP by aerobic respiration which give them a moderately high resistance to fatigue

Answer 77

Have low myoglobin content relatively few blood capillaries and few mitochondria and appear white in colour contain large amounts of glycogen and generate ATP mainly by glycolysis contract strong and quickly due to the rapid ability to produce hydrolyze ATP

Answer 78

The principal tissue in the heart wall are sheets of connective tissue that contain blood vessels, nerves, and the conduction system of the heart cardiac muscle fibres have the same arrangement of actin and myosin in the same band zones and Z discs of skeletal muscle fibres with unique inter-collated discs

Answer 79

Unique to cardiac muscle fibres and are structures with irregular transverse thickening of the sarcolemma that connect the ends of the cardiac muscle fibres to one another Containing desmosomes which hold the fibres together and gap junctions which allow muscle action potentials to spread from one cardiac muscle fibre to another

Answer 80

Found in the skin in tubular arrangements that form part of the walls of small arteries and veins and of Hall of organs it is the more common type of smooth muscle tissue

Answer 81

Consists of individual fibres each with its own motor neuron terminals and with few gap junctions between neighbouring fibres stimulation of one visceral muscle fibre causes contractions of many adjacent fibres but stimulation of one multiunit fibre causes contractions of that fibre only

Answer 82

Sarcoplasm is smooth muscle fibres contains both thick and thin filaments not arranged in orderly sarcomeres Also contains intermediate Filaments Smooth muscle has small pouch like invaginations of the plasma membrane called caveolae that contain extracellular calcium In smooth muscle fibres the thin filaments attached to structures called dance bodies with your functionally similar to Z discs in striated muscles

Answer 83

Contraction in a smooth muscle fibre starts more slowly and last much longer than skeletal muscle fibre contractions smooth muscle fibers shorten and stretch to a greater extent than the other muscle types

Answer 84

After binding to calcium in the Sarcoplasm, calmodulin activates an enzyme called myosin light change kinase, this enzyme uses ATP to add a phosphate group to a portion of the myosin head once the phosphate group is attached, the myosin head can bind to actin and contraction can occur

Answer 85

Slow moving calcium in and out of the muscle fibre delays relaxation this prolonged presence of calcium in the cytosol provides for smooth muscle tone

Answer 86

Is the phenomenon from which tension decreases after smooth muscle fibres are stretched developing increase tension

Answer 87

The enlargement of existing cells how mature skeletal muscle fibres grow after birth

Answer 88

An increase in the number of fibres

Answer 89

Cells that new smooth muscle fibres can arise from these are stem cells found in association with blood capillaries and small veins

Chapter 10 Flashcards

(113 cards)