week 6 (joints, movement & skeletal muscle, smooth and cardiac muscles)

Question 1

skeletal muscle

Answer 1

Muscles are attached to bones by tendons at their origins and insertions. Skeletal
muscles produce movements by pulling on bones.

Those skeletal muscles that produce movements do so by exerting force on tendons, which in turn pull on bones
or other structures (such as skin)

Because
each skeletal muscle fiber arises during embryonic development from
the fusion of a hundred or more small mesodermal cells called myoblasts
each mature skeletal muscle fiber has a
hundred or more nuclei. Once fusion has occurred, the muscle fiber loses
its ability to undergo cell division. Thus, the number of skeletal muscle
fibers is set before you are born, and most of these cells last a lifetime

Skeletal muscle also contains
connective tissues surrounding muscle fibers, and blood vessels and
nerves

Question 1

origin

Answer 1

the attachment of a muscle’s tendon to the stationary bone is called the

origin is usually proximal

Question 2

inseration

Answer 2

the attachment of the muscle’s other tendon to the movable bone

insertion distal

the insertion is usually pulled toward the origin

Question 3

tendons

Answer 3

attach to muscle and secure the muscle to the bone

Question 4

synvoial joint

Answer 4

The bones forming the joint have
a synovial cavity and are united by the dense irregular connective
tissue of an articular capsule, and of en by accessory ligaments

Question 5

synvoial cavity

Answer 5

joint cavity between
the articulating bones. Because the synovial cavity allows considerable movement at a joint, all synovial joints are classified functionally
as freely movable

Question 6

articular cartilage

Answer 6

The bones at a synovial joint are

covered by a layer of hyaline cartilage called

Question 7

articular capsule

Answer 7

or joint capsule surrounds a synovial joint, encloses the synovial cavity, and
unites the articulating bones. The articular capsule is composed of two layers, an outer fibrous membrane and an inner synovial
membrane

Question 8

synvoial membrane

Answer 8

is composed of areolar connective tissue with elastic fibers. At many synovial joints the synovial membrane includes accumulations of adipose tissue, called articular fat pads

Question 9

fibrous membrane

Answer 9

of dense irregular connective tissue (mostly collagen fibers) that attaches to the periosteum of the articulating bones. In fact, the fibrous membrane is literally a thickened continuation of the periosteum between the bones.

The flexibility of the fibrous
membrane permits considerable movement at a joint, while its great tensile strength (resistance to stretching) helps prevent the bones from dislocating, the displacement of a bone from a joint.

The fibers of some fibrous membranes are arranged as parallel bundles of dense regular connective tissue that are highly adapted for resisting strains

Question 10

ligament

Answer 10

is one of the principal mechanical

factors that hold bones close together in a synovial joint

Question 11

synvoial fluid

Answer 11

Synovial
fluid consists of hyaluronic acid secreted by synovial cells in the
synovial membrane and interstitial fluid filtered from blood plasma.
It forms a thin film over the surfaces within the articular capsule. Its
functions include reducing friction by lubricating the joint, absorbing
shocks, and supplying oxygen and nutrients to and removing carbon

Synovial fluid also
contains phagocytic cells that remove microbes and the debris that
results from normal wear and tear in the joint
dioxide and metabolic wastes from the chondrocytes within articular
cartilage

Question 12

menisci

Answer 12

crescent-shaped
pads of fibrocartilage lie between the articular surfaces of the bones
and are attached to the fibrous capsule

1) shock absorption; (2) a better fit between articulating bony surfaces; (3) providing adaptable surfaces for combined
movements; (4) weight distribution over a greater contact surface;
and (5) distribution of synovial lubricant across the articular surfaces
of the joint.

Question 13

hinge joint

Answer 13

in which the articular surfaces are molded to each other in such a manner as to permit motion only in one plane
it is like a line shape and then another bone forming to it

examples: elbow, knee, interphalangeal (IP) joints of the hand and foot and the tibiotalar joint of the ankle

Question 14

ball and socket joint

Answer 14

Ball-and-socket joint, also called spheroidal joint, in vertebrate anatomy, a joint in which the rounded surface of a bone moves within a depression on another bone, allowing greater freedom of movement than any other kind of joint

example: shoulder nad hip joints

Question 15

pivot joint

Answer 15

Pivot joints, also known as rotary joints, are a type of synovial joint that permit axial rotation. The moving bone rotates within a ring formed by the concave surface of a second bone and an adjoining ligament

example would be the 2nd vetrebrea and neck bone and joint of wrist

Question 16

abduction

Answer 16

the movement of a bone away from the midline

Question 17

adduction

Answer 17

is the movement of a bone towards midline

Question 18

circumduction

Answer 18

is movement

of the distal end of a body part in a circle

Question 19

internal/medial rotation

Answer 19

anterior surface of a bone of the limb is turned toward the midline, the movement is called medial (internal) rotation

Question 20

external/lateral rotation

Answer 20

anterior surface of the
bone of a limb is turned away from the midline, the movement is
called lateral (external) rotation

Question 21

extension

Answer 21

Increase in angle between articulating bones,

Question 22

flexion

Answer 22

Decrease in angle between articulating bones,

usually in sagittal plane

Question 23

joint

Answer 23

is a point of contact between two bones, between

bone and cartilage, or between bone and teeth

Question 24

fibrous joint

Answer 24

There is no synovial cavity, and the bones are held together by dense irregular connective tissue that is rich in collagen fibers.

Question 25

cartilaginous joint

Answer 25

There is no synovial cavity, | and the bones are held together by cartilage

Question 26

synarthrosis

Answer 26

An immovable | joint

Question 27

amophiarthrosis

Answer 27

A | slightly movable joint

Question 28

diarthrosis

Answer 28

A freely movable joint. The plural is diarthroses. All diarthroses are synovial joints. They have a variety of shapes and permit several different types of movements.

Question 29

sutures (fibrous joint)

Answer 29

is a fibrous joint composed of a thin layer of dense irregular connective tissue; sutures occur only between bones of the skull They are immovable or slightly movable head bons

Question 30

syndesmoses (fibrous joint)

Answer 30

is a fibrous joint in which there is a greater distance between the articulating surfaces and more dense irregular connective tissue than in a suture between tibia and fibula

Question 31

interosseous membranes (fibrous joint)

Answer 31

which is a substantial sheet of dense irregular connective tissue that binds neighboring long bones and permits slight movement provide an increased attachment surface for muscles that produce movements of the digits of the hand and foot.

Question 32

synchondroses (cartilaginous joint)

Answer 32

is a cartilaginous joint in which the connecting material is hyaline cartilage and is slightly movable the joint between the first rib and the manubrium of the sternum

Question 33

symphyses (cartilaginous joint)

Answer 33

is a cartilaginous joint in which the ends of the articulating bones are covered with hyaline cartilage, but a broad, flat disc of fibrocartilage connects the bones and at the intervertebral joints between the bodies of vertebrae

Question 34

three types of muscle fibres

Answer 34

smooth, caridiac and skeletal

Question 35

excitability of muscules

Answer 35

the ability to respond to a stimulus, which may be delivered from a motor neuron or a hormone a property of both muscle and nerve cells that was is the ability to respond to certain stimuli by producing electrical signals called action potentials (impulses). Action potentials in muscles are referred to as muscle action potentials; those in nerve cells are called nerve action potentials.

Question 36

contractility of muscules

Answer 36

Contractility is the ability of muscle cells to forcefully shorten. Contractility allows muscle tissue to pull on its attachment points and shorten with force the ability of muscular tissue to contract forcefully when stimulated by an action potential. When a skeletal muscle contracts, it generates tension (force of contraction) while pulling on its attachment points.

Question 37

elasticity of muscles

Answer 37

the ability to stretch a muscle to reach its full range of movement without restriction

Question 38

extensibility of muscules

Answer 38

Extensibility is the ability of a muscle to be stretched is the ability of muscular tissue to stretch, within limits, without being damaged. The connective tissue within the muscle limits the range of extensibility and keeps it within the contractile range of the muscle cells. Normally, smooth muscle is subject to the greatest amount of stretching. For example, each time your stomach fills with food, the smooth muscle in the wall is stretched. Cardiac muscle also is stretched each time the heart fills with blood.

Question 39

motor unit

Answer 39

made up of a motor neuron and all of the skeletal muscle fibers, also known as sarcomere innervated by the neuron's axon terminals. Groups of motor units often work together as a motor pool to coordinate the contractions of a single muscl

Question 40

somatic motor nervous system

Answer 40

somatic nervous system, or voluntary nervous system is the part of the peripheral nervous system associated with the voluntary control of body movements via skeletal muscles somatic motor nervous system can not happen withoutthe use of skeletal muscles

Question 41

significance of nerve impulses being delivered to skeletal muscle tissue

Answer 41

when a neurotransmitter binds to a receptor, it triggers a new nerve impulse on the muscle fibre membrane. Because of the special way that muscle fibres are structured, this nerve impulse propagates rapidly throughout the fibre and makes it contract without nerve impulses, we would not be ale to move our skeletal muscle tissue

Question 42

cerebral motor cortex in relation to skeletal muscles

Answer 42

cerebral motor cortex is what sends these impulses to the areas they need to be. without it we would not be able to move.

Question 43

cerebellum

Answer 43

The cerebellum has special sensors that detect shifts in balance and movement. It sends signals for the body to adjust and move maintains balance of the body

Question 44

basal nuclei

Answer 44

The basal ganglia are responsible for voluntary motor control, procedural learning, and eye movement, as well as cognitive and emotional functions

Question 45

what is the importance of calcium ions (Ca2+)

Answer 45

calcium ions cause the release of acetylcholine at the neuromuscular junction. as well, calcium release from the sarcoplasmic reticulum allows 'bridge' formation to occur between actin and myosin

Question 46

tendon

Answer 46

the connective tissues that transmit the mechanical force of muscle contraction to the bones; the tendon is firmly connected to muscle fibres at one end and to components of the bone at its other end. ... A tendon is composed of dense fibrous connective tissue made up primarily of collagenous fibres.

Question 47

epimysium

Answer 47

is the outer layer, encircling | the entire muscle. It consists of dense irregular connective tissue

Question 48

deep fascia

Answer 48

Deep fascia (or investing fascia) is a fascia, a layer of dense connective tissue that can surround individual muscles and groups of muscles to separate into fascial compartments.

Question 49

blood vessel

Answer 49

The blood vessels are the components of the circulatory system that transport blood throughout the human body

Question 50

perimysium

Answer 50

is also a layer of dense irregular connective tissue, but it surrounds groups of 10 to 100 or more muscle fibers, separating them into bundles called fascicles

Question 51

fascicle

Answer 51

Many fascicles are large enough to be seen with the naked eye. They give a cut of meat its characteristic “grain”; if you tear a piece of meat, it rips apart along the fascicles

Question 52

endomysium

Answer 52

penetrates the interior of each fascicle and separates individual muscle fibers from one another. The endomysium is mostly reticular fibers.

Question 53

muscle fiber (cell)

Answer 53

Long cylindrical cell covered by endomysium and sarcolemma; contains sarcoplasm, myofibrils, many peripherally located nuclei, mitochondria, transverse tubules, sarcoplasmic reticulum, and terminal cisterns. The fiber has a striated appearance.

Question 54

blood capillary

Answer 54

the smallest and most numerous of the blood vessels, form the connection between the vessels that carry blood away from the heart (arteries) and the vessels that return blood to the heart (veins). The primary function of capillaries is the exchange of materials between the blood and tissue cells

Question 55

motor neuron

Answer 55

cells in the brain and spinal cord that allow us to move, speak, swallow and breathe by sending commands from the brain to the muscles that carry out these functions

Question 56

sarcolemma

Answer 56

he sarcolemma functions as a barrier between the extracellular and intercellular parts of the muscle fiber cells The sarcolemma is the plasma membrane of the muscle cell and is surrounded by basement membrane and endomysial connective tissue The cell membrane of a myocyte

Question 57

myofirl

Answer 57

Threadlike contractile elements within sarcoplasm of muscle fiber that extend entire length of fiber; composed of filaments

Question 58

filaments (myofilaments)

Answer 58

Contractile proteins within myofibrils that are of two types: thick filaments composed of myosin and thin filaments composed of actin, tropomyosin, and troponin; sliding of thin filaments past thick filaments produces muscle shortening

Question 59

sacroplasm

Answer 59

Within the sarcolemma is the sarcoplasm (SAR-koˉ-plazm), the cytoplasm of a muscle fiber. Sarcoplasm includes a substantial amount of glycogen, which is a large molecule composed of many glucose molecules

Question 60

z plates

Answer 60

Narrow, plate-shaped regions of dense material that separate | one sarcomere from the next.

Question 61

Contractile proteins

Answer 61

Proteins that generate force during muscle contractions.

Question 62

Myosin

Answer 62

Contractile protein that makes up thick filament; molecule consists of a tail and two myosin heads, which bind to myosinbinding sites on actin molecules of thin filament during muscle contraction.

Question 63

Actin

Answer 63

Contractile protein that is the main component of thin filament; each actin molecule has a myosin-binding site where myosin head of thick filament binds during muscle contraction.

Question 64

Tropomyosin

Answer 64

Regulatory protein that is a component of thin filament; when skeletal muscle fiber is relaxed, tropomyosin covers myosin-binding sites on actin molecules, thereby preventing myosin from binding to actin.

Question 65

Troponin

Answer 65

Regulatory protein that is a component of thin filament; when calcium ions (Ca2+) bind to troponin, it changes shape; this conformational change moves tropomyosin away from myosin-binding sites on actin molecules, and muscle contraction subsequently begins as myosin binds to actin.

Question 66

Regulatory proteins

Answer 66

Proteins that help switch muscle contraction process on and off.

Question 67

cardaric muscle tissue

Answer 67

Only the heart contains cardiac muscle tissue, which forms most of the heart wall. Cardiac muscle is also striated, but its action is involuntary. The alternating contraction and relaxation of the heart is not consciously controlled. Rather, the heart beats because it has a natural pacemaker that initiates each contraction. This built-in rhythm is termed autorhythmicity Several hormones and neurotransmitters can adjust heart rate by speeding or slowing the pacemaker.

Question 68

smooth muscle tissue

Answer 68

Smooth muscle tissue is located in the walls of hollow internal structures, such as blood vessels, airways, and most organs in the abdominopelvic cavity. It is also found in the skin, attached to hair follicles. Under a microscope, this tissue lacks the striations of skeletal and cardiac muscle tissue. For this reason, it looks nonstriated, which is why it is referred to as smooth. The action of smooth muscle is usually involuntary, and some smooth muscle tissue, such as the muscles that propel food through your gastrointestinal tract, has autorhythmicity.

Question 69

vertebral column function

Answer 69

is to provide proper positioning and posture for movement of the appendages and maintaining an upright position. the curves of the vertebral column are important in providing proper position. the muscles attached to the vertebrae allow for movement of the column and maintaining proper posture. these muscles are not for lifting

Question 70

fulcrum

Answer 70

h

Question 71

muscle origin

Answer 71

Muscle origin refers to a muscle's proximal attachment the end of the muscle closest to the torso

Question 72

muscle insertion

Answer 72

insertion refers to a muscle's distal attachment—the end of the muscle furthest away from the torso

Question 73

antagonistic skeletal muscle pairs

Answer 73

the muscle that is relaxing or lengthening is called the antagonist An antagonist muscle is in opposition to a prime mover in that it provides some resistance and/or reverses a given movement

Question 74

prime mover

Answer 74

The prime mover, sometimes called the agonist, is the muscle that provides the primary force driving the action. The muscle that is contracting is called the agonist

Question 75

synergist

Answer 75

muscles that work together to create a movement as synergists. For example, iliacus, psoas major, and rectus femoris all can act to flex the hip joint.

Question 76

fixator

Answer 76

serves as a stabilizer of one part of the body during movement of another part. It allows the agonist muscle to work effectively by stabilizing the origin of the agonist muscle so that the latter can pull against the bone without it moving thereby achieve an effective contraction.

Question 77

flexation/extentsion in the elbow

Answer 77

the type of joint is a hinge joint The origin of briceps brachaii at the scapula and the insertion into the radius. it contrations/shortens when you flex brachanii biceps Origin of Long Head: scapula Origin of Lateral Head: Lateral and posterior surfaces of the humerus Origin of Medial Head: Posterior surfaces of the humerus inseration ulna when it contratations the elbow extends

Question 78

muscle tone

Answer 78

is the amount of tension (or resistance to movement) in muscles

Question 79

isotonic contration

Answer 79

An isotonic muscle contraction occurs when the force or tension in the muscle remains constant while the length of the muscle changes

Question 80

isometric contration

Answer 80

isometric contraction is a muscle contraction without motion. Isometric contractions are used to stabilize a joint, such as when a weight is held at waist level neither raising nor lowering it.l

Question 81

tendon sheaths

Answer 81

elongayed bursa wrapped completely around tendon sunjected to friction

Question 82

bursae

Answer 82

sacs lined with synovial membrane contianed synovial fluid reduce friction where ligaments, muscles, skin, tendons, or bones rub together

Question 83

nonaxial

Answer 83

slipping movements only | Found between the proximal ends of the ulna and radius

Question 84

uniaxial

Answer 84

Movement occurs in one plane. An example is the elbow joint.

Question 85

biaxial

Answer 85

Movement can occur in two planes. An example is the wrist.

Question 86

multiaxial

Answer 86

movement in or around all three planes the shoulder/hip joints

Question 87

angular movements

Answer 87

flexion, extension, hyperextention, abduction, adduction, circumduction

Question 88

rotation

Answer 88

medial and lateral rotation

Question 89

smooth muscle tissue

Answer 89

Description Smooth muscle tissue consists of nonstriated fibers (lack striations, hence the term smooth). Smooth muscle fiber is a small spindleshaped cell thickest in middle, tapering at each end, and containing a single, centrally located nucleus. Gap junctions connect many individual fibers in some smooth muscle tissue (for example, in wall of intestines). Usually involuntary; can produce powerful contractions as many muscle fibers contract in unison. Where gap junctions are absent, such as iris of eye, smooth muscle fibers contract individually, like skeletal muscle fibers. Location Iris of eyes; walls of hollow internal structures such as blood vessels, airways to lungs, stomach, intestines, gallbladder, urinary bladder, and uterus. ``` Function Motion (constriction of blood vessels and airways, propulsion of foods through gastrointestinal tract, contraction of urinary bladder and gallbladder). ```

Question 90

autorhythmicity

Answer 90

unique feature of cardiac muscle cells. These cells are able to generate the action potential at a certain rate without any external stimulus due to which the heart beats continuously and rhythmically

Question 91

initiation of contration in smooth muscles

Answer 91

Acetylcholine and norepinephrine released by autonomic motor neurons; several hormones; local chemical changes; stretching Calmodulin and myosin light chain kinase

Question 92

dilation of smooth muscles

Answer 92

h

Question 93

bronchi in relation to smooth muscles

Answer 93

smooth muscle contraction induces airway narrowing. The smooth muscle also contributes to bronchial inflammation by secreting a range of inflammatory mediators, recruiting and activating inflammatory cells, such as mast cells or T-lymphocytes. Postganglionic parasympathetic fibers will release acetylcholine causing the constriction of the smooth muscle layer surrounding the bronchi.

Question 94

arterioles in relation to smooth muscles

Answer 94

The primary function of vascular smooth muscle cells within the media is to control vascular diameter via cell contraction and relaxation processes

Question 95

peristalsis

Answer 95

series of muscle contractions. These contractions occur in your digestive tract. Peristalsis is also seen in the tubes that connect the kidneys to the bladder. Peristalsis is an automatic and important process squeeze of the espoguous

Question 96

factors of which movement function is altered

Answer 96

h

Question 97

motor neuron

Answer 97

cells in the brain and spinal cord that allow us to move, speak, swallow and breathe by sending commands from the brain to the muscles that carry out these functions

Question 98

motor end plate/neauromuscular junctions

Answer 98

Neuromuscular junctions, also called motor end plates, are specialised chemical synapses formed at the sites where the terminal branches of the axon of a motor neuron contact a target muscle cell

Question 99

synaptic vesicle

Answer 99

synaptic vesicle

Question 100

acetylcholine

Answer 100

chief neurotransmitter of the parasympathetic nervous system, the part of the autonomic nervous system (a branch of the peripheral nervous system) that contracts smooth muscles, dilates blood vessels, increases bodily secretions, and slows heart rate

Question 101

acetlycholine receptors

Answer 101

a membrane protein that binds to the neurotransmitter acetylcholine

Question 102

acetylcholinesterase

Answer 102

cholinergic enzyme primarily found at postsynaptic neuromuscular junctions, especially in muscles and nerves. It immediately breaks down or hydrolyzes acetylcholine (ACh), a naturally occurring neurotransmitter, into acetic acid and choline

Question 103

extend of movement in a synvoial joint

Answer 103

h