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NUR111 > TOPIC 4 > Flashcards

TOPIC 4 Flashcards

1
Q

What are the three different types of skeletal cartilage?

A

hyaline, elastic and fibrous

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2
Q

function of hyaline cartilage

A

flexibility and resilience

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3
Q

function of elastic cartilage

A

more stretchy

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4
Q

function of fibrous cartilage and where is it found

A

compressible and very strong.

Found in areas where there is a lot of pressure on the skeleton, Eg. Spinal column, knee joints, pubic synthesis

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5
Q

where is hyaline cartilage found

A

Attached to the nose, intervertebral discs, very common, joint surfaces, trachea

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6
Q

where is elastic cartilage found

A

only 2 areas of body with it: ear and epiglottis

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7
Q

when does cartilage stop growing

A

Cartilage usually stops growing in adolescents once the skeleton stops growing. Most growth in utero, through childhood and adolescentce.

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8
Q

why do the nose and ears appear to keep growing even though they aren’t actually?

A

Appearance of ears and nose growth due to dropping not actual enlargement. Skin also contains collagen and elastic fibres and also droops.

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9
Q

Function of bones and skeleton:

A
  • provide support form for the body
  • Support tissues, protects organs
  • Permit movement by providing points of attachment for muscles
  • Site of blood cell formation= haemotopoeisis
  • Mineral storage particularly calcium and phosphate
  • Fat storage particularly in yellow bone marrow in the shape of triglycerides
  • Hormone production. In Bone some cells also produce osteocalcin which is a hormone that is involved in the regulation insulin secretion
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10
Q

how many bones in the body

A

206 bones ( 80 axial, 126 appendicular )

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11
Q

what is compact bone

A

Compact ( cortical) bone- dense outer layer of bone

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12
Q

what is spongy bone

A

Spongy (cancellous bone) ( contrabecular bone)- honey Combe structure

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13
Q

what is the periosteum

A

Periosteum ( lining or outside of compact bone) and endosteum ( lines inside of compact bone and all trabeculae and perifillating canals)

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14
Q

what are the parts of the skeleton

A

Axial skeleton

Appendicular skeleton

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15
Q

what are the different shapes/ types of bones?

A

Long , flat , (sesamoid)short, irregular bone and short

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16
Q

Long bone examples

A

all appendicular bones except the patella and wrist and ankle bones bones

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17
Q

flat bone examples

A

clavicles, ribs and scapula

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18
Q

short bone examples

A

patella, wrist and ankles

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19
Q

short (sesamoid) bone examples

A

patella, wrist and ankles

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20
Q

irregular bone examples

A

facial bones, skull, vertebrae and hip bones

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21
Q

what is the diaphysis

A

diaphysis ( shaft of long bone)

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22
Q

what is the medullary cavity

A

long bone hollow inside is called the medullary cavity and is lined by endosteum

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23
Q

what does the endosteum line

A

Endosteum also lines all little trabeculae inside the spong bone and the outside of thhe medullary cavity in the compact bone

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24
Q

what connective tissue surrounds te whole outseide of the bone?

A

All around bone is periosteum ( membrane) apart from where bone articulates with another bone where it’s covered by articulate cartilage which is usually hyaline cartilage.

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25
Q

what are the ends of the bone called

A

Ends of bone called epiphysis. Top is proximal epihysis ( proximal to Center of body) and the one on other side is distal epiphany ( distal to Center of body)

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26
Q

what is the line of ossified cartilage at the head of the spongy bone in adults called

A

Also epiphyseal line that is only found in adults. If adolescent or child instead would be replaced by cartilage called epiphyseal plate. Plate allows bone growth to continue

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27
Q

what does the periosteum contain

A

Periosteum around bone also contains Osteoprogenitor cells which turn into osteoblasts and produce bone and osteoclasts which destroy bone

Also blood vessels and nerves which go into bones

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28
Q

where is red bone marrow initially found in children?

A

Red bone marrow is initially in all medullary cavities and in all spongy bone so when children everywhere. As adults most of that is replaced bby yellow bone marrow and only bone marrow left is in head of humerous, head of femur ( thigh bone(p) and in flat bones

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29
Q

where is compact and spongy bone found

A

Compact bone around shaft

Spongy bone towards epiphysis

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30
Q

structure of periostium

A

.it is a dense layer of vascular connective tissue enveloping the bones except at the surfaces of the joints. Periosteum has an inner and outer layer and it’s anchored to bone by perforating ( sharpeys) fibres

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31
Q

where do osteoblasts derive from

A

osteoprogenitor cells ( stem cell)

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32
Q

what do osteoblasts do

A
  • specialised fibroblasts that make collagen fibres for bone, produce ground substance ( non mineralised bone matrix or osteoids)
  • produce osteocalcin hormone
  • Can turn into lining cells on bone surfaces
  • Respond to parathyroid hormones
  • Responsible for bone growth
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33
Q

what are osteocytes

A

Osteocytes ( mature bone cell)
once osteocalcin forms osteoblasts turn into osteocytes where they get embedded into bone matrix.
( initially we start with non mineralised bone matrix which becomes calcified/ mineralised and that’s when osteoblasts turn to osteocytes)

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34
Q

what do osteocytes do

A

Monitor what’s going on with bone/ sense if there’s additional stress on the bone and can trigger more bone regrowth and remodelling
( monitor and maintain the mineralised bone matrix)

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35
Q

how are osteocytes similar to chondroblasts

A

Very similar to chondroblasts living in indents called lacunae

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36
Q

how does the mineralisation process of bone occur?

A

mineralization process occurs by forming of calcium and phosphate salts which then are arranged as little crystals around collagen fibers.
So… the mineralised part is pretty much in organic material and lasts well beyond death

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37
Q

what do osteoclast do

A

a bit like white blood cells don’t derive from osteoprogenitor (come from white blood cell lineage)
Muktinucleiated
Like a phagocyte, eats up bone matrix and also osteoblasts
Contain digestive enzymes so can digests what ever they gobble up

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38
Q

what are the structural components of compact bone

A

Made up of osteon ( Haversian system) which consists of vein, artery and a nerve. around it are lamellae made up of mineralized/ calcified bone matrix with osteocytes interspersed within it ( linked up by canaliculi)

Lamalle contain collagen fibers. Collagen fibers in different lap aloe may go in different directions ( giving bone incredible strength)

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39
Q

would you find osteoblasts in haversian canals

A

yes

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40
Q

what is inbetween haversian canals

A

Inbetween canals are branches in between called perforating canals

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41
Q

are osteons in spongy bone

A

Osteons not in spongy bone, but lamellae are.

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42
Q

in utero what is skeleton made up of

A

in Utero skeleton made purely of hyaline cartilage.
Only by month 3 does bone tissue begin to develop. Bone gets longer and gets ossified by process of endochondrial ossification.

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43
Q

does cartilage get mineralised

A

Bone and cartilage are 2 different types of tissue, so cartilage doesn’t get mineralised, it disappears and replaced by bone tissue which eventually gets mineralised
Initial bone tissue is non mineralised matrix.

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44
Q

long bone ossification process?

A

9 weeks- bone collar forms around diaphysis
Cartilage calcifies in center of the diaphysis and then develops cavities
3 months- periosteal bud invades the internal cavities and spongy bone forms
The diaphysis elongates and a medullary cavity forms. Secondary ossification center appears in the epiphyses
The epiphyses ossify when ossification is complete, hyaline cartilage remains only in the epiphyseal plates and articulated cartilages

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45
Q

flat bone ossification process

A

In flat bones, a bit digferent and is called intramembranous ossification and starts off with fibrous connective tissue and then osteoblasts forming osteotes

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46
Q

when does bone growth stop

A

Bone growth stops roughly 18 girls 21 boys

Bone growth can still occur in adults if there is more pressure/ load and stress on the bone Eg, ppl doing bodybuilding or sports.
We might need to increase the strength of our bones by making it thicker and that usually happens in the shaft area and is called appositional growth.

Length bone growth doesn’t really happen any more…

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47
Q

when does the opposite of bone growth happen

A

Opposite of bone growth happens when ppl are bedridden or don’t use their bone for a long time ( been imobalised) bone gets reabsorbed and uses strength

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48
Q

2 objectives of body when it comes to bone

A

making sure bones are strong enough to deal with daily forces
Keep calcium levels in blood steady ( between range of 9-11mg/ 100ml)

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49
Q

why are calcium levels important

A

Calcium levels important as calcium irons pass on signals from nerves to muscle cells.

If calcium levels were low body does all it can to get calcium out of bone so enough in blood.

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50
Q

low calcium feedback loop

A

S: decrease in calcium
R: parathyroid hormones
M: parathyroid hormone released
E: PTH stimulates osteoblasts by releasing protein Rank L (ps. vitamin d also stimulates this protein increase, oestrogen and testosterone decrease rank l) which then acts on osteoclasts causing it to gobble up bone tissue and release calcium into blood
R: osteoclasts degrade bone matrix and release ca+ into blood
F: increase in calcium levels

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51
Q

how are Bone strength, shape and thickness regulated by body

A

Bone strength, shape and thickness is purely regulated by body used bone, what forces act on them, and how trabeculae are arranged

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52
Q

bone healing process

A

1)hemotoma forms
Bone highly vascularised so blood leaks into tissue and blood clot forms first between bone ends caused by fracture, causes pain and swelling

2) Fibrocartilaginous callus forms ( soft callus connecting 2 bone ends from fracture). Fibroblasts and chondroblast come and produce collagen fibres and ground substance ( a few days).
3) Bony callus forms. Subcalcification occurs and eventual soft fibrocartilaginous fibre gets replaced by bone tissue. Osteoblasts come and produce bone matrix and osteocytes ( 1 week to 2 months)
4) Bone remodelling occurs ( 2 months- year) fine tuning of how the bone should look like, depends on how the bone is used. bone will soon look same as it was before bone. To happen properly needs for bones to be aligned properly and that we immobilise it, needs good nutrients and. Loose circulation. Factors that will impede healing process include: smoking, older age, diabetes,

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53
Q

types of fractures

A

Simple fractures- straight through bone

Compound fractures- bone pokes through skin

Comminuted- several fragments

Compression- bone crushed ( particularly in spinal column)

Spiral- ragged break when excessive twisting forced are applied to bone

Epiphyseal - epiphyseal seperate from diaphysis along plate

Green tick- bone breaks incompletely

Depressed broken bone portion is pressed inward

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54
Q

types of bone markings

A

Crest- narrow ridge of bone; usually prominent
Trochante- large, blunt, irregularly shaped process
Head- bony expansion carried on a narrow neck eg. head of femur
Facet joints-smooth nearly flat articulate (joint) surface eg. vertebrae and spinal column
Foramen- round oval opening through a bone
Notch p- indentation at edge of a structure eg. sternum botch

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55
Q

REVIEW SKELETON

A

REVIEW SKELETON

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56
Q

How many vertebrae in the spine

A

Has 7 cervial, 12 thoracic and 5 lumbar

Remember by…. “ breakfast at 7 lunch at 12 and dinner at 5”

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57
Q

what are the top 2 cervical bones and what do they allow

A

2 top cerviacle bones are the atalas and axis- provides some movement between skill and verbal colum ( allows nodding)
The axis 2nd one has the dense where atlas rests on and atlas can rotate on it enabling us to shake our heads

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58
Q

what does the thoracic vertebrae allow

A

Thoracic vertebrae allow twisting but no flexion or extension ( happens in lumbar spine)

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59
Q

what movement does the lumbar vertebrae allow

A

Lumbar spine also allows lateral flection

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60
Q

what shapes does the spine have

A

Spine has double curvature ( double s bend)
Top- cervicle curvature (concave) , then thoracic curvature (convex), lumbar curvature- inwards( concave), and sacral curvature ( convex)

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61
Q

why does the spine have for stability

A

For stability spine has a lot of ligaments, biggest one is anterior longtudinal ligament which is attached to discs
and vertebral body. ( posterior ligament as well but only attached to discs- reinforced by ligamentum flavum)

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62
Q

from a top view of the spinalcord what is the bone sticking posteriorly

A

the vertebrae spinous process

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63
Q

fro a top view what are the 2 bones to the side of the body and spinous process

A

On 2 sides of body- transverse process

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64
Q

what are the Lamina in the spine

A

the Lamina are indents on transverse process connection to vertebrae spinous process

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65
Q

what are the Pedicles of the vertebrae

A

Pedicle of vertebrae attach the transverse processes to the body. Facet of Superior articular processes protrude up on them

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66
Q

review close up spine diagram

A

review close up spine diagram

67
Q

where do nerves run up and down in the spinal column

A

Between vertebrae on intervertebral foramen nerves come out

68
Q

what are the intervertebral discs in the spinal column like

A

Discs are fibrous and have a ring on outside called anulous fibrousis and a Center called the nucleus palposus, when that fibrosis ruptures nucleus can get out and push onto spinal cord.

69
Q

Some examples spinal issues

A

Some examples spinal issues
Scoliosis - spinal bend to one side
Kyphosis- hunchback. can be caused by osteoporosis,
Lordosis- inward curve of lower back. can happen during pregnancy

70
Q

how many ribs attached to thoracic cage

A

12 ribs
7 are true ribs as they connect directly to sternum
8-12 false ribs
7-10 connect through just cartilage to the 7th
11 and 12 are floating ribs

71
Q

parts of the sternum

A

Sternum has 3 parts
1) manubrium,
2) followed by body ( can feel sternal angle between this and notch)
3) and then the xiphoid process
Jugular notch at top, Clavicular notch at Side of manubrium

72
Q

where should cpr compressions be done

A

Bottom third of sternum is where you should do CPR compressions

73
Q

illiac crest

A

…

74
Q

superior illiac spine

A

…

75
Q

ischium

A

Ischium has rough area at back called the charter ishial tuberosity which we call sits bones
…

76
Q

pubic with superior and inferior Raines

A

…

77
Q

Pubis bones joined by pubic arch ( cartilage )

A

…

78
Q

Sacrum

A

sacrum is pelvis

…

79
Q

iliac bone

A

…

80
Q

why is the pelvis shaped the way it is

A

Pelvic shape important for child birth

81
Q

Do pelivc bone quizlet

A

do pelvic bone quizlet

82
Q

Do pelvic bone quizlet

A

do pelvic bone quizlet

83
Q

how are joints classified

A

Joint are classified by STRUCTURE and FUNCTION

84
Q

joint functional classifications

A

functional classifications is based on the amount of movement allowed at the joint.

synarthroses- which are immovable joints
amphiarthroses - slightly movable joints
diarthroses- freely movable joints.

85
Q

what are synarthroses

A

synarthroses- which are immovable joints

86
Q

what are amphiarthroses

A

amphiarthroses - slightly movable joints

87
Q

what are diarthroses

A

diarthroses- freely movable joints.

88
Q

what are the structural bone classifications

A

Structurally, there are fibrous, cartilaginous, and synovial joints

89
Q

fibrous joints include

A

Fibrous joints include: suture, syndesmosis and Gomphosis

90
Q

difference between ligaments and tendons

A

ligaments join bone to bone, tendons join muscle to bone

Ligaments that join bone to bone depends on how small or long fibrous/ collagen connections are

91
Q

what is a suture

A

fibrous joint
Sutures: skull mostly, joint held together with very short interconnecting fibres and bone edges interlock. (Example of a synarthroses)

92
Q

what is a syndesmosis

A

Syndesmosis: ( can be an amphiarthroses). Joints held together by a ligament. Fibrous tissue can vary in length but is longer than sutures.

93
Q

what is a gomphosis

A

Gomphosis: is a more specific type of fibrous joint where teeth are imbedded into maxillary and manbible. “Peg In socket” fibrous joint. Periodontal ligament hold tooth in socket.

94
Q

Cartilaginous joints include

A

Cartilaginous joints: include synchondroses and symphyses

95
Q

what are Synchondroses joints like

A

cartilaginous joint,

Synchondroses: bones united by hyaline cartilage Eg. Epiphysial plate and between rib and sternum

96
Q

what are Symphyses joints like

A

cartilaginous joint,

Symphyses: bones united by fibrocartilage eg. Intervertebral discs and pubic symphosis ( amphiarthroses)

97
Q

what are some general characteristics of Diarthrosis/ synovial joints

A
  • have a joint cavity ( sometimesr the joint cavity accomodates space between bones by adding Cartilage discs called meniscus and also by containing fluid which acts to buffer and bridge the joints
  • joint surfaces always covered by hyaline cartilage
  • Capsule around joint with fibrous layer
  • Can be ligaments around the joint that stablise the joint. Ligaments are not part of the capsule but are on the outside and are usually covered by the synovial membrane
  • May also see the bursa ( fluid fillled sacks that act like a buffer for protection and also might guide tendons across a joint)
  • Can also have tendon sheaths where several tendons may run within one connective tissue tunnel or stealth around them
  • Can also have some ligaments that are sort of in the joint but not within the joint casplemas such Eg, knee joint looking top done , anterior cruciade ligament and posterior cruciade ligament
98
Q

what do joints do

A

provide a lot of different types of movements

Movements determined by the shape of joint

99
Q

gliding joint movement example

A

Gliding movements at the wrists,

100
Q

angular joint movement example

A

angular movements: flexion, and hypertension of the neck.

flexion, extension, and hyper extension of the vertebral column.

flexion, extension and hypertension at shoulders and knee

abduction ( away from midline of body), addiction ( towards midline of body) and circumduction of the upper limb at shoulder

101
Q

what is flexion

A

…

102
Q

what is hypertension

A

…

103
Q

what is extension

A

…

104
Q

what is abduction

A

abduction ( away from midline of body)

105
Q

what is adduction

A

adduction ( towards midline of body)

106
Q

what is circumduction

A

…

107
Q

rotation joint movement examples

A

Rotation of the head, neck and lower limb
lateral rotation-
medial rotation-

108
Q

what is Pronation ad supination

A

Pronation ( facing palms towards floor) and supination ( moving palms facing upwards)

109
Q

what is Doris flexion and plantar flexion

A

Doris flexion- toes/ feet upwards

plantar flexion- toes feet downwards

110
Q

what is Inversion and eversion of foot

A

inversion- bottom of feet facing outwards

exversion- facing inwards

111
Q

what is Protraction and retraction

A

Protraction moving mandible forward

retraction moving mandible inward

112
Q

what is Elevated and depressed

A

Elevated jaw up

depressed jaw down/ open

113
Q

what is Opposition movement

A

thumb clenching movement

114
Q

what are the 6 types of synovial joints

A

plane joint

Hinge joints

pivotal joints

Condylar joint

Saddle joint

Ball-and-socket joint

115
Q

what is the plane joint and what movement does it allow

A

plane joint - non axial movements ( gliding) Eg. Intercarpal joints, intertarsal joints, joints between vertebral articular surfaces

Six types of synovial joint shapes determine the movements that can occur at a joint.

( allow movement in only one axis)

116
Q

what is the hinge joint and what movement does it allow

A

Hinge joints - uniaxial movement ( flexion and extension) Eg.Elbow joints, interphalangeal joints

117
Q

what is a pivotal joint and what movement does it allow

A

pivotal joints- uniaxial movements ( Rotation) Eg. Proximal radioulnar joints, atlantoaxial joint

( allow movement in 2 axis)

118
Q

what is the condylar joint and what movement does it allow

A

Condylar joint- Biaxial movement ( Flexion and extension ) Eg. Metacarpophalangeal (knuckle) joints, wrist joints
Adduction and abduction

119
Q

what is the saddle joint and what movement does it allow

A

Saddle joint- Biaxial movement (Adduction and abduction
Flexion and extension Eg. Carpometacarpal joints of the thumbs

( allow movement in multiple axis)

120
Q

what is the ball in socket joint and what movement does it allow

A

Ball-and-socket joint- multiaxial movement (Flexion and extension) Eg. Shoulder joints and hip joints

121
Q

what moves joints

A

muscles move joints

122
Q

what attaches muscle to bone

A

Tendon attaches muscle to bone

123
Q

what is the Epiphysium

A

Epiphysium - connective tissue - surrounds the whole muscle / all muscle fibres

124
Q

what are invividual fascicles surrounded by

A

Around individual fascicles is surrounded by perimysium

125
Q

what does the Endomysium surround

A

Endomysium surrounds EACH muscle fibre

126
Q

Fascile is made up of ..

A

Fascile is made up of individual muscle fibres. And a muscle fibre is ONE MUSCLE CELL. ( can be very long, up to 10-100 micrometers in diameter)

127
Q

what are muscle cells like

A

Muscle cells are muktinucleiated, muscle fibre is made up of little structures called myofibrils.
- Muscle fibres have all same organelles and structures but specificly also have myofibrils.

128
Q

structural organisation of muscles

A

Muscle-> fascicle-> muscle fibre-> myofibrils

129
Q

what is the origin and insertion point of a muscle*

A

when we talk about muscles there is ORIGIN ( where it attaches to the bones- less movable part) and INSERTION POINT ( where muscle attaches to more movable part) ????

130
Q

what is an aponeurosis

A

a sheetlike connective tissue that connects the muscle to bone Eg. External oblique abdominal muscles

131
Q

what 2 myofillaments are myofibrils made up of

A

thick- myosin, thin- actin

132
Q

what determines the light and dark sections of myofibrils

A

Depending on where myosin and actin are and whether they overlap or not determines how light or dark it looks giving it the characteristic stripe.
Parts without thick fillaments appear lighter, also parts without double layer appear lighter

133
Q

where are z discs found

A

z disks are on the ends of the sarcomere with actin fillaments suspending from them

134
Q

what is a sarcomere

A

z disc to z disc. In middle is M line.

135
Q

myofibril within muscle fibre has what instead of endoplasmic reticulum

A

Endoplasm reticulum is called sarcoplasmic reticulum, with terminal systems (thick expanding bits), and t tubule which are directly linked to sarcolemma (as extensions of cell plasma membranes)

136
Q

what do t tubules do

A

T tubules conduct electric impulse that arrive at muscle fibre and allow it to travel all the way into the cell and around all those myofibrils

137
Q

what characteristics do thick myosin fillaments have on them

A

have myosin heads poking up

138
Q

what characteristics do thin actin fillaments have

A
  • have little holes that act as attachments sites she myosin head can attach and bridge, but they are usually covered up by proteins called tropomyosin ( strands of protein).
  • Typomyosin anchored to the actin by another protein called troponin
  • Troponin plays an important role when wanting to diagnose if someone has had a heart attack or not as it is released into blood of you have a myocardial infarction ( cell death in Cardiac muscle due to not enough oxygen supply), when cardiac muscles die troponin gets released into blood stream due to leakage in dead cells. Skeletal and cardiac muscle both have troponin and when it leaks into the bloodstream it can be measured. ( diagnostic measures )
  • contraction of the muscle happens when thin fillaments slide against the myosin thick fillaments and move towards the center of the sarcomere - this shortens the whole sarcomere
139
Q

what is muscle contraction

A

original impulse comes from motor cortex in the brain in the frontal lobe in an area called the precentral gyrus. Travels to specific motor neurons/ nerves in our spinal cord and those electrical impulses called action potentials will eventually arrive at a muscle fibre ( of a muscle). That action potential will then spread around the muscle fibres and lead to contraction of those fibres ( shortening of the sarcomeres in those muscle fibres)

140
Q

steps of muscle contraction

A

1) starts in brain prefrontal gyrus. And nerves that from originate there end up in the spinal cord Where they are carried by motor neurons to the muscle cells
2) Events at neuromuscular junction
3) Muscle fibre excitation
4) Excitation- contraction coupling
5) Cross bright cycling

141
Q

what events occur at tthe neruomuscular juction in muscle contraction

A
  • Action potential (AP) arrives at axon terminal at neuromuscular junction
  • Voltage-gated Ca2+ channels open. Ca2+ enters the axon terminal, moving down its electrochemical gradient.
  • Ca2+ entry causes ACh (a neurotransmitter) to be released by exocytosis.
  • diffuses across the synaptic cleft and binds to its receptors on the sarcolemma.
  • ACh binding opens ion channels in the receptors that allow simultaneous passage of Na+ into the muscle fiber and K+ out of the muscle fiber. More Na+ ions enter than K+ ions exit, which produces a local change in the membrane potential called the end plate potential.
  • Acl effects are terminated by its breakdown in the synaptic cleft by acetylcholinesterase and diffusion away from the junction.
142
Q

what is muscle fibre excitataion

A

muscle fibre excitation- local depolarisation triggers an action potential in adjacent sarcolemma

143
Q

what are the steps of muscle fibre excitation

A

1) An end plate potential is generated at the neuromuscular junction.
(EPP) causes a wave of depolarisation that spreads to sarcolemma.

2) Action potential Depolarization: Generating and propagating an action potential.
Depolarisation of the sacrolemma opens voltage gated sodium channels. Sodium enters, following electrochemical gradient. At a certain membrane voltage an AP is generated/ initiated. The AP spreads do adjacent areas of sarcolemma and opens voltagebgated sodium channels there propagating the AP. The AP propagated along the sarcolemma in a L directions, just like ripples from a pebble dropped in a pond.

3) Repolarization: Restoring the sarcolemma to its initial polarized state (negative inside, positive outside).
Depolarisation wave is also a consequence of opening and closing iron channels - voltage gated na channels close and voltage gated potassium channels open. The potassium iron concentration is substantially higher inside the cell than in the extracellular fluid so postaaium diffuses out of the muscle fibre . This restores the negatively charged conditions inside that are characteristic of a sarcolemma at rest.

144
Q

what happens during excitation- contraction coupling

A

AP In sarcolemma travels down t tubules
Sarcoplasmic reticulum releases Ca2+ (due to AP)
Ca+2 binds to troponin which shifts tropomyosin to uncover the myosin binding sites on actin. Myosin head bind actin ( cross bridge)

145
Q

what happens during cross bridge cycle

A

contraction occurs via cross bridge cycling
Thin fillaments slides against thick fillaments ( lots of bonding and detaching)

Original formation of cross bridge ( energised version of myosin- had ATPattached before)-> myosin head bends over over pushing actin towards m line-> atp attaches to myosin head causing it to detach from the actin-> it’s free to then attach to another actin molecule as it moves on
atp not needed for attachment but for detachment

when your dead no more atp so myosin heads permanently attached to actin not being able to detach ( stiff musles)
Protein breakdown of myosin is what causes stiffness to go away

146
Q

what are the types of coontractions

A

isotonic contraction

Isometric contraction

147
Q

what are isotonic contractions

A

Shortening of the muscles through shortening of sarcomeres is called an isotonic contraction eg. Lifting arm, bending leg

148
Q

what are isometric contractions

A

Isometric contraction- no change in muscle length only in the tension. Myosin heads still bind to actin fillaments but they don’t slide against each other Eg. Happens to maintain general muscle tone , stabilise joints, exercising muscles without being able to move joint

149
Q

t of f

muscles dont need alot of energy

A

false.
muscles need a lot of energy
Energy is ATP
3 different ways of how we can produce energy: direct phosphorylation, anaerobic pathway, aerobic pathway
Muscle cells doesn’t have a lot of storage of energy

150
Q

what is Direct phosphorylation metod of producing energy

A

Direct phosphorylation
creatine phosphate gets split into creatine by an enzyme and that oroduces ATP.
Not that efficient, only produce one ATP per CP, creatine
No oxygen use

151
Q

3 ways of producing energy

A

3 different ways of how we can produce energy: direct phosphorylation, anaerobic pathway, aerobic pathway

152
Q

similarities between aerobic and anaerobic pathway

A

Both aerobic and anaerobic are producing atp from glucose/ glycogen breakdown

153
Q

what happens during the anarobic patway

A

Anaerobic energy pathway

  • glucose getting turned into pyruvic acid producing 2 atp per glucose and lactic acid, but lactic acid causes soreness of exersise.
  • no oxygen use
154
Q

what happens during the aerobic pathway

A

Aerobic energy pathway
pyruvic acid being broken down in mitochondria in kerbs cycle producing 32 atp per glucose, carbon dioxide and hydrogen
Uses oxygen
Can also break down fatty acids and amino acids to make glucose to make energy via this process

155
Q

what determines the energy producing pathway used by the body

A

-depending on how much oxygen is available determines which pathway. Oxygen availability depends on 1) how quickly we can breathe, and exchange oxygen demand 2) how much oxygen can get to the muscle ( if we contract muscles= often constrict blood vessels cutting off oxygen supply)

156
Q

smooth muscle characteristics

A
  • one nucleus
  • Line hollow organsm including blood vessels
  • Spindle shapes
  • Not as long and big in diameter as skeletal muscles
  • Arranged in 2 different ways in hollow organs ( circular arrangement vs longtudinal arrangement)
  • No connective tissue attached
  • No proper neuromuscular junction ( have varocosities that attach to smooth muscle cells and AP travels from cell to cell via gap junctions)
  • No t tubules; action potential travels from one cell to another by gap junctions
  • No stripes / no sarcomere but same myofilaments, no troponin
157
Q

difference in how actin and myosin act in smooth muscle

A

Action with myosin and actin pretty much same, still sliding movements and myosin heads binding to actin, still need atp to activate myosin heads and calcium playing a role BUT no troponin that bind to calcium- instead it’s calmodulin protein activates another enzyme called myosin kinase that causes the ATP to attach to myosin head.

158
Q

what are some smooth muscle shapes/name**

A 
convergent
circular
fusiform
parallel
bipennate
unipennate

review**

159
Q

what determines muscle name

A

names determined by location, size, direction, number or heads in a muscle, where the attachments are , shape

160
Q

what is a lever

A
  • A lever is a rigid bar that moves on a fixed point called the fulcrum, when a force is applied to it. The applied force, or effort, is used to move a resistance, or load.
  • In your body, your joints are the fulcrums, and your bones act as levers.
  • Depending how far they ( load, fulcrum and effort) are and how they relate to eat other determines the types of levers.
161
Q

what is a power lever

A

the load is close to the fulcrum and the effort is applied far from the fulcrum, a small effort exerted over a relatively large distance can move a large load over a small distance (Figure 10.2a). Such a lever is said to operate at a mechanical advantage and is commonly called a power lever

162
Q

what is a speed lever

A

the load is far from the fulcrum and the effort is applied near the fulcrum, the force exerted by the muscle must be greater than the load to be moved or supported (Figure 10.2b). This lever system is a speed lever and operates at a mechanical disadvantage.

  • if the effort If further away from the fulcrum than the load you need less force. If it’s closer it improves speed but you need more power.
163
Q

how many layers of abdominal muscle

A

3 layers of abdominal muscles

164
Q

review muscles

A

review muscles

NUR111 (6 decks)

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