Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BIOL1040 EXAM REVISION > Module 3: Skeletal and Muscular Systems > Flashcards

Module 3: Skeletal and Muscular Systems Flashcards

1
Q

Describe all the components of the Skeletal muscle:

A
  • larger than others
  • makes up 40-50% of body mass
  • striated (striped): arrangement of contractile components called sarcomeres, sarcomeres shorten when contracting (generally)
  • muscle attached to bone via connective tissue called tendons and produce movement around a joint
  • muscle cells/muscle fibres are long: during development, muscle fibres form by fusing multiple muscle cells (multi-nucleated, efficiency in repairing muscle fibres)
  • controlled by the somatic nervous system (consciously influenced): innervated by motor neuron (direct from spinal cord), motor axons project to muscle fibres
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe all the components of Smooth muscle:

A
  • non-striated

- found (gastrointestinal tract, blood vessels, lymph, eye)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Describe all the components of Cardiac muscle:

A
  • within contractile walls of the heart
  • some striation
  • ‘branches’, not necessarily parallel
  • interconnect at intercalated disks allowing electrical signals to pass from one cell to another (helps synchronise heart muscle contraction), nucleus, intercalated disk (uninucleate- one nucleus)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How many skeletal muscles are there on each side of the human body?

A

approx 320

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Outline 2 functions and structure points of skeletal muscle

A
  • interact through production of movement and force

- characterised for postural, fine motor and gross motor control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

List 2 characteristics of muscle fibres

A
  • fatiguability

- force generating capacity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

List 2 characteristics of whole muscles

A
  • insertion points

- origin points

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe muscle-tendon origin:

A
  • attachment site that doesn’t move when the muscle contracts
  • origin is usually proximal (closer to body midline)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

List and describe the 4 qualities of skeletal muscle

A
  1. Contractibility: ability to shorten and thicken, develop tension
  2. Excitability: ability to respond to appropriate stimuli (action potential)
  3. Extensibility: ability to be stretched without damage
  4. Elasticity: ability to store some energy, and recoil to the resting length
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the microstructure of the muscle

A
  • made up of a large number of bundles (fascicles) of muscle fibres (cells) surrounded by connective tissue
  • a single muscle fibre cell is very long, runs parallel to other fibres: made from a large number of fused embryonic cells
  • inside each cell is a bundle of myofibrils (muscle-slender fibre) that lie in parallel: a series of sarcomeres make up each myofibril, the sarcomere is the basic contractile unit of muscle, sarcomeres from adjacent myofibrils line up, giving muscle-striated appearance
  • titin anchors myosin to the Z-line and can pull it back
  • M-line contains myosin only: heads of myosin with actin binding site
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Draw a diagram of a sarcomere

A

see booklet for full diagram

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe the 8 steps in which the muscle fibre is stimulated

A
  1. Action potential reaches cavities in the sarcoplasmic reticulum
  2. Voltage-gated calcium channels open
  3. Calcium binds to troponin and causes tropomyosin to reveal myosin binding sites
  4. Myosin heads bind to the binding site
  5. Myosin causes actin to contract using the mechanical energy stored in the myosin head
  6. ADP and Pi detach from the myosin head
  7. ATP binds to the myosin head, causing it to detach from the binding site
  8. ATP is hydrolysed into ADP and Pi. The resulting energy is stored in the myosin head
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe connective tissue and list the 4 types of connective tissue

A
  • tissues are a group of similar cells and extracellular products organised to perform a common function
    1. Epithelial tissue
    2. Muscle tissue
    3. Nervous tissue
    4. Connective tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe 2 components of Muscle tissue

A
  • a muscle is a muscle organ, comprised of muscle tissue and connective tissue
  • little to no extracellular matrix
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe 3 components of Connective tissue

A
  • large amount of ECM: protein, salts, water, dissolved macromolecules
  • located outside cells
  • responds to physical stresses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

List/describe the 5 things connective tissue consists of:

A
  1. Muscle fibres
  2. Fascicle
  3. Endomysium: array of tubes into which muscle fibres insert
  4. Perimysium: thickened area surrounding groups of the muscle fibres
  5. Epimysium: fine structure of connective tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Describe the connection between the nervous system and skeletal muscle (6 points)

A
  • a single motor unit is the smallest functional unit in the musculoskeletal system
  • 1 motor unit = 1 motor neuron, motor axon and all of the muscle fibres it innervates
  • receives excitatory and inhibitory input from descending pathways, spinal interneurons and afferent fibres
  • when sufficient excitatory input to reach firing threshold, an action potential is generated
  • force altered by number and discharge rate of motor units and contractile properties of the muscle fibres
  • distribution of muscle fibres from the same motor unit within a muscle are dispersed (crossover between motor unit muscle fibres, force distributed)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

List the 3 fibre types of skeletal muscle

A
  1. Postural (type 1)
  2. Intermediate
  3. Ballistic (type 2)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Describe the qualities of Postural skeletal muscle fibre

A
  • constantly working: ‘Cinderella’ fibres
  • slow twitch, low force, fatigue resistant
  • produces about 1.5 grams of force, for 150 milliseconds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Describe the qualities of Ballistic skeletal muscle fibre

A
  • fatigue faster
  • fast twitch, more force
  • produces about 45 grams of force, for 100 milliseconds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe some properties of control of simple movements

A
  • CNS receives excitatory and inhibitory input from descending pathways, spinal interneurons and afferent fibres (receptors in muscles and tendons)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

List the 3 steps of signalling by neurons

A
  1. there are many dendrites on the aplha motor neuron
  2. if this is significant, an action potential will be generated
  3. generates myoelectric action potential (within muscle cell)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Describe the functions of the human skeleton and list the 6 components of the human skeleton

A
  • framework of any structure, does not always comprise of bones
    1. Exoskeleton: hard covering on outside of body
    2. Hydrostatic skeleton: fluid held under pressure
    3. Endoskeleton: within soft tissues
  • mechanical functions: support, protect and move
  • metabolic functions: nutrient store (minerals and lipids), blood cell formation
    4. Support: for muscles that contract to maintain posture, body shape and bodily functions
  • without the ribs the lungs would collapse
  • the pelvis is the floor for the pelvic organs
    5. Protect: body organs from potential harm
  • the skull protects the brain
  • the vertebral column protects the spinal cord
  • the rib cage, spine and sternum protect the lungs, heart and major blood vessels
    6. Move: converting muscle contraction into movement of ourselves or something in the environment requires a rigid structure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

List 3 examples of metabolic functions of the human skeleton:

A
  1. nutrient store
  2. blood cell formation
  3. stores 99% of the body’s calcium and 85% of the body’s phosphate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the 2 categories in which the skeleton can be divided into?

A
  1. Axial

2. Appendicular

26
Q

List and describe the 4 main types of Axial bones

A

Axial- relating to or situated in the head and trunk region of the body: contains 80 bones
Skull (22):
- protects the brain
- supports soft tissues of the head
- mandible is separate and allows movement during chewing
Ossicles (middle ear):
- transmit sounds through movement/vibration
- hyoid bone: aids tongue in movement and swallowing
Rib cage (including sternum):
- protects heart and lungs
- supports shoulder girdle and allows movement such as respiration
Vertebral column:
- protection of the spinal cord
- support for rib cage and movement

27
Q

List and describe the 3 main types of Appendicular bones

A

Appendicular- relating to limbs: contains 126 bones
Shoulder girdle:
- supports arm, forearm and hand movement
Pelvic girdle:
- support of abdominal contents and upper body
- support attachment of lower limb
- movement in locomotion
Thigh, leg and foot:
- movement
- supports entire weight of body

28
Q

List/describe the 4 different anatomical planes

A

Anatomical planes: terminology for joint movements in the musculoskeletal system

  1. Sagittal (or median): divides the body into left and right
  2. Parasagittal: parallel with sagittal
  3. Coronal (or frontal): divides the body into dorsal and ventral (back and front; posterior and anterior)
  4. Transverse (or horizontal): divides the body into cranial and caudal (head and tail; superior and inferior)
29
Q

List the 5 types of anatomical movements

A
  1. Abduction (out)/Adduction (in)
  2. Dorsiflexion (foot at right angle)/ Plantarflexion (foot straight down)
  3. Pronation (palm down)/ Supination (palm up)
  4. Extension (wrist/hand at right angle)/ Flexion (wrist/hand straight down)
  5. Lateral (palm and arm facing front/out)/ Medial (palm and arm facing inwards to body)
30
Q

Describe Fibrous joints (3 points)

A
  • contain fibrous connective tissue
  • some cannot move at all, e.g. skull structures
  • some allow little movements: depending on length of connective tissue, e.g. ligaments between tibia and fibula in the ankle
31
Q

Describe Cartilaginous joints (3 points)

A
  • contain cartilage
  • cushion force
  • allow more movement than fibrous joint
32
Q

Describe Synovial joints (3 points)

A
  • fluid filled cavity
  • greatest range of movement
  • 3 different types (hinge, ball and socket, pivot)
33
Q

Describe Antagonistic muscles (2 points)

A
  • oppose joint muscle

- work together

34
Q

Describe Synergist muscle (1 point)

A
  • help same joint motion
35
Q

List the 4 different types of Bone

A
  1. Long
  2. Short
  3. Flat
  4. Irregular
36
Q

Describe 2 components of Long bone

A
  • shaft with ends: femur, phalanges

- leverage and movement

37
Q

Describe 2 components of Short bone

A
  • square-shaped: carpals, patella

- fine movement

38
Q

Describe 3 components of Flat bone

A
  • sternum
  • protection
  • haematopoiesis
39
Q

Describe 2 components of Irregular bone

A
  • pelvis

- protection, support, movement, haematopoiesis

40
Q

Describe 3 components of Bone structure

A
  • stiff and strong, resistant to compression and tension
  • collagen: 40% tough and flexible
  • calcium and salt: 60% hard and rigid between collagen fibres
41
Q

List the 4 different types of Bone cells

A
  1. Osteoclasts
  2. Osteoblasts
  3. Osteocytes
  4. Osteogenic
42
Q

Describe 2 components of Osteoclasts

A
  • large cell with many nuclei

- breaks down bone matrix and responds to mechanical stress

43
Q

Describe 3 components of Osteoblasts

A
  • forms bone matrix in tunnels made by osteoclasts
  • surface
  • differentiate into osteocytes trapped in bone
44
Q

Describe 3 components of Osteocytes

A
  • maintains bone matrix, holds it together
  • mineralises bone matrix
  • can supply nutrients
45
Q

Describe 1 component of Osteogenic

A
  • stem cells develop into osteoblasts and then osteocytes
46
Q

List/describe 3 types of material in composition of bone

A
  • trabecular bone (spongy) for bone marrow development
  • lamellar (compact) supports and stores calcium
  • bones respond to stress
47
Q

Outline key changes of musculoskeletal structures over lifespan

A
  • bone acquisition during childhood affects later likelihood of osteoporosis
  • decay:
  • osteopenia: more reabsorption than deposition
  • osteoporosis: low bone density, less able to absorb mechanical energy
48
Q

List 3 components of muscle architecture

A
  1. Fibre length
  2. Muscle volume
  3. Physiological cross-sectional area
49
Q

Describe 5 components of Physiological cross-sectional area

A
  • longitudinal/parallel: fibre length = muscle length
  • pennate (at an angle): fibre length> muscle length
  • multi-pennate (multiple angles): fibre length&raquo_space; muscle length
  • muscles are a combination of these types
  • different muscles have different force generating capacity
50
Q

Describe force generating capacity in terms of PCSA

A
  • the greatest predictor of force is the muscle’s physiological cross-sectional area
    PCSA= muscle volume/fibre length
  • cross-sectional MRI scans of thigh, determine volume
  • ultrasound reconstruction for fibre length
  • ultrasound reconstruction for pinnation angle
51
Q

Describe pennation angle

A
  • actual muscle force (force applied to tendon)

- PCSA x cos(angle) where angle is the pennation angle

52
Q

Describe sarcomere length (3 different components)

A
  • Hill’s mechanical model of the muscle-tendon unit
    1. Contractile component
    2. Series Elastic component
    3. Parallel Elastic component
53
Q

Outline 5 components of the Contractile component

A
  • muscle fibres, actin and myosin cross bridges
  • relaxed: some overlap
  • contracting: greater overlap
  • fully contracted: full overlap, myosin may overlap (less force)
  • 80 -120% of resting length is optimal sarcomere operating length
54
Q

Outline 1 component of Series Elastic component

A
  • intracellular titin, tendon
55
Q

Outline 1 component of Parallel Elastic component

A
  • connective tissue, epimysium and perimysium, endomysium
56
Q

Describe a single motor unit

A
  • one motor unit is the smallest functional unit in the musculoskeletal system
  • 1 motor neuron, its motor axon and all of the muscle fibres it innervates
  • evert action potential in the muscle fibres generates a little bit of force
57
Q

Outline the importance of ‘number’ of single motor unit

A
  • the more motor units, the more force

- more excitatory input recruits more motor units

58
Q

Outline the importance of ‘discharge rate’ of single motor unit

A
  • every action potential produces a little bit of force: ‘single twitch’
  • summation of forces before twitch has expired
  • series of action potentials at high frequency results in tetanus (highest amount of force able to be produced)
59
Q

Outline the importance of ‘ fibre type’ of single motor unit

A
  • slow twitch/fast twitch
  • Henneman’s size principle: the recruitment of motor units based upon fibre type
    1. Slow oxidative: slow contraction speed, aerobic respiration, slow fatigue, many mitochondria, high myoglobin content (red)
    2. Fast Oxidative: fast contraction speed, aerobic respiration, intermediate fatigue, many mitochondria, high myoglobin content (red)
    3. Fast glycolytic: fast contraction speed, glycolysis ATP source, fast fatigue, few mitochondria, low myoglobin content (white)
60
Q

List/describe the types of contraction

A 
Isometric: 
- static/same length 
Dynamic: 
- concentric (shortening) 
- eccentric (lengthening) 
Maximum force that can be produced is dependent on the direction: 
eccentric > isometric> concentric
61
Q

Outline 4 points to do with the action potential and neuromuscular function

A
  • the connection between the nervous system and the muscle is the neuromuscular junction
  • AKA: motor point, motor end plate, synaptic cleft, synaptic terminal
  • every AP generated in the motor neuron generates an action potential in the motor units’ muscle fibres
  • myo-electric action potentials as they run along muscle fibres can be recorded by electromyography (EMG)
62
Q

Outline 5 points to do with myoelectric action potential and EMG

A
  • muscle action potential
  • myoelectric action potentials are initiated by ACh released by the motor neuron
  • ACh binds to proteins on muscle cell membrane, triggering a myoelectric action potential
  • the action potential sweeps along the muscle fibre and into the transverse tubules
  • surface EMG records myoelectric AP running along muscle fibres under electrodes

BIOL1040 EXAM REVISION (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions