1.1 Skeletal and muscular systems Flashcards
What is the skeleton
a shaping framework for the body- gives protection for internal organs, is the site for blood cell production and is mineral store
Name 2 types of category of bones found in the skeleton
- flat bones- protect internal organs, act as attachments for muscles
- long bones- levers for movement, act as sites for blood cell production
What is a joint?
where two or more bones articulate to create movement
What is a ligament?
tough band of elastic connective tissue that connects bone to bone
What is articular cartilage?
smooth tissue
covers surface of articulating bones
absorbs shock & allows friction free movement
What is a synovial joint?
-give examples
type of joint found between bones that move against each other (shoulder, hip elbow knee)
Name the 5 common features of a synovial joint
-ligament
-synovial fluid
-articular cartilage
-joint capsule
-bursa
Name the three planes of motion and what they are
sagittal plane - divides body into left and right from middle to outside
frontal plane - divides body into front and back
transverse - divides body into top and bottom
What are the 4 types of synovial joint?
hinge joint
condyloid joint
pivot joint
ball and socket joint
What does flexion do?
decreases joint angle, usually to front of body
What does extension do?
increases joint angle, usually to the back of body
What does dorsi-flexion do?
decreases joint angle brining toes closer to tibia (toes upwards)
What does plantar flexion do?
increases joint angle moving toes further away from tibia (toes down)
What plane does flexion and extension movements occur on
sagittal plane
What plane does abduction and adduction movements occur on
frontal plane
What plane of movement does a ball and socket joint use?
sagittal
frontal
transverse
What plane of movement does a condyloid joint use?
sagittal
frontal
What plane of movement does a hinge joint use?
sagittal
What is a tendon?
a fibrous connective tissue that attaches a muscle to a bone
What is muscular origin?
muscular attachment to stationary bone - stays fixed during muscular contraction
What is muscular insertion?
point of muscular attachment to moveable bone which gets closer to origin during muscular contraction
What are the three main roles a muscle can adopt?
agonist
antagonist
fixator
What is an agonist?
muscle responsible for creating movement at a joint (prime mover)
What is an antagonist?
muscle that opposes agonist providing resistance for co-ordinated movement
What is a fixator?
muscle that stabilises one part of a body while another causes movement
What is antagonistic muscle action?
paired muscle action. as the agonist muscle shortens to create movement, the antagonist lengthens to co-ordinate the action
Name the 2 ways isotonic contraction can occur
concentric
eccentric
What is concentric muscle contraction?
muscle shortens producing tension. produces the force to pull two bones closer together causing joint movement
What is eccentric muscle contraction?
muscle lengthens producing tension, resists gravity to control joint movement
Shoulder:
-joint type
-articulating bone
-movement produced (plane) and (movement)
-agonist and antagonist muscles involved
-type of muscle contraction taking place.
-ball and socket joint
-humerus, scapula
-sagittal plane: flexion, extension
-agonist muscles: anterior, posterior deltoid
-frontal plane: adduction, abduction
-agonist muscles: latissimus dorsi, middle deltoid
-transverse plane: horizontal flexion and extension
agonist muscles: pectoralis major, teres minor, posterior deltoid
-transverse plane: medial rotation, lateral rotation
-agonist muscles: teres major, teres minor
Elbow:
-joint type
-articulating bones
-movement produced (plane) and (movement)
-agonist and antagonist muscles involved
-type of muscle contraction taking place.
-hinge joint
-humerus, radius, ulna
-sagittal plane: flexion, extension
-agonist muscle: biceps brachii, triceps brachii
Wrist:
-joint type
-articulating bones
-movement produced (plane) and (movement)
-agonist and antagonist muscles involved
-type of muscle contraction taking place.
–condyloid joint
-radius, ulna, carpals
-sagittal plane: flexion, extension
agonist muscles: wrist flexors, wrist extensor
Hip:
-joint type
-movement produced (plane) and (movement)
-agonist and antagonist muscles involved
-type of muscle contraction taking place.
-ball and socket joint
-sagittal plane- flexion, extension
-agonist muscles: iliopsoas, gluteus maximums
-frontal plane- abduction, adduction
agonist muscles- adductor longus, brevis and magnus, gluteus medius and minimus,
-transverse plane- medial and lateral rotation
-agonist muscles- gluetues medius and maximus
What are motor neurons
specialised cells which transmit nerve impulses rapidly to a group of fibres
What is the motor unit
combination of motor neuron and muscle fibres
Motor unit function
carry nerve impulses from brain and spinal cord to muscle fibres, initiating muscular contraction
What is a neurotransmitter
chemical produced, secreted by neuron -> transmits nerve impulse across synaptic cleft to the muscle fibre
Name the 3 types of muscle fibre
-slow oxidative (SO or type 1)
-fast oxidative glycolytic (FOG or type 2a)
-fast glycolytic (FG or type 2b)
What are slow oxidative muscle fibres
muscle fibre designed to store oxygen in myoglobin & process O2 in mitochondria -> allows to work aerobically
produces small amount of force over a long period of time, resist fatigue
What are fast glycolytic muscle fibres
type of muscle fibre rich in phosphocreatine which produces a maximal force over a short period of time
-designed to work anaerobically
What are fast oxidative glycoltic muscle fibres
produce a large amount of force quickly
-can resist fatigue
What do small motor neurons do
stimulate small muscle fibres
-creating motor unit which produces small, slow amount of force over long period of time- resiting fatigue well
What do large motor units do
stimulate large muscle fibres
-creates a motor unit which produces large amount of force rapidly
-fatigues quickly
What do large motor units do
stimulate large muscle fibres
-creates a motor unit which produces large amount of force rapidly
-fatigues quickly
What do large motor units do
stimulate large muscle fibres
-creates a motor unit which produces large amount of force rapidly
-fatigues quickly
What is isotonic muscle contraction
when muscle changes length during contraction
What is isometric muscle contraction
when muscle contracts but doesnt change length
Ankle:
-joint type
-articulating bones
-movement produced (plane) and (movement)
-agonist and antagonist muscles involved
-type of muscle contraction taking place.
-hinge joint
-tibia, fibula, talus
-sagittal plane
-dorsi flexion, plantar flexion
-agonist muscles: tibialis anterior, gastrocnemius and soleus
Knee:
-joint type
-articulating bones
-movement produced (plane) and (movement)
-agonist and antagonist muscles involved
-type of muscle contraction taking place.
-hinge joint
-articulating bones: femur, tibia
-sagittal plane: flexion, extension
-agonist muscles: biceps femoris, rectus femoris
-concentric contraction
What is rotation
-when articulating bones turn about its longitudinal axis
-occurs at shoulder and hip joints
What is the insertion
-point of muscular attachment to moveable bone which gets closer to origin during muscular contraction
When do muscles contract
when stimulated by electrical impulse from CNS
What are motor neurons
-specialised cells which transmit nerve impulses to group of fibres
What is an action potential
conducts nerve impulse down neuron & into muscle fibre
In bullet points explain how muscular contraction occurs
-nerve impules sent to muscle fibres
-nerve action potential conducts nerve impulses down axon to motor end plates
-axons motor end plates meet muscle fibres- neuromuscular junc
-small gap between motor end plates and muscle fibre- synaptic cleft
-action potent cant cross synaptic cleft without neurotransmitter- so its secreted into synpatic cleft
-if enough of neurotransmitter is secreted- muscle action potential = created
-action potential creates muscular contraction
What can the action potential not cross the synaptic cleft without
neurotransmitter
What is the synaptic cleft
small gap between the motor end plates and muscle fibre
What is the place where the axons motor end plates meet the muscle fibre
neuromuscular junction
Where is the neurotransmitter found and why
secreted in synaptic cleft to help nerve impulses cross gap
What occurs if enough of the neurotransmitter is secreted
wave of contraction
What is he all or none law?
when an motor unit creates action potential that reaches threshold charge, all muscle fibres within motor unit contract at same time
If the action potential does not reach threshold charge, none of the muscle fibres will contract
Describe flow diagram of the role of a motor unit?
- nerve impulse initiated in the motor neuron cell
- nerve impulse conducted down axon of the motor neuron by anerve action potential to the synaptic cleft
- neurotransmitter secreted into the synaptic cleft to conduct the nerve impulse across the gap
- If the electrical charge is above a threshold, muscle fibre will contract
- happens in an all or non fashion
What are slow oxidative muscle fibres designed to store and process
-what does this allow them to do
-store oxygen in myoglobin
-process oxygen in mitochondria- allows them to work anaerobically
What are fast glycolytic muscle fibres designed to store
-what are they rich in
-what are they designed to do
-rich in phosphocreatine (high energy compound)
-designed to work anaerobically
What are mitochondria
structure in the sarcoplasm responsible for aerobic energy production
What is myoglobin
protein in muscle -> transports oxygen -> mitochondria
What does aerobic work mean
low, intensity long duration exercise in the presence of oxygen
What does anaerobic work mean
high intensity, short duration exercise without oxygen
What do small motor neurons stimulate
-what does this cause to occur
stimulate few small muscle fibres
-creates motor unit producing small, slow force over long time
-resists fatigue
What do large motor neurons stimulate
-what does this cause to occur
-stmulate large muscle fibres
-creates motor unit producing large, rapid force
-fatigues quickly
What is a joint capsule
fibrous sac with inner synovial membrane
-encloses and strengthens the joint
what is horizontal extension
moves articulating bone away from midline of body
what is horizontal flexion
moves articulating bone clower to midline of body
what is rotation
movement where articulating bones turn about longitudinal axis in screwdriver motion
give an example of antagonistic muscle action
kicking football
prepartion phase -> biceps femoris creates flexion of knee joint -> agonist
rectus femoris coordinates action -> antagonist
execution phase -> rectus femoris -> agonist -> knee extension
biceps femoris -> antagonist
what is delayed onset muscle soreness
pain & stiffness felt in muscle
-peaks 24-72hrs after exercise
explain how muscular contraction occurs
-nerve impulse initiated in motor neuron
-nerve impulse conducted down axon of motor neuron by nerve action potential -> synaptic cleft
-neurotransmitter acetylchloine - secreted into synaptic cleft to conduct nerve impulse across gap
-if electrical charge = above threshold -> muscle fibre contracts
-happens in an ‘all-or-none’ fashion
Structural characteristics of slow oxidative muscle fibres
neuron size?
fibres p neuron?
capillary density?
mitochondria density?
myoglobin density?
phosphocreatine store?
Functional characteristics
speed of contraction?
force of contraction?
fatigue resistance?
aerobic capacity?
anaerobic capacity?
neuron size -> small
fibres p neuron -> few
capillary density -> high
mitochondria density -> high
myoglobin density -> high
phosphocreatine store -> low
speed of contraction -> slow
force of contraction -> low
fatigue resistance -> high
aerobic capacity -> high
anaerobic capacity -> low
Name 2 types of ball & socket joints
-shoulder
-hip
Name 3 types of hinge joint
-elbow
–knee
-ankle
Name a type of condyloid joint
-wrist
Type of flexion: wrist
-name the agonist, antagonist
agonist: wrist flexors
antagonist: wrist extensors
Type of flexion: elbow
-name the agonist, antagonist
agonist: biceps brachii
antagonist: triceps brachii
Type of flexion: shoulder
-name the agonist, antagonist
agonist: anterior deltoid
antagonist: posterior deltoid
Type of flexion: hip
-name the agonist, antagonist
agonist: iliopsoas
antagonist: gluteus maximus
Type of flexion: knee
-name the agonist, antagonist
agonist: biceps femoris
antagonist: rectus femoris
Type of flexion: ankle
-name the agonist, antagonist
agonist: tibialis anterior
antagonist: gastrocemius, soleus
Name 3 types of sporting events which use slow oxidative muscle fibres
endurance athletes
-marathon
-triathlon
-cross-country skiing
Name 2 types of sporting events which use fast oxidative glycolytic muscle fibres
high-intensity athletes
-800-1500m
-200m freestyle
Name 3 types of sporting events which use fast glycolytic muscle fibres
explosive athletes
-javelin
-long jump
-60-100m sprint
