Chp 1 Bones And Muscles Flashcards
The functions of the neuromuscular and musculoskeletal systems
Protection Support Storage Leverage Mineral balance Blood cell production
The neuromuscular and musculoskeletal system consists of
Skeletal system - bones and joints Skeletal muscle system - voluntary muscles Ligaments -Bone to bone Cartilage - shock absorbing gel Tendons - bone to muscles
The functions: protection
Protection for vital organs
Brain - skull
Lungs - ribs
Spinal cord - vertebral column
The functions: support
Posture
Attachment site for muscles
The functions: storage
Storage of:
Fuels
Fats
Minerals
The functions: leverage
Allow movement to occur
The functions: mineral balance
Homeostasis
The functions: blood cell production
Haematopoiesis
The vertebral column
- involved in 95% of movement
33 bones - 24 unfused
7-12-5-5-4
The cervical vertebra
7 unfused bones
Neck
Top 2 - atlas and axis allow the head to
Move
The thoracic vertebrae
12 unfused
Protects heart and lungs
1-7 attach to sternum
The lumbar vetebrae
- 5 unfused
Weight carrying
Attachment site for muscles
The sacrum
5 fused
Fused to pelvis
Weight of upper body
The coccyx
4 fused
Tailbone
Attachment site for muscles
Types of joints
Fixed or fibrous
Cartilaginous
Synovial
Fixed or fibrous joint
No movement
Skull,pelvis
Cartilaginous joint
Slight movement
Ribs, lumbar
Synovial joint
Move freely
Hip, knee, limbs
Types of bones
Short
Long
Flat
Irregular
Short bone example
Carpals
Long bone example
Tibia
Flat bone example
Pelvis, cranium
Irregular bone example
Spine/ vertebrae
6 synovial joints
Pivot Gliding Ball and socket Hinge Saddle Condyloid
Pivot joint
Uniaxial rotation
Atlas, axis
Gliding joint
Flat bones glide past each other
Biaxial
Carpals , tarsals
Ball and socket joint
Flexion, extension, adduction, abduction, internal / external rotation
Shoulder, hip
Hinge joint
Uniaxial
Flexion and extension
Knee, elbow
Saddle joint
Concave/convex bones align
Biaxial
Carpo-metacarpal joint of thumb
Condyloid / ovoid joint
Like hinge joint but slight rotation
Biaxial, Flexion, extension, adduction, abduction, curcumduction
How many muscles in the body
Over 660
Muscle contraction
Tension being developed in the muscle
Muscle relaxation
Absence of tension in a muscle
Types of muscles
Skeletal muscles
Smooth muscles
Cardiac muscles
Skeletal muscles
Attached to bone
Voluntary
Striped/ striated cells
Smooth muscles
Found in blood vessels, intestine
Involuntary
Spindle cells
Cardiac muscles
Make up the walks of the heart
Involuntary
Striped
Muscle functions:
Support
Produce heat
Store fuels
Muscle functions : support
Support, posture
Isometrically to enable us to stay upright
Muscle functions: produce heat
Contract involuntarily - shivering
Heat from food energy
Muscle attachment
Attached to bones by tendons
Muscle belly- main body of muscle
Point of attachment: origin or insertion
Bicep. Scapula. Radius
Reciprocal inhibition
Muscles work in teams
Agonist
Antagonist
Fixator muscles/ stabilisers
Agonist muscle
Primarily responsible for movement
E.g contracts
Antagonist muscles
Muscle that relaxes when the agonist contract to allow:
Ease if movement
Minimise risk of injury
Fixator muscles/ stabilisers
Are involved to provide stability in the origin so that max force can be contracted
Neuromuscular skeletal system
System of
Nerves
Bones
Muscles
Fusiform muscle fibres
Run longways
Contract quickly
Low force
Bicep
Penniform
Run at angles
Contract slower, greater force
Quads
Unipennate
Muscle fibres branch out to one side
Calf
Bipennate
Branch out on both sides
Quads
Multipennate
Branch out repeatedly from a number of tendons
Deltoid
What’s inside a muscle fibre
Epimysium Endomysium Perimysium Fasicles Myofibril Sarcoplasm Actin and myosin Sarolemma Muscle fibre
Fasicles
Run side by side along the length of the muscle
Perimysium
Surrounds the fasicles
Endomysium
Surround the perimysium and fasicles
Epimysium
Surround the fasicles, perimysium, endomysium
Outer layer
Myofibrilsa
Make up the muscle fibres found in fasicles contain actin and myosin
Sarcomere
Basic unit if striated muscle
Which causes contraction
Actin and myosin
Thin, thick
Protein filaments found in sarcomeres responsible for muscle contraction
Sarolemma
Cell membrane that surrounds muscle fibres
Sarcoplasm
Surrounds the actin and myosin Contains: Mitochondria - powerhouse Myoglobin - transport and store oxygen Fat Glycogen ATP - energy production Enzymes - muscle growth
I-band
Area of myofibril containing actin
Disappears during contraction
A-band
-area found in the centre of the sarcomere containing both actin and myosin
Length stays the same during contractions
H-zone
Centre of the a band
Free from the myosin crossbridges
Disappears during contraction
Nervous control of muscular contraction
Brain sends electrical impulses via the spinal column to the muscles
Sensory neurons
Send info to the brain
Motor neurons
Brain to the muscles
Stimulated a couple for fine movements
Thousands for gross movements
All or nothing principle
Only when the electrical impulses reach a certain threshold will all the fibres contract at the same time as forcefully as possible
3 kinds of muscle contraction
Isotonic
Isometric
Isokinetic
Isotonic concentric contraction
Muscle length shortens
E.g Bicep curl upward phase
Isotonic eccentric contraction
Muscle lengthens
E.g Bicep curl downward phase
Isometric contraction
No change in muscle length
Tension formed
Pushing against a wall, holding your body upright
Isokinetic contraction
Requires gym equipment
No weak spots
Slow twitch fibres
Red Requires oxygen Slow contraction Low force High fatigue resistance Endurance
Fast twitch fibres (b)
White Without oxygen High contraction High force Low fatigue resistance Type a has characteristics of both
Factors affecting muscle strength
Fibre arrangement - e .g Fusiform or pennate Fibre recruitment - 1 or 1000s stimulated Fibre type -Slow or fast twitch Gender differences - f about 2/3 as strong Age differences - strongest 20-30 norm Speed of contraction - e.g multipennate - slow
