1.3 The structure and function of the muscular system Flashcards
(26 cards)
Functions of the muscular system
The human body has over 600 muscles.
These muscles function to allow a range of physical movements that we either consciously or subconsciously control.
Body movement
All the muscles that we can consciously control (voluntary) are attached to bones.
These are known as voluntary muscles.
The CNS sends messages to the relevant muscle, and then the muscle pulls the bones to allow the desired movement.
Adequate posture
Muscles are continually in a state of tone that affects their ability to help our body to maintain an upright posture when awake and to function during sleep.
People with poor muscle tone generally have poor posture and resultant aches and pains
Regular exercise helps improve muscle tone, allows resting muscles to resist being stretched and keeps them in constant readiness.
Essential bodily functions
Involuntary muscles are those which have little or no conscious control
They continuously function and preserve our ongoing body needs whether we are awake or not.
Smooth muscle
Smooth muscles are found in hollow organs
Smooth muscle contractions are involuntary (no conscious control), slow, sustained and rhythmic.
Cardiac muscle
Cardiac muscle is found only in the heart.
The muscle fibres are intertwined, helping the heart push blood into arteries going to the lungs and other body tissues
The heart is an involuntary muscle and it is difficult to fatigue.
When a nerve impulse arrives, the message is relayed from cell to cell, causing rhythmic contractions and relaxations.
Skeletal muscle
Skeletal muscle attaches to and causes movement of the skeleton.
It is striated, meaning that it has a striped appearance
Skeletal muscle is under voluntary control as you are consciously aware and can control
Deltoid
Action: Shoulder abduction, shoulder flexion
and shoulder extension
Example: Bowling in cricket
Pectoralis major
Action: Shoulder flexion
Example: Tennis forehand
Serratus anterior
Action: Shoulder abduction
Example: Boxing punch
Trapezius
Action: Scapula elevation
Example: Shoulder shrug
Latissimus dorsi
Action: Shoulder adduction
Example: Butterfly stroke in swimming
Biceps brachii
Action: Elbow flexion
Example: Pull-up
Wrist flexors
Action: Wrist flexion
Example: Wrist curl
Triceps brachii
Action: Elbow extension
Example: Throwing a javelin
Wrist extensors
Action: Wrist extension
Example: Squash backhand
Abdominals:
- Rectus abdominis
- Obliques
Action: Trunk flexion, trunk flexion and trunk rotation
Example: Sit-up
Erector spinae
Action: Trunk extension and trunk rotation
Example: Gymnastics back-flip
Sartorius
Action: Hip flexion and knee flexion
Example: Breaststroke kick
Adductors
Action: Hip adduction
Example: Riding a horse
Gluteus maximus
Action: Hip extension and hip abduction
Example: Running
Quadriceps:
- Rectus femoris
- Vastus lateralis
- Vastus intermedius
- Vastus medialis
Action: Hip flexion, knee extension, knee extension and knee extension
Example: Kicking/cycling, jumping or rock climbing
Tibialis anterior
Action: Dorsi flexion
Example: Freestyle kick
Hamstrings:
- Biceps femoris
- Semitendinosus
- Semimembranosus
Action: All three muscles, hip extension and knee flexion
Example: Running
