Muscular system
Physical Education
Chapter 1: The musculoskeletal system
1.3 The muscular system: functions, types and major muscle groups
Functions
Body movement (voluntary control)
Adequate posture
Essential bodily functions (involuntary control)
Types
Smooth- digestive system, walks of vital organs and involuntary Cardiac- muscle of the heart, involuntary
Skeletal (striated)- voluntary movements, development and maintenance of good posture
Involuntary – no conscious control of the muscle (cannot be manipulated by you)
Voluntary- conscious control of the muscle
^ Tougher test and exams questions on this ^
1.4 The muscular system: features, arrangement and microscopic- structure
Common features of muscles
Nervous control- muscle has nerve running to it from the brain (not every cell has nerves)
Contractility- muscles contract and become thicker
Extensibility- muscles have the capacity to stretch and extend when force is applied
Elasticity- muscles can return to their original size and shape once stretched
Atrophy- muscles can decrease in size (waste) as a result of injury, illness or lack of exercise
Hypertrophy- muscles can increase in size (growth) with an increase in activity
Muscles fibre arrangement
Fusiform muscles
Fusiform muscles run the length of the muscle belly. They are designed for mobility because they produce contractions over a large range, yet they produce low force (eg. Sartorius and biceps)
Pennate muscles
Pennate muscles run at angles to the tendons. These muscles are designed for strength and power.
Unipennate muscles- found on one side of a central tendon
Bipennate muscles- run off either side of a central tendon (Looks like leaf) (E.g. rectus femoris)
Multipennate muscles- branch out from several tendons (Looks like tree branch, good for force, down in flexibility)
Structure of skeletal muscles
The muscle fibre
Each muscle fibre is surrounded by a cell membrane
Chapter 1: The musculoskeletal system
1.3 The muscular system: functions, types and major muscle groups
Functions
Body movement (voluntary control)
Adequate posture
Essential bodily functions (involuntary control)
Types
Smooth- digestive system, walks of vital organs and involuntary Cardiac- muscle of the heart, involuntary
Skeletal (striated)- voluntary movements, development and maintenance of good posture
Involuntary – no conscious control of the muscle (cannot be manipulated by you)
Voluntary- conscious control of the muscle
^ Tougher test and exams questions on this ^
1.4 The muscular system: features, arrangement and microscopic- structure
Common features of muscles
Nervous control- muscle has nerve running to it from the brain (not every cell has nerves)
Contractility- muscles contract and become thicker
Extensibility- muscles have the capacity to stretch and extend when force is applied
Elasticity- muscles can return to their original size and shape once stretched
Atrophy- muscles can decrease in size (waste) as a result of injury, illness or lack of exercise
Hypertrophy- muscles can increase in size (growth) with an increase in activity
Muscles fibre arrangement
Fusiform muscles
Fusiform muscles run the length of the muscle belly. They are designed for mobility because they produce contractions over a large range, yet they produce low force (eg. Sartorius and biceps)
Pennate muscles
Pennate muscles run at angles to the tendons. These muscles are designed for strength and power.
Unipennate muscles- found on one side of a central tendon
Bipennate muscles- run off either side of a central tendon (Looks like leaf) (E.g. rectus femoris)
Multipennate muscles- branch out from several tendons (Looks like tree branch, good for force, down in flexibility)
Structure of skeletal muscles
The muscle fibre
Each muscle fibre is surrounded by a cell membrane