ROLES
The muscular system plays an essential role in the functioning of the body. It ensures voluntary movement, that is, movements that are consciously controlled, such as walking, writing, or lifting objects. It also performs involuntary movement, such as the heartbeat or movements of the digestive tract, which occur without conscious control.
MUSCLE INJURIES
Muscle injuries occur when muscle fibers are overstretched or forced beyond their limit of strength. Muscle strains occur when a muscle is excessively stretched, causing pain and difficulty in movement.
THE IMPORTANCE OF PHYSICAL ACTIVITY
Physical activity is essential for maintaining a healthy muscular system. Through regular movement, muscles become stronger, more resilient and more flexible. Physical exercise contributes to the development of muscle mass, maintaining correct posture and improving coordination of movements.
Physical activity also stimulates blood circulation, helps maintain a normal body weight, and reduces the risk of developing certain diseases. Regular exercise supports both physical health and general well-being.
INTRODUCTION
The muscular system is the total set of muscles in the human body and plays an essential role in performing movements, maintaining posture, and functioning internal organs. Together with the skeletal and nervous systems, the muscular system contributes to the coordination and control of body activities. The muscular system is made up of all the muscles and associated tissues that allow the body to move. The human body has over 600 muscles, which represent approximately 40–50% of body weight.
THE MAIN GROUPS OF SKELETAL-SOMATIC MUSCLES
By body region, muscles are grouped into:
• Head muscles
• Neck muscles
• Trunk muscles
• Limb muscles
1. THE HEAD MUSCLES are:
a) Mimic-cutaneous muscles: - frontal; - occipital; - muscles grouped around the orifices: nasal, orbital, auditory, role in determining facial expression.
b) Masticatory muscles: - masseters; - storms
c) Tongue muscles
d) Extrinsic muscles of the eyeball: -superior rectus and inferior rectus; -internal rectus and external rectus: superior oblique and inferior oblique
2. THE NECK MUSCLES are: -Platysma muscle; -the sternocleidomastoids; -the hyoid muscles.
3. THE TRUNK MUSCLES are:
a) Muscles of the back and neck: - trapezius; - dorsalis; - intervertebral foramina
b) Muscles of the chest: - pectorals; - serratus; - intercostals; - diaphragm
c) Abdominal muscles: - rectus abdominis; - external obliques; - internal obliques
4. THE LIMB MUSCLES
Upper limb muscles are:
a) Shoulder muscles-deltoid
b) Arm muscles - biceps and triceps brachii
c) Forearm muscles - flexors and extensors of the fingers, pronators and supinators of the forearm
d) Hand muscles
The muscles of the lower limbs are:
a) Gluteal muscles - in the hip joint
b) Thigh muscles: - the tailor muscle: - the quadriceps femoris muscle; - the biceps femoris muscle; - the adductor muscles of the thigh;
c) Calf muscles:
- the triceps surae muscle consisting of the gastrocnemius and soleus muscles;
- the extensor muscles of the fingers, flexors of the fingers; pronators and supinators of the foot
TYPES OF CONTRACTIONS
Muscles are active organs of movement that ensure posture, tone, balance, facial expressions and voluntary movements.
• ISOMETRIC CONTRACTIONS are characterized by:
- the muscle does not change its dimensions, but the state of tension in the muscle;
- the energy is transformed into heat;
- it does not perform mechanical work;
- they are characteristic of the postural muscles that ensure the bipedal position of the body.
• ISOTONIC CONTRACTIONS are characterized by:
- the muscle shortens and movement occurs;
- the tension remains the same;
- it performs mechanical work;
- they are characteristic of most limb muscles (e.g., walking is achieved by contracting the muscles of the lower limbs).
• SIMPLE CONTRACTION or muscle twitch is obtained if a single, short-term excitation is applied to the muscle, triggered by a single stimulation of the muscle
• FUSIONED CONTRACTIONS are of several types:
a) incomplete tetanus;
b) complete tetanus;
c) muscle tone.