Muscular System

The muscular system is made up of the various muscles in the human body.

Muscles are tissues whose cells or muscle fibers have the function of allowing contraction and production of movements.

Muscle fibers, in turn, are controlled by the nervous system, which is responsible for receiving information and responding to it by carrying out the requested action.

Functions of the Muscular System

The Muscular System has some functions that are fundamental to the human body. See below what these functions are:

Body stability;
Production of movements;
Body warming (maintaining body temperature);
Body filling (support);
Helps with blood flow.

Muscle Groups

The human body is made up of approximately 600 muscles , which work together with bones, joints and tendons to allow us to make different movements.

They are grouped as follows: muscles of the head and neck, muscles of the chest and abdomen, muscles of the upper limbs, and muscles of the lower limbs.

Learn about each of these groups below.

Muscles of the Head and Neck

The head and neck muscle group is made up of more than 30 small muscles that help express feelings, move the jaw or hold the head up.

See the table below to see how some of the main muscles in this group work:

Muscle	Action
Front	Chew or bite.
Masseter	They move their jaws.
Sternocleidomastoid	Allows the head to turn or tilt forward and backward.

Muscles of the Chest and Abdomen

The muscles in the chest and abdomen group allow breathing, prevent the body from bending and giving in to its own weight, among other movements.

The table below shows some of the muscles in this group and how they act in our body:

Muscle	Action
Pectoral and Deltoid	Lift weights.
Intercostals	They work together with the diaphragm to carry air into the lungs.
Oblique	Tilt your chest forward.

Muscles of the Upper Limbs

The muscles of the upper limbs are capable of applying precise pressure and allow flexibility and precision for delicate tasks or those that require a lot of strength.

Some examples of these muscles and their respective actions are described in the table below:

Muscle	Action
Biceps	It is connected to the scapula and radius bones, and when it contracts it causes the arm to bend.
Opponent of the thumb	Allows movement of the thumb, as it uses muscles in the forearm and hand
Short adductor	Outward movement of the thumb.

Muscles of the Lower Limbs

The muscles in the lower limbs are the strongest in the body. Thanks to the leg muscles, we can stand upright and maintain balance.

See the table below for some muscles in this group:

Muscle	Action
Tailor (or sartorius)	It is the longest muscle in the body, when contracted it bends the leg and rotates the hip. It is the seamstress’ muscle, hence the name.
Dorsal flexors	They make your toes lift.
Achilles tendon	It is the strongest tendon in the body, inserted into the calcaneus bone.
Soleus, plantaris and gastrocnemius	They are plantar flexor muscles responsible for the movement of ballerinas standing on their toes.

Types of Muscles

Muscles have different sizes, shapes and functions, which is why they are classified into three types: smooth, striated cardiac and striated skeletal.

Find out more details about each of them below.