Human muscle anatomy
- Muscles of the Head
- Muscles of the Neck
- Muscles of the Trunk
- Muscles of the Shoulder
- Muscles of the Arm
- Muscles of the Forearm
- Muscles of the Hand
- Muscles of the Leg
- Muscles of the Foot
Muscles of the Head
The muscles of the head are responsible for a wide range of facial expressions, as well as the movement of the eyes, nose, and mouth. These muscles are divided into two groups: the muscles of facial expression and the muscles of mastication. The muscles of facial expression are innervated by the facial nerve, while the muscles of mastication are innervated by the trigeminal nerve. The muscles of the head work together to create a complex and expressive range of movements that allow us to communicate, eat, and interact with the world around us.
Muscles of the Neck
The muscles of the neck are responsible for a wide range of movements, including flexion, extension, rotation, and lateral flexion. They are divided into two main groups: the anterior and posterior cervical muscles. The anterior cervical muscles are located on the front of the neck and include the sternocleidomastoid, omohyoid, and scalene muscles. The posterior cervical muscles are located on the back of the neck and include the trapezius, splenius capitis, and semispinalis capitis muscles. These muscles work together to provide support and mobility to the head and neck.
Muscles of the Trunk
The muscles of the trunk are located in the chest, abdomen, and back. They are responsible for protecting the internal organs, moving the trunk, and breathing. The chest muscles include the pectoralis major and minor, which are responsible for moving the arm and shoulder. The abdominal muscles include the rectus abdominis, obliques, and transversus abdominis, which are responsible for flexing the trunk and supporting the spine. The back muscles include the erector spinae, which is responsible for extending the spine, and the latissimus dorsi, which is responsible for adducting and extending the arm.
Muscles of the Shoulder
The shoulder is a complex joint that allows for a wide range of motion. It is made up of three bones: the clavicle, scapula, and humerus. The muscles of the shoulder work together to stabilize the joint, move the arm, and rotate the shoulder blade. Some of the most important shoulder muscles include the deltoids, which are responsible for abducting (lifting away from the body) and flexing the arm; the rotator cuff muscles, which help to rotate and stabilize the shoulder; and the trapezius, which helps to elevate and retract the shoulder blade.
Muscles of the Arm
The muscles of the arm are divided into two groups: the anterior (front) and posterior (back) muscle groups. The anterior muscle group includes the biceps brachii, brachialis, and coracobrachialis muscles, which are responsible for flexing the elbow joint. The posterior muscle group includes the triceps brachii muscle, which extends the elbow joint.
Muscles of the Forearm
The forearm is a region of the upper limb that extends from the elbow to the wrist. It contains two groups of muscles: the anterior forearm muscles and the posterior forearm muscles. The anterior forearm muscles are responsible for flexion and pronation of the wrist and hand, while the posterior forearm muscles are responsible for extension and supination of the wrist and hand. The muscles of the forearm are essential for performing everyday activities such as grasping, holding, and lifting objects.
Muscles of the Hand
The muscles of the hand are responsible for a wide range of movements, from delicate finger manipulations to powerful grasping. They are divided into two groups: the intrinsic muscles, which are located within the hand itself, and the extrinsic muscles, which originate in the forearm and insert into the hand. The intrinsic muscles control the movements of the fingers, thumb, and wrist, while the extrinsic muscles provide power for grasping and other movements of the hand.
Muscles of the Leg
The muscles of the leg are divided into three compartments: anterior, posterior, and medial. The anterior compartment contains the quadriceps, which are responsible for extending the knee. The posterior compartment contains the hamstrings, which flex the knee and extend the hip. The medial compartment contains the adductor muscles, which adduct the thigh, and the gracilis and sartorius muscles, which flex the knee and rotate the leg medially.
Muscles of the Foot
Muscles of the Foot
The muscles of the foot play a crucial role in walking, running, and maintaining balance. They are divided into intrinsic muscles, which are located within the foot, and extrinsic muscles, which originate in the leg and extend into the foot. The intrinsic muscles provide fine movements of the toes and arches, while the extrinsic muscles contribute to plantar flexion, dorsiflexion, and inversion and eversion of the foot.