Muscular System PDF - Types, Functions, and Anatomy

Muscular System Types of muscles 1. Skeletal muscles Site Attached to skeleton (bones) Contraction Voluntary Striations Present Nerve supply Somatic nerve Muscle cell (fibers) Multinucleated 2. Smooth muscles...

Muscular System Types of muscles 1. Skeletal muscles Site Attached to skeleton (bones) Contraction Voluntary Striations Present Nerve supply Somatic nerve Muscle cell (fibers) Multinucleated 2. Smooth muscles Site Wall of blood vessels & viscera. Contraction Involuntary Striations Absent Nerve supply Autonomic nerve Muscle cell (fibers) Spindle-shaped with single nucleus 3. Cardiac muscles Site In the myocardium of heart Contraction Involuntary Striations Present Nerve supply Autonomic nerve Muscle cell (fibers) single nucleus.  Muscle Skeletal Smooth Cardiac 1- Site Attached to the In the wall of blood In the myocardium of skeleton (bones) vessels and viscera the heart 2- Contraction Voluntary Involuntary Involuntary 3- Striations Present Absent Present but less than in skeletal muscle 4- Nerve supply Somatic nerve Autonomic nerve Autonomic nerve 5- Muscle cell Multinucleated Spindle-shaped with Bsingle nucleus. (fiber) single nucleus The skeletal muscles General features: 1. They form about 40-50 % of the total body mass. 2. Usually each muscle arises from an origin and terminates in an ORIGIN insertion. 3. The origin is usually fleshy mass while the insertion is cord –like structure termed the tendon. Muscle function: ▪ Produce movement ▪ Maintain posture INSERTION ▪ Stabilize joints ▪ Generate heat  The main muscle groups of the body: 1.Muscles of the head and neck: 1. Muscles of facial expression. 1. Muscles of mastication (grinding the food) as temporalis and masseter 1. Muscles of the tongue, pharynx (swallowing) and Temporalis larynx (voice production & respiration). masseter Sternomastoid muscle Action : rotates the head Sternomastoid Trapezius muscle  2.Muscles of the shoulder DELTOID MUSCLE Site of IM injection  Muscles of arm and chest Pectoralis major triceps biceps  Muscles of forearm Flexors extensors muscles of the gluteal region gluteus MAXIMUS N.B , site of intramuscular injection muscles of back of thigh hamstring muscles of the muscles of medial front of thigh side of thigh quadriceps adductors  MUSCLES OF THE LEG calf muscles: ANTERIOR GROUP Site of deep venous thrombosis  4.Muscles of the trunk and diaphragm Muscles of the thoracic wall Muscles of the anterior intercostal muscles (respiratory abdominal wall (allow protection muscles, in-between the ribs) of the abdominal contents and movements of the trunk). the diaphragm: - between the thoracic and abdominal cavities - the main respiratory muscle. - It is attached to the sternum, ribs and lumber vertebrae. - Has 3 major openings for 1- aorta 2- inferior vena cava (IVC) 3- esophagus  5.Muscles of the pelvis: These muscles attached to the hip bones, sacrum and coccyx Support the pelvic viscera They are more important in female than in males because of the process of labor. Anterior View Posterior View Thank you