ANAPHY

• MUSCULAR SYSTEM

  FUNCTIONS: There are about 600 muscles in the human body. Muscles have a range of functions from pumping blood and supporting movement to lifting heavy weights or giving birth. Muscles work by either contracting or relaxing to cause movement.
• FUNCTIONS OF MUSCLES: (M-M-S-R-M) •Movement of the body as a whole within the body. •Maintaining body position. •Support of soft tissues. •Regulating entrances/exits. •Maintaining body temperature.
• Functional characteristics of muscle tissue

  • Contractility
  • Excitability
  • Extensibility
  • Elasticity
• Contractility


  The ability of muscle cells to forcefully shorten
• Elbow flexion


  1. Biceps brachii and other elbow flexor muscles contract (shorten)

  2. Elbow extensor muscles contract (shorten)
• Muscles can only pull, never push
• Excitability


  The ability to respond to a stimulus, which may be delivered from a motor neuron or a hormone
• Extensibility


  The ability of a muscle to be stretched
• In order to flex the elbow

  The elbow extensor muscles must extend to allow flexion to occur
• Elasticity


  The ability to recoil or bounce back to the muscle's original length after being stretched
• 3 TYPES OF MUSCLE TISSUE: • SKELETAL • CARDIAC • SMOOTH
• Skeletal Muscle Cells


  • Multinucleated with the nuclei located on the periphery of the cell under the cell plasma membrane (also called sarcolemma in muscle)
  • Formed by embryonic myoblasts, each with its own nucleus, fusing with hundreds of other myoblasts to form long multinucleated skeletal muscle fibers
• Cardiac Muscle Cells


  • Generally have one nucleus centrally located in the cell
  • Physically and electrically connected to each other so that the contraction signals spread through cells and the entire heart contracts as one unit
• Smooth Muscle Cells


  • Contain a single nucleus
  • Can exist in electrically linked units contracting together as a single-unit or as multi-unit smooth muscle where cells are not electrically linked
• Organ Systems Involved in Movement

  •Muscular system, which is the muscles.

  
  

  •Nervous system, which involves brain, spinal cord, and nerves.

  
  

  •Skeletal system, which involves bones and connective tissue.
• Muscle contraction is the tightening, shortening, or lengthening of muscles when you do some activity. It can happen when you hold or pick up something, or when you stretch or exercise with weights. Muscle contraction is often followed by muscle relaxation, when contracted muscles return to their normal state.
• Isometric striated Muscle Contraction


  Characterized by a change in muscle tension without change in muscle length. Seen when pushing against an immovable object or trying to lift a weight that is too heavy.
• Isotonic striated Muscle Contraction


  Characterized by a constant muscle tension without a change in muscle length. Occurs when the contraction force matches the total load on a muscle. Seen during activities such as walking, running, or squatting.
• Concentric striated Muscle Contraction


  Occurs when there is sufficient muscle tension to overcome the load, and the muscle contracts and shortens. Seen during activities such as a biceps curl or standing from a squatting position.
• Eccentric striated Muscle Contraction


  Occurs when the muscle works to decelerate a joint at the end of a movement as opposed to pulling a joining in the direction of the contraction. Can occur involuntarily (ex: while attempting to move a weight too heavy for the muscle to lift) or voluntarily (ex: when the muscle is 'smoothing out' a movement or resisting gravity, such as during downhill walking).
• Muscle Arrangement


  The organization and alignment of muscle fibers within a muscle or muscle group.
• Types of Muscle Arrangement

  • Circular Muscle
  • Convergent Muscle
  • Parallel Muscle
  • Pennate Muscle
• Circular Muscle


  Fascicular pattern where the fascicles are arranged in concentric rings. Also known as skeletal sphincter muscles.
• Convergent Muscle


  A broad origin with fascicles converging toward a single tendon of insertion. Triangular or fan shaped.
• Parallel Muscle


  The length of the fascicles run to the long axis of the muscle. Types: Quadrilateral, Strap, Fusiform.
• Pennate Muscle


  The fascicles are short and they attach obliquely to a central tendon that runs the length of the muscle. Types: Unipennate, Bipennate, Multipennate.
• Muscle Tone


  The measure of tension that exists when our muscles are in a relaxed state. Allows for the maintenance of body position and the ability to make quick and coordinated movements. Helps to protect joints and maintain their proper alignment.
• Cranial Nerves


  • 12 pairs of cranial nerves emerge from the brain stem or other parts of the brain. Carry impulses for functions involving the head, as well as more far-reaching destinations.
• Cranial Nerves


  The name cranial indicates their origin, and many of them carry impulses for functions involving the head. Some carry motor impulses to muscles of the face and eyes or to the salivary glands. The vagus nerves branch extensively to the larynx, heart, stomach and intestines, and bronchial tubes.
• I. Olfactory


  Function(s): Sense of smell
• II. Optic

  Function(s): Sense of sight
• III. Oculomotor


  Function(s): Movement of the eyeball; constriction of pupil in bright light or for near vision
• IV. Trochlear


  Function(s): Movement of eyeball
• V. Trigeminal


  Function(s): Sensation in face, scalp, and teeth: contraction of chewing muscles
• VI. Abducens


  Function(s): Movement of the eyeball
• VII. Facial


  Function(s): Sense of taste, contraction of facial muscles, secretion of saliva
• VIII. Acoustic (vestibulocochlear)


  Function(s): Sense of hearing, sense of equilibrium
• IX. Glossopharyngeal


  Function(s): Sense of taste; sensory for cardiac, respiratory and blood pressure reflexes; contraction of pharynx, secretion of saliva
• X. Vagus


  Function(s): Sensory in cardiac, respiratory, and blood pressure reflexes, sensory and motor to larynx (speaking); decreases heart rate; contraction of alimentary (peristalsis) secretions increases tube digestive secretion
• XI. Accessory


  Function(s): Contraction of neck and shoulder muscles, motor to larynx (speaking)