muscular
system
The muscular system consists of the set of skeletal
muscles, whose mission is the movement of the body. Along with the bones is the
musculoskeletal system, which is the active part, since muscles are responsible
for the movements of the bones.
Skeletal muscles contract in response to nerve
impulses. These impulses travel by motor nerves that terminate in the muscles.
The area of contact between a nerve and skeletal striated muscle fiber is
called the neuromuscular junction or motor endplate.
The human body has over 600 muscles. These muscles are
attached directly or indirectly (through tendons) to bone and generally work in
antagonistic pairs when one contracts the other relaxes.
MUSCULAR SYSTEM FUNCTIONS
The main functions of the muscular system are: Body
movement (locomotion) or any of its parts. Heat production. The muscles produce
40% of body heat at rest and up to 80% during the
exercise. Maintaining the posture. Mimicry: a share of
certain muscles, especially of the face, you can take certain gestures
used to
express feelings.
TYPES OF MUSCLES
Depending on the type of movement they make, one can
distinguish the following types of muscles:
Flexors and extensors: closer or apart, respectively,
two parts of a member.
The application of these terms in relation to the hip
and shoulder requires a special definition. The bending in these structures is
a movement by which the thigh and arm are moved
front, by extension, thigh and arm move back.
Abductors and adductors: away or moving parts come to
a central axis.
Rotator: a bone rotated around a longitudinal axis.
Pronation and supination are two special forms of rotation.
Pronation is the joint rotation of the forearm and
hand, leaving the palms facing backwards. Supination is the opposite movement.
Elevators or depressants: raise or lower a body part.
Sphincters and dilators: make or break a body orifice.
KEY MUSCLES OF THE HUMAN BODY
MUSCLES OF THE HEAD
mimic muscles
˙ Front: Raise your eyebrows and wrinkle the forehead.
˙ risorius: pull the mouth corners sideways.
˙ Orbicularis oculi: closes eyes.
˙ Orbicularis oris: close the mouth.
masticatory muscles
˙ Masseter: close your mouth and clench their teeth.
˙ Temporary: close the mouth, clench and retract the
mandible.
NECK MUSCLES
˙ Sternocleidomastoid: rotation and flexion of the
head.
MUSCLES OF THE TRUNK
anterior
˙ Pectoralis major: flexion of the arm. Collaborate
with the latissimus dorsi in adduction of the arm.
Serratos ˙ older adults: move the shoulders forward.
˙ Intercostal: situated between the ribs. Involved in
respiratory movements. (Not observed in
the drawing)
˙ Diaphragm: separates the thoracic and abdominal
cavities. Involved in respiratory movements. (Not
seen in the drawing)
˙ rectus abdominis: trunk flexion and compression of
abdominal contents.
Or ˙ External oblique abdominis: trunk flexion and
compression of abdominal contents.
posterior
˙ Trapeze: involved in the adduction and abduction of the
arm.
Dorsal ˙ width: arm extension. Help support the
pectoral adduction of the arm.
˙ Teres major, extension, adduction and internal
rotation of the arm.
˙ Teres minor: adduction and rotation of the arm out.
MUSCLES OF THE UPPER LIMB
shoulder
˙ Deltoids: abduction of the arm. It also participates
in flexion and extension arm.
arm
˙ Biceps brachii: flexion and supination of the
forearm. Flexion of the arm.
Brachial ˙ previous: flexion of the forearm.
˙ Triceps brachii: extension of the forearm. A portion
is involved in the extension arm.
forearm
˙ Pronator: pronation of the forearm and hand.
˙ Supinator: supination of the forearm and hand. Ulnar ˙ previous: flexion of the hand.
˙ Palmar flexion of the hand on the forearm.
˙ flexors and extensors of the fingers: flexion and
extension of the fingers. hand
˙ short muscles of the hand: the fingers move.
MUSCLES OF THE LOWER LIMB
Thigh and buttocks
˙ Gluteus maximus: extension of the thigh.
˙ gluteus medius: abduction of the thigh.
˙ Iliopsoas: flexion of the thigh and trunk.
˙ pectineus: flexion and adduction of the thigh.
˙ Sartorio: flexion, adduction and rotation of the
thigh outward. Flexion of the leg.
˙ gracilis: adduction of thigh and leg flexion.
˙ Adductor magnus: adduction of the legs.
Adductor ˙ medium: adduction of the legs.
˙ quadriceps femoris: includes the vastus lateralis,
the vastus intermedius (not shown in the drawing), the vast and internal rectus. Extension of the leg.
˙ Biceps femoris: leg flexion and extension of the
thigh.
˙ Semitendinosus: leg flexion and extension of the
thigh.
˙ Semimembranosus: leg flexion and extension of the
thigh. leg
˙ Tibialis anterior: dorsiflexion of the foot.
˙ Soleo: along with the twins can lift the body on the
toes (plantar flexion).
˙ Twin: plantar flexion of the foot and leg flexion.
This muscle attaches to the calcaneus through the Achilles tendon.
˙ peroneus longus: it turns out the foot.
˙ flexors and extensors of the toes: flex or extend
the toes.
˙ short muscles of the foot: the toes move.
Disorders
These injuries range from discomfort to permanent
disability (Ergonomía!!). Are injuries to the tendons, nerves and muscles
caused by overwork ... I rate it as overwork and improper position. For example
activities such as loading, assembling parts, computer use and even sweep cause
a tightening in the body (and limbs). This type of injury do not appear
overnight, they develop over time (months, years) in persons performing
activities that require movement constantly stressed.
Over time the tissues become damaged causing pain and
impaired mobility of the extremities, the tendons may become inflamed in turn
damaging blood vessels and nerves.
The risk of developing muscle injury is greater if the
movements of the activity:
require strength
are repetitive
are performed in awkward positions
there is an adequate rest of the body members.
Muscular diseases occur, regardless of disturbances
that originate efferent nerve central nervous system by:
Disorder of the nerve impulse: to be both a disorder
presynaptic release of acetylcholine stored in vesicles such as botulism or
Lambert-Eaton syndrome, a disorder as postsynaptic by failure of the function
of acetylcholine receptors as myasthenia gravis.
Disorders of muscle membrane excitability: myotonia
can be for as myotonia congenital Thomsen, by tetany, periodic paralysis,
hyperkalemia or hypokalemia.
Disorders of the contractile proteins: are due to
multiple causes such as physical inactivity, malnutrition, deficiency of amino
acids, inflammatory myopathies such as polymyositis and dermatomyositis and
inherited disorders such as progressive muscular dystrophy.
Disorders of energy release: metabolic myopathies are
due to glycogenosis or as mitochondrial myopathies.
muscular dystrophies
Duchenne muscular dystrophy.
Becker muscular dystrophy.
Facioscapulohumeral muscular dystrophy.
Muscular Dystrophy Emery-Dreifuss.
Duchenne muscular waists.
Congenital muscular dystrophies with central nervous
system disorders.
Fukuyama congenital muscular dystrophy.
Walker-Warburg syndrome.
Muscle-eye-disease brain.
Congenital muscular dystrophy with merosin deficiency.
Congenital muscular dystrophy with merosin normal.
Oculopharyngeal muscular dystrophy.
Adhalinopatía primary.
Tumors
The WHO classification differentiates these types of
malignant tumors arising in skeletal muscle:
- Embryonal rhabdomyosarcoma.
- Alveolar rhabdomyosarcoma.
- Pleomorphic rhabdomyosarcoma.
Rhabdomyosarcoma is a soft tissue
sarcomas more common in childhood and adolescence to be relatively rare beyond
age 50. 40% of the cases in the head and neck, with soft tissue sarcoma that
most commonly located in head and neck.
In children account for 50% of
turmores malignant soft tissue. In the child presented as a tumor sulen showing
themselves as embryonic striated muscle of a fetus from 7 to 10 semanas.Su most
common clinical manifestation is that of a mass, for example in a neck muscle,
but sometimes the first manifestation is metastatic lymph node. It is not
usually painful on palpation. The latter is typical of rhabdomyosarcoma of
nasopharynx.
The diagnosis requires imaging
techniques to determine the extent and biopsy.
Your treatment includes
chemotherapy followed by radiation therapy or concomitant. Surgery is reserved
for cases when the tumor debulking or can be completely resected without
cosmetic or functional deformities. Survival is 80-90%, depending on tumor
type, stage, location, patient age and presence or absence of metastasis. The
control must be very narrow.
Radiation therapy is often
associated with sclerosis of the irradiated muscle and bone trophic changes.
Primarily metastasize to lungs, bone, lymph nodes and
CNS.
You can raise hematosarcoma
differential diagnosis, Hodgkin's disease and carcinoma of rinofarinte.
The three subtypes present clinical
characteristics of both mofológica as peculiar.
Embryonic and alveolar forms are
more characteristic of adolescence and childhood, loq ue also have been
denomiando juvenile rhabdomyosarcoma, reserving the term of rhabdomyosarcoma of
the adult pair pleomorphic subtype more common in this age group.
CERVICAL chondrosarcoma.
The WHO histological classification
of tumors difference chondro-osseous in three types:
- Condromadetejido soft.
- Mesenchymal chondrosarcoma.
- Extraskeletal osteosarcoma.
Chondrosarcoma is a malignant cartilage-producing DC. Generally it is a
low grade tumor and slow growth level cervical His presentation is very rare.
Classification.
Laclasificación most helpful to
establish the prognosis is based on histologic grade:
- Primary (de novo).
- Secondary (associated with a
preexisting injury).
By or origin may be central or
peripheral, with respect to its location in the medullary canal bone or on the
surface of this.
For the histological grade of the
tumor:
- Level 1 or low grade.
- Grade 2, or medium.
- Grade 3 or higher.
Grade 1 is the most similar to
normal c
artilage and those who remember abnormal cartilage are described as
grade 3. The latter is the one most likely to metastasize.
