MUSCLES Flashcards
considered together as functional unit that permit body movements and locomotion
Skeletal muscles and skeleton
Muscles are attached to the bones by connective tissue called
tendon
broad, flat and sheet-like tendon
aponeurosis
often have two points of attachment
Skeletal muscles
2 points of attachment
fixed or stationary
movable
fixed point of attachment of the muscle
anatomical origin
movable point of attachment
insertion
part between the origin and insertion of a muscle
Belly
muscles could have more than one origin, called
heads
When muscles have several insertions, these are termed
slips
move a part towards the main axis of the body
Adductor
move a part away from the main axis of the body
Abductor
move jointed parts away from each other
Extensor
move jointed parts towards each other
Flexor
raises a part
Levator
lowers a part
Depressor
large spaces between the skin and muscles where the skin is not attached
subcutaneous lymph sacs
small transverse muscle located at the anterior tip of the mandible (lower jaw)
OIA
Submentalis
Origin Anterior tip of the mandible
Insertion Anterior angle of the lower jaw
Action Raises the tip of the lower jaw
Lateral to the median raphe is the thin, broad, transversely-oriented fibers
Mylohyoid
Origin Median surface of the mandible
Insertion Median raphe
Action Raises the floor of the mouth during breathing or swallowing
median longitudinal connective tissue on the ventral of the lower jaw
median raphe
A pair of longitudinal flat muscles can be seen on the ventral midline is seen after cutting the median raphe and deflect the mylohyoid laterally
Geniohyoid
Origin Anterior angle of the lower jaw
Insertion Posterior cornua and thyroid processes of the hyoid
Action Draws the hyoid forward and upward
median pair of muscles which is partly covered by the posterior rim of the mylohyoid
Sternoradialis
Origin Episternum and omosternum
Insertion Proximal end of the radius
Action Flexes the forearm
most ventral, thin, pocket-like, superficial muscle found posterior to the sternoradialis.
Cutaneous pectoralis
Origin Xiphisternum; from the anterior margin of the sheath that covers the rectus abdominis
Insertion Dermis of the skin at the pectoral region
Action Tenses the skin that overlies the pectoral girdle
deflect ventrally the cutaneous pectoralis and locate this group of fan-shaped muscles that are also found posterior to the sternoradialis.
Pectoralis
Origin Sternum
Insertion Humerus
Action Flexor, adductor, and rotator of the arm
Pectoralis can be divided into three parts
anterior, medial, and posterior pectoralis
Lateral to the linea alba is a longitudinal muscle, The muscle is subdivided by a series of transverse, tendinous inscriptions
Rectus abdominis
Origin Pubic border
Insertion Sternum
Action Support the abdominal viscera; hold the sternum in place
thin connective tissue running at the
midventral portion of the abdomen
linea alba
sheet-like muscle lateral to the rectus abdominis
External oblique
Origin Ilium; dorsal fascia of vertebrae
Insertion Linea alba
Action Help constrict the abdomen; support the viscera
thin sheet of muscle closely applied to the external oblique but differs in the direction of the fibers
Internal oblique
Origin Ilium; dorsal fascia; transverse process of vertebrae
Insertion Anterior portion of the same aponeurosis to which the external oblique attaches
Action Help constrict the abdomen; support the viscera
locate the flat strap-like muscle running obliquely along the ventral side of the thigh.
Sartorius
Origin Pubis
Insertion Tibiofibula
Action Flexes the shank; adducts the thigh
muscle can be seen by cutting the belly of the sartorius muscle
Adductor longus
Origin Ilium
Insertion Femur
Action Adducts the thigh
thick muscle near the groin area. This is seen as a triangle when the sartorius is in place. This is also the muscle immediately posterior to the adductor longus.
Adductor magnus
Origin Pubic symphysis; ischial symphysis
Insertion Distal end of the femur
Action Adducts the thigh; flexes or extends the shank
large muscle with oblique fibers situated posterior to the adductor magnus.
Gracilis major
Origin Ischium
Insertion Tibiofibula
Action Adducts the thigh; flexes the shank
find this long strip, narrow muscle at the posterior margin of gracilis major.
Gracilis minor
Origin Ischium
Insertion Tibiofibula
Action Adducts the thigh; flexes the shank
deep muscle. In order to see this muscle, separate gracilis major and the adductor magnus, between the two is
Semitendinosus
Origin Ischium
Insertion Tibiofibula
Action Adducts the thigh; flexes the leg
large muscle situated at the back of the shank. white tissues surrounding the belly of this muscle. Also in the thigh and shank
Gastrocnemius
Origin Distal end of the femur; anterior portion of the knee
Insertion Ankle of the foot
Action Extensor of the foot
white tissue
(fascia)
narrow but thick muscle anterior to the gastrocnemius and partly covered by it. This is seen attached to the surface of the tibiofibula.
Tibialis posticus
Origin Posterior surface of the tibiofibula
Insertion Proximal end of the astragalus
Action Extensor or flexor of the foot depending on the position of the foot
locate this short, slender muscle at the anterior proximal half of the tibiofibula. In the toad, this muscle is not well-defined.
Extensor cruris
Origin Distal end of the femur
Insertion Anterior surface of the proximal half of the tibiofibula
Action Extensor of the foot
find this narrow muscle distal to the extensor cruris. In the toad, this muscle is not well-defined.
Flexor tarsi anterior
Origin Anterior surface of the middle and distal half of tibiofibula
Insertion Proximal end of astragalus; fascia of the foot
Action Flexor of the foot
locate the most anterior muscle of the shank which can also be seen dorsally. This muscle splits into two slips distally.
Tibialis anticus
Origin Femur
Insertion Distal end of the astragalus and calcaneus
Action Flexor of the foot
thick muscle that passes obliquely ventral to the lateral portion of the sternoradialis.
Scapulohumeralis (Deltoid)
Origin Scapula
Insertion Deltoid ridge
Action Adducts the forearm
locate this large muscle that is situated at the posterior side of the upper arm which could be seen both dorsally and ventrally
Triceps brachii
Origin Base of the scapula; shaft of the humerus
Insertion Proximal end of the radioulna
Action Extends the forearm
locate a pair of stout muscles posterior to the eye and at about the level of the tympanic membrane.
Temporalis
Origin Middorsal line of the skull
Insertion Posterior region of the mandible
Action Raises the lower jaw; closes the mouth
find this flattened muscle immediately posterior to the temporalis muscle. In the toad, this muscle is a stout muscle posterolateral to the temporalis muscle.
Depressor mandibulae
Origin Through the tough fascia in the middorsal line
Insertion Mandible
Action Depresses the jaw
this large, broad muscle underneath the depressor mandibulae, which can be exposed by cutting the fascia of the depressor mandibulae along the middorsal line. In the toad, this is a large broad muscle immediately posterior to the depressor mandibulae and concealed under the paratoid gland.
Dorsalis scapulae
Origin Dorsal surface of suprascapula and scapula
Insertion Lateral side of the humerus
Action Abducts the arm
pair of narrow muscles medial to the dorsalis
scapulae and is found lying lateral to the middorsal line.
Cucullaris
Origin Middorsal line
Insertion Portion of the pectoral girdle
Action Draws forelimbs upward
pair of large, flat, triangular muscles immediately posterior to and partly covered anteriorly by the depressor mandibulae. In the toad, this is a two-prong V-shaped muscle with dorsal and ventral slips. The dorsal slip is found posterolateral to the cucullaris, while the ventral slip is found posterior to the dorsalis scapulae.
Latissimus dorsi
Origin Lumbodorsal fascia
Insertion Lateral side of the proximal end of the humerus
Action Draws the forelimb upward and backward
find the mass of muscle posterior to the latissimus dorsi lying alongside the middorsal line and tapering posteriorly.
Longissimus dorsi
Origin Anterior third of the urostyle
Insertion Posterior end of the skull; dorsal surfaces of the vertebrae
Action Extends the back; elevates the head
locate the muscle lateral to the longissimus dorsi. The lateral or horizontal skeletogenous septum, a strong connective tissue, separates the ____ from the lateral external oblique.
Ilio-lumbaris
Origin Anterior part of the ilium
Insertion Transverse processes of the trunk vertebrae
Action Bends the back
find the pair of small V-shaped muscles immediately posterior to the longissimus dorsi.
Coccygeo-sacralis
Origin Lateral side of the half of the urostyle
Insertion Transverse processes of the sacral vertebrae
Action Draws the back and urostyle nearer to each other
locate a pair of large V-shaped muscles immediately posterior to the coccygeo-sacralis and is situated between the ilia of the pelvic girdle.
Coccygeo-iliacus
Origin Lateral side of the posterior half of the urostyle
Insertion Ilium
Action Extends the back; fixes the urostyle with respect to the pelvic girdle
largest, three-headed muscles that cover the lateral surface of the thigh. has three heads
Triceps femoris
Triceps femoris three heads which are
Vastus externus- dorsally situated
Rectus femoris (Tensor fascia lata)- medially located
Vastus internus- ventrally located
Vastus externus OIA
O crest of the ilium
Insertion Front of tibia
Action Draws the hindlimb forward; extends the leg
Tensor fascia lata or Rectus femoris OIA
Origin ventral side of the ilium
Insertion Front of tibia
Action Draws the hindlimb forward; extends the leg
Vastus internus
O acetabulum
Insertion Front of tibia
Action Draws the hindlimb forward; extends the leg
find this small but thick muscle found anterior to the vastus externus and medial to the rectus femoris.
Gluteus
Origin Ilium
Insertion Proximal end of the femur
Action Rotates the femur forward
slender muscle posterior to the triceps femoris with the proximal end being covered by the vastus externus.
Biceps femoris (Iliofibularis)
slender muscle posterior to the
triceps femoris with the proximal end being covered by the vastus externus.
find this large muscle situated posterior to the biceps femoris.
Semimembranosus
Origin Posterior part of the ischium
Insertion Proximal end of the tibiofibula
Action Flexes or extends the shank
slender, short muscle found between the proximal end of the biceps femoris and the semimembranosus.
Pyriformis
Origin Urostyle
Insertion Femur
Action Pulls the urostyle to one side; draws the femur dorsally
this muscle of the shank immediately anterior to the gastrocnemius and partly covered by it.
Peroneus
Origin Distal end of the femur
Insertion Distal end of the tibiofibula; proximal end of calcaneus
Action Extensor or flexor of the foot
Muscles act by
contraction
