Intro To Muscles And Directional Terminology Flashcards
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Name the components of skeletal muscles from smallest to largest
Myofibril -> Muscle fibre -> Fascicle -> Skeletal muscle
Describe myofibril
-Smallest unit of muscle
-Thread-like structures with contractile function
-Made up of thick and thin filaments called actin and myosin
Describe muscle fibre/myofibre/muscle cell
A group of myofibrils encased in a fascial sleeve called the endomysium
Describe fascicle
A group of muscle fibres encased in a fascial sleeve called the perimysium
Describe skeletal muscle
A group of fascicles encased in a common fascial sleeve called the epimysium
Name the 3 types of muscle tissue
Skeletal, cardiac, smooth
Describe skeletal muscle tissue
-Primarily move bones
-Striated-alternating light and dark bands due to thick and thin filaments
-Primarily under voluntary control
-Can become involuntary (diaphragm, postural muscles, and resting tone)
-Fibre direction typically parallel to direction of muscle pull
Describe cardiac muscle tissue
-Striated-alternating light and dark bands under a microscope
-Involuntary control
-Has intercalated discs which allow communication between neighbouring cardiac myocytes
Describe smooth muscle tissue
-Non-striated
-Involuntary control
-Present in gastrointestinal tract around hollow organs
-Around blood vessels, airways, hair follicles
Describe fascia
Fibrous membrane covering, supporting and separating muscle tissue
Describe aponeurosis
Sheet-like tendon joining one muscle with another, or a muscle with a bone
Describe tendon
-White, fibrous cord of dense, regular connective tissue
-Attaches muscle to bone
Outline the functions of muscle tissue
-Motion
-Maintain posture/stabilize
-Venous flow
-Thermogenesis
-Register volume of internal organs
Name the various fibre arrangements
-Longitudinal
-Quadrate
-Triangular
-Circular
-Fusiform
-Penniform (unipennate, bipennate, and multipennate)
Describe longitudinal fibres and give examples
Long, strap-like fibres running parallel to longitudinal axis
Ex. rectus abdominus, sartorius
Describe quadrate fibres and give examples
Flat, four sided muscles with fibres that run parallel to line of pull
Ex. rhomboids, pronator quadratus
Describe triangular fibres and give examples
-Flat, fan-shaped muscles
-Fibres radiate from a narrow attachment to a broad attachment or vice-a-versa
Ex. pectoralis major and minor
Describe circular fibres and give examples
Circular, typically sphincter muscles that surround an opening
Ex. orbicularis oris, orbicularis occuli
Describe fusiform fibres and give examples
Round, spindle-shaped, tapered at both ends
Ex. brachialis, brachioradialis
Describe penniform fibres and give examples
-Unipennate: Short parallel fibres originating from one side of a tendon
Ex. extensor digitorum longus, tibialis posterior
-Bipennate: Double pennate fibres on both sides of a central tendon, like a feather
Ex. rectus fermoris, flexor hallucis longus
Describe multipennate fibres and give examples
Several tendons with muscle fibres running diagonally between
Ex. deltoid, serratus posterior superior
Describe origin and insertion
-Origin: generally refers to the proximal attachment or stationary bone
-Insertion: generally refers to the distal attachment or moving bone
Describe prime mover, synergist, and antagonist
-Prime Mover: the muscle directly responsible for producing a desired motion
-Synergist: a muscle that assists the prime mover
-Antagonist: a muscle that has the opposite action to the prime mover
Name muscular terms for direction
-Rectus: implies parallel to midline
-Transverse
-Oblique
Name muscular terms for size
-Maximus
-Minimus
-Longus
-Brevis
Name muscular terms for shape
-Serratus
-Quadratus
Name muscular terms for action
-Flexor
-Adductor
-Levator
-Pronator
-Rotatores
Name muscular terms for no. of origins
-Bi
-Tri
-Quad
Name muscular terms for location
-Temporalis
-Lateral
-Medial
-Superior
-Inferior
Describe inferior/caudal and superior/rostral/cephalad
-Inferior/caudal: toward feet
-Superior/rostral/cephalad : toward the head
Describe ipsilateral and contralateral
-Ipsilateral: to same side
-Contralateral: to opposite side
Describe midsagittal, parasagittal, oblique
-Midsagittal: vertical, divides body into equal left and right halves down the midline
-Parasagittal: vertical, divides body into unequal left and right halves
-Oblique: plane passes through the body or organ at an angle between two planes
Describe superior and inferior rotation of the scapula
-Superior rotation: glenoid fossa faces superiorly
-Inferior rotation: glenoid fossa faces inferiorly
Describe medial (internal) and lateral (external) rotation of the scapula
-Medial rotation: medial border lifts from thorax, occurs with protraction
-Lateral rotation: medial border returns to thorax, occurs with retraction
Describe elevation and depression of the scapula
-Elevation: humeral head moves superior
-Depression: humeral head moves inferior
Describe the positions of the whole body
-Supine: on back
-Prone: on front
-Lateral recumbent: on side, sidelying
-Semi-fowlers position/semi-supine: partially supine
