A&P wk7 Skeletal muscle anatomy

winniesmith's version from 2017-01-27 18:12

Section 1

Question Answer
What are the three types of muscle tissueskeletal,cardiac and smooth
What does a tendon do?connects muscle to bone
What is the function of skeletal muscles?Attach to bones directly or indirectly.Produce movement of skeleton. Maintain posture and body position. Support soft tissues. Guard entrances and exits. Maintain body temperature
What are the muscle mechanicsMuscles contract actively and elongate passively ( by elastic forces, contraction of opposing muscles, effects of gravity).
What is the originmuscle attachment that remains fixed/still
What is the insertionmuscle attachment that moves
What is the actionthe key movement/s the muscle produces.

Section 2

Question Answer
what is flexiondecreasing the angle
what is extension increasing the angle
what is hyperextentionincreasing the angle more than at rest/normal
what is abductionmoving away from body (alien abduction)
what is adductionmoving towards the body (adding)
Two types of hand rotationsSupination (hand lying flat on ground) Pronation (hand lying down palm first)
Two types of foot movementPlantarflexion (point toes) Dorsiflexion (point upwards)

Section 3

Question Answer
How does structure effect functionmore fibres/area (produce more tension) long fibres (allow greater contraction)
Function of Parallelwhen contracting it shortens in length and increases in diameter, a lot of movement. Has a central body known as the belly.
Function of Pennatemost strength- creates more tension due to more myofibrils.
Fascicles form common angle with the tendon.
Unipennate- all muscle fibers are on one side.
Bipennate- fibers on both sides of the tendon.
Multipennate- if the tendon branches within a pennate muscle.
Function of convergentgreatest diversity of movement.
muscle fascicles extend over a broad area (spread out like a triangle) and converge on a common attachment site.
how do we move when muscles can only contractdue to levers/leverage
Function of circularcontract to close openings.
concentrically arranged around an opening.

Section 4

Question Answer
What are the levers/ classes of leversbones, joint acts as fulcrums, muscles apply force to overcome a load.
How do you classify leversThe relative position of fulcrum, point at which force and load are applied affect mechanics
What is a first class leverwhen the applied force and the load are on opposite sides of the fulcrum. “see-saw”
what is a second class leverThe load lies between the applied force and the fulcrum, similar to a wheelbarrow
what is a third class leverThe force is applied between the load and the fulcrum. Most common type of lever

Section 5

Question Answer
What are the primary action categoriesPrime mover (agonist) -Main muscle in an action. Synergist- Helper muscle in an action. Antagonist- Opposed muscle to an action. Fixator- Stabilises; prevents unwanted movement.
Major muscles of the spineErector spinae muscles- iliocostalis, longissimus, spinalis.
Actions of the spine muscles Bilateral contraction- extends vertebral column. Unilateral, lateral flexion.
Major muscles of the thoraxAxial muscles of the trunk- thoracic region-External intercostals – elevate ribs. Internal intercostals – depress ribs. Diaphragm – expands thoracic cavity
Major muscles of the abdominal musclescause flexion. Rectus abdominis (vertal fibres, from ribs too pelvis). External oblique (diagonal fibres). Internal oblique (diagonal fibres). Trancversus abdominis, connects one side to the other)
two groups of appendicular muscles Muscles of the shoulder and upper limbs. Muscles of the pelvic girdle and lower limbs
Posterior shoulder musclesTrapezius (keeps the shoulders held back) Levator scapulae (lifts the shoulder blade). Rhomboid muscles (Abduct the shoulder blade)
Anterior shoulder muscles Serratus anterior (pulls the scapula forward). Pectoralis minor (plus the scapula fowards and down)
Muscles that move the armPectoralis major (what does this do) Deltoid (abduct the arm). Rotator cuff muscles ((form circle around shoulder joing to produce roatation) Subscapularis, Infaspinatus, Teres minor.) Latissimus Dorsi
Muscles that move the forearmElbow flexors (biceps brachii, Brachialis, Brachioradialis). Elbow extensors (triceps brachii). Muscles which rotate the arm- Pronators (radius crossing over ulna) (pronator quadratus and pronator teres) and Supinator (pulls round the other way, with help from biceps brachii)
what do the extrinsic muscles of the hand Bellies in anterior compartment of forearm. Long tendons. Powerful grip
what do the intrinsic muscles of the hand do Bellies in hand Small muscles Many parallel Allow precise movement

Section 6

Question Answer
Muscles that move the thigh gluteal muscles (powerful extension of the hip) Gluteus minimus and medius (ad or ab ?? duction the hip). Thigh adductors and Thigh flexors
Thigh adductors musclesAdductor magnus Adductor brevis Adductor longus Pectineus Gracilis
Thigh flexors muscles Iliopsoas (psoas major + iliacus)
Flexors of the knee (muscles on the back of the knee)hamstrings group, sartorius, popliteus (unlocks the knee)
What muscles make up the hamstrings groupBiceps femoris Semimembranosus * Semitendinosus
Extensors of the knee quadriceps femoris group (Rectus femoris, Vastus lateralis ,Vastus intermedius, Vastus medialis.
Muscles that move the foot (posterior)Plantar flexion (Gastrocnemius, Soleus).
Muscles that move the foot (anterior)Eversion and plantar flexion (Fibularis (peroneus)) and Dorsiflexion (Tibialis anterior)