Test 2 Flashcards
Origin
refers to the structure to which the muscle is attached that remains relatively fixed when
the muscle contracts
Insertion
refers to the structure to which the muscle is attached that moves when the muscle
contracts
Belly
the thick part of the muscle between the origin and insertion
Tendon
cords of fibrous connective tissue by which a muscle is attached to its insertion and origin
Aponeurosis
a broad, flat sheet of fibrous connective tissue by which a muscle is attached to its
insertion or origin; these are less common than tendons
Flexor
muscle which decreases an angle between two structures; or a muscle that bends one
skeletal part in relation to another
Extensor
a muscle which increases an angle between two structures; or a muscle that
straightens one skeletal part in relation to another
Abductor
a muscle which moves a part away from the main axis (midline) of the body
Adductor
a muscle that moves a part toward the main axis (midline) of the body
Levator
muscle which raises a body part. Ex: The masseter which raises or closes the jaw
Depressor
a muscle which lowers a body part
Protractor
a muscle which moves a body part forward
Retractor
a muscle which moves a body part backwards
Latissimus dorsi
O; Spinous process of thoracic vertebrae
I; Intertubercular groove of humerous
A: Internal rotation, adduction, extension of arm
External Oblique
O: Ribs and lumbodorsal fascia
I: linea alba
A: Rotation and lateral and anterior flexion
Internal oblique
O: Lumbodorsal fascia
I: Aponeurosis on linea alba
A: Flexion (rotation of trunk)
Appendicular skeleton includes
- Pectoral girdle
- Shoulder bones
- Upper limbs
- Pelvic girdle
- Hip bones
- Lower limbs
Carpal bones
- Eight bones of the wrist
- Consists of two rows
- Proximal carpal bones and distal carpal
bones
coxal bones
- Ilium/ischium/pubis
- Acetabulum
- Acetabular notch/acetabular fossa/lunate
surface
Greater pelvis
Spans the distance from left iliac crest to right
iliac crest
Pelvic inlet
superior space between the pelvic
brim of each coxal bone
Pelvic outlet
inferior space between the ischial
spine of each coxal bone
Differences in male/female pelvis
- Pelvic outlet
- Larger in females than in males
- Sacrum curve
- Less curvature in females than in males
- Pelvic inlet
- Wider in females than in males
- Pubic angle
- Greater than 100º in females and less than 90º in
males
Seven bones of the ankle (tarsus)
- Calcaneus
- Talus (contains trochlea)
- Navicular
- Cuboid
- Medial cuneiform bone
- Intermediate cuneiform bone
- Lateral cuneiform bone
Joints (articulations)
exist wherever two or more
bones meet
Classify joints on Function: range of motion
- Synarthrosis
Immovable - Amphiarthrosis
Slightly movable - Diarthrosis
Freely movable
Classify joints on Structure
- Synarthrosis (Immovable Joint)
- Amphiarthroses (Slightly Movable Joints)
- Diarthroses (Freely Movable Synovial Joints)
Rheumatism
Pain and stiffness affecting the skeletal system,
muscular system, or both
Arthritis
- Includes all rheumatic diseases that affect synovial
joints - Involves damage to the articular cartilages
Bursae
Synovial tendon sheaths surround some tendons
Ligaments
There are accessory ligaments and capsular
ligaments such as extracapsular ligaments and
intracapsular ligaments
Cartilages and fat pads
- Menisci
- Fat pads
Synovial Fluid
- Lubricates the surfaces of the articular cartilages
and reduces friction - Nourishes the chondrocytes by entering and
exiting the articular cartilages due to the forces
acting on the joint - shock absorber
synovial joints
have
* The presence of articular cartilages
* A joint cavity with synovial fluid
* A synovial membrane
* Accessory structures (cartilage, ligaments,
tendons, bursae)
* Sensory nerves and blood vessels
Syndesmosis (type of Amphiarthroses)
ligaments that connect two bones
but limit their motion
Symphysis (type of Amphiarthroses)
bones are separated by a wedge or
pad of cartilage
Sutures (type of Synarthrosis)
Sutures (joints found only in the skull
Gomphosis (type of synarthrosis)
fibrous joint between teeth and jaw
bones (Periodontal ligaments)
Synchondrosis (type of synarthrosis)
cartilaginous joint within
epiphysis of bone
Synostosis (type of synarthrosis)
bony fusion joint between two bones (ex Fusion of the three coxal bones)
4 basic properties of muscle tissue:
Excitability
* respond to stimuli
Contractility
* shorten and exert a pull or tension
Extensibility
* continue to contract over a range of
resting lengths
Elasticity
* rebound toward its original length
Functions of Skeletal Muscles
- Movement
- Maintain Temperature
- Maintain posture
- support soft tissue
- regulate entering and exiting of material
Epimysium
dense tissue that surrounds the entire
muscle
Perimysium
dense tissue that divides the muscle
into parallel compartments of fascicles
Endomysium
dense tissue that surrounds
individual muscle fibers
What repairs damaged muscle tissue
Myosatellite cells
Tendons
Connect muscle to bone, and are comprised of Epimysium, perimysium, and endomysium
Aponeuroses
thick, flattened sheets that connect a
muscle to a muscle
Neuromuscular junction [NMJ]
Where the chemical communication between the muscle and nerve occur
Sarcolemma
Membrane that surrounds the muscle cell
Sarcoplasm
The cytosol of the muscle cell
Myoblasts
Embryonic cells that form skeletal muscle fibers
Transverse tubules (T tubules)
Tubules that conduct electrical impulses for muscle
fiber contraction
myofibrils
Responsible for the contraction of muscles
Actin
thin protein filaments
Myosin
thick protein filaments
sarcoplasmic
reticulum (SR)
Consists of terminal cisternae and triads
Sarcomere
Functional unit of muscle
Precise motor unit
Controls 2-3 muscle fibers (ex eye)
Less precise motor unit
~ 2000 muscle fibers (ex leg)
Muscle tone
The tension of a muscle when it is relaxed
Muscle spindles
Specialized muscle cells that are monitored by
sensory nerves to control muscle tone
Hypertrophy leads to
- An increase in the number of mitochondria
- An increase in the activity of muscle spindles
- An increase in the concentration of glycolytic
enzymes - An increase in the glycogen reserves
Atrophy leads to
- A decrease in muscle mass
- A decrease in muscle tone
- Muscle becomes flaccid
- Muscle fibers become smaller and weaker
Fast fibers
(White fibers ex eye)
Muscles contract using anaerobic metabolism
during glycolysis
Few mitocondria
Slow fibers
(red fibers, contain myoglobin)
- Use aerobic metabolism
- more mitochondria that fast fibers
Intermediate fibers
(pink fibers)
Lots of mitochondria, low myoglobin
4 types of muscle organizations
- Parallel muscle fibers
- Convergent muscle fibers
- Pennate muscle fibers
- Circular muscle fibers
Parallel Muscles
Muscle fascicles are parallel to the longitudinal
axis
Ex: biceps brachii (body becomes shorter during contraction
Convergent Muscles
Muscle fibers form a broad area but come
together at a common point
Ex pectoralis major (raphe)
Pennate
Muscle fibers form an oblique angle to the tendon
of the muscle
3 TYPES:
Unipennate - fibers on same side (extensor digitorum)
Bipennate - fibers on both sides (rectus femoris)
Multipennate - branches within muscle (detolid)
Circular muscles
AKA sphincter muscles
form concentric rings
example: orbicularis oris
2 ways of describing muscle actions
- reference to the bone region the
muscle is associated with - reference to a specific joint the
muscle is associated with
4 types of muscle ACTION groupings
- Prime movers (agonists)
- Antagonists
- Synergists
- Fixators
Prime movers
Responsible for producing a particular movement
Biceps brachii—flexes the lower arm
Antagonists
Actions oppose the action of the agonist
Triceps brachii—extends the lower arm
Synergists
Assist the prime mover in performing an action
Latissimus dorsi and teres major—contract to move
the arm medially over the posterior body
Fixators
Agonist and antagonist muscles contracting at the
same time to stabilize a joint
Flexor and extensor muscles contract at the same
time to stabilize an outstretched hand
Aging in muscular system
- Skeletal muscle fibers become smaller in diameter
- Due to a decrease in the number of myofibrils
- Contain less glycogen reserves
- Contain less myoglobin
- All of the above results in a decrease in strength
and endurance - Muscles fatigue rapidly
- Develop fibrosis
5 key facial muscles
- Orbicularis oris
- Buccinator
- Temporoparietalis
- Occipitofrontalis
- Platysma
(All are innervated by CN VII)
Extra-ocular Muscles
- Medial and lateral rectus muscles
- Superior and inferior rectus muscles
- Superior and inferior oblique muscles
Eye movements of Extra-ocular
- Lateral rectus: rotates the eye laterally
- Medial rectus: rotates the eye medially
- Superior rectus: rotates the eye upward
- Inferior rectus: rotates the eye downward
- Superior oblique: rotates the eye downward and
laterally - Inferior oblique: rotates the eye upward and
laterally
Muscles of Mastication
- Masseter
- Temporalis
- Pterygoids
Muscles of the Tongue
- Genioglossus
- Hyoglossus
- Palatoglossus
- Styloglossus
Muscles of the Pharynx
- Pharyngeal constrictors:
Superior/Middle/Inferior constrictors - Laryngeal elevators: Palatopharyngeus/
Salpingopharyngeus/Stylopharyngeus - Palatal muscles: Tensor veli palatini/levator
veli palatini
Muscles of the Neck
- Digastric
- Mylohyoid
- GeniohyoidI
- Stylohyoid
- Sternocleidomastoid
- Omohyoid
- Sternothyroid
- Sternohyoid
- Thyrohyoid
3 layers of back muscles
- Superficial layer (extrinsic back muscles): move
the neck - Intermediate layer (extrinsic back muscles): move
the vertebral column - Deep layer (intrinsic back muscles): interconnect
the vertebrae
Superficial Layer of the Intrinsic Back
Muscles
- Splenius capitis
- Splenius cervicis
Intermediate Layer of the Intrinsic Back
Muscles
Erector spinae (group of three muscles)
* Spinalis (most medial of the three)
* Longissimus
* Iliocostalis (most lateral of the three)
The Deep Layers of the Intrinsic Back Muscles
- Transversospinales (a group of five muscles)
- Semispinalis
- Multifidus
- Rotatores
- Interspinales
- Intertransversarii
Spinal Flexors
- Longus capitis
- Longus colli
(The above two muscles rotate or flex the neck) - Quadratus lumborum
(Flexes the vertebral column laterally)
Cervical muscles
Scalene muscles (elevate ribs)
* Anterior
* Middle
* Posterior
Thoracic muscles
- Intercostal muscles
External intercostal: elevates the ribs
Internal intercostal: depresses the ribs - Transversus thoracis: depresses the ribs
Abdominal muscles
- External oblique
Compresses the abdomen/depresses ribs/laterally
flexes the torso - Internal oblique
Compresses the abdomen/depresses ribs/laterally
flexes the torso - Transversus abdominis
Compresses the abdomen
Abdominal region rectus muscle
- Rectus abdominis
Depresses ribs/flexes vertebral column - Consists of linea alba and tendinous inscriptions
Diaphragm
When it contracts, the diaphragm lowers to
increase the volume of the thoracic cavity
* Exhalation
perineal region
- Urogenital triangle (anterior triangle)
- Anal triangle (posterior triangle)
Pelvic diaphragm: forms the foundation
Appendicular muscle function
Stabilization, absorption, and movement
Action lines
Show:
Direction of pull
Muscles That Position the Pectoral Girdle
Trapezius: Rotates scapula and extend the neck
- Rhomboid: Adducts the scapula
- Levator scapulae: Elevates the scapula
- Pectoralis minor: Protracts the shoulder
- Serratus anterior: Protracts the scapula
- Subclavius: Protracts the scapula
Muscles That Move the Arm (8)
- Deltoid: Abducts the arm
- Supraspinatus: Abduction at the shoulder
- Infraspinatus: Lateral rotation at the shoulder
- Subscapularis: Medial rotation at the shoulder
- Teres major: Extension and medial rotation at
shoulder - Teres minor: Lateral rotation and adduction at
shoulder - Coracobrachialis: Adduction and flexion at
shoulder - Pectoralis major: Adducts, flexes, and medially
rotates the arm - Latissimus dorsi: Extension, adduction, medial
rotation at shoulder
Muscles That Move the Forearm and Hand (13)
- Extensor carpi ulnaris: Extension and adduction
at wrist - Triceps brachii: Extension at the elbow
- Biceps brachii: Flexion at the elbow and
supinates the forearm - Brachialis: Flexion at the elbow
- Brachioradialis: Flexion at the elbow
- Anconeus: Extension at the elbow
- Pronator teres: Pronates the forearm
- Supinator: Supinates the forearm
- Flexor carpi ulnaris: Flexion and adduction at
wrist - Flexor carpi radialis: Flexion and abduction at
wrist - Palmaris longus: Flexion at wrist
- Extensor carpi ulnaris: Extension and adduction
at wrist - Extensor carpi radialis: Extension and abduction
at wrist - Pronator quadratus: Pronates forearm and hand
Extrinsic Tendons of the Hand (2)
Flexor retinaculum and Extensor retinaculum (not muscles, pass through synovial tendon sheaths)
Intrinsic Muscles of the Hand (3)
- Lumbrical
- Dorsal interossei
- Palmar interossei
Muscles That Move the Thigh
- gluteal muscles
- lateral rotator
- adductor
- iliopsoas
gluteal muscles (5)
- Gluteus maximus
- Extension and lateral rotation at the hip
Inserts within the tensor fasciae latae via the
iliotibial tract to the tibia - Gluteus medius
Abduction and medial rotation at the hip - Gluteus minimus
Abduction and medial rotation at the hip - Tensor fasciae latae
Extension of the knee and lateral rotation of the leg
Lateral rotators (4)
- Obturator muscles
Lateral rotation and abduction of hip - Piriformis
Lateral rotation and abduction of hip - Gemelli muscles
Lateral rotation and abduction of hip - Quadratus femoris
Lateral rotation of hip
adductors (6)
- Adductor brevis
Adduction and flexion at the hip - Adductor longus
Adduction and medial rotation at the hip - Adductor magnus
Adduction at the hip - Pectineus
Flexion and adduction at the hip - Gracilis
Flexion and medial rotation at the knee - Adduction and medial rotation at the hip
iliopsoas (2)
- Iliacus
Flexion at the hip - Psoas major
Flexion at the hip
Muscles That Move the Leg (7)
- Vastus intermedius
- Vastus lateralis
- Vastus medialis
- Rectus femoris
All extend the leg
- Biceps femoris
- Semimembranosus
- Semitendinosus
All flex the leg
Flexors of the knee (2)
- Sartorius
Flexes, abducts, and laterally rotates the hip - Popliteus
Medially rotates the hip
Extrinsic Muscles of the Foot (6)
- Tibialis anterior: Dorsiflexion and inversion of the foot
- Gastrocnemius: Plantar flexion
- Fibularis brevis: Plantar flexion and eversion of the
foot - Fibularis longus: Plantar flexion and eversion of the
foot - Plantaris: Plantar flexion
- Soleus: Plantar flexion
- Tibialis posterior: Plantar flexion and inversion of the
foot
The gastrocnemius and soleus insert onto
calcaneal tendon, which inserts onto the
calcaneus
What stabilize the tendons in the
tarsal area
The superior extensor retinaculum and inferior
extensor retinaculum
Extrinsic Muscles of the Foot (4)
Flexor digitorum longus: flexion of toes 2–5
- Flexor hallucis longus: flexion of the hallux
- Extensor digitorum longus: extension of toes 2–5
- Extensor hallucis longus: extension of the hallux
Intrinsic Muscles of the Foot (6)
- Abductor hallucis: abduction of the hallux
- Flexor digitorum brevis: flexion of toes 2–5
- Abductor digiti minimi: abduction of the little toe
- Lumbricals: extension of toes 2–5
- Flexor hallucis brevis: flexion of the hallux
- Flexor digiti minimi brevis: flexion of the little toe
- Plantar aponeurosis is superficial fascia tissue of
the plantar surface of the foot
