Term
Lever Systems: Bone-Muscle Relationships
*Bones –
*Joints –
*Muscle contraction –
*Load – |
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Definition
Lever Systems: Bone-Muscle Relationships
*Bones – act as levers
*Joints – act as fulcrums
*Muscle contraction – provides effort
-Applies force where muscle attaches to bone
*Load – bone, overlying tissue, and anything lifted |
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Term
Levers allow a given effort to:
2 |
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Definition
Levers allow a given effort to:
Move a heavier load
Move a load farther |
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Term
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Definition
Mechanical advantage
Moves a large load over small distances |
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Term
First-class lever
Effort applied at
Load is at
Fulcrum is located |
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Definition
First-class lever
Effort applied at one end
Load is at the opposite end
Fulcrum is located between load and effort
lifting the head |
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Term
Second-class lever
Effort applied at
Fulcrum is at the
Load is
Examples –
An uncommon type of lever in the body
Work at a mechanical _____ |
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Definition
Second-class lever
Effort applied at one end
Fulcrum is at the opposite end
Load is between the effort and fulcrum
Examples – wheelbarrow or standing on tiptoe
An uncommon type of lever in the body
Work at a mechanical advantage |
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Term
Third-class lever
Effort is applied ____
Work _____
mecanincal ______
most common for _____ muscles |
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Definition
Third-class lever
Effort is applied between the load and the fulcrum
Example – biceps brachii
Fulcrum – the elbow joint
Force – exerted on the proximal region of the radius
Load – the distal part of the forearm
Work speedily
mecanincal disadvantage
most common for skeletal muscles |
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Term
Types of fascicle arrangement
Parallel – fascicles run parallel to the long axis of the muscle
Strap-like – _______
Fusiform – ______ |
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Definition
Types of fascicle arrangement
Parallel – fascicles run parallel to the long axis of the muscle
Strap-like – sternocleidomastoid
Fusiform – biceps brachii |
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Term
Types of fascicle arrangement
Convergent
Origin of the muscle is _____
Fascicles _____ toward the tendon of insertion
Example – ________ |
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Definition
Types of fascicle arrangement
Convergent
Origin of the muscle is broad
Fascicles converge toward the tendon of insertion
Example – pectoralis major |
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Term
Types of fascicle arrangement
Pennate
Unipennate – fascicles insert ____
Bipennate – fascicles insert into ____
Multipennate – fascicles insert into _____ |
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Definition
Types of fascicle arrangement
Pennate
Unipennate – fascicles insert into one side of the tendon
Bipennate – fascicles insert into the tendon from both sides
Multipennate – fascicles insert into one large tendon from all sides |
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Term
Circular – fascicles are arranged in __
Surround external ____
Sphincter – general name for a circular muscle
Examples – ________,______ |
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Definition
Circular – fascicles are arranged in concentric rings
Surround external body openings
Sphincter – general name for a circular muscle
Examples – orbicularis oris and orbicularis oculi |
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Term
| Muscles with opposite actions lie on opposite sides of a ______ |
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Definition
| Muscles with opposite actions lie on opposite sides of a joint |
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Term
| Prime mover (____) – has major responsibility for a certain movement |
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Definition
| Prime mover (agonist) – has major responsibility for a certain movement |
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Term
| ______ – opposes or reverses a movement |
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Definition
| Antagonist – opposes or reverses a movement |
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Term
_____ – helps the prime mover
By adding _____
By reducing _____
_____ – a type of synergist that holds a bone firmly in place |
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Definition
Synergist – helps the prime mover
By adding extra force
By reducing undesirable movements
Fixator – a type of synergist that holds a bone firmly in place |
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Term
Naming the Skeletal Muscles
Location of attachments – name reveals point of origin and insertion
Example – brachioradialis
Origin is always named _____ |
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Definition
Naming the Skeletal Muscles
Location of attachments – name reveals point of origin and insertion
Example – brachioradialis
Origin is always named first |
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Term
| Number of _____ is indicated by the words biceps, triceps, and quadriceps |
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Definition
| number of origins is indicated by the words biceps, triceps, and quadriceps |
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Term
| Muscles develop from _____ (germ layer) |
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Definition
| Muscles develop from mesoderm |
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Term
| Limb muscles arise from ______ |
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Definition
| Limb muscles arise from lateral parts of nearby myotomes |
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Term
| Muscle mass dorsal to limb bones – _____ |
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Definition
| Muscle mass dorsal to limb bones – extensors |
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Term
| Muscle mass ventral to limb bones – ____ |
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Definition
| Muscle mass ventral to limb bones – flexors |
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Term
| _______ tissue divides limb muscles into compartments |
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Definition
| Dense fibrous connective tissue divides limb muscles into compartments |
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Term
Muscles in opposing compartments are
_____ and ____ pairs |
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Definition
Muscles in opposing compartments are
Agonist and antagonist pairs |
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Term
| Each compartment is innervated by _____ |
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Definition
| Each compartment is innervated by a single nerve |
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Term
| The upper limb has ____ and _____ compartments |
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Definition
| The upper limb has anterior and posterior compartments |
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Term
Anterior arm compartment muscles
____ the shoulder or arm
____ the wrist and digits |
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Definition
Anterior arm compartment muscles
Flex the shoulder or arm
Flex the wrist and digits |
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Term
Muscle Compartments of the Thigh
Posterior compartment muscles
____ the hip and ___ the knee
Medial compartment
___ the thigh
Anterior compartment muscles
___ the hip and ____ the knee |
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Definition
Muscle Compartments of the Thigh
Posterior compartment muscles
Extend the hip and flex the knee
Medial compartment
Adduct the thigh
Anterior compartment muscles
Flex the hip and extend the knee |
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Term
Compartments of the Leg
Posterior compartment muscles
Contains digital and plantar _____
Anterior compartment muscles
Contains digital ____ and ____
Lateral compartment muscles
Plantar flex and avert the foot |
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Definition
Compartments of the Leg
Posterior compartment muscles
Contains digital and plantar flexors
Anterior compartment muscles
Contains digital extensors and dorsiflexors
Lateral compartment muscles
Plantar flex and avert the foot |
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Term
Muscles of facial expression
Lie in the ___ and ___
Thin and variable in shape
Often insert in the ___ – not on bones
Innervated by cranial nerve VII – the ___ nerve |
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Definition
Muscles of facial expression
Lie in the face and scalp
Thin and variable in shape
Often insert in the skin – not on bones
Innervated by cranial nerve VII – the facial nerve |
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Term
Four main pairs of muscles involved in mastication
Innervated by mandibular division –
the trigeminal nerve
Prime movers of jaw closure – ____ and ____
Side-to-side movement – _____ muscles
Compression of cheeks – _____ muscles |
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Definition
Four main pairs of muscles involved in mastication
Innervated by mandibular division –
the trigeminal nerve
Prime movers of jaw closure – masseter and temporalis
Side-to-side movement – pterygoid muscles
Compression of cheeks – buccinator muscles |
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Term
Tongue Movement
Extrinsic muscles of the tongue
protracts-
retracts-
depresses-
All innervated by cranial nerve XII – the ____ nerve |
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Definition
Tongue Movement
Extrinsic muscles of the tongue protracts-genioglossus, retracts-styloglossus, depresses-hyoglossus
All innervated by cranial nerve XII – the hypoglossal nerve |
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Term
Head movement
Sternocleidomastoid - head _____ |
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Definition
Head movement
Sternocleidomastoid - head flexion |
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Term
Deep muscles provide movements for breathing
External intercostal muscles
____ the ribcage
Internal intercostal muscles
May aid _____ during heavy breathing
Diaphragm – most important muscle of respiration
Flattens as it ____ – increases the volume of the thoracic cavity |
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Definition
Deep muscles provide movements for breathing
External intercostal muscles
Lift the ribcage
Internal intercostal muscles
May aid expiration during heavy breathing
Diaphragm – most important muscle of respiration
Flattens as it contracts – increases the volume of the thoracic cavity |
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Term
Lateral and anterior abdominal wall
Formed from three flat muscle sheets
External oblique-
Internal oblique-
Transversus abdominis- |
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Definition
Lateral and anterior abdominal wall
Formed from three flat muscle sheets
External oblique - flexes vertebra compresses ab wall, lateral flexion, trunk rotation
Internal oblique
Transversus abdominis _compresses abdominal contents |
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Term
| Rectus abdominis – inserts at linea ___ |
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Definition
| Rectus abdominis – inserts at linea alba |
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Term
Muscles of the Pelvic Floor
Pelvic floor (pelvic diaphragm)
Sheet of two muscles – both support pelvic organs
name one ____ |
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Definition
Muscles of the Pelvic Floor
Pelvic floor (pelvic diaphragm)
Sheet of two muscles – both support pelvic organs
Levator ani – |
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Term
Muscles of the Perineum
Inferior to the muscles of the pelvic floor
Urogenital diaphragm formed from:
____ and the deep ______ |
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Definition
Muscles of the Perineum
Inferior to the muscles of the pelvic floor
Urogenital diaphragm formed from:
Sphincter urethrae and the deep transverse perineus |
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Term
Superficial Muscles of the Anterior Thorax
Movements of the scapula
Pectoralis major
Pectoralis minor
Serratus anterior |
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Definition
Superficial Muscles of the Anterior Thorax
Movements of the scapula
Pectoralis major- prim mover of arm flexion, rotates arm medially, adducts arm against resistance
Pectoralis minor- dras scapula down and forward, or ribs up.
Serratus anterior- protacts and holds scapula against chest |
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