Lecture 7 Flashcards
Latin word Muscle
little mouse
How much of the body mass does the muscle tissue take up?
aprox half of BM
What are the functions of the muscles?
(Makes Philip Jump High)
Movement
Posture maintenance
Joint stabilisation
Heat generation
What are the functional characteristics of muscle? CEEE
Contractibility – muscle cells are able to contract & generate strong pulling force
Excitability – nerve signals/ other chemical signals – excite muscles- electric pulse – muscle contraction
Extensibility – are able to stretch due to pulling force of the apposing muscles
Elasticity – are elastic, resume normal length after contraction, stretching
Name 3 things muscles are characterised by:
Three types –characterised by
How they are controlled – voluntary / involuntary
Appearance – striated (stripped) / smooth
Association – Body wall (somatic) / organs (blood vessels)
What are the 3 types of Muscles
Skeletal
Cardiac
Smooth
How much of body mass os skeletal muscle made up of?
Aprox 40%
Function of skeletal muscle
attach and move the skeleton
provides support & gives shapes / form of body
Describe the make up of the skeletal muscle
striated, parallel bundles of long multi-nucleated fibres
Is the contraction of skeletal muscle voluntary/involuntary
voluntary
Describe cardiac muscle
striated - wall of the heart & some large vessels (near heart)
cellular network – connected electronically & mechanically- fatigue resistant
Is the contraction of cardiac muscle voluntary/involuntary
Involuntary
Where is smooth muscle found?
blood vessels wall, hair follicles, eyeball, gastrointestinal, gastro urinal,
respiratory system
Describe the smooth muscle
elongated spindle shaped fibres
Describe the contraction of the smooth muscle
slow & sustained
What compartments make up muscle fibres?
are formed from the fusion of myofibres which are in turn composed of myofilaments – Myosin and actin repeated as a sacromere
What forms a fascicle?
Several muscle cells group together to form a fascicle
What forms the muscle itself.
Several fascicles group together to form the muscle itself
Name the 3 layers of a basic skeletal muscle.
Epimysium
Perimysium
Endomysium
Epimysium
overcoat, dense irregular fibres – hold whole muscle organ
Perimysium
surround fascicles (bundles of sticks)
Endomysium
surround each muscle fibre
Fuctions of the Epimysium, perimysium & endomysium :
hold muscle fibres together
Give elasticity to muscles
Hold blood vessels and nerves
Transmit the force of contraction to bones
Extend into thick cord like tendons or flat sheet called aponeurosis – attachment to bone
What is each musclel supplied by?
Each muscle – supplied by one nerve, artery & veinall these enter & exit near the middle of its length
Direct attachment?
Fascicles themselves attach
Connective tissues are short
Indirect attachment
more common
Via tendons / aponeuroses
Attach to bones, cartilage , skin, raphe (sheen of fibrous tissue), sheets of facia
Raised marking in bones for tendon attachment
Tubercles, trochanters & crests
Origin
less movable attachment
Insertation
more movable attachment
brevis
short
Direction of fasicles
- rectus
straight - parallet to body’s midline
Direction of fascicles
transvers/oblique
at the angles to midline
Location
First origin then insertation
Action
named for action
examples: flexor, extensor, adductor/ abductor
SUB OCCIPITAL group
RORO
(4)
- Rectus capitus posterior major (capitis –related to scalp)
- Rectus capitus posterior minor
- Oblique capitus superior
- Oblique capitus inferior
POSTERIOR NECK group
Cap & Cer (2)
Splenius capitus
Splenius cervicus
EXTRINSIC MUSCLE GROUP
Lets Take Ron Running Later
(5)
Levator Scapulae
Trapezius
Rhomboid minor
Rhomboid major
Latissimus dorsi
Longer the muscle
more superficial
Shorter
Deeper
Rectus capitus posterior major
Origin
spinous processes of axis (C2 vertebra)
Rectus capitus posterior major
INSERTATION
lateral portion of inferior nuchal line of occipital bone
Rectus capitus posterior major
ACTION
Extension and rotation of the head
Rectus capitus posterior major
NERVE SUPPLY
Suboccipital nerve
Describe the Nuchal lines
- curved lines on the ecternal surface of the occipital bone
- Highest nuchal line
- Superior ‘’
-Median “ - Inferior ‘’
Rectus capitus posterior minor
Origin
posterior tubercle of C1
Rectus capitus posterior minor
Insertation
Medial aspect of the inferior nuchal line of occipital bone
Rectus capitus posterior minor
Action
Extends head
Rectus capitus posterior minor
Nerve Supply
Suboccipital nerve
Oblique capitus superior
Origin
TVP of atlas
Oblique capitus superior
Insertation
occipital bone between the
superior and the inferior nuchal lines
Oblique capitus superior
Action
Extends head and flexes head laterally to the same side
Oblique capitus superior
Nerve Supply
Suboccipital nerve
Oblique capitus inferior
Origin
spinous process of the axis
Oblique capitus inferior
Insertation
TVP of atls
Oblique capitus inferior
Action
Rotates atlas
Oblique capitus inferior
Nerve supply
suboccipital nerve
Describe the Splenius capitus
broad, straplike muscle in the back of the neck
What does the Splenuis capitus pull on?
pulls on the base of the skull from vertebrae in the neck and upper thorax
What does the Splenuis capitus lie deep to? RTS
the rhomboid, trapezoid and sternomastoid muscles
Splenius capitus
Origin
Lower part of ligamentum nuchae, SP of C7 and upper 3 or 4 thoracic vertebrae (T1-T4)
Splenius capitus
Insertation
(runs upward and laterally)
mastoid process of the temporal bone, lateral part of the superior nuchal line
Splenius capitus
Action
Acting together: Extend, hyperextend head and neck
Acting on one side: laterally flex, rotate head and neck
Splenius capitus
Nerve Supply
dorals primary rami
Splenius cervicus
Origin
SP T3- T6
Splenius cervicus
Insertation
posterior tubercles of TVPS of C1-c3
Splenius cervicus
Action
Acting together: Extend, hyperextend head and neck
Acting on one side: laterally flex, rotate head and neck
Splenius cervicus
Nerve supply
dorsal primary rami
splenion
meaning a bandage
Levator Scapulae
Shoulder girdle
Levator Scapulae
Origin
posterior tubercles of TVPs of C1-C4
Levator Scapulae
Insertation
: medial border of scapular at and above spine
Levator Scapulae
Action
Elevates medial border of scapula
Rotates scapula to lower the lateral angle
Acts with trapezius and rhomboids to pull scapula medially and upward. Bends neck laterally
Levator Scapulae
Nerve supply
dorsal scapular nerve
Trapezius
(superficial back musculature group)
Trapezius
Origin
Medial 1/3 of sup nuchal line
EOP ligamnetum nuchae
SP & Supraspinous ligaments of C7-T12
Trapezius
Insertation
Upper part – lateral third of clavicle
Middle part – acromion and spine of scapula
Lower part – medial portion of spine of scapula
Where does the deltiod originate from ?
Anatomical horse shoe
Trapezius
Actions
Upper part – elevates scapula
Middle part – retracts (adducts) scapula
Lower part – depresses scapula
Upper and lower parts together rotate scapula
Trapezius innervation
Accessory nerve
cranial nerve 11
Rhomboid major
Origin
spinous processes of T2-T5
supraspinous ligament
Rhomboid major
Insertation
medial boreder of scapula below of the spine
Rhomboid major
Action
Retract - adduct scapula - towards midline
Rhomboid major
Innervation
Dorsal scapular nerve
Rhomboid minor :
origin
spinous process of C7 & T1
lower part of ligamentum nuchae
Rhomboid minor :
Insertion:
medial border of scapular at root of spine
Rhomboid minor :
Action
retract sacpula
Rhomboid minor
Innervation
dorsal scapula nerve
Latissimus dorsi:
(superficial back musculature group)
Latissimus dorsi:
Origin
SP T7-T12
SP L1- L5
SP S1- S4
Supraspinal ligament, iliac crest, outer surfaces of lower 3 or 4 ribs
Inferior angle of scapula
Latissimus dorsi:
Insertation
Bottom of intertubercular groove (humerus)
Latissimus dorsi:
Action
Extends, adducts, and medially rotates arm, downward rotation of the scapula
Latissimus dorsi:
innervation
Thoracodorsal Nerve
