8.Muscles Of The Head Comnpleted

Question 1

What is the essential function of the muscle

Answer 1

Is to contract/or shorten- a unique charter is tic that sets it apart from other body tissues
]as a result- muscles are responsible for all body tissue movements Anne can be viewed as the machines of body

Question 2

What are the three types of muscle ?

Answer 2

1- skeletal- striated, voluntary
2- cardiac, striated, involuntary
3- smooth involuntary

Question 3

What are skeletal muscle fibres>

Answer 3

Fibres are Packaged into organs called skeletal muscles that attach to skeleton
Fibres are large, cigar shaped,multinucleate cells
Largest of muscle fibres
Also known as striated muscle and voluntary

Question 4

Describe an overview of skim structure

Answer 4

Striated
Structure: joined muscle cells from muscle fibres surrounded by endomysium
Bundles of f form fascicles surrounded by perimysium
Multiple fascicles form muscle surrounded by epimysium
Muscle and epimysium are covered by fascia
Muscle attaches to bones via tendons

Question 5

Explain the mysiums of skim

Answer 5

Endomysium- ct sheath enclosing each muscle fibre
Peri- fibrous membrane wrapping several sheathed muscle fibres, which forms bundle called fascicle
Epi- tougher overcoat of ct which bounds many fascicles
Tendon/aproneurosis - the ends of epi that extend beyond muscle blend into either cork like tendon, sheath like aponeurosis

Question 6

Describe the cardiac muscle

Answer 6

Is found in the heart only where it forms the bulk of heart wall
Heart serves as a pump- propelling blood through blood vessels to all body tissues
Sriated
Uni nucleate
Involuntary control

Question 7

Describe the smooth muscle

Answer 7

No striations
Involuntary
Found mainly in walls of hollow organs
Uni nucleate
Arranges un layers- normally one running circularly and one longitudinally
These layers can change size/shape of orga as they contract/relax

Question 8

What is the function of the skeletal muscle ?

Answer 8

Produce movement
Maintain posture/body position
Stabilise joints
Generate heat

Question 9

Describe the interactions of sk m in body

Answer 9

Muscles can’t push- only pull as they contract- most body movement results from two+ muscles working together or against each other
They are arranges so that whatever one can do, the other muscles can reverse
In general - groups of m that produce opposite movements lie on opposite sides of joint
Prime mover- muscle that has major responsibility for causing a particular movement

Question 10

What are antagonists?

Answer 10

Antagonists- muscles that reverse/oppose movement- when prime move is active- antagonist = stretched and relaxed- they can be prime movers in their own right but for different actions
Ie biceps brachii and brachial muscles of arm (prime moral of elbow flexation|) are antagonised by triceps brachii |(a prime mover of elbow extension?

Question 11

What are synergists?

Answer 11

Help primers move by producing same movement or by reducing under sir able movements.
When muscle crosses two/more joints its contraction will cause movement in all the joints crossed unless synergists are used to stabilise them

Question 12

What are fixators?

Answer 12

Specialised synergists, they hold a bone still or stabilise the origin of a prime mover

Question 13

Naming skeletal muscle fibres

Answer 13

Direction of m fibres- rectus - straight
Relative size of m- maximus(largest), minimus (smallest)
Location of muscle
Number of origins- biceps,triceps,quadriceps
Location of muscles origin and insertion- sternocleidomastoid ( sterno= sternum cleido= clavicle)
Shape of muscle- deltoid - triangular
Action of muscle- flexor, extensor, adductor

Question 14

What are the arrangement of fascicles ?

Answer 14

Circular
Convergent
Parallel
Fusiform
Pennate- up pen ate -bi-multi

Question 15

Describe muscle of the scalp

Answer 15

Occio-pito-frontalis

Orgin- occipital belly : lateral thirds of superior nuchal line on occipital bone and mastoid part of temporal n bone
Frontal belly- fibres continuos with those of procerus medially and orbicularis oculi laterally

Insertion- into galea aponeurotia
Innervation- posterior auricular branch of facial nerve v11
Action- draws back scalp, raises eyebrows, wrinkles forehead in expression of surprise

Question 16

Muscles of scalp

Answer 16

TEMPORO-PAREITAL-IS

Origin- from temporal fascia above and in front of auricle of ear
Insertion- onto temporal fascia and skin on side of head
Innervation- temporal branch of facial nerve v11
Action- tightens scalp and draws back skin of temples

Question 17

Extrinsic muscle of ear

Answer 17

Anterior Auricular

Origin- anterior part of temporal fascia
Insertion- onto spine of helix
Innervation- posterior auricular branch of facula nerve v11
Action- draws auricle backward - minimal action

Question 18

Extrisinc muscle of ear

Answer 18

Superior Auricular

Origin- epicranial aponeurosis
Insertion- upper part of cranial surface of auricle of ear
Innervation- temporal b ranch of facial nerve v11
Action- draws auricle of ear upward- minimal action

Question 19

Extrinsic muscle of ear

Posterior auricular

Answer 19

Posterior auricular
Origin- mastoid process of temporal bone
Insertion-medial surface of auricle at convexity of concha
Innervation- temporal branch if facial nerve v11
Action- draws auricle of ear upwards- minimal action

Question 20

Muscle of the eyelid
Orbi-cularis : palpebral part

Answer 20

Origin- medial palpebral ligament
Insertion- cross the eyelids and interlace t form lateral palpebral raphe (ridge/groove)
Innervation: temporal and zygomatic branches if factual nerve v11
Action- closes eyelids gently as in sleeping/blinking

Question 21

Muscles of eyelids
Orbi-cularis oculi : orbital part

Answer 21

Origin- nasal part of frontal bone, frontal process of maxilla: medial palpebral ligament]
Insertion- forms elipse around orbit without interruption on lateral side
Innervation- temporal/zygomatic branches of facial nerve v11
Actions- closes eyelids when a more forceful contraction is nessecary- winking

Question 22

Muscle of eyelids
Corrugator supercilii

Answer 22

Origin- medial end of superciliary arch
Insertion- deep surface of sin above middle of supraorbital margin
Innervation- temporal branch of facial Nerve v11
Action- draws eyebrows medially and down

Question 23

Muscles of the nose
Procerus

Answer 23

Origin- from fascia over lower part of nasal bone
Insertion- into skin of lower part of forehead between eyebrows
Innervatiob- buccal branch of facial nerve v11
Action- draws down the medial angle of eyebrows- frowning- or in concentration

Question 24

Muscles of nose]
Nasalis transverse part

Answer 24

Origin- from maxilla lateral to nasal notch
Insertion- ascends to bridge of nose
Innervatiion- buccal branch if facial nerve v11
Action- compresses nasal aperture

Question 25

Muscles of nose Nasalis alar part

Answer 25

Origin- from maxilla above the lateral incisor tooth Insertion- attaches to cartilaginous ala of nose Innervation- buccal branch of facial nerve v11 Action- assists in opening the nasal aperture in deep inspiration

Question 26

Muscles of the mouth Levator labii superioris

Answer 26

Origin- along lower part of orbit from maxilla/zygomatic bones Inversion- upper lip between levators anguli orris and labii superioris alaque Nass Innervation- buccal branch of the facial nerve v11 Action raises upper lip and carries it forward

Question 27

Muscle of mouth Levator labii superioris alaque nasi

Answer 27

Origin- upper part of frontal process of maxilla Insertion- Insterys by two slips: into alar cartilage and into upper lip with Levator labii superioris Innervation- buccal branch if facial nerve v11 Action- raises upper lip_+ dilates nostril

Question 28

Muscles of mouth Levator anguli orris

Answer 28

Origin : canine fossa of maxilla - just below infra orbital fora men Insertion- into angle of mouth, merging with orbbicularis orris, depressor anguli orris and zygomatic us major Innervation- buccal branch of facial nerve v11 Action- raises angle of mouth +forms nasolabial furrow

Question 29

Muscles of mouth Zygomaticus minor

Answer 29

Origin- lateral surface of zygomatic bone Insertion - upper lip between Levator superioris and zygomaticus major Innervation- buccal branch of facial nerve v11 Action- elevates upper lip and helps form nasolabial furrow

Question 30

Muscles of mouth Zygomaticus major

Answer 30

Origin- from zygomatic bone in front of zygomatic o-temporal suture Insertion- into angle of mouth with Levator and depressor anguli orris and orbiculari orismuscles Innervation- buccal branch facial nerve v11 Action- draws angle of mouth upwards/backwards- laughing

Question 31

Muscles of mouth Risorious

Answer 31

Origin- from parotid over masseter muscle Insertion- into skin at angle of the mouth Innervation- buccal branch facial nerve v11 Action- retracts angle of mouth

Question 32

Muscles of mouth Depressor labii inferior-is

Answer 32

Origin- oblique line of mandible between symphysis Menti and the mental fora men Insertion- into lower lip and at midline , blending with muscle from other side Innervation- Mandi ulnar branch of facial nerve v11 Action- draws the lower lip downward and bit laterally

Question 33

Muscle mouth Depressor anguli orris

Answer 33

Orgin- from oblique line of mandible , lateral and below depressor labii inferior-is Insertion- into angle of mouth. Blending with orbicularis orris and risorius Innervation- Mandibular branch of facial nerve v11 Action- draws angle of mouth down and laterally - in expression of sadness

Question 34

Muscles of mouth Mentalist

Answer 34

Origin- from incisive fossa of mandible Insertion- into skin of chin Innervation- mandibular branch of facial nerve v11 Action- raise/protrudes lower lip: wrinkles chin in expression of doubt/distain

Question 35

Muscle of mouth Orbicularis orris

Answer 35

Origin- fibres derived from other facial muscles- (buccinator, levators, depressors, of lips and angles, zygomatic muscle) pass into lips: also some intrinsic muscle fibres make up orbicularis orris Insertion- several strata of muscle fibres form spinchter like muscle with fibers that decussate (intersect) at angles of mouth Innervation- buccal branch of facial nerve v11 Action- closes lips and its deep fibres can press lips against teeth, also it protrudes the lips - important in speech

Question 36

Muscle of mouth Buccinator

Answer 36

Origin: alveolar process of mandible and maxilla; posteriorly it arises from the pterygomandibular raphe (ridge) opposite superior constrictor Insertion: fibers course forward to blend into the formation of the orbicularis oris, decussating at the angles of the mouth Innervation: buccal branch of the facial nerve (VII) Action: compresses the cheeks during chewing; also compresses the

Question 37

MUSCLES OF MASTICATION Masseter

Answer 37

Origin: zygomatic surface of maxilla and the zygomatic arch Insertion: lateral surface of ramus mandible and the coronoid process of mandible Innervation: masseteric branch of mandibular nerve (branch of trigeminal cranial nerve V) Action: closes the jaw by elevating the mandible

Question 38

MUSCLES OF MASTICATION Lateral pterygoid

Answer 38

Origin: superior head: infratemporal crest and lateral surface of greater wing of sphenoid bone; inferior head: lateral surface of lateral pterygoid plate of sphenoid Insertion: neck of condyle of mandible; articular disk and capsule of temporomandibular joint Innervation: lateral pterygoid branch of mandibular nerve (branch of trigeminal cranial nerve V) Action: opens mouth by drawing condyle and disk forward; acting together: protrudes mandible

Question 39

MUSCLES OF MASTICATION Medial pterygoid

Answer 39

Origin: Deep head: medial surface of lateral pterygoid (wing like) plate of sphenoid; pyramidal process of palatine bone; Superficial head: pyramidal process of palatine bone; tuberosity of maxilla Insertion: lower and posterior part of medial surface of ramus and angle of mandible Innervation: medial pterygoid branch of mandibular nerve (branch of trigeminal cranial nerve V) Action: elevates mandible closing jaw; acting together protrudes mandible; acting alone: protrudes one side 45