Week 4: Muscles Flashcards
2
Stylohyoid Muscle
Name the extraoculae muscle/s that would be primarily active in the following movement of the eye:
Intorsion
Superior oblique
7
Medial rectus muscle
3
Auricularis Posterior muscle
What are the 4 intrinsic muscles? What is their role and how do they work?
Superior longitudinal, Vertical, Transverse and the Inferior longitudinal muscles.
Intrinsic muscles protrude, retrude, curl, uncurl, flatten and round the tongue.
They do this by working in pairs, or by one side at a time to perform precise movement.
What muscle/s is/are primary being used here:
Occipitofrontalis
List the 7 extraocular eye muscles and explain their attachments.
- 4 rectus muscles; Superior, inferior, lateral and medialand they all share a common posterior origin at a tendenous ring known as the annulus of Zinn, and they insert anteriorly onto the eye’s sclera (white part)
- 2 oblique muscles: Supeior and inferior. They insert on a more posterior aspect of the sclera.
- 1 within the eyelid: Levator palpebrae superioris and this muscle opens the upper eyelid.
8
Superior Rectus muscle
3
Genioglossus Muscle
What is the role of the Musculus Uvulae?
Shortens and pull uvula superiorly
11
Zygomaticus minor muscle
What muscle/s is/are primary being used here:
Risorius
What is the role of the transverse intrinsic tongue muscle?
Narrow (elongate) and protrude tongue (acts simultaneously with vertical muscle)
8
Depressor labii inferioris muscle
2
Palatoglossus
9
Short limb of incus
4
Palatoglossal arch
2
Stapes (specifically the footplate)
4
Mylohyoid Muscle
How is the palate divided between the soft and hard regions?
Anterior 2/3 is hard palate
Posterior 1/3 is soft palate
3
Palatine Tonsils
In relation to the oral cavity, Name the structure being described by the following general terms:
area between cheeks and teeth
Oral vestibule
What muscle/s is/are primary being used here:
Levator labii superioris and depressor labii
16
Procerus muscle
2
Hyoglossus Muscle
What is the role of the vertical intrinsic tongue muscle?
Flattens and broadens tongue (acts simultaneously with transverse muscle)
6
Tympanic Cavity
In relation to the oral cavity, Name the structure being described by the following general terms:
Posterior aperture (opening)
Oropharyngeal isthmus (which opens into to orophraynx)
In relation to the oral cavity, Name the structure being described by the following general terms:
Inner area enclosed by dental arch
Oral cavity (proper)
13
Alar part of nasalis muscle
5
Eustachian tube (aka; Pharyngotympanic tube or auditory tube)
List the main functions of the oral cavity. (3)
- Inlet for digestive system: Mastication and salivary secretion
- Manipulates sounds produced by larynx for speech
- Can be used for breathing as it opens into pharynx
What is the role of the palatoglossus?
Draws soft palate onto tongue
10
Zygomaticus major muscle
In relation to the oral cavity, Name the structure being described by the following general terms:
Opening to the oral cavity
Oral fissure
1
Head of malleus
4
Palatoglossus Muscle
2
Auricularis superior muscle
1
Uvula
8
Tympanic Membrane
10
Superior oblique muscle
What is the role of the superior longitudinal intrinsic tongue muscle?
Curls apex of tongue upward and can retrude the tongue.
10
Tegman typani
2
Lateral Rectus muscle
5
Mentalis
4
Platysma Muscle
5
Hyoglossus Muscle
What muscle/s is/are primary being used here:
Orbicularis oris
What is the muscle labeled “A” ?
Temporalis Muscle (Left)
7
Depressor anguli oris muscle
5
Lateral rectus muscle
What is the role of the inferior longitudinal intrinsic tongue muscle?
Curls apex of tongue downward, and can retrude the tongue.
17
Corrugator supercilii muscle
What is the origin, Insertion and Action of the Lateral Pterygoids?
O: Greater wing of sphenoid, Infratemporal fossa, and lateral surface or lateral pterygoid plate.
I: Condyloid process and joint disc and capsule of TMJ
A: Bilateral: Protrusion of mandible. Unilateral: Lateral incursion to opposite side of the contracting muscle.
What is the origin, insertion, and action for the Temporalis muscle?
O: Termporal fossa
I: Coronoid process on mandible and also on the anterior border of ramus of mandible.
A: Elevation of mandible, retraction (using oblique fibers) and lateral incursion to same side as the muscle
3
Palatine Tonsils
Name the extraocular muscle/s that would be primarily active in the following movements of the eye:
Elevation
Inferior oblique and superior rectus. (mainly superior rectus)
In relation to the oral cavity, Name the structure being described by the following general terms:
Floor
Mainly soft tissue including tongue and musclular diaphragm.
6
Buccinator muscle
7
External acoustic meatus
9
Mentalis Muscle
What muscle/s is/are primary being used here:
Orbicularis Oculi
5
Risorius Muscle
3
Handle of malleus
Name the extraoculae muscle/s that would be primarily active in the following movement of the eye:
Abduction
Lateral rectus
3
Nasalis (alar part)
1
Trochlea (pulley)
What muscle/s is/are primary being used here:
Risorius and depressor labii inferioris
18
Frontal belly of occipitofrontalis muscle
What muscle/s is/are primary being used here:
Zygomaticus Major and Zygomaticus Minor
What is the structure labelled “A” ?
Medial pterygoid (left)
What is present in the posterioinferior margin of the soft palate?
The Uvula
What muscle/s is/are primary being used here:
Corrugator Supercilli
20
Orbital part of orbicularis oculi muscle
1
Nasalis (transverse part)
What muscle/s is/are primary being used here:
Buccinator and orbicularis oris
What are the two types of movements of the eyes? explain them.
Conjugate movements: Two eyes move the same amount in the same direction as in visual tracking of an object (move an object onto the tetina and keep it there)
Vergence movements: Two eyes move in opposite directions as in convergence when we look at close objects (slightly cross eyed)
What muscle/s is/are primary being used here:
Procerus and transverse part of nasalis
Name the extraoculae muscle/s that would be primarily active in the following movement of the eye:
Extorsion
Inferior Oblique
4
Musculus Uvulae
9
Levator Palpebrae superioris muscle
What is the structure labelled “A” ?
Lateral pterygoid (Right)
In relation to the oral cavity, Name the structure being described by the following general terms:
Lateral Walls
Cheeks
What is the role of the Palatopharyngeus
Tenses soft palate and pulls walls superiorly, anteriorly and medially during swallowing.
What muscle/s is/are primary being used here:
Dilators of mouth: Risorious, levator labii superioris and depressor labii interioris
1
Palatopharyngeus
What are the 3 groups of muscles involved in facial expression (include thier actions)? What nerve innervates them? What do most of these bones have in common as far as GENERAL origin and insertion go?
The orbital group: Eyebrows: elevate, draw inferiorly and medially. Cose eyes gently and more forcefully
Nasal Group: Flare nostrils, compress nasal apertures, draw nose inferiorly, wrinkle skin on the upper nose.
Oral/Cheek Group: Mouth: Close mouth, open upper lip, depress lower lip, act on angle of the mouth to elevate, widen or depress, protrude lips, compress cheeks against teeth of compress distended cheeks.
- Innervated by facial nerve VII
- Most of these muscles originate on bone or fascia and insert into skin to change facial expressions and convey mood.
List the extrinsic muscles of the tongue. What nerve/s are they innervated by? What movements of the tongue are they responsible for?
- Styloglossus, hpyoglossus and genioglossus are innervated by the hypoglossal nerve (XII)
- The palatoglossus is innervated by a branch of the vagus nerve (X)
The extrinsic muscles can protrude, retract, elevate and depress the the tongue
What muscle/s is/are primary being used here:
Platysma
1
Auricularis Anterior Muscle
14
Transverse part of nasalis muscle
What muscle/s is/are primary being used here:
Depressor anguli oris
The oblique and recti extraocular muscles can move the eyeball in a:
Horizontal plane (abduction and adduction)
- Up and down (superiorly and inferiorly)
- around an anteroposterior axis (intorsion/internal rotation: Where the upper part of the pupil is rotated medially towards the nose, and Extorsion/external rotation: where it is rotated laterally)
3
Inferior oblique muscle
Name the extraoculae muscle/s that would be primarily active in the following movement of the eye:
Adduction
Medial rectus
12
Orbicularis oris muscle
4
Levator Labia superioris
Laterally the soft palate is coninuous with what structure?
Walls of the pharynx
Name the suprahyoid muscles. What do they attach to? What do they do? What are their innvervations?
- Anterior digastric: Trigeminal nerve (V)
- Mylohyoid: Trigeminal Nerve (V)
- Stylohyoid: Facial Nerve (VII)
- Posterior Digastric: (Facial Nerve (VII)
All attach to the superior margin of hyoid bone.
They serve to: Help lift the floor of the mouth, Push up against the tongue, Lift the hyoid bone, and help depress the mandible.
4
Inferior rectus muscle
1
Posterior Digastric Muscle
2
Palatopharyngeal arch
19
Palpebral part of orbicularis oculi muscle
2
Levator labia superioris alaeque nasi muscle
Name the two muscles found within the tympanic cavity and breifly explain the attachments and explain their purposes.
Tensor Tympani - Inserts onto malleus and pulls it medially therefor decreasing the amplitude of its oscillations.
Stapedius - Attaches to the stapes and prevents excessive movement
Both muscles prevent damage to the inner ear when exposed to loud noises.
what 2 arches connect the soft palate laterally to the tonge and pharynx?
The palatoglossal and palatopharyngeal arches.
1
Styloglossus Muscle
3
Anterior Digastric Muscle
What muscle/s is/are primary being used here:
Levator Labii Superioris Alaeque nasi and alar part of nasalis
15
Levator labii superioris muscle
What is the origin, insertion and action for the medial pterygoid muscles?
O: Medial surface of lateral pterygoid plate, partly on the tuberosity of the maxilla and also partly on the process of the palatine bone.
I: Medial surface of ramus of mandible
A: Bilateral: Elevation of mandible. Unilateral: Lateral incersion to opposite side of the contracting muscle.
What is the origin, isertion and action for the masseter muscle?
O: Zygomatic arch and maxillary process of zygomatic bone
I: Angle and lateral surface of ramus of mandible
A: Elevation of mandible
List the 4 muscles of mastication. What nerves supply all 4 of these muscles? What joint do they act on? What movements are permitted by these muscles at this joint? Which two of the muscles are superficial, and which two are deep?
- Massetter, Temporalis, Lateral and medial Pterygoids.
- All supplied by trigeminal nerce (V3)
- All acting on the mandible at the temporomandibular joint (TMJ)
- TMJ can; Elevate/depress, Protrude/Retrude, and laterally incur.
- Masseter and temporalis are superficial whilst both the lateral and medial pterygoids are deep.
4
Tensor tympani muscle
In relation to the oral cavity, Name the structure being described by the following general terms:
Roof
Hard and soft palate
Name the extraoculae muscle/s that would be primarily active in the following movement of the eye:
Depression
Superior oblique and inferior rectus (primarily inferior rectus)
What muscle/s is/are primary being used here:
Mentalis
What is the muscle labelled “A” ?
Masseter (Deep and superfical parts) (Left)
6
Common tendinous ring at the superior orbital fissure/of Zinn
Label Muscles A and B.
A = Lateral Pterygoid (superior and inferior heads) (left)
B = Medial Pterygoid (left)
1
Levator Veli palatini
2
Palatopharyngeus
3
Palatoglossus
4
Tensor veli palatini
What is the role of the levator veli palatini?
Elevates the soft palate
What is the role of the tensor veli palatini?
Tenses the lateral walls of the nasopharynx to hold fauces (arched opening leading to pharynx) open
1
Stylopharyngeus
2
Superior Constrictor muscle of the pharynx
3
Middle constrictor muscle of the pharynx
4
Inferior Constrictor muscle of the pharynx
1
Salpingopharyngeus
2
Palatopharyngeus
1
Levator Veli Palatini
2
Salpingopharyngeus
3
Palatopharyngeus
4
Inferior constrictor muscle of the pharynx
5
Middle constrictor muscle of the pharynx
6
Stylopharyngeus
7
Superior Constrictor muscle of the pharynx
What is the neurocranium derived from?
The neural crest cells and mesoderm.
What is the viscerocranium derived from?
From neural crest cells or cartilage within pharyngeal arches 1 and 2 (mainly 1 though)
What are the muscle groups within the head derived from? (generally speaking)
Pharyngeal arches
How do the somitomeres come about?
In week 3 the mesoderm either side of the notochord forms cylindrical structures called paraxial mesoderm which then become rounded structures called somitomeres.
what happens next to the somitomeres in week 3-4? explain the differentiation between which somitomeres get paired and which dont.
In week 3 to 4 the somitomeres continue to develop in craniocaudal sequence from cervical to coccygeal regions.
Most somitomeres develope further into discrete blocks called somites (approx 37 pairs) except the first 7.
Some cells from within somitomeres 1-7 enter the pharyngeal arches and give ride to muscles of face, jaw and throat.
How do pharygeal arches develop? describe the ordering of the layers, and also explain what the arches will contain (generally).
Pharyngeal arches develop in a craniocaudal sequence during day 22-29.
Consists of a mesodermal core with an ectoderm on the outside and an endoderm on the inside.
Within each pharyngeal arch there will be central cartilage, muscles with thier artery and nerve.
5 arches will form: 1,2,3,4,6 (5 dissapears)
What are some notable features that can be seen on an image of a day 27 embryo?
Maxillary and mandibular swelling on pharyngeal arch 1
What muscles derive from pharyngeal arch 1 (somitomere 4)? What is their common innervation?
Muscles of mastication (Masseter, Temporalis, medial and lateral pterygoids), 2 suprahyoids (anterior digastic and mylohyoid), tesnsor tympani, tensor veli palatini.
All innervated by cranial nerve V (Trigeminal Nerve)
What muscles derive from pharyngeal arch 2 (somitomere 6)? What is their common innervation?
The muscles of facial expression (Occipitofrontalis muscle, Temporoparietalis muscle, Procerus muscle, Nasalis muscle, Depressor septi nasi muscle, Orbicularis oculi muscle, Corrugator supercilii muscle, Depressor supercilii muscle), 2 suprahyoids (posterior digastric and sylohyoid), and the stapedius.
They are all innervated by cranial nerve VII (Facial nerve)
What muscles derive from pharyngeal arch 3 (somitomere 7)? What is their common innervation?
Only the stylopharyngeus muscle.
Innervated by cranial nerve IX (Glossopharyngeal nerve)
What muscles derive from pharyngeal arch 4 (occipital somite 2 and 4)? What is their common innervation?
Pharyngeal constrictor muscles and levator veli palatini.
Innervated by cranial nerve X (Vagus nerve)
What muscles derive from pharyngeal arch 6 (occipital somites 1 and 2)? What is their common innervation?
Laryngeal muscles
Innervated by cranial nerve X (vagus nerve)
Extraocular and tongue muscles are not derived from pharyngeal arches. Where do they derive from?
Extraocular eye muscles (all 6 of them as well as levator palpebrae superioris) develop from mesenchymal cells from the mesoderm surrounding the developing eye.
Most tongue muscles are formed from mesodermal myoblasts derived from occipital somites.
