Module 2 Overall Flashcards

Parts of the nasal/oral cavity

1. Nose

2. Nasopharynx

3. Mouth

4. Vestibule

5. Oral cavity proper

6. Oropharynx

7. Laryngopharynx

8. Larynx

Label the diagram of the vestibule and oral cavity proper

Functions of the tongue

Digestion

Speech

Breathing

Taste

• sweet

• sour

• salty

• bitter

• umami

What are the main surfaces of the tongue

1. Dorsal

2. Ventral

Describe the dorsal part of the tongue

Contains oral part [also called palatal part] (anterior 2/3) and pharyngeal part (posterior 1/3)

Oral/pharyngeal parts divided by:

• Palatoglossal fold - contains palatoglossal muscle

• Sulcus terminalis - V shaped groove separating the parts

• Foramen caecum - remnant of embryonic duct associated with the thyroid gland

Describe the ventral part of the tongue

Contains:

1. Body

2. Apex

3. Root

What does the tongue develop from

2 lateral swellings and 1 medial swelling from the 1st pharyngeal arch

What are the lingual papillae found on the palatal tongue

1. Fungiform - white spots

2. Filiform - spongy looking papilla

3. Vallate papilla - (7-12 of them), look like mushrooms, line the sulcus terminalis

4. Foliate papilla - on side of tongue, look like ridges

Note** All papilla have tastebuds EXCEPT filiform

V-FLuffy Fungus Feeds Taste (Vallate, Filiform, Fungiform, Foliate)

(FLuffy = no flavor)

Describe the structure of the pharyngeal tongue

• from the sulcus terminalis to the epiglottis

  • lingual tonsils between these structures - lymph nodes

• pharyngeal fold, palatine tonsil, palatopharyngeal fold

• median and lateral glossoepiglottic folds (MGF/LGF)

  • attachments between posterior tongue and epiglottis

  • Valleculae = indentations between MGF and LGF that are sites of food lodgement

Describe the structures on the ventral surface of the tongue

• Lingual frenulum

• deep lingual veins (lateral to frenulum)

• fimbriated folds (further lateral from frenulum)

• sublingual folds

  • on floor of oral cavity in alveolar-lingual sulcus

  • sits above sublingual glans and secretes saliva

• sublingual papilla - on either side of lingual frenulum

  • for opening of submandibular duct of submandibular gland

What is the alveolar lingual sulcus

a horseshoe cavity that wraps around the attachment of the tongue to the floor of the mouth

• contains submandibular duct and submandibular gland

What are the extrinsic muscles of the tongue and their innervations

• Genioglossus (innervated CN XII): protrusion and deviation of the tongue

• Hyoglossus (CN XII): depression and retraction of the tongue for sucking

• Styloglossus (CN XII): lifts tongue up and back

• Palatoglossus (CN X): elevates posterior tongue for swallowing

Geniuses Hide Silly Palates

What are the attachment sites of the extrinsic tongue muscles

Genioglossus

• upper genial tubercle/mental spine to the hyoid bone and base of tongue

Hyoglossus

• Hyoid bone to the side of the tongue

Styloglossus

• styloid process to the side of the tongue

Palatoglossus

• palatal aponeurosis to the side of the tongue

Hard Palate

formed by palatine process of maxilla and horizontal plate of the palatine bone

Landmarks of the hard palate

• incisive foramen

• greater palatine foramen

• lesser palatine foramen

• posterior nasal spine

Soft tissue landmarks:

• incisive papilla (posterior to the maxillary papilla)

• rugae

• median raphe

Soft palate

• oral mucosa on oral side

• respiratory mucosa on nasal side

• within palate

  • muscles and palatal aponeurosis

  • fat and glands

Palatine Aponeurosis

thin, firm, fibrous sheet formed by an extension of the tendon of the tensor palati muscles

• provides support for other muscles to attach to

Muscles of the palate and their innervations

1. Levator palati (CN IX and CN X): lifts palate up and back

2. Tensor palati (CN V3): tightens the soft palate ad pulls the auditory tube open

3. Palatoglossus (CN X): elevates tongue

4. Palatopharyngeus (CN X): depress the soft palate and narrows/shortens the isthmus and pharynx

5. Uvular (CN X): assists in palatopharyngeal closure

Tense Living People Prefer Ubers

Attachment sites of palatal muscles

Lavator palati

• attaches from petrous temporal bone → the palatal aponeurosis

Tensor palati

• attaches from the scaphoid fossa → the hamulus → palatal aponeurosis

Palatoglossus

• attaches from soft palate → tongue

Palatopharyngeus

• attaches from soft palate → pharynx

Uvula

• attaches from posterior nasal spine and palatine aponeurosis → uvula mucosa

What percentage of the body’s blood does the brain receive

30%

How much does the brain weigh

1.4 kg

What are the meninges layers of the brain

1. Dura mater (outer layer)

2. arachnoid mater

3. pi mater (inner)

What fills the space between the meninges layers

cerebrospinal fluid (CSF)

Anatomical directions of the brainstem

Rostral = up

Caudal = down

Ventral = front

Dorsal = back

Anatomical directions of the cerebrum

Rostral = front

Caudal = back

Ventral = down

Dorsal = up

Grey matter

• Makes up 40% of the brain

• makes up surface of brain

• consists of cell bodies, dendrites, nerve terminals, and synapses

• where info is processed and integrated

White matter

• comprises 60% of the brain

• makes up deep part of brain

• comprised of nerve axons

• where info is transmitted between grey matter regions

Brainstem

• most caudal part of brain

• attaches to spinal cord

• comprised of

  • medulla oblongata

  • pons

  • midbrain

• regulates BP, HR, respiratory function

Diencephalon

• located rostral to brainstem

• consists of

  • thalamus

  • hypothalamus

• involved in homeostasis

Cerebellum

• attached to dorsal side of brainstem

• contains 50% of brain’s neurons

• responsible for motor control and planning of movements that require multiple segments

Cerebrum (telencephalon)

• makes up 80% of brain volume

• consists of

  • cortex

  • gyri (thick folds)

  • sulci (shallow grooves)

• hemispheres separated by longitudinal fissure

Lobes of the cerebrum and their functions

Parietal

• somatosensory processing (touch, vibration, proprioception)

Occipital

• visual processing

Temporal

• hearing, comprehension, cognition, emotion

Frontal

• motor control, speech, emotion, cognition, personality

Insular

• sensation for internal parts of the body, pain, nociception, emotion

Duration of pregnancy

30-48 weeks

Oocyte

• female egg

• carries x chromosome

• ~100 microns in size

• rich in cholesterol

• surrounded by zona pellucida

Sperm

• male germ cell

• y chromosome

• ~50 microns in size

Week 1 of embryological stage

Fertilization and implantation

• Zygote → blastomere (2 cell size) → morula (16 cell size) →blastocyst

• Zygote remains incased in zona pellucida the whole time

Blastocyst

Contains blastocyst cavity (blastocoel) and inner cell mass

Inner cell mass:

• Trophoblast - becomes placenta

• Embryoblast - becomes future embryo

Week 2 of embryological stage

Implantation and bilaminar formation

Differentiation of trophoblast into:

• syncytiotrophoblast

• cytotrophoblast

Differentiation of embryoblast into:

• epiblast (embryo)

• hypoblast (yolk sac)

New tissues form bilaminar disk

ZP hatches and uses L-selectins to adhere to uterine wall

Week 3a of embryological stage

Gastrulation and Organogenesis

• Oral pharyngeal membrane develops (future oral cavity)

• head of embryo develops

• primitive streak develops (tail)

  • differentiates into:

    • Endoderm

    • Mesoderm

    • Ectoderm

What does endoderm give rise to

• digestive tract

• respiratory tract

• endocrine glands

What does mesoderm give rise to

• muscle

• bone

• circulatory system

What does ectoderm give rise to

• Neural tissue

• Skin

• Glands

• Teeth

Week 3b embryological stage

Heart formation

• mesoderm differentiates into:

  • somatic (dorsal) mesoderm layer: bones, ligaments, blood vessels, connective tissue of limbs

  • splanchnic (ventral) mesoderm layer: heart tube

Week 4 Embryological stage (Neurulation)

Ectoderm differentiates into:

• Central - neural ectoderm, forms neural tube and groove →brain and spinal cord

• Lateral - dermal ectoderm

Week 4 Embryological stage (Neural crest cell formation)

NCC develop from neural ectoderm into:

• dentine

• pulp

• periodontal tissue

• TMJ condylar cartilage

• melanocytes

• neural cells and glia

• sensory organs

When does the body cavity formation occur

Weeks 3-4

Week 4 Embryological stage (Stomodeum formation)

Stomodeum = groove between head and the heart - leads to formation of oral cavity

• also begins to form frontonasal prominence and cardiac bulge

Week 5 embryological stage (pharyngeal arches)

Formation of Pharyngeal Arches

Arches develop from all 3 germ layers:

• Ectoderm = dermal coverage and sensory placodes

• Mesoderm = muscle, bone/cartilage, vascular progenitors

• Endoderm = inner linings

What are the pharyngeal arches

5 pairs of pharyngeal arches:

• 1

• 2

• 3

• 4

• 6

Note** pharyngeal arch 5 is not visible

What are the parts of the pharyngeal apparatus

Arches:

• main portion containing mesenchymal tissue, muscle, bone, nerves

Clefts:

• external surface of each pharyngeal arch

Pharyngeal pouches

• located internally and opposite to clefts

1st pharyngeal arches

• contributes to all things related to chewing

• When formed, divides into maxillary and mandibular processes

  • become the maxilla and mandible

• forms trigeminal ganglion

  • becomes trigeminal nerve (CN V3)

Muscles developed from the 1st pharyngeal arch

• temporalis

• masseter

• medial pterygoid

• lateral pterygoid

• mylohyoid

• anterior belly of digastric

• tensor tympani

• tensor veli palatini

Other derivatives of the 1st pharyngeal arch

• malleus

• maxilla

• zygomatic bone

• hard palate

• vomer

• mandible

• temporal bone (squamous)

• anterior ligament of malleus

• sphenomandibular ligament

• maxillary artery

2nd pharyngeal arches

• contribute to everything swallowing and smiling

• gives rise to facial nerve (CN VII) and vestibulocochlear nerve (CN VIII)

Muscles developed by 2nd pharyngeal arch

• all muscles of facial expression

• posterior belly of digastric belly

• stylohyoid

• stapedius

Other derivatives of the 2nd pharyngeal arches

• hyoid bone

• part of temporal bone

• tapes

• long limb of incus

• styloid process

• lesser horn of hyoid

• upper part of hyoid

• stylohyoid ligament

• temporal bone

• stapedial artery

• caroticotympanic arteries (arteries of the nose and throat)

1st/2nd pharyngeal pouches and clefts

Pouches and Clefts located between the 1st and 2nd arches

• 1st pouch: forms internal acoustic meatus, tympanic membrane, eustachian tube

• 1st cleft: forms external acoustic meatus, tympanic membrane

1st/2nd pouches and clefts form the ear

3rd Pharyngeal arch

• forms glossopharyngeal nerve (CN IX)

• forms common carotid and internal carotid arteries

4th pharyngeal arches

• forms vagus nerve (CN X)

• forms superior parathyroid epiglottic cartilages

5th pharyngeal arches

• become incorporated into 4th arch, therefore not visible

6th pharyngeal arches

• forms vagus nerve (CN X)

• forms intrinsic muscles of larynx, cricoid cartilage

Mnemonic for Arches the Cranial Nerves they Form

Tense Face Gives Voice

• Trigeminal → 1st arch

• Facial → 2nd arch

• Glossopharyngeal → 3rd arch

• Vagus → 4th / 6th arch

Pharyngeal arch contributions to the tongue

1st arch: innervates anterior 2/3rds of tongue via CN V (trigeminal)

3rd and 4th arches: innervates posterior 2/3rd of tongue via CN IX (glossopharyngeal) and CN X (vagus)

3rd pharyngeal pouch

• forms thyroid and parathyroid glands

4th pharyngeal pouch

• forms parathyroid gland

What happens to the other clefts

they disintegrate

• if they remain, they can become branchial cleft cysts

Week 5 of embryological stage (facial development)

Frontal prominence

• divides into medial and lateral nasal process

  • contains olfactory pits → future nostrils

Maxillary and mandibular processes

• become more prominent in week 5

Oral pharyngeal membrane

• disintegrates, allows connection of resp. and digestive tracts.

Week 6 of embryological stage (upper lip formation)

Formed by fusions of medial/lateral nasal processes and maxillary processes

Medial nasal process forms bridge of nose and philtrum of upper lip

Lateral nasal process forms lateral nostrils

Cleft lip

Upper lip cleft: Failure of fusion of the medial nasal process with the maxillary process

Midline cleft: failure of fusion between two medial nasal processes (can be unilateral or bilateral)

Occurs 1:700 births, males > females

Week 6 of embryological stage (maxilla formation)

• 1st pharyngeal arch gives rise to maxillary process

• maxillary process, palatine process are ossified to form hard palate - via periosteal osteoblasts

• maxillary sinus forms during 3rd month of pregnancy

• maxilla continues to grow down and forward until 14-15 years old

Week 7 of embryonic stage (palate formation)

• fusion of medial nasal processes form primary palate and maxillary anterior teeth

• fusion of maxillary processes forms secondary palate

Cleft palate

1:700 births, females > males

• failure of fusion of medial nasal process and maxillary process

Week 7 of embryonic stage (lower face formation)

• mandibular processes fuse to for lower lip and mandible

• mandible forms in 2 parts:

  • main body - formed around meckel’s cartilage

  • ramus/condyle - fuses with main body at 4 months

Meckel Makes the Mandible, Condyle Keeps it Growing

Features of skeletal muscle

• peripheral, multi-nucleated

• striated

• non-branching cells

Skeletal muscle organization

Skeletal muscle > Muscle fascicle > muscle fiber > myofibril > myofilaments (sarcomeres)

Features of cardiac muscle

• single, central nucleus

• striated

• branching via intercalating disks

Features of smooth muscle

• non-striated, tapered shaped (fusiform)

• single, central nucleus

• non-branching

Primary muscles of mastication

• temporalis

• masseter

• lateral pterygoid

• medial pterygoid

Accessory muscles of mastication

• digastric

• buccinator

• supra-hyoid muscle

• infra-hyoid muscle

Articulating surfaces of the temporomandibular joint (TMJ)

• head of condyle of mandible

• mandibular/glenoid fossa

• articular tubercle on the temporal bone

• articular disc between superior and inferior synovial cavities

Stabilizing structures of the TMJ

• joint capsule and lateral ligament

• postglenoid tubercle

• stylomandibular ligament

• sphenomandibular ligament

Ginglymoarthrodial joint

involved in hinging and sliding motion

• ginglymus = hinging

• arthrodial = sliding

Functions:

• depression (open mouth)

• elevation (closing mouth)

• protrusion (forward movement)

• retrusion (backward movement)

• lateral movements

Temporalis

Origin:

• temporal fossa, along inferior temporal line

Insertion:

• coronoid process and anterior border of the ramus

Actions:

• elevation, retrusion

Innervation:

• anterior and posterior deep temporal branches of anterior division of mandibular branch of the trigeminal nerve (CN V3)

Masseter

Superficial Head

• Origin:

  • inferior border of the anterior 2/3rds of the zygomatic arch and the maxillary process of the zygomatic bone

• Insertion:

  • angle of the mandible, inferior and lateral ramus

Deep Head

• Origin:

  • medial border of zygomatic arch, inferior border of posterior 1/3rd of zygomatic arch

• Insertion:

  • superior and lateral ramus, coronoid process

Actions (both):

• elevation

• protrusion

Innervations (both):

• masseteric branch of anterior division of mandibular branch of trigeminal nerve (CN V3)

Lateral Pterygoid

Upper Head:

• Origin:

  • infratemporal surface of sphenoid

• Insertion:

  • capsule of TMJ, anterior and medial portion of articular disc, neck of mandible

Lower Head:

• Origin:

  • lateral surface of lateral pterygoid plate

• Insertion:

  • neck of condyle of mandible

Actions:

• depression, protrusion, lateral movements

Innervations:

• lateral pterygoid branch of anterior division of mandibular branch of trigeminal nerve (CN V3)

Medial Pterygoid

Superficial Head

• Origin:

  • pyramidal process of palatine bone and maxillary tuberosity

• Insertion:

  • medial ramus and angle of mandible

Deep Head

• Origin:

  • medial surface of lateral pterygoid plate

• Insertion:

  • medial ramus and angle of mandible

Actions (both):

• elevation

• protrusion

• lateral movements

Innervations (both):

• medial pterygoid branch of mandibular branch of trigeminal nerve