medical sciences exam 1

what are the swallowing stages called?

1. Pre-oral

2. Oral preparatory

3. oral

4. pharyngeal

5. oesphageal

what is hyolaryngeal elevation?

the upward and forward movement of the hyoid bone when the swallow repsonse triggers.

what happens in the pre-oral stage of swallowing?

sensory recongnition of food.

what happens in the oral prepatory stage of swallowing?

the food is chewed and organised.

velum is lowered to keep bolus from spilling posteriorly

buccinator tenses to keep food out of lateral sulcus

bolus is mixed with salivia while being chewed

tognue controls bolus and moves it around the oral cavity

rotary movement of jaw

matieral pulled into a cohensive bolus held between hard palate and tongue

what happens in the oral stage of swallowing?

bolus is pushed backwards by stripping movement of tongue

tongue is grooved and so acts as a chute when it moves backwards

the velum is raised to close the nasopharynx

what is the lateral sulcus?

space between teeth and molars where food can gather

What are the 6 stages within the pharyngeal stage?

1. Hyolarygeal elevation- pulls larynx into a protected postion under the base of the tongue

2. epiglottis, tue and false vocal folds close

3. elevation of soft palate (velopharyngeal closure)

4. The UES relaxes

5. base of tongue retracts towards posterior pharyngeal wall, pushing bolus backwards

6. pharyngeal constrictors contract to squeeze bolus downwards

what is the swallow response?

triggers when the bolus touches the sensory recpetors in the anterior palatglossal arches

the sensory nerves relay a signal to the brain stem

the brainstem intiates pharyngeal response

what happens in the oesophageal stage of swallowing?

Begins when bolus reaches the oesophagus

entirely reflexive

bolus is moved down to the stomach by peristalis of the oesophageal wall musculature

what is the oesphagus?

Oesphagus is hollow muscular tube with UES at upper end and LES at entrance to stomach

what are the 3 pharyngeal constrictor muscles?

1. superior pharyngeal constrictor

2. middle pharyngeal constrictor

3. inferior pharyngeal constrictor (lower portion is cricopharyngeus which forms UES)

what is mastication?

chewing- the process of crushing and grinding by the teeth.

how many muscles are involved in chewing?

4

what are the types of muscles in the tongues and how many in each?

intrinsic tongue muscles (entirely in the tongue) X4

Extrinstic tongue muscles (in structures outside the tongue and insert into the tongue) X4

What 2 categories can muscles attached to the hyoid bone and are involved in hypolaryngeal elevation and what do they do?

• supra hyoid muscles- pull the hyoid upwards (elevate) and forward (anteriorly)

• infra hyoid muscles- below the hyoid that lower (depress) the hyoid and stabilises the movement.

why does the larynx move during hyolaryngeal elevation?

because it is attached to the hyoid bone via muscles. 

How does the manidble joint close?

• the mandible opens and closes at the temporomandibular joint (TMJ)

• the joint allows movement between the temporal bone of the skull and the mandible. 

• in the TMJ the condylar proccess of the mandible articulates with the temporal bone of the skull

what 4 muscles allow us to masticate and what do they do

1. Temporalis (elevates and retracts mandible)

2. massester (elevates mandible and is a powerful biting muscle)

3. medial pterygoid (elevates mandible, lateral movemrnt for grinding)

4. lateral pterygoid (protrudes manible, lateral movement for grinding)

What Cranial Nerve is the motor supply of the mastication muscles?

CN V Trigeminal

which 2 muscles allow the jaw to move?

• medial pterygoid

• lateral pterygoid

What 3 parts can the tongue be split into and how are they each descirbed?

• Anterior 2/3rds tongue: in oral cavity, covered in oral muscosa with taste buds (papillae)

• Posterior 1/3rd: in orapharynx, smooth nodular surface (lingual tonsils)

• lingual fenulum: connects underside of tongie to the floor of the mouth.

what does the lingual frenulum do?

connects the underside of tongue to the floor of mouth 

what are the 4 intrinstic tongue muscles and what layer do they make?

1. inferior longitudinal (lowest layer)

2. tranverse (middle layer) 

3. vertical (middle layer)

4. superior longitiudinal (top layer)

how long are the intrstic muscles?

• they go the full length of the tongue.

what do the intristic muscles of the tongue do?

• move the the tongue tip up/down/side to side

• narrow and flatten the tongue

• Assit with; elevating, pulling tongue down, retracting.

what are the 4 extrinstic tongue muscles?

1. Genioglossus

2. hyoglossus

3. styloglossus 

4. palatoglossus

What does the genioglossus muscle do and where does it attach?

• prime for tongue movement

• makes up most of deep bulk of tongue

• retracts, protudes, and depresses.

• Attachements: inner mandible, fans up and back and forward to insert into the tongue tip and in the hyoid bone.

What does the hyoglossus muscle do and where does it attach?

attaches: from the hyoid bone to sides of tongue

• pulls the side of the tongue down

What does the styloglossus  muscle do and where does it attach?

attaches: from styloid proccess of skulls to inferior sides of tongue 

• moves tongue back and up

What does the palatoglossus muscle do and where does it attach?

attaches- from soft palate to sides of posterior tongue and muscles of anterior faucial arches (palatglossal arches)

• elevates the tongue and depresses the soft palate

What Cranial nerves supply motor to the tongue?

• Hypoglossals nerve (CNXII) provides motor supply to all muscles

• except for palatoglossal CN X vagus and CN XI accessory

Why is it an issue if the CN responsible of sensory supply to the tongue are damaged?

• if your tongue is numb you will find speech difficult, as you cannot sense where the tongue is.

• could burn tongue on drinks

• might not swallow effectively cannot feel where the bolus is.

Which cranial nerves are involved in sensory supply to the tongue?

• sensation in 2/3rds tongue, CN V trigeminal

• taste in anteior 2/3rds CN VII facial nerve 

• taste and sensation in posterior 1/3rd CN IX glossopharyngeal nerve

which spinal nerves are involved in propicoception of tongue?

cervical spinal nerves C1-4

what cranial nerve and spinal nerve supplys the thyrohyoid muscle?

• CN XII Hypoglossal

• Spinal nerve C1

what cranial nerve and spinal nerves supplys the sternothyroid muscle?

CN XII Hypoglossal

Spinal nerves C1 and C2

What spinal nerves supply the sternohyoid omohyoid?

Spinal nerves C1-C3