SHS 315 Exam 1 Review

primary muscles of inspiration

diaphragm and external intercostal muscles

primary muscles of expiration

diaphragm and internal intercostal muscles

explain inspiration (5 steps)

diaphragm and external intercostal muscles contract→ thoracic cavity expands in volume → lungs expand in volume due to pleural linkage→ inside pressure drops due to Boyle’s law → air rushes into the lungs (because air moves from high pressure to low pressure, aka diffusion)

explain expiration (5 steps)

diaphragm and internal intercostal muscles contract while external intercostal muscles relax → thoracic cavity decreases in volume → lungs to decrease as well due to pleural linkage → the pressure inside the lungs rise due to Boyle’s Law which states that a decrease in volume causes an increase in pressure → air rushes out of lungs due to diffusion which states that molecules go from an area of high concentration (inside the lungs) to an area of low concentration (outside of the lungs)

explain how the lungs and the rib cage function as one unit

pleural linkage links the lungs and ribcage/thorax and make them function as one unit due to the negative intrapleural pressure which adheres them together

Boyle’s law

if the volume of a gas is increased, the pressure will decrease when the temperature and amount of gas remain unchanged within a closed system

how does Boyles law apply to breathing mechanics

volume and pressure have an inverse relationship - as lungs expand in volume, and pressure drops and vice versa

what is the very small potential space between the two pleurae?

pleural space

what does the pleural space contain?

pleural fluid

is the pressure inside the pleural space positive or negative?

negative

what part of the inspiration process described below can be accounted for by the Boyle’s Law?

lungs expand in volume inside pressure drops

what part of the expiration process described below can be accounted for by the Boyle’s Law?

lungs reduce in volume  inside pressure rises

what part of the inspiration process described below can be accounted for by diffusion?

air rushes in because air moves from an area of high pressure (atmospheric pressure) to low pressure (the pressure inside the lungs)

what part of the expiration process described below can be accounted for by diffusion?

air rushes out because air moves from an area of high pressure (atmospheric pressure) to low pressure (the pressure inside the lungs)

what part of the inspiration process described below can be accounted for by pleural linkage?

thoracic cavity expand in volume  lungs expand in volume

what part of the expiration process described below can be accounted for by pleural linkage?

thoracic cavity reduce in volume  lungs reduce in volume

what is the only muscle that abducts the vocal folds to open the glottis?

PCA

what is Bernoulli’s principle?

explains the inverse relationship between velocity and pressure

explain how Bernoulli’s principle applies to phonations mechanisms

creates the negative pressure between the VFs which seals them together completely to close the glottis at the end of a vibration cycle

according to hirano’s cover-body model, the main component of body is what?

vocalis (TA muscle)

what is the function of the LCA?

adductor- when it contracts, VFs move towards midline (medial compression)

what is the function of the IA?

adductor- when it contracts, VFs move towards midline (medial compression)

what is the function of the PCA?

abductor- when it contracts, VFs move away from midline

what is the function of the CT?

pitch changer - stretches TA muscle (VF) by tilting thyroid cartilage forward and downward and cricoid upward

explain how we phonate (6 steps)

1. To initiate vocal fold vibration, the vocal folds must adduct to close the glottis. This is achieved by IA and LCA muscles, which exert a force called medial compression.

2. Subglottal pressure builds up. When the subglottal pressure is strong enough, it forces the vocal folds apart.

3. The vocal folds begin to recoil back to the midline due to their natural elasticity.

4. The air passing through the constriction formed by the closing glottis becomes negative in pressure.

5. The negative pressure between the folds further helps to close them completely

6. The whole process repeats itself.

what is the mucosal wave?

the VFs open from bottom to top and close from bottom to top in a wavelike motion

what do the arytenoid cartilages do during VF vibration?

maintains adduction of the vocal folds

what force opens the vocal folds during eh cycle of vocal fold vibration?

subglottal pressure

what forces close the vocal folds during the cycle of vocal fold vibration?

negative pressure between the VF and elasticity of the VF

what is class I occlusion?

normal orientation of mandible and maxillae

what is class II malocclusion?

a relatively retracted mandible (overbite)

what is class III malocclusion?

a relatively protruded mandible

what is the term for the opening between the oropharynx and nasopharynx?

velopharyngeal port

if there is a weakness in the orbicularis oris muscle, what speech sounds would be affected?

/b/, /o/

if a patient presents velopharyngeal insufficiency, what speech sound would be affected?

/p/

in which clinical condition might the tensor veli palatini muscle play a significant role, especially related to ear health?

otitis media (infection-related fluids in the middle ear)

if the palatoglossus is affected, what speech sound would be difficult to produce?

/k/

innervation and function of genioglossus

XII hypoglossal nerve, retracts tongue, draws tongue forward

innervation and function of hyoglossus

XII hypoglossal nerve, pulls down sides of tongue

innervation and function of styloglossus

XII hypoglossal nerve, retracts and elevates tongue

innervation and function of palatoglossus

X vagus nerve/XI accessory nerve, elevates back of tongue, depresses velum

innervation and function of tensor veli palatini

V trigeminal, opens Eustachian tube

innervation and function of levator veli palatini

X vagus nerve/XI accessory nerve, raises velum to close pharyngeal port

innervation and function of palatopharyngeus

X vagus nerve/XI accessory nerve, narrows pharyngeal cavity

innervation and function of levator labii superioris alaeque nasi

VII facial nerve, raises upper lip

innervation and function of levator labii superioris

VII facial nerve, raises upper lip

innervation and function of zygomatic major

VII facial nerve, retracts and elevates corner of mouth

innervation and function of zygomatic minor

VII facial nerve, retracts and elevates corner of mouth

innervation and function of risorius

VII facial nerve, retracts lips at the corners

innervation and function of depressor anguli oris

VII facial nerve, depresses corner of mouth

innervation and function of depressor labii inferioris

VII facial nerve, lowers lip

innervation and function of mentalis

VII facial nerve, raises and protrudes lower lip

innervation and function of orbicularis oris

VII facial nerve, closes and protrudes lips

when a person is breathing quietly, the VFs abduct or adduct?

abduct

when a person is vocalizing, the vocal folds abduct or adduct?

adduct

what are the rides that are directly connected to the sternum by their own costal cartilages?

true ribs

which ribs are considered floating ribs?

ribs 11-12

T/F: the lungs contain muscles which contract or relax to increase or decrease the volume of the lungs for inhalation and exhalation

false

what is the name of the tiny airsick where oxygen and carbon dioxide exchange occurs in the lungs?

alveoli

what are the accessory muscles in respiration?

abdominal muscles, neck accessory muscles, thorax accessory muscles

to decrease pressure inside the lungs, the volume of the thoracic cavity and lungs must be enlarged. This is done by contracting the ____ and ____

diaphragm and ext. intercostals

during inhalation, what happens to the diaphragm?

it contracts and moves downward

when ext. intercostals contract they (lift/lower) the ribcage

lift

when int. intercostals contract they (lift/lower) the ribcage

lower

when innermost int. intercostals contract they (lift/lower) the ribcage

lower

how many layers of intercostal muscles are there?

3

what is the name of the internal intercostal muscle that is deep to the ext. intercostal muscle?

int. intercostal

int. intercostal muscles are muscles of (inspiration/expiration)

expiration