Neurons specialized cells. Building blocks of the nervous system Divided into central nervous system, peripheral nervous system. CNS consists of brain and spinal cord. PNS consist of cranial nerves starts from brain nerves responsible in producing speech. spiral nerves start from neck abdomen and spinal cord responsible in respiratory muscles. Nerve fibers bundle of neurons. Nerves a bundle of fibers. There are two types of neurons in the body and spinal cord. motor neurons/efferent moves from the cons to pns and is the act of conscious efforts deciding to close you lips. aferent/sensoer neurons moves from pns to cns when the lips have closed they send info to the brain that the lips have touched via the sensory fibers. have a cell body and extensions (dendrites)that receive and transmit impulse through axons which is vocered by a thin like material called myolean which helps the info travel faster 60 to 120m/s. The info terminates at the terminal arbor for that neurons. Jumps the synaptic cleft a space between the terminal arbor and the dendrites of the reciever. Neurons firing is basically that every axons has anaural threshold which is th eminumum intesity level required for the stimulus to prduce an effect. when a stimuls reches the thresholds or overpasses it the neuorns in the axons will fire at a maximum intensity. If the timulus doess not reach the threshold the neuron will not fire it is an all or nothing action of potential of neurons. What happens when neuorns fire is that stimulus has an impulses and the threshold is reched. the neurons get excited which rsults in the change of chemical properties within the neuron. This depolarazis becausue when a neruon is at rest the never fibers is negative 50 to 80 mv. if astimulus is above the threshold the cell memabre surroinding the axon will become permeable allowing sodium to eneter and therefore chainign the chemical properties for about 0.5ms the interior of the axons is more psotively charged than the exterie 30 to 50 mv. each point the begins to deoplarize until it reached the synpatic cleft once this is reached start nerotransmitter chemicals that transmits message are relased, this depolarization the continues until the dendirete of the following neuron is stimulated..

We still don't know how language is processed in the brain but we know what structures are involved. This includes the crebrum, cerebellum and basal ganglia.

2. What is INHALATION?

never impulses conve a need for oxygen the meddulla oblongata which is part of the brann stem send a message to the resipartory system that their is a suprlus of CO2 via the phrenic nerve which emerges form the spinal cord at the level of the neck this innvervates the diaphragm. The diaphragm contracts and flattens increase in volume of thoracic cavity resulting in a decrease in pressure as boyle's law states. as a diaphraggm lowers the external intercostals contract th and causes the ribs to go up and out. This is call negative pressure breathing.

3. What is EXPIRATION?

the diaphragm relax returns to resting place under the lungs separates thoracic and abdominal cavities intercostals pulls in the rib these actions work together to decrees the volume in the thorax forcing the LUNGS to release air. Three passive forces elasticity of lungs and rib cage torque of ric cage untwisting of cartilage and grVITY THAT LOWERS RIB Cge. during expriation point in hwich presure inside and outside of lungs is equal.

4. Differences between quiet breathing and speech breathing

SPEECH BREATHING 10% in 90% out 3.5 l of VC concious activity. involve modying and using the air that the body uses during normal respiration.

during inhalation The external intercostal muscles (rib muscles) and the muscles of the clavicles and neck can pull the ribs upwards in an untorquing, rotating motion to expand the chest walls. The diaphragm constricts or tightens This action flattens the diaphragm downwards. the chest cavity increases and the pressure decreases. inhlataion tiem is decreased to allow the speaker to pause in middle of utterances.

during the expiration phase the internal intercostals and abdominal muscles are at work.( rectus abdominus, external and internal oblique and transevrse abdominus contractThe abdomen is pushed outwards in order to increases breATHING RATE THIS forcES the diaphrahm up.

QUIET BREATHING 40 in 60 out .5l, 2.5l of VC 2.0 l RV

is reflexive The diaphragm contracts and flattens 9moves down) increase in volume of thoracic cavity resulting in a decrease in pressure as boyle's law states. as a diaphraggm lowers the external intercostals contract this causes the ribs to go up and out and expand the thoracic cavity. this increases its volume and deccreasing its pressure so that aire comes rushing in. This is call negative pressure breathing.

EXPIRATION the diaphragm relax returns to resting place under the lungs separates thoracic and abdominal cavities intercostals pulls in the rib these actions work together to decrees the volume in the thorax forcing the LUNGS to release air. Three passive forces elasticity of lungs and rib cage torque of rib cage untwisting of cartilage and graVITY THAT LOWERS RIB Cage. during expriation point in hwich presure inside and outside of lungs is equal.

5. What is boyles law?

Volume and pressure are inversely related. During inspiration the thoracic cavity increases causing a decrease in pressure. During experitation the the thoracic cavity decreases causing an increase in pressure.

6. What is Cover body theory? explains how structures of vocal folds determines the characterisitc of the phonation like frequency, amplitude and picth.

Vocal folds are made of tendon,muscle,and mucous membrane. The mucous membrane (cover) overlies (stiffer) body of the VF vibration btwn both varies.

7. What is bernoulli effect As air goes through a constricted passage like the larynx, subglottal pressure builds which opens the folds and air passes the velocity (speed) increases and the pressure decreases this decrease will cause the vocal folds to come together and close. This occuring frequently is what causes the vocal folds to vibrate and thus leading to phonation. Phonation needs vibration of vocal folds

8. Myoelastic aerodynamic theory of phonation. Vibration of vocal folds happen when aerodynamics forces act on the elasticity of the vocal folds. Muscles makes changes to folds tension mass length while they are vibrating to produce different sounds.

9. What are the functions of LArynx.

Primary function (eppiglotis) prevents food from going through the trache and enetring the lungs.. and assist in swallowing Second Function (produce speech)

False vocal folds/ True vocals Folds, Glottis is horizontal speace b/t true voal folds.

10, How are speech sounds created in Phonations? What muscles are needed to help abduct the vocal folds.

air coming form lungs mmust be converted into speech sounds. vibration of the vocal folds occur periodically and creates phonation. it starts off as abducted (open likea v shape). this occurs because of posterior cricoarytenoid (PCA) roates the arytenoids out and down and creates voiceless consonants. and then goes to ADDUCTION (CLOSED) this occurs becuase of contracction of the Interarytenoid muscles (IA) and lateral cricoarytenoid (LCA) which assists. when the VF are closed production of vowels, dipthongs, approximants and voiced stops are both IA and LCA are used. to voiced speech consonants like fricatives, and /z/ only Ia is used.

HOW IS VIBRATION OF THE VOCAL FOLDS ACCOMPLISHED to create phonation?

WIth the MYOELASTIC AERODYNAMIC THEORY OF PHONATION: in order to make phonation the subglottal pressure must be greater than the supraglottal pressure. the goal of phonation is to maintain equal subglottal pressure throught entire utterances (7cm H20). increasing the subglottal pressure increases the intesit of sound by creating high pressure amplitude waves. this pressure exceed the resistance of muscles and the Vf are blown apart this is the aerodynamic part. Myolelasticy comes in and makes the VF elastic which allows them to reutn back to orignal shape. the muscles make changes in the tension,mass and length of the VF while they ar evbrating to produce diff sounds. the sound emitted as result of phonation is called glottal sound source.

How do VF come back together?

with the leasticty o th vocal folds an dby the benroulli effects which expains how when air passes though a constircited passage the velocity or speed of air inceases the increased in velocity caused the pressur to decreased and in reurtn makes the vocal folds come back together.

What is fundamental frequency?

i is the number of times the vocal folds oepn and close per seocond. for males is 100hz for femaLES IS 200 HZ AND FOR CHILDREN IS 300 HZ.

WHAT ARE THEY WAYS WE MODULATE fUNDAMENTAL FREQUENCY? Increase?

1. lengthen the VF- we contract the cricothyroid muscle this streches the Vf (lengthens) and increases the tension. 2. elevate the larynx (suprahyoid/sternohyoid muscles) whichincreases the vertical tension to VF these muscles help produce extremly high pitches and low pictches. 3. VAry the dubglottal pressure increase the subglottal pressure in cresed in ssubglottal will lead to increase my Fundamental frequency leading to a very loud sound. also the BErnoulli effect has to do with this too and this is the relation between frequency and intensity. to decrease the VF decrease the cricothyroid acitivity, muscles of neck lower larynx decrese vertical tension. decrease the subglottal pressure.

what are the VOICE QUALITY

BReathiness 9whisper) vf not fully closed,inneficeint Vf vibraton, very noisy. glottal ATTack creaky voice vf are close to tightly high subglottal pressure. Hoarseness Vf dont vibrate normally noudles- polyps contact ulcers. Harshness extreme tension of entire larynx Vf over approximate.