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organs of the respiratory system:
- Nose
- Pharynx (throat)
- Larynx (voice box)
- Trachea (windpipe)
- Bronchi
- Lungs
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functions of the paranasal sinuses?
drain into:
- the nasal cavities
- air-filled cavities in the frontal, maxillary, ethmoid, and sphenoid bones
- surround the nasal cavity and open into it
- Functions:
- - reduce the weight of the skull
- -produce mucus
- -influence voice quality by acting as resonating chambers
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the pharynx is used by what 2 systems?
pharynx is subdivided into what 3 parts:
- digestive and respiratory systems
- 3 parts:
- 1. nasopharynx
- 2. oropharynx
- 3. laryngopharynx
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where is the larynx located?
at the entrance to the trachea
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opening between the vocal folds through which air enters the larynx
glottis
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what are the aspects of speech?
- 1.Phonation: (larynx) The vocal folds of the larynx vibrate
- 2. Articulation (lips, tongue and soft palate)
- 3. Resonators (mouth, nose, sinus and pharynx)
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primary function of the digestive system?
4 other functions:
- PF: Transfer nutrients, water, and electrolytes from ingested food into body’s internal environment
- others:
- –Motility
- –Secretion
- –Digestion
- –Absorption
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•Accessory digestive organs:
- Salivary glands
- Exocrine pancreas
- –Bilary system
- •Liver
- •Gallbladder
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lips:
- –Form opening
- –Help procure, guide, and contain food in the mouth
- –Important in speech
- –Well-developed tactile sensation
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palate:
- –Forms roof of oral cavity (separates mouth from nasal passages)
- –Uvula (seals off nasal passages during swallowing)
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tongue:
- –Forms floor of oral cavity
- –Composed of skeletal muscle
- –Movements aid in chewing and swallowing
- –Plays important role in speech
- –Taste buds
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pharynx:
- –Cavity at rear of throat
- –Common passageway for digestive and respiratory systems
- –Tonsils
- •Within side walls of pharynx
- •Lymphoid tissue
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teeth:
- –Responsible for chewing (mastication)
- –First step in digestive process
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functions of chewing:
- Grind and break food into smaller pieces to make swallowing easier and increase food surface area on which salivary enzymes can act
- Mix food with saliva
- Stimulate taste buds
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saliva-
produced by:
composition:
- Produced largely by three major pairs of salivary glands
- 99.5% H2O
- 0.5% electrolytes and protein (amylase, mucus, lysozyme)
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functions of saliva:
- Salivary amylase begins digestion of carbohydrates
- Facilitates swallowing by moistening food
- Mucus provides lubrication
- Antibacterial action:
- -Lysozyme destroys bacteria
- –Saliva rinses away material that could serve as food source for bacteria
- Solvent for molecules that stimulate taste buds
- Aids speech by facilitating movements of lips and tongue
- Helps keep mouth and teeth clean
- Rich in bicarbonate buffers
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swallowing is the process of:
- moving food from mouth thru esophague to stomach).
- –Motility associated with pharynx and esophagus
- –Sequentially programmed all-or-none reflex
- –Initiated when bolus is voluntarily forced by tongue to rear of mouth into pharynx
- –Most complex reflex in body
- –Can be initiated voluntarily but cannot be stopped once it has begun
- –Process divided into two stages:
- •Oropharyngeal stage
- •Esophageal stage (moves bolus from mouth through pharynx and into esophagus)
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what are the 2 sphincters and their function btwn the pharynx and the esophagus?
- Pharyngoesophageal sphincter
- –Keeps entrance closed to prevent large volumes of air from entering esophagus and stomach during breathing
- Gastroesophageal sphincter
- –Prevents reflux of gastric contents
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taste and smell receptors are:
chemoreceptors
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chemoreceptors are housed in:
present in:
lifespan of:
- taste buds
- oral cavity and throat
- 10 days
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taste bud consists of:
- Taste pore
- Opening through which fluids in mouth come into contact with surface of receptor cells
- Taste receptor cells
- Modified epithelial cells with surface folds called microvilli
- Plasma membrane of microvilli contain receptor sites that bind selectively with chemical molecules
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a taste provoking chemical:
tastant
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Binding of tastant with receptor cell alters:
cell’s ionic channels to produce depolarizing receptor potential
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Receptor potential initiates:
•action potentials within terminal endings of afferent nerve fibers with which receptor cell synapses
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taste Signals are conveyed via:
•synaptic stops in brain stem and thalamus to cortical gustatory area
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5 primary tastes:
- Salty
- •Stimulated by chemical salts, especially NaCl
- –Sour
- •Caused by acids which contain a free hydrogen ion, H+
- –Sweet
- •Evoked by configuration of glucose
- –Bitter
- •Brought about by more chemically diverse group of tastants
- •Examples – alkaloids, toxic plant derivatives, poisonous substances
- –Umani
- •Meaty or savory taste
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taste buds are sensed best at:
diff regions of the tongue
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sides of the tongue sensitive to:
back of the tongue:
tip of the tongue:
(not going t ask where)
- sour
- bitter
- sweet and salty
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most taste buds respond to:
many substances produce:
some substances change in flavor as they:
- all 5 taste qualities
- a mixture of the basic taste sensation
- move thru the mouth
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what are factors that influence taste perception?
- information derived from other receptors, especially odor
- Temperature and texture of food
- Psychological experiences associated with past experiences with food
- How cortex accomplishes perceptual processing of taste sensation is currently unknown
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olfactory receptors in the nose are:
specialized endings of renewable afferent neurons
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olfactory contains what 3 cell types:
- Olfactory receptor cell
- –Afferent neuron whose receptor portion is in olfactory mucosa in nose and afferent axon traverses into brain
- –Axons of olfactory receptor cells collectively form olfactory nerve
- Supporting cells
- –Secrete mucus
- Basal cells- precursers of the base cells
- –Precursors of new olfactory receptor cells (replaced about every two months)
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odorants act thru:
afferent signals are sorted according to:
- second-messenger systems to trigger APs
- to scent component by glomeruli within olfactory bulb
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odorants are molecules that can be smelled. To be smelled, substance must be:
- –Sufficiently volatile that some of its molecules can enter nose in inspired air
- –Sufficiently water soluble that it can dissolve in mucus coating the olfactory mucosa
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series of events to smell:
- 1) the chemical must be volatile
- •it must be in the gaseous state as it enters the nasal cavity
- 2) the chemical must be water soluble
- •so that it can dissolve in the fluid containing the olfactory epithelium
- 3) the dissolved chemicals stimulate the olfactory receptors by binding to protein receptors in olfactory cilium membranes
- 4) the generation of APs in the olfactory cells
- 5)an impulse travels through the olfactory cell axons to the olfactory nerve where the smell sensation is transmitted to the brain
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