Please enable JavaScript.
Coggle requires JavaScript to display documents.
SALIVA - Coggle Diagram
SALIVA
ANATOMY OF MAJOR SALIVARY GLAND AND THEIR DUCTS
PAROTID GLAND
Unstimulated produces 25% saliva;
stimulated 50% saliva
Largest salivary gland
Pyramid shaped
Located in anterior of ramus mandibula
Fat cells seen in spaces in the gland
Lined with cuboidal epithelial cells
SUBMANDIBULAR GLAND
Unstimulated produces 60% saliva;
stimulated 35% saliva
Second largest salivary gland
Secretes serous (95%) and mucous (5%) saliva
Located in the anterior submandibular
triangle
SUBLINGUAL GLAND
Unstimulated produces 7% saliva; stimulated 7% saliva
Smallest salivary gland
Located in the oral cavity between oral mucosa and mylohyoid masseter
DUCTS
INTERCALATED DUCTS
Connected directly to the acini
Formed by simple cuboidal epithelium
Partially covered by contractile myoepithelial cells
STRIATED DUCTS
Permeate the glandular lobes
Regulating the secretion and reabsorption of electrolytes
Bidirectional transport
between the lumen and the extracellular space
INTERLOBULAR DUCTS
Found between the glandular lobules
Continuing the reabsorption of sodium and potassium secretion
Formed by pseudostratified epithelium
VASCULARIZATION AND INNERVATION OF MAJOR SALIVARY DUCTS
SUBMANDIBULAR GLAND
BLOOD SUPPLY
Submental artery, sublingual
artery
VENOUS DRAINAGE
Facial vein and sublingual vein
PARASYMPHATHETIC INNERVATION
Superior cervical ganglion
SYMPHATHETIC INNERVATION
Superior salivatory nucleus through presynaptic fibres
SUBLINGUAL GLAND
BLOOD SUPPLY
Sublingual and submental arteries (external
carotid artery)
VENOUS DRAINAGE
Sublingual and submental veins
SYMPHATHETIC INNERVATION
Superior salivatory nucleus through pre-synaptic fibres via the chorda tympani branch of the facial nerve (CNVII)
PARASYMPHATHETIC INNERVATION
Superior cervical ganglion
PAROTID GLAND
BLOOD SUPPLY
Posterior auricular and
superficial temporal arteries
SYMPHATHETIC INNERVATION
Glossopharyngeal nerve
(cranial nerve IX)
VENOUS DRAINAGE
Retromandibular vein
PARASYMPHATHETIC INNERVATION
Superior cervical ganglion
MICROSCOPIC STUCTURE OF SALIVARY GLANDS
PAROTID GLAND
Fat cells seen in spaces in the gland
Lined with cuboidal epithelial cells
Interlobular ducts are lined by a pseudostratified columnar epithelium
Contains small lymph nodes near or within the gland, which arise from interstitial lymphocytes
SUBMANDIBULAR GLAND
Serous (95%) and mucinous (5%)
Serous and mucous cells are polarized
Have rough ER and secretion granules
Intercalated are lightly stained and are low cuboidal shaped
Straited ducts are columnar with basal striations and are
surrounded by capillaries
SUBLINGUAL GLAND
Mucous (65%) and serous (35%)
Mucous cells are rich in carbohydrates
Serous cells are rich in proteins and are darkly stained
Main excretory duct are simple columnar, pseudostratified columnar or stratified
cuboidal epithelium (contain goblet cells)
MINOR SALIVARY GLANDS
Placed below the epithelium in the oral cavity
Lack a distinct capsule, instead mixing with the connective tissue of the
submucosa or muscle fibers of the tongue or cheeks
Labial and buccal glands, glossopatine glands, palatine glands, lingual glands
SALIVARY SECRETION RELEX
STIMULATED
Secretion upon oral stimuli
Chemoreceptors and pressure receptors
respond to oral stimuli
Sympathetic nerves will stimulate adrenergic receptor
Release of norepinephrine
Involving the facial nerve (cranial nerve VII) and the glossopharyngeal nerve (cranial nerve IX)
Stimulate the glands through
muscarinic/cholinergic M3 receptors a
UNSTIMULTED
Without oral stimuli
Thinking, seeing or smelling food, the thought
process switches on a band of neurotransmitters
Sends responses through carrier nerves to stimulate the saliva-secreting glands
FACTORS IN SALIVA SECRETION
HYDRATION
When body water content is reduced by 8%, the
salivary flow decreases to virtually zero
EXPOSURE TO LIGHT
Unstimulated salivary flow decreases in the dark
BODY POSTURE
When standing, an individual secretes more
unstimulated saliva than when seated
BIOLOGICAL RYTHMS
Unstimulated saliva flow is not constant during a 24-hour period
Peak flow rate occurs in the late
afternoon with the lowest flow rate in the early morning
OLFACTION
Unstimulated salivary flow increases with
olfaction stimulation
SALIVA FLOW RATE
UNSTIMULATED
Average total for 16 hours of unstimulated flow (during waking hours) being 300 mL
Normal: >0.25 mL/min
Low: 0.1-0.25 mL/min
Very low: <0.1 mL/min
STIMULATED
Contribute 80%-90% of average daily salivary production
Normal: >1.0 mL/min
Low: 0.7-1.0 mL/min
Very low: <0.7 mL/min
SALIVA COMPOSITION
PHYSICAL PROPERTIES
Very dilute transparent fluid
Composed of more than 99% water
Contains mucin to provide lubrication
Promotes adhesion by vacuum pressure
Consistency varies
CHEMICAL COMPOSITION
Normal pH of saliva is 6 to 7 (slightly acidic)
Contains 99.5% water, 0.3% protein, and 0.2% inorganic and organic substances
Sodium, potassium, calcium, magnesium,
bicarbonate, and phosphates
Bicarbonates and phosphates act to modulate pH and the buffering capacity of saliva
Calcium, phosphate, and proteins work together as an antisolubility factor and modulate demineralization and remineralization
Inorganic constituents are sodium, potassium,
calcium, magnesium, chlorides, and carbonates
BIOCHEMICAL COMPOSITION
Composed of immunoglobulins, proteins, enzymes, mucins, and nitrogenous products, such as urea and ammonia
Macromolecule proteins and mucins serve to cleanse, aggregate, and/or attach oral microorganisms and contribute to dental plaque metabolism
Immunoglobulins, proteins, and enzymes provide antibacterial action
Organic components include amylases, peroxidases, lipases, mucins, lysozyme, lactoferrin, kallikreins, cystatins, hormones, and growth factors
SALIVA PRODUCTION IN SLEEP AND SPEECH
DURING SLEEP
2–10% of saliva is produced at night
Rate of salivary secretion decreases to
less than 0.25 ml/minute
During a period of 8 hours, 15 mL of
saliva is produced
Saliva is most viscous during early waking hours and thinnest before sleeping
MECHANISM
Influenced by the circadian rhythm
Related to the hormones melatonin and
cortisol
In the dark, the hormone melatonin will
increase, whereas cortisol will decrease
The increased concentration of the hormone cortisol causes a decrease in salivary secretion
DURING SPEECH
Normal saliva secretion is 0.33-0.55
mL/min
Rate of salivary secretion increases
substantially up to 10mL/min
Amount of saliva secreted in 24 hours
usually amounts to 1–1.5 litres