Salivary glands and ducts - lecture

What is the only way to tell the difference between the salivary gland and the pancreas histologically

Only ther islets of langerhan, same secretions, they look the same and exocrine in the same way. just have a diff structire..

What ate the 4 key salivary glands to note in the dog and cat

• Parotid

• zygomatic (carnivore)

• mandibular

• subllingual glands

Major glands will exit vua one large duct, smaller glands may have multiple shorter openings…

What is the structure that produces saliva and what type of cells are present.

• A salivon will produce saliva

• contains serous cells - watery serum and mucus cells - mucus

• Ratio of serous to mucus glands varies by gladna nd species, therefore producing different consistencies of saliva…

(the bulb at the top = the acinus)

What are the key cells which make up the salivon …

Serous cells - watery secretio

mucus cells - mucus secretion

Plasma cells -- produce IgA

Myoepithelial cells — envelop each acinus - squeeze os saliva comes out prior too eating/ smelling favourite food etc

intercalated ducts - secrete HCo3- and absord cl-

striated ducts — Secrete K+ and HCo3- and absorb Na +

secretory — convey saliva to the mouth

What is in the contents of the slavia once it is produced

• high bicarbonate and high potassium

• small amounts of electrolytes, proteins, amatlase, lymphocytes and mycin.

• primary secretion - from epithelial cells in the acini

• hypotonic - electrolystes move in via osmosis..

• 
  

What can happen with faster flow rates of saliva

LEss time between primary secretion and excreteion, therefore less modification..

slower the flo = more hypotonic as more carbonate has been activly moved in, therfore has the function to remove acidity, this process also increases the potassium concentration. Due to potassiums relationship with sodium, the sodium concentration will then decrease

What are the variations in salivary secretions

e/g/ carnivores havemore of a mucus secretion, e.g. need a coating for bones etrc..

What is the composition and function of saliva..

Water —> mositen food and dissolves food eases mastication and swallowing

lubrication —> mucose _ removes food debris and microbones ,, IgA antivoides help destroy pathogens

AMylase — chem digestions…

BICARBONATE —> buffering, stops ph becoming too acididc. AT ph 6.5 dentine will dissolve..

what are the biochemial pasts compostion and functions of saliva…

• Phosphate buffer — aids healthy microbial growth

• Hydroxyapatite — contains calcium ions to maintain the enamel (+ this mineralised dental plaque causing calculus)

• Salivary mucoproteins act with other agent + increases the surface tension

• Saliva can form a peroxide based antibiotic to limit bacterial ingestion.

How much saliva does a cow produce per day…

approx 150 litres

a human will produce 1.5 l/ day

Ptyalism = the production of more than normal slaiva for that species

(can also get it stuk….)

What responses will the salivary glands have to parasympatheteic vs sympathetic stimulation….

sympathetic — viscouse amylase and more protien - dry

Parasympathetic — Watery and highervolume - increased response too taste, visual + olfactory stimuli…

Reflex— autonomic = taste and smell and can also have indirect conditioned responses…

Why is it important too block the parasympathetic nervouse system in aneathetic

can use atropine, this will lower saliva production. If this does not happen then the saliva production will be too high it may block theur own airways..

What is the autonomic nerve supply to the salivary glands…

Supply reaches via arterial supplies..

travel allong trigeminal nerves thi will include the mandibular and the parotid glands.. e.g… ‘Hitching a ride’ on the trigeminal nerve. There is no endocrine controle of the salivary gands.

what are the key salviaary glands

What is the structure of the parotid gland

Salivary glands + ducts

Parotid gland + duct

PArotid duct

What is parotiditis

Beginine mass in theh parotid gland - shows visibly.. Can be extensive, no issue too horses.

OCcours form a CHANGE in grazing..

Zygomatic gland

• only in carnivores

• Duct opens in upper buccal mucosa opposite the first molar tooth

• duct = caudal to the parotid duct

• 1-4 ducts twhich come out…

Mandibular and Sublingual glands

has multiple ducts leading from the primary gland.. Monostomatic part of SLG nect too MG and has a long duct

many ducts under the tongue - sublinguial galnd, THERE is 2 part sof the sub lingual gland - monosomatic duct AND the monosomatic u

Mandibular glands..

The monosomatic part of the sublingual gland is attatched to the mandibular gland

What is a caruncle

fusion of salviary ducts where slavia is released under the tongue

Monor salivary glands

Buccal and palatine glands - tiny salivons thorugout the mucosa - respond in the same way….

What is prehension

food into mouth, different methods, e.g. suction beak dipping + active prehension

HOw to mammels swallow

impossible for them too swallow and breath at the same time..

What is the process of swallowing…

food, mouth pharynz , oesophagus stomch

registered in the medulla oblongata

can become a natural reflex

STAGES of SWalloing —- LEARN!!

STiomach tubing importatn info..

tap tube on pharynz then horse will swallow and horse will swallow the tube..

What is a palatal ostium

• soft palate seals off the oropharny from the laryngopharanx…

• Therefore intubation can be very difficuft ar cannot push down

• intubation impossible

What is teh difference betweeen regurigtation and vommiting

regurgitation is a passive process (less activate than vommiting

this is normal for many ruminants, dogs feeding weaned pups and birds deeding young..