By Billy Hammond (Copyright AELS)

July 11, 2021

Saliva

Saliva is an important part of the digestive system. Without it, you’d have trouble swallowing large bits of food.

Saliva is produced in the parotid, submandibular and sublingual glands. A human normally secretes about 1,000 ml/day within a range of 850-1500 ml. It’s pH ranges between 6.0 – 7.0. It’s pretty unique in that its secretion can be stimulated by both the sympathetic and parasympathetic nervous systems, although the parasympathetic activity plays the major role.

Saliva production is increased by food in the mouth, smells, conditioned reflexes and nausea. Sleep, dehydration, fear and anticholinergic drugs decrease its production.

It has three major functions: (1) the initial digestion of starch by α-amylase (ptyalin) and the digestion of triglycerides by lingual lipase; (2) the lubrication by mucus; and (3) protection of the mouth and esophagus by diluting and buffering foods.

The composition of saliva varies with its flow rate. At low flow rates, it has low osmolarity and low Na+, Cl, and HCO3 concentrations. It also has a high K+ concentration. At high flow rates its composition is close to plasma.

Saliva can also be a transmitter of diseases (ex. roseola infantum, mononucleosis, HSV-1) as well a protector against them since it contains lysozome that can attack bacteria and assist thiocyanate ions in entering bacteria. It also contains protein antibodies that destroy oral bacteria.

References

Costanzo, Linda S.. BRS Physiology (Board Review Series) (Chapter 6, Gastrointestinal Secretion). Lippincot (Wolters Kluwer Health). Kindle Edition.

Hall, John E.. Guyton and Hall Textbook of Medical Physiology E-Book (Guyton Physiology) . (Ch. 64, Secretory Functions of the Alimentary Tract) Elsevier Health Sciences. Kindle Edition.

唾液

唾液は消化器系の大切な一部である。唾液がなければある程度のサイズの食べ物を飲み込めない。

唾液は耳下腺、顎下腺及び舌下腺で生成される。人間は1日に約850-1500mlを作り出す(1日平均量:1,000ml)。pH6.07.0。唾液の分泌は交感神経系(SNS)と副交感神経系(PNS)の両方で刺激できるので珍しい(但しPNSの方がメイン)。

唾液分泌は口の中の食べ物の存在、匂い、条件反射や悪心で増加される。睡眠、脱水、恐怖や抗コリン薬によって減少される。

唾液は主に3つの役割を果たす:(1) α-アミラーゼ でのでんぷん消化と舌リパーゼ でのトリグリセリド 消化、(2)粘液での潤滑、(3)食べ物の希薄・中和をする

唾液の成分は流量によって変わる。低い流量では低浸透性や低Na+, Cl, and HCO3濃度を保つ。他方ではK+濃度が高い。高い流量では成分は血漿に近い。

唾液は病気の伝説物質にもなれる(例:小児バラ疹 、感染性単核球症 、HSV-1)と同時に病気を防止する媒体にもなれる。唾液成分にはリゾチームが含まれているのでバクテリアを殺傷できるし、バクテリアに入るためにチオシアン酸イオンも助ける。

参考

Costanzo, Linda S.. BRS Physiology (Board Review Series) (Chapter 6, Gastrointestinal Secretion). Lippincot (Wolters Kluwer Health). Kindle Edition.

Hall, John E.. Guyton and Hall Textbook of Medical Physiology E-Book (Guyton Physiology) . (Ch. 64, Secretory Functions of the Alimentary Tract) Elsevier Health Sciences. Kindle Edition.

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English novels by Billy Hammond published by AELS

(AELS出版英語書籍リスト)

 

I. Majoh Gakuin and Hikari Juku – Japanese Witch Schools Trilogy

1. Majoh Gakuin & Hikari Juku – Japanese Witch Schools

2. Lost Witch (The second book)

3. Fate & Magic (The final book in the trilogy)

II. Brindle – Scryer Extraordinaire Trilogy

1. Brindle – Scryer Extraordinaire

2. Brindle – Scryer Extraordinaire – Returns

3. Brindle – Scryer Extraordinaire – Challenges (The final book in the trilogy)

III. Fantasy fiction set in Japan

1. 21st Century Ninja

2. Regressed

3. Japanese Woman

IV. Fantasy fiction set outside of Japan

1. Dimension Jumpers

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