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short answer type question :
Very short ans
In what sense lungi
ng & What is latex
n mention its sources
mation ? // When
I acretory products 9. Wi
fine and rubber ? 11.
staliu (c) Salivary gland (d) Digestive gland
[Each question carries 1 mark]
lung is an excutory organ ?2 What is the prinary organ of excretion in human
Latex ? Name a plant where it is found ? 4. Write down the name of an alkaloid
eest . Stractures 6 What are the essential substances absorbed before Urine
when double geh Herle's loop 8 Name the processes by which plants remove
te 9. Which organ in man maintains water balance ? 10. What are the sources of
Wher 2 11. None two won nitrogens sources of excretory materials in man.
[Each question carries 5 mark]
Long answer type question :
What is excretion ? Name the main exeretory substances of plants and animals 2. What is
What is its utility in human beings 3. What is anephuron how its functions ? 4. What are
the differences between the excretory against of plants and animals ? 5. Name the main excretory
organs of vetebrate animals. 6. State the position of inverbetrate excretory organs and how they
work? 7. Give the names of excretory products of plants useful to human beings ? . Draw and
discribe a typical nephron 9. Name the functions of kidney of human beings 10. Describe very
briefly the structure of human kidney in a section 11. What is corp of Henle? Where its is found?
What is its function 12. Describe very briefly the mechanism of Urine formation.​
Answers
Answer:
The salivary glands in mammals are exocrine glands that produce saliva through a system of ducts. Humans have three paired major salivary glands (parotid, submandibular, and sublingual) as well as hundreds of minor salivary glands.[1] Salivary glands can be classified as serous, mucous or seromucous (mixed).
In serous secretions, the main type of protein secreted is alpha-amylase, an enzyme that breaks down starch into maltose and glucose,[2] whereas in mucous secretions the main protein secreted is mucin, which acts as a lubricant.[1]
In humans, between 0.5 and 1.5 litres of saliva are produced every day.[3] The secretion of saliva (salivation) is mediated by parasympathetic stimulation; acetylcholine is the active neurotransmitter and binds to muscarinic receptors in the glands, leading to increased salivation.
Explanation:Parotid glands
Main article: Parotid gland
The two parotid glands are major salivary glands wrapped around the mandibular ramus in humans.[5] These are largest of the salivary glands, secreting saliva to facilitate mastication and swallowing, and amylase to begin the digestion of starches.[6] It is the serous type of gland which secretes alpha-amylase (also known as ptyalin).[7] It enters the oral cavity via the parotid duct. The glands are located posterior to the mandibular ramus and anterior to the mastoid process of the temporal bone. They are clinically relevant in dissections of facial nerve branches while exposing the different lobes, since any iatrogenic lesion will result in either loss of action or strength of muscles involved in facial expression.[7] They produce 20% of the total salivary content in the oral cavity.[6] Mumps is a viral infection, caused by infection in the parotid gland.[8]
Submandibular glands
Main article: Submandibular gland
The submandibular glands (previously known as submaxillary glands) are a pair of major salivary glands located beneath the lower jaws, superior to the digastric muscles.[5] The secretion produced is a mixture of both serous fluid and mucus, and enters the oral cavity via the submandibular duct or Wharton duct.[6] Approximately 65-70% of saliva in the oral cavity is produced by the submandibular glands, even though they are much smaller than the parotid glands.[6] This gland can usually be felt via palpation of the neck, as it is in the superficial cervical region and feels like a rounded ball. It is located about two fingers above the Adam's apple (laryngeal prominence) and about two inches apart under the chin.
Sublingual glands
Main article: Sublingual gland
The sublingual glands are a pair of major salivary glands located inferior to the tongue, anterior to the submandibular glands.[5] The secretion produced is mainly mucous in nature; however, it is categorized as a mixed gland.[7] Unlike the other two major glands, the ductal system of the sublingual glands does not have intercalated ducts and usually does not have striated ducts either, so saliva exits directly from 8-20 excretory ducts known as the Rivinus ducts.[7] Approximately 5% of saliva entering the oral cavity comes from these glands.[6]
