Problem 64 - Objective Biology for NEET

Question

Select the incorrect match: Position \(\quad\) Gland (a) Cheeks Parotid (b) Lower jaw Sub-maxillary/sub-mandibular (c) Below tongue Sub-lingual (d) Pineal gland Dorsal side of mid brain

Step-by-Step Solution

Answer

The incorrect match is (d) Pineal gland – Dorsal side of mid-brain. The correct location of Pineal gland is in the epithalamus, near the center of the brain.

Step 1: Check matches for correctness

Start by checking each match of position and gland. The parotid gland is indeed located in the cheeks, the sub-maxillary or sub-mandibular gland is in the lower jaw, and the sub-lingual gland is below the tongue. Therefore, choices (a), (b), and (c) are correct.

Step 2: Validate Pineal gland position

When we look at (d), the pineal gland is stated to be on the dorsal side of the mid-brain. However, the pineal gland is actually part of the epithalamus, located near the center of the brain, not on the dorsal side of mid brain, which makes this the incorrect match.

Key Concepts

Salivary Glands

Salivary glands are essential components of the digestive system that produce saliva. They play a crucial role in not only beginning the digestion of food but also in maintaining oral hygiene and in the lubrication of food. Saliva contains enzymes like amylase that begin breaking down carbohydrates. It also helps in forming a food bolus, making it easier to swallow.
There are three primary pairs of salivary glands found in humans:

• Parotid glands: Largest salivary glands, located near the cheeks.
• Submandibular glands: Located beneath the lower jaw.
• Sublingual glands: Located under the tongue.

These glands work together to ensure that the mouth remains moist, aiding in the initial stages of digestion and needs for clear speech.

Parotid Gland

The parotid glands are the largest of the salivary glands and they are primarily responsible for the secretion of serous saliva, which is rich in enzymes. These glands are situated on either side of the mouth, located just in front of and below the ear.
They function around the clock but increase their production of saliva when you eat, helping to break down food and cleanse your mouth.
Some key points about the parotid glands include:

• The parotid duct, also known as Stensen's duct, is the channel through which saliva passes from the parotid gland into the mouth.
• The nerves, blood vessels, and lymph nodes in and around the parotid gland are crucial for facial expression and sensation.
• Issues like mumps or stones can affect the parotid glands, impacting their function and causing discomfort.

Pineal Gland

The pineal gland is a small, pinecone-shaped endocrine gland in the brain. It is unique due to its several remarkable features and functions.
Situated near the center of the brain, it is tucked between the hemispheres in a tiny cone-shaped structure.
This gland acts primarily as a producer of the hormone melatonin, which regulates sleep-wake cycles.

• The secretion of melatonin is influenced by light exposure, with production peaking at night to promote sleep and diminishing during daylight hours.
• While it's known for its role in circadian rhythms, the pineal gland has historically been linked to philosophical and spiritual discussions about consciousness.
• Conditions like tumors in the pineal gland can lead to imbalances in melatonin levels, affecting sleep quality and even mood.

Thus, while small, the pineal gland plays a significant role in maintaining several key bodily functions, especially those related to sleep and daily biological rhythms.