Tag: pineal gland and thymus

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Questions Related to pineal gland and thymus

Multiple choice zoology plants and animal hormones thymus thymus gland pineal gland and thymus

The regression in size of which organ is associated with reduction in the power of defence against invasion by pathogens with ageing?

  1. Bone marrow

  2. Thymus

  3. Spleen

  4. Peyer's patches
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The thymus gland, located behind our sternum and between our lungs, is only active until puberty.

After puberty, the thymus starts to slowly shrink and become replaced by fat.
So, the correct option is 'Thymus'.

Multiple choice zoology plants and animal hormones thymus thymus gland pineal gland and thymus

Central tolerance takes place in

  1. Lymph nodes

  2. Thymus

  3. Spleen

  4. Liver
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Central tolerance is the tolerance established by deleting autoreactive lymphocyte clones before they develop into fully grown immunocompetent cells. It occurs primarily in the thymus.

So, the correct option is 'Thymus'.

Multiple choice zoology plants and animal hormones thymus thymus gland pineal gland and thymus

Which one of these does not pertain to B-cells?

  1. Have passed through the thymus

  2. Synthesize and liberate antibodies

  3. Have antibody-mediated immunity

  4. Have specific receptors
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

B cells develop in the bone marrow but achieve maturity in peripheral lymphoid organs. Developmental stages are defined by the successful expression of heavy-chain and light-chain immunoglobulin genes. B cells provide humoral immunity against extracellular pathogens through antibody production. Antibodies neutralize pathogens and toxins, facilitate opsonization, and activate complement. The B-cell receptor or BCR is composed of immunoglobulin molecules that form a type 1 transmembrane receptor protein usually located on the outer surface of a lymphocyte type known as B cells. 


So, the correct option is 'Option A'.

Multiple choice zoology control and coordination in living organisms pineal gland pituitary gland and pineal gland pineal gland and thymus

The recently discovered hormone, melatonin is derived from serotonin which is synthesised by

  1. Adrenal gland

  2. Pineal gland

  3. Thymus gland

  4. Thyroid gland
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The pineal gland is a small endocrine gland in the vertebrate brain. It produces melatonin, a serotonin derived hormone, that affects the modulation of sleep patterns in both seasonal and circadian rhythms.

Multiple choice zoology control and coordination in living organisms pineal gland pituitary gland and pineal gland pineal gland and thymus

Pineal body originates from

  1. Dorsal part of diencephalon

  2. Ventral part of diencephalon

  3. Ventral part of cerebellum

  4. Dorsal part of cerebellum
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The diencephalon is the region of the embryonic vertebrate neural tube that gives rise to posterior forebrain structures including the thalamus, hypothalamus, posterior portion of the pituitary gland, and pineal gland. The pineal gland arises as a dorsal outgrowth of the caudal portion of the diencephalon. In the adult animal, it lies in the midline of the roof of the third ventricle. 

Multiple choice zoology control and coordination in living organisms pineal gland pituitary gland and pineal gland pineal gland and thymus

According to recent knowledge, the pineal body is considered as

  1. A vestigial organ

  2. An organ of intelligence

  3. An endocrine gland

  4. An organ of involuntary action
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The pineal body (or pineal gland) is a small endocrine gland in the brain that produces melatonin, which regulates circadian rhythms.

Multiple choice zoology control and coordination in living organisms pineal gland pituitary gland and pineal gland pineal gland and thymus

Serotonin is secreted from

  1. $\alpha $- cells
  2. $\beta $- cells
  3. $\delta $- cells

  4. Enterochromaffin cells
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Serotonin is the hormone that contributes the feeling of well being and happiness in animals including humans. It is basically derived from tryptophan and is located in the gastrointestinal tract (GI tract), blood platelets and central nervous system. 90% of the total serotonin is primarily located in GI tract in Enterochromaffin cells and used for regulation of intestinal movements. Hence, answer D is correct.

Multiple choice zoology control and coordination in living organisms pineal gland pituitary gland and pineal gland pineal gland and thymus

"Pinealocytes cells" occurs in 

  1. Pineal body

  2. Pituitary gland

  3. Adrenal gland

  4. Thyroid gland
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Pinealocytes are the main cells contained in the pineal gland, located behind the third ventricle and between the two hemispheres of the brain. The primary function of the pinealocytes is the secretion of the hormone melatonin, important in the regulation of circadian rhythms.

Multiple choice zoology control and coordination in living organisms pineal gland pituitary gland and pineal gland pineal gland and thymus

Which one of the following endocrine glands functions as a biological clock and neurosecretory transducer? 

  1. Adrenal gland

  2. Thyroid gland

  3. Pineal gland

  4. Thymus gland
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The pineal gland or epiphysis synthesizes and secretes melatonin hormone, that communicates information about environmental lighting to various parts of the body. It is attached to the roof of third ventricle in the rear part of brain. It functions as a biological clock and a neurosensory transducer, converting the neural information.