Podcast
Questions and Answers
Where is oxytocin stored in the posterior pituitary?
Where is oxytocin stored in the posterior pituitary?
- Anterior lobe of the pituitary
- Median eminence
- Nerve endings of hypothalamo-hypophyseal tract (correct)
- Supraoptic nucleus
What effect does oxytocin have on females?
What effect does oxytocin have on females?
- Prevents uterine contraction
- Ejection of milk from mammary glands (correct)
- Stimulates milk production
- Inhibits lactation
Where is the thyroid gland located?
Where is the thyroid gland located?
- Above the kidneys
- At the base of the brain
- On either side of the trachea at the root of the neck (correct)
- Next to the heart
What changes occur in the thyroid gland during pregnancy?
What changes occur in the thyroid gland during pregnancy?
What connects the two lobes of the thyroid gland?
What connects the two lobes of the thyroid gland?
Which hormone is NOT secreted by the thyroid gland?
Which hormone is NOT secreted by the thyroid gland?
Which gland is located in the brain?
Which gland is located in the brain?
Which hormone is secreted by the anterior pituitary gland?
Which hormone is secreted by the anterior pituitary gland?
What is the primary function of endocrine glands?
What is the primary function of endocrine glands?
Which of the following glands is located above the kidneys?
Which of the following glands is located above the kidneys?
Which of the following hormones is a mineralocorticoid?
Which of the following hormones is a mineralocorticoid?
Which of the following glands is located in the neck?
Which of the following glands is located in the neck?
Which type of messenger is synthesized by endocrine glands?
Which type of messenger is synthesized by endocrine glands?
Leukotrienes are examples of which type of chemical messenger?
Leukotrienes are examples of which type of chemical messenger?
Which of the following messengers diffuse through the interstitial fluid to target neighbouring cells?
Which of the following messengers diffuse through the interstitial fluid to target neighbouring cells?
Which type of chemical messenger includes neurotransmitters and neurohormones?
Which type of chemical messenger includes neurotransmitters and neurohormones?
Which of the following is an example of a paracrine messenger?
Which of the following is an example of a paracrine messenger?
What are juxtacrine messengers also known as?
What are juxtacrine messengers also known as?
What is another name for endocrine glands?
What is another name for endocrine glands?
How do endocrine glands release their hormones?
How do endocrine glands release their hormones?
Which gland is NOT shown in the provided image?
Which gland is NOT shown in the provided image?
What is the primary role of endocrine glands?
What is the primary role of endocrine glands?
Which gland is located in the brain according to the image?
Which gland is located in the brain according to the image?
Which hormone is responsible for the general growth of the body?
Which hormone is responsible for the general growth of the body?
What is a consequence of hypersecretion of growth hormone (GH)?
What is a consequence of hypersecretion of growth hormone (GH)?
Which hormone is required for the growth and secretory activity of the thyroid gland?
Which hormone is required for the growth and secretory activity of the thyroid gland?
Which hormone accelerates the process of spermeogenesis in males along with testosterone?
Which hormone accelerates the process of spermeogenesis in males along with testosterone?
What hormone is responsible for ovulation in females?
What hormone is responsible for ovulation in females?
Which hormone is necessary for the final preparation of mammary glands for milk production and secretion?
Which hormone is necessary for the final preparation of mammary glands for milk production and secretion?
Which hormone is responsible for the structural integrity and secretory activity of the adrenal cortex?
Which hormone is responsible for the structural integrity and secretory activity of the adrenal cortex?
Which of the following is a posterior pituitary hormone?
Which of the following is a posterior pituitary hormone?
Which mechanism is utilized by thyroid and steroid hormones to execute their functions?
Which mechanism is utilized by thyroid and steroid hormones to execute their functions?
What is the primary method by which neurotransmitters act in the synapse or neuromuscular junction?
What is the primary method by which neurotransmitters act in the synapse or neuromuscular junction?
What is another name for the anterior pituitary gland?
What is another name for the anterior pituitary gland?
Where is the pituitary gland located?
Where is the pituitary gland located?
Which part of the connective structure between the hypothalamus and the pituitary gland is known as the pituitary stalk?
Which part of the connective structure between the hypothalamus and the pituitary gland is known as the pituitary stalk?
Which hormones activate intracellular enzymes?
Which hormones activate intracellular enzymes?
Which hormone stimulates the release of thyroid stimulating hormone?
Which hormone stimulates the release of thyroid stimulating hormone?
What is the role of growth hormone-inhibitory hormone (GHIH) or somatostatin?
What is the role of growth hormone-inhibitory hormone (GHIH) or somatostatin?
How does the hypothalamus control the anterior pituitary?
How does the hypothalamus control the anterior pituitary?
What is another name for the anterior pituitary?
What is another name for the anterior pituitary?
Which hormone is believed to inhibit prolactin secretion?
Which hormone is believed to inhibit prolactin secretion?
Where are antidiuretic hormone (ADH) and oxytocin synthesized?
Where are antidiuretic hormone (ADH) and oxytocin synthesized?
What action does antidiuretic hormone (ADH) primarily have on the kidneys?
What action does antidiuretic hormone (ADH) primarily have on the kidneys?
How are hormones transported from the hypothalamus to the posterior pituitary?
How are hormones transported from the hypothalamus to the posterior pituitary?
Which hormones are stored at the nerve endings in the posterior pituitary?
Which hormones are stored at the nerve endings in the posterior pituitary?
What effect does a large amount of ADH have on blood vessels?
What effect does a large amount of ADH have on blood vessels?
Which structure does NOT secrete any hormones?
Which structure does NOT secrete any hormones?
What type of messenger diffuses through interstitial fluid to a nearby target cell?
What type of messenger diffuses through interstitial fluid to a nearby target cell?
Which of the following is an example of a neurotransmitter?
Which of the following is an example of a neurotransmitter?
Which type of messenger acts on the same cell that released it?
Which type of messenger acts on the same cell that released it?
What is another name for endocrine glands?
What is another name for endocrine glands?
Which of the following is NOT a chemical messenger listed in the introduction?
Which of the following is NOT a chemical messenger listed in the introduction?
Which chemical messenger category includes dopamine and acetylcholine?
Which chemical messenger category includes dopamine and acetylcholine?
Which type of messenger is released by endocrine glands and transported through the blood?
Which type of messenger is released by endocrine glands and transported through the blood?
In which scenario does a messenger diffuse through a gap junction?
In which scenario does a messenger diffuse through a gap junction?
What are the two major systems that regulate the physiological activities of the body?
What are the two major systems that regulate the physiological activities of the body?
How does the endocrine system function in regulating body functions?
How does the endocrine system function in regulating body functions?
What does 'cell-to-cell signaling' refer to?
What does 'cell-to-cell signaling' refer to?
From where are most chemical messengers involved in cell signaling secreted?
From where are most chemical messengers involved in cell signaling secreted?
What do chemical messengers carry from signaling cells to target cells?
What do chemical messengers carry from signaling cells to target cells?
What are classical hormones classified as?
What are classical hormones classified as?
Study Notes
Pituitary Gland
- The pituitary gland is a small endocrine gland with a diameter of 1cm and weight of 0.5 to 1g.
- It is situated in the sphenoid bone at the base of the skull in a depression called 'sella turcica'.
- It is connected to the hypothalamus by the pituitary stalk or hypophyseal stalk.
Anterior Pituitary or Adenohypophysis
- The anterior pituitary secretes six hormones:
- Growth hormone (GH) or somatotropic hormone (STH)
- Thyroid-stimulating hormone (TSH) or thyrotropic hormone
- Adrenocorticotropic hormone (ACTH)
- Follicle-stimulating hormone (FSH)
- Luteinizing hormone (LH) in females or interstitial cell-stimulating hormone (ICSH) in males
- Prolactin
- Growth hormone (GH) is responsible for the general growth of the body.
- Hypersecretion of GH causes enormous growth of the body, leading to gigantism.
- Deficiency of GH in children causes stunted growth, leading to dwarfism.
Actions of Hormones
- Thyroid-stimulating hormone (TSH) is necessary for the growth and secretory activity of the thyroid gland.
- Adrenocorticotropic hormone (ACTH) is necessary for the structural integrity and the secretory activity of the adrenal cortex.
- Follicle-stimulating hormone (FSH) acts along with testosterone and accelerates the process of spermeogenesis in males.
- In females, FSH causes the development of graafian follicle from primordial follicle and causes secretion of estrogen.
- Luteinizing hormone (LH) is essential for the secretion of testosterone from Leydig cells in males and is responsible for ovulation in females.
- Prolactin is necessary for the final preparation of mammary glands for the production and secretion of milk.
Posterior Pituitary or Neurohypophysis
- Posterior pituitary hormones are:
- Antidiuretic hormone (ADH) or vasopressin
- Oxytocin
- The posterior pituitary does not secrete any hormone.
- ADH and oxytocin are synthesized in the hypothalamus.
- These hormones are transported to the posterior pituitary through the nerve fibers of the hypothalamo-hypophyseal tract.
- In the posterior pituitary, these hormones are stored at the nerve endings.
- When impulses from the hypothalamus reach the posterior pituitary, these hormones are released from the nerve endings into the circulation.
Antidiuretic Hormone (ADH)
- Antidiuretic hormone has two actions:
- Retention of water
- Vasopressor action
- The major function of ADH is retention of water by acting on the kidneys.
- It increases the facilitative reabsorption of water from the distal convoluted tubule and collecting duct in the kidneys.
- In large amounts, ADH shows vasoconstrictor action.
- This causes constriction of the arteries in all parts of the body.
Endocrine Glands
- Endocrine glands are the glands which synthesize and release the classical hormones into the blood.
- Endocrine glands are also called ductless glands because the hormones secreted by them are released directly into blood without any duct.
- Endocrine glands are distinct from exocrine glands which release their secretions through ducts.
- Endocrine glands play an important role in homeostasis and control of various other activities in the body through their hormones.
Major Endocrine Glands
- Pineal gland
- Pituitary gland
- Thyroid gland
- Parathyroid glands
- Thymus
- Adrenal gland
- Pancreas
- Ovary (in females)
- Testis (in males)
Hormones Secreted by Major Endocrine Glands
- Anterior Pituitary
- Growth hormone (GH)
- Thyroid-stimulating hormone (TSH)
- Adrenocorticotropic hormone (ACTH)
- Mineralocorticoids
- Aldosterone
- 11-deoxycorticosterone
Classification of Chemical Messengers
- Endocrine messengers
- Paracrine messengers
- Autocrine messengers
- Neurocrine messengers
Endocrine Messengers
- These are the classical hormones.
- Examples are growth hormone and insulin.
Paracrine Messengers
- These are the chemical messengers which diffuse from the control cells to the target cells through the interstitial fluid.
- Examples are prostaglandins and histamine.
Autocrine Messengers
- These are the chemical messengers that control the source cells which secrete them.
- Examples are leukotrienes.
Neurocrine or Neural Messengers
- These are neurotransmitters and neurohormones.
- Examples are acetylcholine and dopamine.
Thyroid Gland
- The thyroid gland is an endocrine gland situated at the root of the neck on either side of the trachea.
- It has two lobes, which are connected in the middle by an isthmus.
- The thyroid gland secretes three hormones:
- Tetraiodothyronine or T4 (thyroxine)
- Triiodothyronine or T3
Neurocrine or Neural Messengers
- Neurocrine or neural messengers: These are neurotransmitters and neurohormones.
- Neurotransmitter: An endogenous signaling molecule that carries information from one nerve cell to another nerve cell or muscle or another tissue.
- Neurohormone: A chemical substance that is released by the nerve cell directly into the blood and transported to the distant target cells.
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Description
Learn about the six hormones secreted by the anterior pituitary gland, including growth hormone, thyroid-stimulating hormone, and more. Understand their functions and roles in the body.
