Adrenal Gland Anatomy

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Questions and Answers

What is the shape of the adrenal glands?

Cuboidal

Cylindrical

Spherical

Half-moon (correct)

What type of tissue surrounds the adrenal glands?

Nervous tissue

Muscle tissue

Epithelial tissue

Connective tissue (correct)

From where does the yellow cortex of the adrenal gland arise?

Ectoderm

Endoderm

Mesoderm (correct)

Neural crest

What is a characteristic feature of steroid-secreting cells in the adrenal cortex?

Acidophilic cytoplasm rich in lipid droplets Signup and view all the answers

Which organ do the adrenal glands have an anatomical relationship with?

Kidneys Signup and view all the answers

What characterizes the mitochondria of steroid-producing cells in the adrenal cortex?

Spherical with tubular cristae Signup and view all the answers

How do steroids produced by adrenal gland cells exit into the bloodstream?

Diffused freely through the plasma membrane Signup and view all the answers

What separates the adrenal glands from the kidneys?

Perirenal fat Signup and view all the answers

What is primarily produced in the zona reticularis of the adrenal cortex?

Weak androgens Signup and view all the answers

Which of the following functions do mineralocorticoids primarily control?

Fluid and electrolyte balance Signup and view all the answers

What characteristic is true for the cells in the innermost zona reticularis?

They are more eosinophilic and contain more lipofuscin pigment Signup and view all the answers

What role do weak androgens play in the body according to the content?

They may contribute to the prepubertal development of sex organs Signup and view all the answers

What describes the general histologic appearance of the adrenal gland?

Cells are grouped in cords along wide capillaries Signup and view all the answers

Which of the following statements about the arterial supply of the adrenal gland is true?

It is supplied by superior, middle, and inferior suprarenal arteries. Signup and view all the answers

What type of blood supply does the adrenal medulla receive?

Arterial blood from medullary arterioles and venous blood from the cortex Signup and view all the answers

What hormone is released by the cells influenced by ACTH in the adrenal cortex?

Cortisol Signup and view all the answers

What type of cells primarily comprise the adrenal medulla?

Chromaffin cells Signup and view all the answers

Which of the following statements about chromaffin cells is true?

They possess several electron-dense granules. Signup and view all the answers

Which molecule is primarily responsible for converting norepinephrine to epinephrine?

Chromaffin cells Signup and view all the answers

What is the main catecholamine secreted by the adrenal gland?

Epinephrine Signup and view all the answers

Which statement correctly describes the effect of norepinephrine?

It constricts vessels in the digestive system. Signup and view all the answers

How does the adrenal medulla respond during stress?

By releasing catecholamines. Signup and view all the answers

What is the main function of aldosterone produced by the zona glomerulosa?

Regulates fluid and electrolyte balance Signup and view all the answers

What structure supports the chromaffin cells in the adrenal medulla?

Reticular fiber network Signup and view all the answers

Which of the following statements is true regarding the zona fasciculata?

Is the largest zone of the adrenal cortex Signup and view all the answers

Which of these is a characteristic feature of epinephrine-secreting cells?

They contain less electron-dense granules. Signup and view all the answers

What triggers the secretion of aldosterone from the zona glomerulosa?

Increase in plasma K+ concentration Signup and view all the answers

Which hormone is primarily secreted by the zona fasciculata?

Cortisol Signup and view all the answers

Which layer of the adrenal cortex is involved in cortisol production?

Zona Fasciculata Signup and view all the answers

What primarily distinguishes chromaffin cells in the adrenal gland?

They have a prominent nucleus and are part of a parasympathetic ganglia. Signup and view all the answers

In which of the following does the zona glomerulosa primarily contain?

Closely packed, rounded or arched cords of cells Signup and view all the answers

What metabolic processes are affected by cortisol produced in the zona fasciculata?

Stimulates gluconeogenesis and glycogen synthesis Signup and view all the answers

Which of the following cells is more innervated by a capillary network?

Spongiocytes Signup and view all the answers

How does ACTH influence the secretion of glucocorticoids?

Promotes secretion and is affected by negative feedback. Signup and view all the answers

Which component is typically absent in a histological image of the posterior pituitary?

Adipose tissue Signup and view all the answers

What is a primary characteristic of epithelial cells in the zona glomerulosa?

Columnar or pyramidal shape with many capillaries Signup and view all the answers

What hormone is associated with the hypophyseal portal circulation?

TRH Signup and view all the answers

Which layer of the adrenal cortex is known for being lightly stained and containing polyhedral cell layers?

Zona Glomerulosa Signup and view all the answers

What is a key characteristic of the adrenal medulla?

It consists mainly of chromaffin cells. Signup and view all the answers

What major effect would removal of hypothalamic input have on pituitary gland function?

Absence of TRH stimulation Signup and view all the answers

Study Notes

Adrenal Gland

The adrenal glands are paired organs located near the superior poles of the kidneys.
They are embedded in pararenal adipose tissue and fascia.
They have a half-moon shape and are flattened.
Adults have adrenal glands that are 4-6 cm long, 1-2 cm wide and 4-6 mm thick.
They are retroperitoneal and lie on the upper poles of the kidneys.
Each gland has a capsule of dense connective tissue.
The capsule sends trabeculae into the gland's parenchyma.
The gland has no fat covering.
The stroma primarily consists of reticular fibers and microvasculature.
Separated from the kidneys by perirenal fat.
It has a cortex and a medulla.
The cortex arises from mesoderm and is yellow.
The medulla arises from neural crest and is dark brown.
The adrenal gland lacks a hilum.
Suprarenal arteries penetrate the capsule independently.
Blood supply penetrates through different regions.

Adrenal Cortex

The cortex is divided into three zones: glomerulosa, fasciculata, and reticularis.
The glomerulosa zone is immediately inside the capsule, comprising about 15% of the cortex.
The glomerulosa zone consists of rounded or arched cords of columnar cells.
It makes mineralocorticoids like aldosterone, regulating electrolyte balance.
The fasciculata zone occupies 65-80% of the cortex.
The fasciculata zone has long cords of large polyhedral cells, separated by fenestrated sinusoidal capillaries.
The cells of the fasciculata zone have lipid droplets in routine preparations.
It produces glucocorticoids like cortisol.
The reticularis zone is the innermost zone, comprising about 10% of the cortex.
The reticularis zone has a network of smaller cells in irregular cords.
The cells are more eosinophilic than in other zones because they contain less lipid and more lipofuscin pigment.
It produces weak androgens in small amounts.

Adrenal Medulla

The adrenal medulla is composed of large pale-staining polyhedral cells.
These cells are arranged in cords or clumps and supported by a reticular fiber network.
The adrenal medulla has a profuse supply of sinusoidal capillaries.
It contains chromaffin cells (modified postganglionic sympathetic neurons).
Chromaffin cells store and secrete catecholamines (epinephrine or norepinephrine).
Epinephrine granule density is less profound and smaller than Norepinephrine granules.
Catecholamines (together with Ca2+ and ATP) are bound to chromogranins in storage complexes.
About 80% of the catecholamine secreted is epinephrine.
Medullary chromaffin cells are innervated by preganglionic sympathetic neurons.
These sympathetic neurons trigger the release of epinephrine and norepinephrine during stress and intense emotional reactions.
Epinephrine increases heart rate, dilates bronchioles, and dilates arteries in cardiac and skeletal muscles.
Norepinephrine constricts vessels in the digestive system and skin, increasing blood flow to the heart and brain.
Both hormones elevate blood glucose levels.

Histology Notes

The adrenal gland shows a characteristic histological appearance of an endocrine gland.
Cells of both cortex and medulla are grouped in cords along wide capillaries.
Suprarenal arteries form a subcapsular plexus, branching to adrenal cortex and medulla.
Cortical capillaries irrigate endocrine cells and drain to medullary microvasculature.
The adrenal medulla gets a dual blood supply: arterial blood from medullary arterioles and venous blood from cortical capillaries.
Venous drainage occurs via suprarenal veins.
The adrenal medulla is composed of chromaffin cells (modified postganglionic sympathetic neurons).
These cells lack axons and dendrites, are pale and polymorphic.
They're arranged in cords and clumps with a reticular fiber network
Chromaffin cells, innervated by preganglionic sympathetic neurons, trigger catecholamine release.

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Description

Explore the structure and function of the adrenal glands in this quiz. Learn about their location, composition, and blood supply, as well as the distinctive features of the cortex and medulla. Test your knowledge on the anatomy and physiology of these vital organs.