NCERT Class 11 Science — Chapter 9: Chemical Coordination and Integration

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The innermost layer of the adrenal cortex is the:

Official previous-year question

Verified 1 Aug 2026.

Options

AMedulla
BZona reticularis
CZona glomerulosa
DZona fasciculata

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Solution

The correct option is Zona reticularis.

Explanation

The adrenal glands are paired endocrine glands situated superior to the kidneys. Structurally and functionally, the gland is divided into two distinct regions: the outer adrenal cortex and the inner adrenal medulla. The adrenal cortex is further differentiated into three distinct histological zones.

Zonal Arrangement of the Adrenal Cortex (from Outer to Inner):

Zona Glomerulosa: This is the outermost layer of the adrenal cortex, located immediately beneath the connective tissue capsule. It is responsible for secreting mineralocorticoids (e.g., aldosterone).
Zona Fasciculata: This is the middle and widest layer of the cortex. It primarily secretes glucocorticoids (e.g., cortisol).
Zona Reticularis: This is the innermost layer of the adrenal cortex, adjacent to the adrenal medulla. It is responsible for producing weak androgens (sex hormones).

Note on Medulla: The Medulla is the central core of the adrenal gland, not a layer of the cortex. It secretes catecholamines (epinephrine and norepinephrine).

Key Takeaway: The layers of the adrenal cortex, from the capsule inwards, follow the sequence: Glomerulosa → Fasciculata → Reticularis (Mnemonic: GFR).

Your note

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The correct option is Zona reticularis.

Explanation

Zonal Arrangement of the Adrenal Cortex (from Outer to Inner):

Zona Glomerulosa: This is the outermost layer of the adrenal cortex, located immediately beneath the connective tissue capsule. It is responsible for secreting mineralocorticoids (e.g., aldosterone).
Zona Fasciculata: This is the middle and widest layer of the cortex. It primarily secretes glucocorticoids (e.g., cortisol).
Zona Reticularis: This is the innermost layer of the adrenal cortex, adjacent to the adrenal medulla. It is responsible for producing weak androgens (sex hormones).

Note on Medulla: The Medulla is the central core of the adrenal gland, not a layer of the cortex. It secretes catecholamines (epinephrine and norepinephrine).

Key Takeaway: The layers of the adrenal cortex, from the capsule inwards, follow the sequence: Glomerulosa → Fasciculata → Reticularis (Mnemonic: GFR).