Question

1. Describe the structures of the adrenal gland. How you would identify each of the five layers seen under the microscope (Hint, the outermost is made of dense irregular connective tissue)? And, name 1-2 materials produced by each of the four inner layers. 9pts

Answer 1

Adrenal gland is an endocrine gland and is also known as suprarenal gland as it lies above the kidneys.

It has three two parts - adrenal medulla and adrenal Cortex.

Adrenal Cortex is the outer part and adrenal medulla forms inner zone.

Layers of adrenal gland seen on histology are -

Fibrous capsule - it encloses the inner layers of gland

Zona glomerulosa- it is the outermost zone which is formed of fibrous connective tissue and cells are arranged in irregular cords,this layer is supplied by capillaries, and this layer is responsible for secreting mineralocorticoid ( aldosterone).

Zona fasciculata is located between zona glomerulosa and zona reticularis, it is formed of cells which are arranged radially and this layer is responsible for secretion of glucocorticoid (cortisol). This layer appears foamy due to presence of lipid droplets.

Zona reticularis is the innermost zone of adrenal Cortex which is formed of cells arranged in clusters and connective tissue. This layer secretes androgen ( DHEA).

Adrenal medulla is the innermost layer of all five layers and is formed of chromaffin cells which are arranged in clusters and is responsible for secretion of catecholamines ( epinephrine and norepinephrine).