The adrenal gland is encased in a connective tissue capsule that extends septae into the substance of the gland. The organ is richly vascularized and capsular blood vessels, nerves and lymphatics penetrate along with the connective tissue septae.
What are the three layers of the adrenal gland?
Anatomy of the Adrenal Glands It is divided into three separate zones: zona glomerulosa, zona fasciculata and zona reticularis.
What tissue makes up adrenal glands?
The adrenal gland consists of an outer cortex of glandular tissue and an inner medulla of nervous tissue. The cortex itself is divided into three zones: the zona glomerulosa, the zona fasciculata, and the zona reticularis.
What is the capsule of the adrenal?
A thick capsule consisting of connective tissue surrounds the entire adrenal gland. The zona glomerulosa is responsible for the synthesis of mineralocorticoids, of which the most important is aldosterone. This hormone plays an important role in electrolyte balance and regulation of blood pressure.
What are histological features?
Histology, also known as microscopic anatomy or microanatomy, is the branch of biology which studies the microscopic anatomy of biological tissues. Histology is the microscopic counterpart to gross anatomy, which looks at larger structures visible without a microscope.
What cells are in the adrenal medulla?
The adrenal medulla, which is composed of pheochromoblasts/chromaffin cells, forms the gray core of the adrenal gland. These cells synthesize and store the catecholamines norepinephrine, epinephrine, and dopamine. The adrenal medulla is considered a specialized postganglionic sympathetic neuron devoid of an axon.
What are the three histological zones of adrenal cortex?
The adrenal cortex comprises three zones, or layers: Zona glomerulosa (outer), Zona fasciculata and Zona reticularis. The outermost layer, the zona glomerulosa, is the main site for production of mineralocorticoids, mainly aldosterone. Zona fasciculata is the layer situated between the glomerulosa and reticularis.
What is the principal mineralocorticoid?
The principal mineralocorticoid is aldosterone, which acts to conserve sodium ions and water in the body. Glucocorticoids are secreted by the middle region of the adrenal cortex. The principal glucocorticoid is cortisol, which increases blood glucose levels.
What is the zona reticularis?
The zona reticularis is the innermost layer of the adrenal cortex, lying just above the adrenal medulla.
What is the difference between norepinephrine and epinephrine?
Epinephrine and norepinephrine are very similar neurotransmitters and hormones. While epinephrine has slightly more of an effect on your heart, norepinephrine has more of an effect on your blood vessels. Both play a role in your body’s natural fight-or-flight response to stress and have important medical uses as well.
What does zona glomerulosa secretes?
1. Zona glomerulosa, the outermost zone of the adrenal cortex secretes mineralcorticoids. These hormones are important for fluid homeostasis. These include aldosterone, which regulates absorption/uptake of K+ and Na+ levels in the kidney.
What type of tissue is the adrenal medulla made of?
nervous tissue The adrenal medulla is made up of nervous tissue and secretes catecholamines in response to neuronal signals. The most abundant cells in the medulla is the chromaffin cells.
What is the structure of adrenal glands?
Anatomical Structure The adrenal glands consist of an outer connective tissue capsule, a cortex and a medulla. Veins and lymphatics leave each gland via the hilum, but arteries and nerves enter the glands at numerous sites. The outer cortex and inner medulla are the functional portions of the gland.
What is a chromaffin cell?
Chromaffin cells (CCs) of the adrenal gland and the sympathetic nervous system produce the catecholamines (epinephrine and norepinephrine; EPI and NE) needed to coordinate the bodily fight-or-flight response to fear, stress, exercise, or conflict.
What does the zona fasciculata secrete?
The zona fasciculata cells of the adrenal cortex synthesize and secrete glucocorticoids in response to ACTH secreted by the anterior pituitary (Jacobson, 2005). Glucocorticoids, cortisol in humans and corticosterone in rodents, are the final effectors of the HPA axis.
What is histological structure?
Histology: The study of the form of structures seen under the microscope (light, electron, infrared ). Also called microscopic anatomy, as opposed to gross anatomy which involves structures that can be observed with the naked eye. … The word histology came from the Greek histo- meaning tissue + logos, treatise.
What is an example of histology?
The study of human tissue is an example of histology. The anatomical study of the microscopic structure of animal and plant tissues. … The anatomical study of the microscopic structure of animal and plant tissues.
What is cytology vs histology?
Cytology generally involves looking at a single cell type. Histology is the exam of an entire block of tissue.
What Innervates the adrenal medulla?
The cells of the adrenal medulla are innervated by preganglionic fibers of the sympathetic nervous system. Most of the blood supply of the adrenal glands enters through the cortex and drains into the medulla, except for some vessels which supply the medulla directly.
Why adrenal medulla secretes more epinephrine than norepinephrine?
Noradrenaline has a more specific action working mainly on alpha receptors to increase and maintain blood pressure whereas epinephrine has more wide-ranging effects. Norepinephrine is continuously released into circulation at low levels while epinephrine is only released during times of stress.
What are the layers of adrenal cortex?
The adrenal cortex takes part in steroidogenesis, producing glucocorticoids, mineralocorticoids, and androgen precursors. It has 3 distinct functional and histological zones: the zona glomerulosa (outermost layer), the zona fasciculata (middle layer), and the zona reticularis (innermost layer).
Where is adrenaline Synthesised?
adrenal medulla Adrenaline is synthesized in the chromaffin cells of the adrenal medulla of the adrenal gland and a small number of neurons in the medulla oblongata in the brain through a metabolic pathway that converts the amino acids phenylalanine and tyrosine into a series of metabolic intermediates and, ultimately, adrenaline.
Which zone of the adrenal gland secretes cortisol?
The zona fasciculata (ZF) is the middle zone of the adrenal cortex, and it primarily produces cortisol. The zona reticularis (ZR) is the inner most zone of the adrenal cortex and it is adjacent to the adrenal medulla.
Where is the adrenal medulla?
The inner part of the adrenal gland (a small organ on top of each kidney). The adrenal medulla makes chemicals such as epinephrine (adrenaline) and norepinephrine (noradrenaline) which are involved in sending nerve signals.
What is the principal glucocorticoid?
Cortisol, the principal glucocorticoid in humans, and its rodent counterpart, corticosterone, are synthesised from cholesterol in cells of the zona fasciculata of the adrenal cortex. … Glucocorticoids are also released in response to physical and/or emotional trauma.
What is the difference between mineralocorticoid and glucocorticoid?
Mineralocorticoids and glucocorticoids are key steroid hormones secreted by the adrenal cortex. These hormones are vital for life with mineralocorticoids regulating the water and electrolyte balance, whilst glucocorticoids control body homeostasis, stress and immune responses.
What is the main glucocorticoid?
Cortisol (or hydrocortisone) is the most important human glucocorticoid.
Does zona reticularis secrete glucocorticoids?
The human adrenal cortex comprises three distinct zones with unique steroid products, namely the zona glomerulosa, which secretes the mineralocorticoids, the zona fasciculate, which secretes the glucocorticoids and the zona reticularis (ZR), which at adrenarche, begins to produce the so-called adrenal androgens.
How do you say zona reticularis?
What does Reticularis mean?
: the innermost of the three layers of the adrenal cortex that consists of irregularly arranged cylindrical masses of epithelial cells.
Graduated from ENSAT (national agronomic school of Toulouse) in plant sciences in 2018, I pursued a CIFRE doctorate under contract with Sun’Agri and INRAE in Avignon between 2019 and 2022. My thesis aimed to study dynamic agrivoltaic systems, in my case in arboriculture. I love to write and share science related Stuff Here on my Website. I am currently continuing at Sun’Agri as an R&D engineer.