THE ENDOCRINE SYSTEM

•REPRODUCTION•METABOLISM •OSMOREGULATION•EMBRYONIC DEVELOPMENT

•GROWTH•METAMORPHOSIS•DIGESTION

It is made up of endocrine glands that secretes hormones and coordinate slower but longer-acting responses to stimuli

Hormone is a chemical signal that is secreted into the blood and communicates regulatory messages within the body

Target cells are equipped to respond to these hormones

HYPOTHALAMUS & PITUITARY GLAND

Pituitary gland is located at the base of the human brain.

PITUITARY GLAND

Anterior lobe

This regulates the other endocrine glands

Hormones secreted:Somatotropin

Prolactinthyroid – stimulating hormoneadrenocorticotropic hormonefollicle – stimulating hormone

luteinizing hormone and; melanocyte – stimulating hormone

Posterior lobe

This regulates water conservation, milk letdown, and uterine contraction in women

Hormones secreted:

antidiuretic hormone and oxytocin

Pituitary Gland (Anterior)

FISHES AMPHIBIA REPTILIA AVES MAMMALIA

TSH Present Present Present Present Present

LH Present Present

FSH Present

ACTH Present Present

GH Present Present Present Present Present

PROLACTIN Absent Absent Absent Present Present

MSH Present Present*(color change)

Present*(color change)

Present Present

Pituitary Gland (Posterior)

FISHES AMPHIBIA REPTILIA AVES MAMMALIA

ADH Absent Present Present Present Present

OXYSTOCIN Absent Present

Antidiuretic Hormone (ADH) – controls water balance in the body and blood pressure.

Oxytocin – a peptide hormone that stimulates uterine contractions during childbirth.

THE PINEAL GLAND

The Pineal gland is located at the midbrain of the vertebrates

The Pineal gland secretes Melatonin

Fishes Amphibia & Reptilia Aves & Mammalia

Function Act as Third eye

Controls color change Allows to respond to changes in Photoperiod

THE THYROID GLAND

It produces, stores, and releases two separate thyroid hormones that regulate metabolic rate, metamorphosis, growth, and reproduction (Kardong, 2012).

2 types of thyroid hormones:

Thyroxine (T3)

Triiodothyronine (T4)

THE THYROID GLAND

Fishes Reptilia Amphibia Aves Mammalia

MetabolismUnresponsive

Elevate oxygen consumption and heat production by tissues

Growth & Development

Growth depends on Thyroid hormones

Their thyroid hormones arrest

growth of the larvae and promote

metamorphosis

Normal growth depends on normal levels of thyroid

hormones

Molting Thyroxine promotes sloughing or shedding of the skin

Reproduction Correlates with gonad maturation and oogenesis or

spermatogenesis

Arrest physiological

processes that promote

reproduction

Correlates with gonad maturation and oogenesis

or spermatogenesis

ULTIMOBRANCHIAL BODY & PARATHYROID GLAND

ULTIMOBRANCHIAL BODY secretes calcitonin

(thyrocalcitonin), which lowers blood levels of calcium.

Calcitonin causes calcium to be extracted from the blood and used to build new bone matrix, causing blood levels of calcium to fall

PARATHYROID GLAND secretes parathyroid

hormone ( parathormone), which elevates levels of blood calcium

raises blood levels of calcium by promoting kidney retention of calcium, encouraging its absorption across the walls of the digestive tract, and affecting bone deposition

PARATHYROID GLAND

Fishes Amphibia Reptilia Aves Mammalia

Location Absent Either on the thyroid or dispersedalong the major veins in the neck

Mouse, Cat & Human – embedded in the Thyroid gland

Goat & Rabbit – embedded near the thyroid gland

ADRENAL GLAND•One of the most important functions of the adrenalgland is coordinating the whole organism’s response to stress

THE ADRENAL GLANDS

Chromaffin Tissue releases adrenalin

(epinephrine) and norepinephrine in times of stress

Corticosteroids produces the

corticosteroid hormone produces aldosterone -

acts in the kidney to promote the uptake of sodium & other salts from the urine

In Fishes:

The Chromaffin cells may vary in location. These are found with the sympathetic ganglia in clumps between the anterior kidney and spine or in the interrenal tissue.

In Reptiles:

The adrenocortical tissue receives its own arterial and venous blood supply, and does not rely on the kidney and renal portal system for distribution of its secretory products

In Amphibians and Birds:

Adrenocortical and Chromaffin tissues mingle or reside adjacent to each other and form strands or rows of adrenal tissue, now lying on or near the kidneys

In Mammals:

Adrenocortical and Chromaffin tissues form a cortex and a medulla respectively to create the composite adrenal gland or suprarenal

THE PANCREAS

•a composite gland consisting of exocrine which consists of Acini that secrete digestive enzymes into ducts and endocrine portions known as the Islets of Langerhans consists of masses of endocrine cells embedded within the exocrine pancreas

THE ISLETS OF LANGERHANS

secretes insulin and glucagon

Insulin removes glucose from the blood.

Glucagon returns glucose to the blood. Alpha cells produces glucagon Beta cells insulin

GONADS

In males, gonads is known as testes which secretes androgens and testerone.

In females, gonads is known as ovaries which secrets estrogen and progesterone

CLASS MAMMALIA

TESTES

It stimulates bones and musles growth and development of the secondary sexual characters like beard and mustaches

CLASS AVES

TESTES

It controls the secondary sexual characters like bright plumage colour, comb and spurs.

VERTEBRATES:

UNIQUE ENDOCRINE GLANDS

CLASS PISCES:

UROPHYSIS

A neurosecretory neurohemal organ which is associated with the spinal cord at the base of the tail

CLASS AMPHIBIA

In larval stage, the thyroid hormone secretion and glucocorticoid secretion are ultimately stimulated by a single hypothalamic releasing hormone – corticotropin-releasing hormone that stimulates ACTH.

CLASS MAMMALIA

THYMUS GLAND

It lies in upper part of chest, behind breast-bone and consists of 2 lobes that join in front of trachea. It secretes thymosine that stimulates develoment and differentiation of T cells which defends the body against viruses.

THE ENDOCRINE SYSTEM

Aballe, Karen Marie

Sebastian, Marie Elaine