ENDOCRINE Flashcards
- It is also called the ductless glands.
- responsible for the synthesis and secretion of
chemical messenger known as hormones via the bloodstream on specific target
organs. - no duct system and therefore sometimes called the ductless glands.
Endocrine Glands
are highly vascular and you have
blood vessels that are fenestrated
Endocrine organs
Divisions of the Pituitary Gland:
ANTERIOR PITIUTARY
POSTTERIOR PITIUTARY
- also known as Hypophysis or Hypophysis Cerebri
- secretes several hormones.
- situated in the Sella turcica of the sphenoid bone and base of the brain via the infundibulum or stalk.
- Pea shaped
- master gland because influences the rest of the endocrine glands
Pituitary Gland
regulates the function of the anterior lobe of the pituitary gland hence this was regarded untrue
hypothalamus
Hormones secreted by Anterior Pituitary:
- Growth hormones - LONG BONES
- Thyroid stimulating hormone - THYROID GLAND
- GnRh (follicles stimulating hormone, luteinizing hormone) - TESTIS AND OVARY
- Prolactin - MAMARY GLAND FOR MILK PRODUCTION
- ACTH(adrenocorticotrophic hormone) - ADRENALS GLANDS/CORTEX
- MSH (melanocyte stimulating hormone) - SKIN
- also called the adenohypophysis
- 75% of the total weight of the gland arises as an epithelial outgrowth from primitive oral cavity
Anterior Pituitary
primitive oral cavity known as
Rathke’s pouch
- also called neurohypophysis
- downgrowth of nervous tissue from the hypothalamus to pituitary stalk
- coming from diencephalon
- not synthesize hormones. Instead stores and releases two hormones
Posterior Pituitary
(produces vasopressin or ADH)
supraoptic nucleus
(produces oxytocin)
paraventricular nucleus
Hormones stored by Posterior Pituitary:
ADH (antidiuretic hormone, Vasopressin)
Oxytocin (pitocin)
modified neuroglial cells found in the pars nervosa
Pituicytes
- Stimulates uterine contraction -
- stimulates milk ejection (milk “letdown) from
the mammary glands
Pitocin (oxytocin)
thyrocalcitonin secreted by the
____________ which helps regulate calcium homeostasis
parafollicular cells
- also called epiphysis cerebri or conarium
- located at the caudal end of the diencephalon of the brain.
- consists of cells called pinealocytes
- Hormones secreted: Melatonin
Pineal Gland
- increases water reabsorption at the distal
convoluted tubules of the kidneys. - vasopressor effect
- raises blood pressure
Pitressin or ADH
2 thyroid hormones:
thyroxine (T4) and triiodothyronine
(T3)
- small oval endocrine glands associated sa
posteriorly with the thyroid gland - supplied by inferior thyroid artery
- secretes parathormone
PARATHYROID GLAND
Hormones secreted: Melatonin derived from
_____________, which may promote sleepiness
serotonin
- lobulated gland lying in front of the neck
- Also secretes thyrocalcitonin
- 2 thyroid hormones:
- containing thyroglobulin
Thyroid gland
DECREASE YOUR CALCIUM LEVEL
CALCITONIN
INCREASE YOUR CALCIUM LEVEL
PARATHORMONE
small flattened endocrine glands closely applied to the upper pole of the kidneys
Adrenal (Suprarenal) Gland
- outer and thicker portion
- CONTAINS 3 layers of cell: zona glomerulosa, zona fasciculata, and zona reticularis
Adrenal Cortex
- regulate fluids and electrolytes
- help adjust blood pressure and blood volume
Mineralocorticoids (aldosterone and deoxycortisones)
regulate metabolism and resistance to stress
Glucocorticoids (e.g. cortisone)
- promote libido in females and are converted to estrogen,
- also stimulate growth of axillary and pubic
hairs in boys and girls and contribute to the
prepubertal growth spur
ANDROGENS
Secretes the catecholamines - epinephrine and
norepinephrine
- Produces effects that enhance those of the sympathetic division of the autonomic nervous system during stress
Adrenal medulla
- pistol shaped
- head part of which is enclosed by the duodenum
- body at the back of stomach and tail related with spleen
- Islets of Langerhans
Pancreas
- the exocrine portion is secretion of enzymes.
Islets of Langerhans
vary in size and most numerous at
the tail of the pancreas
pancreatic islets
Cells in the Islets of Langerhans :
- alpha cell
- beta cell
- delta cell
- f cell
- less numerous containing acidophilic
granules. - found at the periphery of the islet
- secrete glucagon – which increases blood
sugar
alpha cells
- found at the center of the islets
- it secretes insulin which decreases blood
Beta cells
- secrete somatostatin, which inhibits
secretion of insulin and glucagon and slows
absorption of nutrients from the GIT
delta cell
- secrete pancreatic polypeptide
f cells
- are paired organs lodging in the scrotum are
responsible for the production of the male
gametes, spermatozoa, and male sex hormones - interstitial cells of Leydig
Testis
interstitial cells of Leydig which secrete these androgens:
a) Testosterone
b) Dihydrotestosterone
c) Androstenedione
- regulates production of sperm and stimulates the development and maintenance of masculine secondary sex characteristics
- main hormone in testis
testosterone
- the follicular cells of the ovarian follicle secrete estrogen and the corpus luteum secretes progesterone
- hese hormones regulate the female reproductive cycle.
Ovaries
also producing a hormone - syncytiotrophoblast, human
chorionic gonadotropin (HCG)
placenta
autoimmune disorder associated with increased circulating levels of thyroid hormones
Grave’s Disease
disorder of metabolism and chronic hyperglycemia
Diabetes Mellitus
refers to the manifestations of excessive
corticosteroids
Cushing’s Syndrome
disorder caused by the destruction of the adrenal cortices characterized by chronic deficiency of cortisol, aldosterone and androgens causing skin pigmentation
Addison’s Disease
Endocrine Gland Diseases
- Grave’s Disease
- Diabetes Mellitus
- Cushing’s Syndrome
- Addison’s Disease
