Endocrine System Flashcards
How does the endocrine system communicate?
With cells with chemicals called hormones
Role of hormones
Regulate metabolic processes in the body
Describe their action?
It is precise and they only affect specific target cells
The endocrine glands include
Pituitary
Thyroid
Parathyroid
Adrenal
Pancreas
Hypathalamus
Pineal
What mechanism do hormones use?
Lock and key mechanism
Combined hormone actions
Antagonism, permissiveness and synergism
Types of hormones
Sex
Tropic
Anabolic
Steroid
Non steroid
Examples of steroid hormones
Cortisol, aldosterone, estrogen, progesterone, testosterone
What is the size of the pituitary gland?
1.2 - 1.5 cm (about 1/2 inch across)
Weighs 0.5 g
Location of pituitary gland?
Located on the central part of the brain within the skull
Two glands of the pituitary gland?
Adenohypophysis and neurohypophysis
What forms the major portions of the anterior pituitary gland
Pars anterior
Cells in the adenohypophysis
Chromophobes- no stain
Acidophils stain with acids
Basophils stain with bases
What does the anterior pituitary consists of?
Mostly epithelial tissue arranged around blood vessels and enclosed in a capsule is collagenous connective tissue.
What is the purpose of the neurohypophysis
Storage and release of ADH and oxytocin
What is the role of ADH?
prevents the formation of large volumes of urine and hence helps the body to save water. Causes a portion of each tubule in the kidney to reabsorb water from urine
Oxytocin’s role in child birth
Contracting of muscles in the uterine wall and milk let down by forcing milk into ducts from milk glands
Pineal gland shape
Pine nut shaped
Location of pineal gland
Dorsal aspect of the brain’s diencephalon region
Why is the pineal gland a member of the nervous system?
It receives visual stimuli
What does the pineal gland secrete?
Melatonin - sleep
What is the structure of the thyroid gland
Made up of two large lateral lobes and a narrow connecting isthmus
What extends upward from the isthmus?
Pyramidal lobe
What is the weight of the thyroid gland in adults?
30 g
What is in the thyroid gland?
Follicles with hormone storing colloid
Role of calcitonin
Decrease blood Ca 2+
What kind of glands are in the posterior surface of the gland
4 or 5 parathyroid glands
What is a antagonist to calcitonin and what does it act on
PTH, acts ok bone and kidney
Where are adrenal glands located?
On top of the kidneys
Two portions of adrenal gland
Cortex- endocrine tissue and medulla- neurosecretory tissue
The adrenal cortex is composed of three distinct layers of secreting cells:
Zona glomerulosa
Zona reticular is
Zona fasiculata
The adrenal medulla secretes
Epinephrine and norepinephrine into the blood stream
Weight of pancreas?
100 g
Position of pancreas
A head of duodenum, behind stomach and touches the spleen
The islet of pancreas contains five primary cells joined by junction
alpha, betta, epsilon, delta and pancreatic polypeptide
HCG stimulates the
Corpus luteum
Symptoms of hyper thyroidism
Large thyroid, heat intolerance, weight loss, diarrhea, tremor
Hypothyroidism
Lethargy, amoung other
