lecture 7 endocrine system Flashcards
Endocrine system
organs that secrete hormones through or by blood stream.
- controls the function of other target organs
- long distance communication
Primary endocrine organs
- Hypothalamus
- pituitary gland (dependent on hypothalamus)
- pineal gland
- thyroid and para thyroid
- thymus
- adrenal gland (associated w/ kidneys)
- Pancreas
- testes and ovaries
Hypothalamus structure
neural secretary cells and nuclei that connect to pitutary gland
Neural secretory Cells
neurons that secrete hormones at the axon terminal
Function of Hypothalamus
controls release of pituitary hormones
what does the hypothalamus secrete
releasing and inhibiting of tropic hormones to the pituitary glands
Tropic Hormone
secreted from one gland and causes another gland to secrete
Hypothalamus connections
Posterior Pitutary
Anterior Pituitary
Hypothalamus Posterior Pituitary (PP) Connection
- neurons in hyothalamus synthesize and secrete hormones
- hormones stored in terminal vessicle (in PP)
- When stimulated the veissicles release hormones in the capillary beds of PP
What are the hormones secreted by the hypothalamus PP connection
Supraoptic nucleus: releases oxytocin
Paraventrcular nucleus: releases antidiuretic hormone (ADH)
Hypothalamus anterior pituitary (AP) connection
Portal system
- stiulated neurosecretory cells release hormones in 1st capillary bed
- 1st capillary bed –> portal vein –> 2nd capillary bed (in AP)
- hormones exit 2nd capillary bed –> stimulate AP endocrine cells
- AP endocrine cells secrete hormones in capillaries
Pituitary Gland incudes
- posterior
2. anterior
Posterior Pituitary Gland Structure
neural tissue (axon terminals) from hypothalamus
Posterior Pituitary Gland Secretes what ?
Antidiuretic Hormone (ADH)or vasopressin
Targets : Kidney
Results in: water reabosorption
Oxytocin
Targets : uterus and breasts
Results: Uterine contraction , milk expulsion
Anterior Pituitary Gland Structure
Epithelial Tissue
What does the Anterior Pituitary Gland secrete
- Prolactic
- Thyroid Stimulating hormone (TSH)
- Adrenocorticotropic (ACTH)
- growth hormone (GH)
- lutenizing hormone (LH)
- follice stimulating hormone (FSH)
Prolactin
Controlled by hypothalamus
acts on breasts
results in: milk secretion / production, mammary gland development
What are the two types of Prolactin
Prolactin Releasing hormone (PRH)
Prolactin inhibiting hormone (PIH) or dopamine
both controlled in hypothalamus
TSH
Thyroid Stimulating hormone (AP hormone)
Controlled by the hypothalamus
Thyrotropin releasing hormone: causes the release of TSH
Acts on thyroid
Results : release of thyroid hormones—> metabolism
ACTH
Adrenocorticotropic Hormone (AP) Controlled by the hypothalamus corticotropin releasing hormone (CRH) Acts on Adrenal Gland results: release glycocorticoids--> stress responses
GH
Growth Hormone (AP )
Controlled by hypothalamus
1. Growth Hormone : releasing hormone ( GRH)
2. Growth Hormone Inhibiting Hormone (GHIH) or somatostatin
- Acts on Liver, cells
-Results: Release insulin like growith factors (Liver), signals growth metabolism cells
LH
Luteinizing Hormone controlled by the hypothalamus Gonadtropin Hormone (GnRH) Acts on ovaries and Testes Results: ovulation, secretion of sex hormones
FSH
Follicle Stimulating Hormone Controlled by the hypothalamus Gonadotropin releasing hormone (GNRH) Acts: on ovaries and testes Results: development of egg and sperm
Pineal Gland Structure
Epithelial Tissue in brain
What does the pineal gland secrete
Melatonin
What does the Pineal gland regulate
Regulates circadian rhythm
Thyroid structure
Butterfly structure , ventral surface of trachea
What does the Thyroid secrete
- Tetraoidothyronine (T4): and Triodothyronine (T3)
- Calcitonin
What is the thyroid responsible for
- T3/T4: in crease metabolism
2. calcitonin: Lowers Calcium levels in blood, deposition / deposit om bone
Parathyroid structure
4 small glands behind the thyroid
What does Parathyroid secrete?
parathyroid hormone ( PTH)
What is Parathyroid responsible for
Increase blood Ca+2 (calcium) levels
What is thymus structure ?
Two lobed gland in front of the heart
What does the thymus secrete
Thymosin
what is the thymus responsible
T cell functional regulation
Adrenal Gland Structure
Multi layered glands above the kidneys
- cortex
- medulla
Cortex
Outer layer
what does the Cortex secrete
- mineral corticoids
- glucocorticoids
- androgens
what is the responsibility of the cortex?
- Mineral corticoids : stimulate reabsorption of sodium ( NA+
- glucocorticoids: Catabolism of fats and proteins raise blood glucose , stress response
- Androgens: promotes sex drive
Medulla
inner core
What does the medulla secrete
epinephrine and norepinephrine
what is the the medulla responsible for?
increased heart rate , mobilization of energy sources
Pancreas structure
exocrine and endocrine gland below stomach
- Exocrine cells: acinor cells
- Endocrine cells: islets of langerhans
Exocrine Cells
Secrete enzymes to GI tract
Endocrine Cells
Alpha cells
what do endocrine cells secrete
glucagon
what are is the function of endocrine cells
raise blood glucosem glycogenolysis, glucogensis
Beta cells:
- secrete insulin
- Results lowers blood glucose promotes energy
storage
Delta cells:
- secrete: somatostatin
- results: inhibits secretion of pancreatic hormone
F Cells:
- secrete” pacreatic polypeptide
- results: inhibits pacreatic exocrine secretions
what do testes secrete
androgens
what are the testes responsible for
sperm production, sex drive, secondary sex characteristics
what do the ovaries secrete
estrogens
What are the ovaries responsible for
follicular development secondary sex characteristics
