Endocrine System Flashcards
What are the 4 ways cells can communicate
Paracrine
Synaptic
Endocrine
Contact Dependent.
What does the endocrine system consist of
cells
tissues
organs
What is the primary function of the endocrine system
Endocrine are ductless glans which secrete hormones in the interstitial fluid and blood throughout the body.
What structures do the endocrine system utilise
Pituitary Thyroid Parathyroid Endocrine pancreas Adrenal glands Pineal Glands.
What is the role of the hypothalamus
Most of the involuntary mechanisms including Body temperature Hunger Thirst Sleep
What is the role of the Thyroid gland
Regualtes energy and metabolism
What is the role of the pancreas
Aids in digestion of protein fats and carbohydrates.
Produces insulin which controls blood sugar levels.
Role of the ovaries
Influences how the blood circulates and determines sex drive.
What is the role of the adrenal glands
Secretes many hormones such as cortisone and adrenaline which helps in fight or flight situations.
What is the role of the thymus
Helps build resistance to diseases
What is the role of the parathyroid
Secretes hormones necessary for calcium absorption.
What is the role if the pituitary gland
Controls all other endocrine glands such as
growth
metabolism
regeneration
What is the main function of the endocrine cells
Secrete hormones
How do endocrine cells work
Can be gathered together to form a specialised organ
Form discreet clusters in another specialised organ
May be dispersed singly amongst cells in other epithelial tissues.
What hormones are released from the hypothalamus
CRH corticotropin releasing hormone
TRH thyrotropin releasing hormone
GHRH growth hormone releasing hormone
GnRH gonadotropin releasing hormone
What hormones are released via the anterior pituitary gland
ACTH TSH thyroid stimuling hormone GH FSH LH Prolactin
What hormones are released via the posterior pituitary gland
ADH
OXYTOCIN
What hormones are released by the thyroid gland
T4
T3
What hormones are released in the cortex of the adrenal glands
CORTISOL
CORTICOSTERONE
ALDOSTERONE
ANDROGENS
What hormones are released in the medulla of the adrenal glands
Epinephrine
Norepinephrine
What hormones are released by the pancreas
insulin
glucagonn
What hormone is released via the pineal gland
Melatonin
What is a hormone
Chemical substance that is classified as a peptide steroid or amine.
How do hormones work
They are secreted in small amounts into the blood circulation and delivered to the target tissues where they can emit a physiological response.
What are the 3 biosynthetic pathways for hormones synthesis
- Peptides and proteins are synthesised form amino acids.
- Steroids derived from cholesterol
- Amines derived from tyrosine.
What do peptide hormones secrete and their source and function
Secrete
Insulin
Glucagon
Both from the pancreas
Function
Fuel and storage and glucose use.
What do amine hormones secrete and their source and function
Secrete
Epinephrine
From
Adrenal Medulla
Function
Muscles glycogenolysis
Fat cell lipolysis
What do steroid hormones secrete and their source and function
Secrete
Cortisol
From
Adrenal cortex
Function
Glucose production
Protein mobilisation.
How are hormones regulates
They need to be turned off and on by neural mechanisms and feedback mechanisms.
Differentiate the difference between positive feedback and negative feedback
Negative Feedback
A mechanism that occurs when the body systems need to slow down or stop a process that is occurring
Positive Feedback
A mechanism that occurs when the body systems needs to encourage or amplify a process that is occurring.
What effect does FSH and LH have on the ovaries
Ovulation and stimulation of oestrogen secretion.
What cell type secrete Thyroid stimulating hormone TSH and their function
Secreted by
Thyrotrophs
Stimulate the synthesis and secretion of thyroid hormone.
What cell type secrete LH and FSH and their function
Secrete by
Gonadotrophs
Function
MALES- Stimulate sperm production
Females- Stimulate growth of an ovarian follicle and ovulation
What cell type secrete Adrenocorticotropic hormone ACTH and its function
Secreted by
Corticotrophs
Function
Synthesis and Secretion of adrenal cortisol hormones.
What cell type secretes growth hormone GH and its function
Secreted by
Somatotrophs
Function
Stimautes growth of bone and muscle and promotes protein synthesis and fat metabolism
What secrete prolactin
Lactrophs
How are peptide hormones synthesised
Transcription of DNA to mRNA
Translation of mRNA to final hormone
What are the 4 different types of epithelial tissue of the anterior pituitary
Pars distalis
Pars Trabecula
Pars intermedia
Pars intermedia
What is the function of ADH
Decrease water loss by kidneys
What is the function of oxytocin
Promotes contraction of smooth muscle in the uterus.
What are the 2 lobules the pineal gland is composed of
Pinealocytes which produces melatonin
Glial cells
What are the 2 different cell types in parathyroid glands
Chief cells
Oxyphils
What happens if the thyroid hormone does not function properly
Disturbances of thyroid hormones will affect growth, CNS, BMR, nutrient metabolism and the CV system.
What is hypothyroidism
Graves disease is an autoimmune disease characterised by increased circulating levels of thyroid stimulating immunolglobina.
What symptoms occur with hypothyroidism
Weight loss
Rapid heart due to up regulation
What are the 3 layers of the medulla of the adrenal gland
Zona rectiualris
Zona fasciculata
Zona glomerulosa
