1/28- Endocrine System (Exam 1) Flashcards
What are the endocrine glands?
No duct and release secretions into blood
Secretions are hormones (chemical messengers)
Discrete structures
Whole reason is to secrete these hormones
Pancreas is both endo and exo
What does a chemical messenger do?
Causes the body to react
Directed to a particular target
- target organ
- target tissue
- target cells (TRUE TARGET)
What 2 organs secrete hormones?
Stomach
Heart
What kind of tissue secretes hormones?
Adipose tissue (fat)
Explain the endocrine and neuron system relationship
Work hand in hand to regulate the body
Line b/n 2 is blurry
Some specialized neurons in the hypothalamus release chemical messengers in the blood
What do axon terminal branches release and in what?
Neurotransmitter
Synaptic cleft
What are neurohormones?
Release of neurotransmitters straight into the blood
What is epinephrine?
Released by endocrine glands into the blood with same effect acting as a hormone
Also released from synaptic cleft
Into blood- adrenaline
Synaptic cleft- epi
What are the 3 major groups hormones are divided in?
1) Amino Acid Derivatives or Amines
- come from amino acids
- polar
2) peptide hormones
- string of amino acids
- polar
3) lipid derivatives
- steroids (built from cholesterol and non polar
What are the 2 ways hormones interact with their target?
1) polar
- hydrophilic
- acts like a magnet
- makes hydrogen bonds
2) nonpolar
- hydrophobic
- lipophilic
Which kind of hormone goes through a phospholipid lipid bilayer?
Non polar
Polar gets spit out
How do polar hormones bring their message to the cell?
Hormone attaches to a receptor protein making it a ligand
Then second messenger (chemical inside cell) delivers the message
What are 2 hormones working together to give the same result called?
Synergist
Action is synergetic
What are 2 hormones working opposite of each other have opposite effects called?
Antagonist
Action is antagonistic
What are the 2 types of synergist hormones and explain
1) additive- 2 hormones doing exactly the same thing
Ex: epi and norepi
2) complimentary- hormones contributing to the same process. Need one to do the other
Ex: FSH and testosterone both contribute to making sperm but for different steps
What is a permissive effect?
Hormone A makes the target more sensitive to Hormone B
What is the primate effect or upregulation?
Hormone A makes the target more sensitive for Hormone A
What is downregulation?
Hormone released too much the target becomes desensitized
What is the half life of a hormone?
Amount of time is takes for the concentration to be reduced by half
Most hormones half life are minutes to hours
Thyroid hormones is days
Are hormones endlessly in the blood?
No, liver and target organs pull out concentrations of the hormone
What are the different types of endocrine glands?
1) pituitary glands or hypophysis
2) thyroid gland
What are the 2 types of the pituitary gland or hypophysis?
1) posterior pituitary
2) anterior pituitary
What is the space between the anterior and posterior pituitary gland?
Rathke’s Pouch
How is the posterior pituitary gland and the thalamus connected?
Infundibulum
What hormones does the posterior pituitary or neurohypophysis secrete?
1) Antidiuretic Hormone (ADH) or Vasopressin:
- kidney to conserve water
2) oxytocin:
- stimulates contraction of smooth muscle
- causes labor muscles to contract
- ejection of milk from breasts
What happens if your posterior pituitary gland doesn’t make enough Antidiuretic Hormone (ADH)?
Diabetic Insipidus
- urinating excessively
Where is ADH and oxytocin produced and how does it get secreted in the blood?
Produces by nerve cell bodies in the hypothalamus
Then hormone migrates down axon to axon terminal branches
Nerve impulses release hormone into blood
What is the anterior pituitary gland?
Produces hormones it releases
Cause target to grow or mature
Secrets Tropic or Trophic Hormone
What are the 5 different types of tropic or trophic hormones?
1) Thyroid stimulating hormone (TSH)
2) Adrenocorticotropic hormone (ACTH)
3) Growth Hormone (GH)
4) Gonadotropic Hormones
5) Prolactin hormone (PRC)
What is the thyroid stimulating hormone (TSH)?
Stimulates hormone to release hormones of the thyroid
What is the adrenocorticotropic hormone (ACTH)?
Causes adrenal gland to release Glucocorticoids
Adrenal gland
Outer part- adrenal cortex
Adrenal cortex tropic hormone
What is the growth hormone (GH)?
Causes body to grow
Not enough- midget
Too much- gigantism
Acromegaly:
- exposes to GH after being fully grown
- high forehead
- big hands and feet
- lantern jaw
- body builders use this
What are the 2 types of Gonadotropic hormones and explain
1) follicle stimulating hormone (FSH)
2) Lutenizing hormone (LH)
Found in gonads (testicles and ovaries)
FSH and LH names for female roles but found in both sexes
What is proclatin hormone?
Milk production
What is the anterior pituitary gland referred as?
Master gland
Although it’s a communication
What are releasing hormones?
Hypothalamus produces hormones to talk to anterior pituitary gland to release particular hormones on the list before
Each has a separate releasing hormone
What are hypophyseal portal veins?
Specialized part of circulatory system that helps hypothalamus and anterior pituitary gland communicate
What a portal vein?
Specialized system of veins
Capillaries—-> Veins——> capillaries
What is a thyroid gland?
Has a colloid liquid
Colloid liquid has Thyroglobulin protein
Simple cuboidal epithelium
Follicular cells
Located on the base of neck
Shield shape gland under microscope
What are follicular cells?
Produce major hormones of the gland
Target for Thyroid Stimulating Hormone
- take colloid by pinocytosis
Needs iodine to make hormone
Take iodine from blood (tiny trace)
What is a tetraiodothyronine or thyroxine (T4)?
1 amino acid with 4 iodines
Amines
Target takes T4 and turns it into T3
What is a triiodothyronine (T3)?
1 amino acid with 3 iodine’s
Active hormone
Amines
What is basal metabolic rate?
Rate the body uses energy
What is hyperthyroidism?
Too much T3 and T4
Anxious
Lots of energy
Loses weight
What is hypothyroidism?
Not a lot of T3 and T4
Tired all the time
Gains weight
What happens when you have goiter?
Not enough iodine in diet
Thyroid grows and can pop out of neck
