Endocrinoloy/Quiz 3 Flashcards
Hormones
Chemical messengers that allow for this communication
Function of hormones
1) reproduction 2) growth and development 3) maintenance of the internal environment 4) energy production, utilization and storage
What are the five classes/types of hormones?
Steroid, proteins, peptides, amines and lipid derived Sppal
Steroid
Ex: testosterone, estrogen, progesterone, cortisol Chemical prop: nonpolar, diffuse thru membrane
Proteins
Ex: insulin, glucagon, growth hormone Chemical prop: polar/nonpolar, big, doesn’t diffuse through receptor
Peptides
Ex: oxytocin, parathyroid Chemical prop: much smaller, chain of amino acid
Amines
Ex: epinephrine and norepinephrine Chemical prop: N-H
Lipid derived
Ex: prostagladins Chemical prop: nonpolar
Endocrinology
Communication and control within living organism through chemical messengers that are synthesized in whole or in part by the organism.
What are the types of cell communication?
Intracrine, paracrine, intercrine, neurocrine, autocrine, juxtacrine, solinocrine, hemocrine
Intracrine
Within cell
Paracrine
Local action O ->O
Intercrine
Tube between cells O=O
Neurocrine
Neuron release hormones into blood
Autocrine
Release own hormone which then signal cell
Juxtacrine
Immune system
Solinocrine
Hormone released within lumen, small intestine
Hemocrine
Release of hormone into blood
Mechanism of action for steroid/lipid hormones vs. protein/peptide/amine hormones
Nonpolar/steroid - can go straight into nucleus and act as transcription factor Protein/peptide/amine - attach to receptor, triggering signal cascade
Effects of hormones are determined by…
- Responding cell type/ receptor type 2. Concentration - how much? 2. Presence of other stimuli
What is the actual response of receptor dependent on?
It depends in the transducing domain, NOT determined by the hormone itself.
Hormone - receptor equilibrium reaction
R + H R * H
Scatchard Equation
Bound hormone / free hormone = Ka[R] - Ka[Bound] Ka = [R*H]/([R]*[H])
How does sensitivity shift the % response vs. [hormone] graph?
Shifts it left or right
How does change in responsiveness shift the response magnitude vs. [hormone] curve?
Up or down
Synergistic response
Effect is much larger than if you added up individual effects
Hormone stimulus can result in
- alters plasma membrane permeability - stimulates synthesis of proteins or inhibitors - activates or deactivates enzymes - induces secretory activity - stimulates mitosis and other cell behavior
At cell level, hormones affect
- cell survival - cell proliferation - cell differentiation - cell behavior
As you increase or decrease concentration of hormone concentration…
You shift the curve to the left or to the right, increase or decrease biological response
As you increase or decrease the number of spare receptors
You shift curve up or down, increase or decrease specific binding
Additive response
effects are independent but additive
Describe (diagram) the control system for an endocrinological response.
Positive feedback for an endocrine system
Endocrine pathology - How can you have a loss of homeostasis in terms of hormones
- Subnormal hormone production (Type I diabetes)
- Hormone excess
- Production of abnormal hormones (maybe don’t bind to receptor too well)
- Resistance to hormone action (lose sensitivity)
- Abnormalities of hormone transport or metabolism
- Multiple hormone abnormalities
Acromegaly
- Excess of growth hormone being produced after you stop growing
- Cancer in AP
Gigantism
- Abnormally large growth
- Tissues not growing proportionally with bone
- Tumor in AP occurred during growth
Myxedema
- Severe hypothyroid syndrome in adults
- low metabolic rate, puffy eyes, mental sluggishness
- Lack of iodine in diet
Creatinism
- Hypothyroidism in children
- short stature, disproportionate body, thick tongue and neck
- Genetic deficiency in fetal thyroid gland or materal factors
Graves’ disease
- hyperthyroid syndrome
- elevated metabolic rate, sweating, rapid and irregular heatbeat
Cushing’s disease
- excess of cortisone
- hyperglycemia, water and salt retention, hypertension
- ACTH-releasing tumor of the pituitary
Addison’s disease
- Hyposecretory disorder of the adrenal cortex
- Weight loss, low Na and high K, severe dehydration and hypertension
- Caused by deficiencies in glucocorticoids and mineralcorticoids
Diabetes Mellitus
- Hyposecretion or hypoactivity of insulin
- Insulin absent or deficient, blood sugar remains high after meal
Type I diabetes
- Insulin-dependent, juvenile-onset
- Destruction of pancreatic islet cells (source of insulin)
(iselt -sense blood sugar levels and release insulin to maintain normal levels)
Type II diabetes
- non-insulin dependen
- unresponsive insulin receptors (insulin resistance)
- can be managed by diet and exercise
