Basics
Both the Nervous and Endocrine systems control and integrate activity of body cells: What is the difference between how they do this, speed of response, and duration of effect?
Nervous: NTs and neurons, quick response
Endocrine: Hormones in blood, slower/longer lasting
Which type of hormones can enter the cell? Which type of hormones cannot?
Why? (think solubility)
Can: Lipid-soluble hormones (steroid and thyroid hormones)
Cannot: Water-soluble hormones (all amino acid-based except thyroid hormone)
BONUS: For 2x the points, what type of receptors do each act upon?
What structure connects the hypothalamus to the pituitary gland?
Infundibulum
This important hormone is also called somatotropin as it is produced by somatotropic cells
Growth Hormone
What are Cortisol's main effects?
1. Metabolic - provoke gluconeogenesis
2. Enhance vasoconstriction (started by the sympathetic nervous system)
Name 3 aspects of the body that the Endocrine system controls and integrates.
(for 2x the points, name all 5)
1) Reproduction
2) Growth and Development
3) Maintenance of electrolytes, water, and nutrient balance
4) Regulation of cellular metabolism and energy balance
5) Mobilization of body defenses
Target Cell Activation depends on 3 factors:
1) Blood levels of hormone
2) Relative number of receptors on/in target cell (upregulation/downregulation)
3) Affinity (strength) of binding between receptor and hormone
What is the difference between the Posterior pituitary and the Anterior pituitary?
Posterior pituitary: composed of neural tissue that secretes neurohormones (neurohypophysis)
Anterior pituitary: consists of glandular tissue (adenohypophysis)
What are the direct actions of Growth Hormone?
BONUS: for 2x the points, name the indirect actions as well
Fat Metabolism and Carb Metabolism (glucose sparing / anti-insulin effects because they increase glucose in the bloodstream)
Indirect actions require the liver (and other organs) to release Insulin-like growth factors (IGFs). This stimulates
- skeletal growth (growth of long bone at the epiphyseal plate)
- increase in skeletal muscle mass
- increased protein synthesis for cell growth and proliferation
The parathyroid cells secrete parathyroid hormone in response to low levels of ________ in the blood.
BONUS: For 2x the points, how does PTH regulate this?
- Calcium
- PTH stimulates osteoclast activity in bone - break down bone and release calcium to bloodstream. Stimulates kidney to reabsorb calcium into blood, and stimulates small intestine to absorb calcium from diet
What is the difference between Exocrine and Endocrine Glands?
Exocrine: nonhormonal substances, ducts carry secretion to surface
Endocrine: produce hormones, no ducts
Name the 3 types of Stimuli that cause Hormone Release
Humoral Stimulus: Hormone release caused by altered levels of certain critical ions or nutrients
Neural Stimulus: Hormone release caused by neural input
Hormonal Stimulus: Hormone release caused by another hormone (tropic hormone)
Which Posterior Pituitary hormone acts in positive feedback mechanisms?
Oxytocin
What components form T3/T4 = thyroid hormone? Where in the thyroid gland is this produced?
Thyroglobulin (hormone precursor produced by the follicular cells) and Iodine (oxidized iodide in the colloid)
Cortisol
Explain how Hormones, Autocrines, and Paracrines:
1) Travel (long distance or local chemical messengers)
2) What they affect / how
Hormones: long-distance chemical signals; travel in blood or lymph
Autocrines: Act (has affect) on the organ that releases it
Paracrines: Acts on (affects) locally or adjacent
BONUS: For an extra turn, are Autocrines and Paracrines considered part of the Endocrine system? Why?
Hormone action on target cells may be to... (5 things)
1) Change plasma membrane permeability (change membrane potential --> open and close ion channels)
2) Stimulate synthesis of enzymes & other proteins within the cell
3) Change activity of enzymes (activate or deactivate)
4) Induce Secretory activity
5) Stimulate mitosis
Name the Anterior Pituitary Hormones (and what type of hormone they are)
Growth Hormone (GH)
Thyroid-stimulating hormone (TSH)
Adrenocorticotropic hormone (ACTH)
Follicle-stimulating hormone (FSH)
Luteinizing hormone (LH)
Prolactin (PRL)
BONUS: For 2x the points, identify which of these are tropic hormones
Thyroid hormone can enter the cell (lipid soluble) and cause 3 main effects:
- Calorigenic effect: Increase basal metabolic rate and heat production
- Regulate tissue growth and development
- Maintain blood pressure (by increasing adrenergic receptors in blood vessels)
What are the 2 main regulators of Aldosterone secretion?
1. Decrease in blood pressure / blood volume
2. Increase in K+ in blood
Name the two main classes of hormones and what they are respectively synthesized from
Amino acid-based: amino acid derivatives, peptides, proteins
Steroids: cholesterol
When multiple hormones act on the same target cell at the same time, different types of interactions can occur. Name all 3!
BONUS: For 2x the points, give an example of each
Permissiveness: one hormone cannot exert its effects without another hormone being present (ex. reproductive hormones need thyroid hormone)
Synergism: more than one hormone produces effects on target cell, causing amplification (ex. glucagon and epinephrine both cause the liver to release glucose)
Antagonism: one or more hormones opposes action of another hormone (ex. insulin and glucagon)
What are the components of the hypophyseal portal system?
Primary capillary plexus (hypothalamus -> capillary network),
Hypophyseal portal veins (capillary network -> ant. pituitary),
Secondary capillary plexus (ant. pituitary -> capillary network to circulate throughout body)
Adrenocorticotropic hormone acts on the adrenal gland. What are the 3 histological layers of the adrenal cortex (and what is released in each layer).
Superficial: Zona glomerulosa - releases mineralocorticoids (an example is Aldosterone)
Zona Fasciculata - releases glucocorticoids (an example is Cortisol)
Deep: Zone Reticularis - releases gonadocorticoids (weak androgens that get converted to testosterone)
BONUS: For an Extra turn, are steroid hormones stored in cells?
Symptoms including elevated metabolic rate, sweating, rapid and irregular heartbeats, nervousness, exophthalmos, and weight loss despite adequate food are all indicative of the homeostatic imbalance disorder _____________ cause by the hypersecretion of _____________
Grave's disease
Thyroid hormone