Learning Outcome 1 Endocrine System Flashcards
What is the primary role of the endocrine system?
Synthesize and secrete hormones
How is the endocrine system like the nervous system?
Nervous System - chemical and electrical signalling
Endocrine Sytstem - Chemical Signalling (Hormones through the bloodstream)
What is the difference between direct, paracrine, endocrine and synaptic intercellular
communication?
Direct - Via Gap Junctions Ions, small solutes, rare
Paracrine - via extracellular fluid, most common
Endocrine - Via blood, hormone
Synaptic - Neurotransmitters
Which type of communication uses hormones to increase or decrease enzyme
synthesis and/or metabolic activity?
Endocrine
What is the most common type of intercellular communication?
Paracrine
What are the functions of the endocrine system?
- Regulate development, growth and metabolism
- Maintain blood composition and volume
- Control digestive processes
- Control reproductive processes
Identify the major endocrine glands of the endocrine system.
the pituitary, thyroid, parathyroid, adrenal, and pineal glands
How is the control of homeostasis of the endocrine system similar and different to the
nervous system?
Endocrine system: Uses hormones, works slower, and has a long-lasting, widespread effect. It regulates long-term processes like growth, metabolism, and reproduction.
Nervous system: Uses neurotransmitters, works faster, and has a short-term, localized effect. It controls rapid actions like reflexes and muscle contractions.
What is a hormone?
A hormone is a chemical messenger that is produced and secreted by endocrine glands or specialized cells in the body. Hormones travel through the bloodstream to target organs or tissues where they exert specific effects to regulate various physiological processes.
List the three types of hormones. Are they water-soluble or lipid soluble? List
two hormones for each category.
- Peptide (or Protein) Hormones
Solubility: Water-soluble - These hormones are composed of chains of amino acids and cannot easily pass through the lipid bilayer of cell membranes. Therefore, they bind to cell surface receptors. - Steroid Hormones
Solubility: Lipid-soluble - These hormones are derived from cholesterol and can pass through cell membranes because they are fat-soluble. They bind to intracellular receptors in the cytoplasm or nucleus to influence gene expression. - Amine (or Biogenic Amine) Hormones
Solubility: Can be either water-soluble or lipid-soluble, depending on the specific structure of the hormone.
- Water-soluble amine hormones typically bind to cell surface receptors, while lipid-soluble amine hormones bind to intracellular receptors.
What is the most common second messenger? What type of protein is it
associated with?
cAMP is the most common second messenger
- it is involved in many signaling pathways.
It is associated with G-protein-coupled receptors (GPCRs) and activates Protein Kinase A (PKA), a type of serine/threonine kinase, to regulate cellular responses.
________ hormones diffuse through the cell membrane and bind to receptors
either in the cytoplasm or the nucleus, which alters the metabolic activity and
structure of the target cell
Lipid Soluble
What is the difference between intracellular and extracellular hormone
receptors?
intracellular receptors are for lipid-soluble hormones that affect long-term changes by altering gene expression, while extracellular receptors are for water-soluble hormones that trigger rapid cellular responses.
What type of feedback loop is most common with hormones?
Negative
What are the three reflexive mechanisms that control hormone secretion?
Humoral stimuli (changes in blood levels of substances).
Neural stimuli (signals from the nervous system).
Hormonal stimuli (hormones triggering the release of other hormones).
Review where the hypothalamus is in relation to the pituitary gland.
bean-sized organ suspended from it by a stem called the infundibulum (or pituitary stalk) from the hypothalamus. The pituitary gland is cradled within the sellaturcica of the sphenoid bone of the skull. It consists of two lobes that arise from distinct parts of embryonic tissue: the posterior pituitary (neurohypophysis) is neural tissue, whereas the anterior pituitary (also known as the adenohypophysis) is glandular tissue that develops from the primitive digestive tract.
What 2 hormones are synthesized by the hypothalamus? Where are they stored?
Oxytocin and Antiduiretic Hormone (ADH)
- Stored and released by the posterior pituitary gland
The hypothalamus secretes regulatory hormones called ________ hormones and
__________ hormones which control the secretions of the anterior pituitary gland
inhibiting and stimulating
Which hormones are produced by the anterior pituitary gland?
- growth hormone (GH)
- thyroid-stimulating hormone (TSH)
- adrenocorticotropic hormone (ACTH)
- follicle-stimulating hormone (FSH)
- luteinizing hormone (LH)
- beta endorphin
- Prolactin.
(*Good To Learn Anterior Pituitary Fast)
Anterior
pituitary hormones are also called ______ hormones because they stimulate
other endocrine glands.
Tropic
For each hormone, identify the primary target cells/organs, the functions of the hormone, and what condition(s) cause the
release of the hormone (control of the hormone release
See Flash Cards
Where is the thyroid gland located
the thyroid gland is located anterior to the trachea, just inferior to the larynx
Which hormone regulates the thyroid gland?
thyroid-stimulating hormone (TSH) and thyrotropin-releasing hormone (TRH)
What are the two types of cells in the thyroid gland? What hormones do each type of
cells in the thyroid produce?
Follicular cells produce T3 and T4.
Parafollicular cells (C cells) produce calcitonin.
