Endocrine System Prerecording 1 Flashcards
What is the thyroid?
Endocrine organ
Overall, the endocrine system is a ______ system
Regulatory
Label the endocrine tissues and organs
The endocrine system is a collection of _____ and _____ that secrete _____ ____ (______) into the blood, directly or via interstitual fluid or lymph
The endocrine system is a collection of glands and tissues that secrete chemical messengers (hormones) into the blood, directly or via interstitual fluid or lymph
What is a gland?
Glandular epithelium = consists of specialized cells that synthesize, store and secrete chemical substances
What are the two types of glands?
- Exocrine
- Endocrine
What is the difference between Exocrine glands and endocrine glands?
Exocrine: release their secretions into ducts that carry the secretions to an epithelial surface (eg sweat, mammary, salivary)
Endocrine: Release their secretions into blood (directly or via interstitial fluid)
Hormones are produced by which type of gland?
Endocrine
What is a hormone?
(include where hormones are produced, how they “get around” and why they don’t elicit responses from every cell they encounter)
A chemical messenger that:
- is produced and secreted by an endocrine cell
- travels through the circulatory system to reach other tissues
- acts upon specific target cells within the tissue (via receptors)
Paracrine signalling:
Autocrine signalling:
These are not hormones by our definition
Paracrine signalling: cells secrete messengers to communicate with neighbouring cells
Autocrine signalling: cell secretes messengers to act on self
These are not hormones by our definition
How is the endocrine system targeted/specific with its hormones?
Cells have receptors that are selective to specific hormones.Only matching hormones can bind to that receptor
=only cells with that receptor will respond
how can you have graded responses with hormones?
By the number of receptors a cell has
Compare the nervous system to the endocrine system:
- Signals are sent by:
- Signals are:
- Duration
- Specificty
Compare the nervous system to the endocrine system:
- Signals are sent by: neurons (NS) or endocrine glandular cells (endocrine)
- Signals are: electrical impulses conducted along axons + transmitters or hormones secreted in bloodstream
- Specificity: highly specific; widespread activity
- Duration: short term; long duration (takes time to get a response and also come down from that response)
What are some examples of overlap between the endocrine and NS? (4)
- Brain regulates secretions from endocrine glands; hormones impact CNS function
- Both secrete chemical messengers that act on target cells
- In some cases, the same molecule can act as NT and hormone (Adrenaline and vasopressin)
- Some neurons (neurosecretory cells or neuroendocrine cells) release Hormones (into blood)
What are the four types of hormones?
- Amino acid (eg adrenaline)
- Peptide (oxytocin)
- Steroid (estrogen)
- Eicosanoid (prostaglandins)