Interview
IB Biology HL unit 6.6 notes (hormones)
- Course
- Institution
Straight 7 HL unit 6.6 notes
[Show more]
Seller
Follow
matteotessaro
Content preview
6.6 - HormonesHomeostasis:
= the ability to maintain a stable internal environment
● To maintain homeostasis, the body has several negative feedback loops or mechanisms,
which are processes that bring a value back towards a set point.
Endocrine system = series of glands that produce hormones that circulates in the bloodstream to
target tissue
● Sensory neurons send messages to the brain, the brain interprets the message, brain sends
messages to the endocrine glands to release hormones
Hormone: a lipid-based or protein molecule that is secreted into the bloodstream by an endocrine
gland; only affects targeted tissues
Insulin, glucagon and diabetes:
→ cells in the pancreas respond to changes in blood glucose level
If the glucose concentration deviates substantially from the set point of about 5 mmol L-1,
homeostatic mechanisms mediated by the pancreatic hormones insulin and glucagon are initiated.
Two hormones, insulin and glucagon, are produced by the Islets of Langerhans in the pancreas and
are responsible for maintaining and controlling blood glucose concentrations
Insulin - reduces sugar levels in the blood
Glucagon: Increases blood sugar level
Negative feedback mechanism:
Blood Glucose Level Hormone Secreted Effect on blood glucose concentration
Higher than normal Insulin - produced and secreted Levels Fall: insulin stimulates glucose
by β-cells of Islets of uptake into muscles and liver cells, where
Langerhans in the pancreas it is converted into glycogen
Lower than normal Glucagon - produced and Levels rise: Glucagon stimulates glycogen
secreted by ɑ-cells of Islets of hydrolysis to glucose in the liver, which in
Langerhans in the pancreas turn releases glucose into the blood
***glucagon = protein-based hormone released from the pancreas.
** glycogen = carbohydrate found in the liver that is the form that glucose takes when stored there
The pancreas has both exocrine and endocrine functions.
● As an exocrine gland (gland associated with a duct), it secretes enzymes that help in
digestion;
● As an endocrine gland (ductless gland) it secretes hormones that regulate blood sugar levels.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller matteotessaro. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $7.06. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
67232 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now