Summary of the topic of ethology from Campbell Biology a Global Approach, 11th edition. This summary includes notes of accompanying MasteringBiology assignments, lectures and any lectures.
Summary of the topic of ethology from Campbell Biology a Global Approach, 11th edition. This summary includes...
Samenvatting Hoofdstuk 8 van Biology a Global Approach 11th edition
Samenvatting Hoofdstuk 7 van Biology a Global Apprach 11th edition
Samenvatting Hoofdstuk 5 Biology A Global Approach 11th edition
All for this textbook (58)
Written for
Universiteit Utrecht (UU)
Biologie
Biologie van dieren
All documents for this subject (115)
Seller
Follow
stijnvantrijp
Content preview
Ethologie (BOOK)
Pagina’s 933----1241
Pagina 933-935
Homeostasis
Setpoint, regulator, conformer, stimulus, sensor, response, positive- and negative
feedback.
A circadian rhythm is intrinsic in the body, but extern stimuli (zeitgebers) can reset the
biological clock. The biological clock has a sleep/wake cycle of 24.2 hours in a constant
environment instead of 24 hours. The circadian rhythm is coordinated by the
suprachiasmatic nucleus (SCN).
Pagina 964-966
Homeostatic control of Ca2+ levels is vital. If the levels fall substantially, skeletal muscle
begin to contract convulsively, if the levels raise substantially, calcium phosphate can form
precipitates in body tissues, leading to widespread organ damage.
In mammals, the parathyroid glands play a major role in blood Ca2+ regulation. When levels
fall below a setpoint of about 10mg/100mL, these glands release parathyroid hormones
(PTH). PTH stimulates Ca2+ release from bones, Ca2+ uptake in kidneys and activation of
vitamin D which increases Ca2+ uptake in intestines. The thyroid gland can release
calcitonin when Ca2+ levels are too high.
Adrenal glands are actually made up of two glands with different cell types, functions and
origins, the adrenal cortex and the adrenal medulla.
Adrenal medulla
Epinephrine and norepinephrine are two hormones of the adrenal medulla, which are
responsible for the fight-or-flight reflex. They increase the rate of glycogen breakdown. Both
are catecholamines and do also function as neurotransmitters.
Effects of epinephrine;
In liver cells it binds to B-type receptors in the plasma membrane, which activates
kinase A which regulates enzymes of glucogen metabolism.
In smooth muscle cells the same kinase is activated which leads to smooth muscle
relaxation which leads to vasodilation and hence blood flow in skeletal muscle.
In the smooth muscle cell lining blood vessels, epinephrine binds to an a-type
receptor which triggers a signalling pathway involving a different G protein and
different enzymes which leads to smooth muscle contraction.
Adrenal cortex
The adrenal cortex becomes active under stressful conditions that include low blood sugar,
decreased blood volume and pressure, and shock. These stimuli can cause the hypothalamus
to secrete releasing hormones that stimulates the anterior pituitary to release
adrenocorticotropic hormone (ACTH) (tropic hormone). When it reaches the adrenal cortex,
it stimulates the endocrine cells to synthesize and secrete corticosteroids, the two main
, types are glucocorticoids (promote glucose synthesis form noncarbohydrate sources) and
mineralocorticoids (maintaining salt and water balance).
Sex hormones
The gonads (testes and ovaries) is the main resource of sex hormones. There are three
major types of steroid sex hormones; androgens (testosterone; male secondary sex
characteristics), estrogens (estradiol; female reproductive system and secondary sex
characteristics) and progesterone (growth and development of embryo).
An endocrine disrupter is a molecule that interrupts the normal function of a hormone
pathway, which can be either harmful or beneficial.
Melatonin is important for regulating functions related to light and seasons and is controlled
by a group of neurons in the hypothalamus, the suprachiasmatic nucleus SCN.
Pagina 1150-1152
An electroencephalogram (ECG) is a registration of the patterns of electrical activity called
brain waves.
The reticular formation is a phylogenetically primitive network of small neurons extending
throughout the brainstem and into the spinal cord.
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 stijnvantrijp. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $3.88. You're not tied to anything after your purchase.
