Work for 3005sps – human anatomy and physiology – week 20
Endocrine system
Panopto notes:
Intergration and control: endocrine
Outline:
- An introduction to homeostatic control via the endocrine system
- Overview of the general concepts of communication in relation to the endocrine
system
- Brief introduction to endocrine responses to exercise
Cell to cell communication by chemical messengers
Communication via chemical signals involves secretion of modules (chemical messengers) by
cells, into the extracellular fluid.
Cells that receive the chemical messengers are known as target cells
Target cells contain receptor proteins which are specific to particular chemical messengers
Chemical messengers are ‘ligands’ i.e. they combine with proteins reversibly
Protein + ligand protein-ligand
Functional classification of chemical messengers
Most chemical messengers can be classified into 6 main categories:
1. Paracrines
2. Autocrines
3. Neurotransmitters
4. Cytokines
5. Hormones
6. Neurohormones
Paracrines
- Chemical messengers that communicate with neighboruing cells
- Paracrines are secreted into extracelluar fluid and reach the target cell by diffusion
Autocrines
- Are similar to paracrines, however the secretory cell is also the target cells
Neurotransmitters
- Are secreted by neurones from the axon terminal, located close to the target cell
- An example of a neurotransmitter is acetylcholine, released by neurones that trigger
skeletal muscle contraction.
Hormones
- Chemical messengers secreted from endocrine tissue/glands into the extracellular
fluid where they diffuse into the blood
- The bloodstream acts as the transport system for hormones to reach their target
cells
- Via the blood the hormones are transported to almost all cells of the body, but only
target those whose receptors are compatible
Endocrine system
Panopto notes:
Intergration and control: endocrine
Outline:
- An introduction to homeostatic control via the endocrine system
- Overview of the general concepts of communication in relation to the endocrine
system
- Brief introduction to endocrine responses to exercise
Cell to cell communication by chemical messengers
Communication via chemical signals involves secretion of modules (chemical messengers) by
cells, into the extracellular fluid.
Cells that receive the chemical messengers are known as target cells
Target cells contain receptor proteins which are specific to particular chemical messengers
Chemical messengers are ‘ligands’ i.e. they combine with proteins reversibly
Protein + ligand protein-ligand
Functional classification of chemical messengers
Most chemical messengers can be classified into 6 main categories:
1. Paracrines
2. Autocrines
3. Neurotransmitters
4. Cytokines
5. Hormones
6. Neurohormones
Paracrines
- Chemical messengers that communicate with neighboruing cells
- Paracrines are secreted into extracelluar fluid and reach the target cell by diffusion
Autocrines
- Are similar to paracrines, however the secretory cell is also the target cells
Neurotransmitters
- Are secreted by neurones from the axon terminal, located close to the target cell
- An example of a neurotransmitter is acetylcholine, released by neurones that trigger
skeletal muscle contraction.
Hormones
- Chemical messengers secreted from endocrine tissue/glands into the extracellular
fluid where they diffuse into the blood
- The bloodstream acts as the transport system for hormones to reach their target
cells
- Via the blood the hormones are transported to almost all cells of the body, but only
target those whose receptors are compatible
