Chemical Diversity Enables Hormones and Neurotransmitters to Perform Specialized Roles
- Hormones and neurotransmitters are classified into various chemical groups based on their structure, including amines, proteins, steroids, amino acids, peptides, and nitrous oxide.
Hormones Are The Chemical Messengers of the Endocrine System
- Hormones are signalling chemicals produced by specialized cells and transported through the bloodstream to target cells.
- They regulate a wide range of processes, from growth and metabolism to reproduction.
- They can be classified into three main chemical groups: amines, peptides, and steroids.
Amines
- Amines are hormones derived from amino acids, particularly those involving modifications to amino groups.
- These hormones are generally water-soluble and often have rapid, short-term effects.
- Adrenaline (Epinephrine): A hormone produced by the adrenal glands that prepares the body for the fight-or-flight response by increasing heart rate, dilating airways, and increasing blood flow to muscles.
- Thyroxine (T4): A hormone produced by the thyroid gland, crucial for regulating metabolism and growth.
Proteins and Peptides
- Proteins and peptides are chains of amino acids that act as signaling molecules.
- These are typically water-soluble and bind to receptors on the cell surface to initiate a cellular response.
- Insulin: A peptide hormone produced by the pancreas that helps regulate glucose levels in the blood by promoting glucose uptake in cells.
- Growth Hormone (GH): Stimulates growth, cell reproduction, and regeneration in the body.
Steroids
- Steroid hormones are derived from cholesterol and are lipid-soluble, meaning they can pass through cell membranes and bind to intracellular receptors.
- Steroid hormones typically have longer-lasting effects.
- Cortisol: Produced by the adrenal glands, cortisol helps regulate metabolism, immune response, and stress reactions.
- Testosterone: A male sex hormone that regulates male reproductive functions, muscle mass, and bone density.
- Estrogen: Female sex hormones that regulate the female reproductive system and secondary sexual characteristics.
Chemical Diversity of Neurotransmitters Shapes Neuronal Communication
- Neurotransmitters also show a vast chemical diversity.
- These chemicals transmit signals between neurons at synapses, and they can be categorized into several groups based on their structure.
- Each group of neurotransmitters acts differently, influencing various aspects of neuronal communication.
Definition
Neurotransmitter
Neurotransmitters are chemical signals used by neurons to communicate across synapses, the tiny gaps between nerve cells or between nerve cells and other target cells.
Amino Acids
- Amino acids are the building blocks of proteins and are among the most common neurotransmitters.
- These are typically fast-acting and can directly influence the postsynaptic membrane.
- Glutamate: The primary excitatory neurotransmitter in the brain, involved in learning and memory.
- GABA (Gamma-aminobutyric acid): The primary inhibitory neurotransmitter in the brain, responsible for calming neural activity and preventing over-excitation.
Peptides
- Peptides, similar to their role as hormones, can also act as neurotransmitters.
- They typically have longer-lasting effects compared to amino acid neurotransmitters.
