bio notes 4

bio notes 4 - HORMONES SOLUBLE IN LIPIDS Steroids - Bind to...

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HORMONES SOLUBLE IN LIPIDS Steroids - Bind to intracellular receptors - Cycling between the cytoplasmic and nuclear components - Activated receptor in the nucleus activates specific genes by binding to DNA Ligands for Steroid Receptors (the following bind to these steroid receptors) - Steroid hormones - Thyroid hormones (ex: T 3 and T 4 ) - Vitamin D - Retinoic acid Steroid Effects - Produced by steroids increasing protein synthesis - Slow in onset due to this Testes - Produce androgens (ex: testosterone) Support sperm formation; male secondary sex characteristics Ovaries - Produce estrogens Stimulate uterine lining growth Development and maintenance of female secondary sex characteristics Stress and Steroid Hormones - Increased production of epinephrine and norepinepherine Adrenal medulla - Increased production of mineralo- and gluco- corticoids (steroids) (involved in regulating blood glucose levels) Adrenal cortex Short-Term Stress Response - Glycogen broken down, blood glucose increased - Increased blood pressure, breathing rate, and metabolic rate - Change in blood flow decreasing digestive and kidney activity Long-Term Stress Effects - Mineralocorticoids Retention of sodium and water Increased blood volume and blood pressure - Glucocorticoids Breakdown of proteins and fats to increase blood glucose Suppression of the immune system Neurons - Process and act on sensory information Nervous System - Rapid transfer of information through the body by electrical signals or nerve impulses Cell Body - Contains the nucleus and organelles - Clusters of cell bodies are ganglia Dendrites - Highly branched processes - Receive incoming information - Carry this information as an electrical signal to the cell body Axon - Longer processes - Only one per neuron - Carry information to other cells - Vertebrate axons are insulated with myelin sheaths - Myelinated (fast conducting) - Non-myelinated (slow conducting) Synaptic Terminal - Specialized ending of axon that communicates with other cells - Relays a message to target cell by releasing neurotransmitters Synapses
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- Contact between synaptic terminal and target cell Support Cells - Glia (from the Greek word for glue) Radial Glia - Form tracts for neuron growth in the developing embryo Astrocytes - Structural and metabolic support in the mature CNS - Form tight junctions resulting in the blood-brain barrier Oligodendrocytes - In CNS (central nervous system) - Form myelin sheath that insulates the axon of vertebrates Schwann Cells
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bio notes 4 - HORMONES SOLUBLE IN LIPIDS Steroids - Bind to...

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