What Are the Major Physiological Systems ? Nervous system – relays messages through nerve impulses Responsible for controlling and integrating the other systems of the body Neurons are the basic units Endocrine system – glands which secrete chemical messages (hormones) What Are the Major Parts of a Neuron ? Dendrites – receive information Cell body – generates electrical signals or action potentials Axon – transmits signals at the synapse by way of neurotransmitters Neuron Action Potential Movie What Are the Major Divisions of the Nervous System ? Central nervous system (CNS) Brain and spinal cord Peripheral nervous system (PNS) Sensory and motor neurons that connect the CNS to the rest of the body CNS & PNS What Are Some of the Major Features of the Brain’s Structure ? The brain consists of 3 major parts Hindbrain – brainstem Midbrain – limbic system Forebrain – cerebral cortex Hindbrain Graphic Midbrain Graphic Forebrain Graphic What Are Some of the Major Features of the Brain’s Structure ? The brain is divided into a left hemisphere and a right hemisphere Left hemisphere movie What Are Some of the Major Features of the Brain’s Structure ? The corpus callosum connects the hemispheres Split Brain Movie What Are the Major Divisions of the Peripheral Nervous System ? Somatic nervous system – connects CNS with the skeletal muscles & senses Autonomic nervous system – connects CNS with the internal organs and glands Sympathetic division – produces the emergency reaction Parasympathetic division – returns body to normal functioning Endocrine System What Are the Major Divisions of the Endocrine System ? Pituitary gland – the most influential gland Influenced by the hypothalamus Regulates growth Controls other glands Located on the underside of the brain What Are the Major Divisions of the Endocrine System ? Thyroid gland – located below the larynx Produces thyroxin Regulates body’s metabolism Parathyroid glands – 4 pea-shaped organs in the thyroid gland Regulates calcium in blood Related to excitability of nervous system What Are the Major Divisions of the Endocrine System ? Pancreas – located in stomach area Regulates level of sugar in blood by secreting insulin Gonads – ovaries & testes Produces secondary sex characteristics Adrenal glands – located above kidneys Helps with fight/flight/fright reaction