Week 1

• The nervous system controls everything you do including breathing, walking, thinking, and even feelings.
• The nervous system is the most complex and highly organized body system, receiving information from the sensory organs through nerves, transmitting the information through the spinal cord, and processing it in the brain.
• The nervous system directs our body's reactions to the world and manages all of these activities by sending lightning quick signals of electrochemicals between cells.
• The basic unit of the nervous system is a nerve cell or neuron, with the human brain containing about 100 billion neurons.
• A neuron has a cell body which includes the cell nucleus and special extensions called axons and dendrites.
• Nerves are bundles of axons found throughout the body.
• Dendrites allow neurons to communicate even across long distances, receiving messages from other nerve cells.
• Axons transmit messages from the cell body to the dendrites of other neurons or to other body tissues.
• Modern neurons transmit messages from the brain to the muscles to generate movement.
• Sensory neurons detect light, sound, other taste, pressure, and heat and send messages about those things to the brain.
• Other parts of the nervous system control involuntary processes such as keeping a regular heartbeat, releasing hormones like adrenaline, opening the pupil in response to light, and regulating the digestive system.
• When a neuron sends a message to another neuron, it sends an electrical signal down the length of its axon at the end of the action the electrical signal changes to a chemical signal, and the accent then releases the chemical signal with chemical messengers called neurotransmitters into the synapse.
• The brain stem acts as a release center connecting the cerebrum and cerebellum to the spinal cord, performing many automatic functions such as breathing, heart rate, body temperature, wake and sleep cycles, digestion, sneezing, coughing, vomiting, and even swallowing.
• The spinal cord comprises three parts: the cervical, thoracic, and lumbar for the neck, chest, and lower back regions respectively.
• The cerebellum is located under the cerebrum and coordinates muscle movements, maintains posture, and balance.
• The cerebrum is the largest part of the brain and is composed of right and left hemispheres, performing higher functions like interpreting touch, vision, and hearing as well as speech, reasoning, emotions, learning, and fine control of movement.
• If the brain is the command center for your body, the spinal cord is the pathway for messages sent by the brain to the body and from the body to the brain.
• The spinal cord is a long bundle of nerves and cells that extends from the lower portion of the brain to the lower back, carrying signals between the brain and the rest of the body.
• The brain plays a central role in the control of most bodily functions including awareness, movements, sensations, thoughts, speech, memory, and has three major parts: the cerebrum, cerebellum, and brain stem.
• The Central Nervous System (CNS) consists of the brain and the spinal cord, and is referred to as central because it combines information from the entire body and coordinates activity across the whole organism.
• The nervous system is composed of the Central Nervous System (CNS) which includes the brain and spinal cord, and the Peripheral Nervous System (PNS) which includes nerves and sensory organs that go through the body.
• The spinal cord is protected by three layers of tissue: the pia mater, arachnoid matter, and the dura mater, which doctors call the meninges.
• The PNS regulates involuntary body functions like heartbeat and breathing.
• The spinal cord carries signals from the brain that control movement and autonomic functions.
• The PNS is divided into two parts: the somatic nervous system and the autonomic nervous system.
• The autonomic system consists of two branches: the sympathetic system that helps maintain normal body functions and conserve physical resources, and the parasympathetic system regulating the flight or fight response that prepares the body to expand energy in response to environmental threats.
• The spinal cord may act independently of the brain in conducting motor reflexes, for example, the patellar reflex which causes a person's knee to involuntarily jerk when tapped in a certain spot.
• The spinal cord transmits the nerve impulses for movement, sensation, pressure, temperature, pain, and more.
• The peripheral nervous system (PNS) connects the central nervous system to the organs, limbs, and skin, allowing the brain and the spinal cord to receive and send information to other areas of the body.
• The somatic system is responsible for transmitting sensory information as well as for voluntary movement, containing two major types of neurons: motor neurons or efferent neurons, and sensory neurons or apparent neurons.
• The nervous system is the most vital system of the body, its purpose is to coordinate and regulate all communication and processes within the body as well as help you adapt to your ever-changing environment.
• The spinal cord nerves transmit messages to the brain from the body such as sensations of touch, pressure, and pain.
• The PNS carries sensory and motor information to and from the central nervous system.
• The motor neurons allow us to take physical action in response to stimuli in the environment, while the sensory neurons allow us to take in sensory information and send it to the brain and spinal cord.
• The autonomic system is the part of the peripheral nervous system that is responsible for regulating involuntary body functions such as blood flow, heartbeat, digestion, and breathing.
• The spinal cord is responsible for reflex responses.
• The nervous system coordinates and regulates all communications and processes within the body, and helps us to adapt to changes in our environment to survive.
• The nervous system works with the endocrine system to coordinate and direct the activity of the body's cells.
• The endocrine system provides a slower but longer lasting coordination than the nervous system.
• The endocrine system is a series of glands that produce and secrete hormones that the body uses for a wide range of functions.