Key Questions: What are the functions of the nervous system? What are the 3 types of neurons and how do they interact? Key Terms: Stimulus Neuron Dendrite Nerve Interneuron Synapse Response Nerve Impulse Axon Sensory Neuron Motor Neuron Receiving Information Awareness of what is around you. Senses and sensory cells help map out surroundings. Responding to Information A response is created for what you sense. Duck!!!! Dendrites- Are where a cell receives a chemical signal. The “receptor” of chemical signals. Nucleus- The Brain of the cell. Cell Body- The body of the cell. Axon- An arm like figure that sends an electric signal to the synapse. Synapse- Where chemicals are released from the neuron into intercellular space. Nerve Impulse- The Neuron signal. Nerve- Is a bundle of axons and dendrites. Interneuron Sensory Neuron Pick up stimuli from the internal or external environment and converts it into a nerve impulse. Is a neuron that carries nerve impulses from one neuron to another. Motor Neuron Sends an impulse to a muscle, and the muscle contracts in response. Key Questions: What is the function of the central nervous system? What functions does the peripheral nervous system perform? What is a reflex? Key Terms: Central nervous system Brain Spinal Cord Cerebrum Brainstem Somatic Nervous System Autonomic Nervous system Reflex Concussion The “control center” of the body. Contains the brain and spinal cord. The peripheral nervous system consists of the nerves located outside of the central nervous system. Two-way traffic The Brain, located in the skull and controls most functions of the body’s functions. The spinal cord, is the thick column of nerve tissue that links the brain to most of the nerves in the peripheral nervous system. Consists of the brain and spinal cord. The brain and spinal cord are surrounded by a fluid called cerebral spinal fluid (CSF). No blood comes directly into contact with the brain or the spinal cord. The PNS extends from the CNS to various parts of the body. The PNS sends messages to the CNS (sensory) as well as receives messages from the CNS(motor). Somatic Nervous System- This system controls your voluntary movements (tying shoelaces, throwing a ball). Autonomic Nervous System- This system controls automatic functions like breathing. Reflexes- an automatic response that occurs very rapidly and without conscious control (blinking, knee-jerk). Website: Brain Interactive Key Questions: What overall function do the sense perform? How do your eyes enable you to see? How do you hear? Key Terms: Cornea Pupil Iris Lens Retina Nearsightedness Farsightedness Eardrum Cochlea Semicircular Canal Vision is controlled by the eye and eye muscles. The eye responds to light, dilating in dark rooms and contracting in well lit rooms. Key Terms: Lens- Focuses light onto the retina. Iris- Circular structure that surrounds the pupil and regulates the amount of light entering the eye. Cornea- Clear tissue that covers the front of the eye. Pupil- The opening through which light enters the eye. Aqueous Humor- Liquid in the front of the eye. Vitreous Humor- Liquid in the body of the eye. Key Terms: Conjunctiva- Mucous membrane covering the eyeball. Sclera- Fibrous outer layer of the eyeball. Retina- The layer of receptor cells that line the back of the eye. (Rods 120 million black and white. Cones 6 – 7 million color) Macula (Fovea centralis)Where the light focuses on. Optic Nerve- Relays messages from the eye to the brain. Check your blind spot. Does your vision vary from others? Click Here Reflections: 1. Circle and Plus Sign 2. Bar Code and Plus Sign 3. Moving Red Dot and Plus Sign 4. Peripheral Marker Test Sounds starts as a vibration (guitar string, vocal cord, etc.). The vibration creates waves (sound waves). The ear receives sound vibrations. Key Terms: Ear Canal- Funnels sound into the ear. Eardrum- Vibrates in response to sound. Separates middle and outer ear. Hammer (Malleus)Vibrations pass from the eardrum to this bone. Anvil (Incus)- Vibrations pass from the hammer to this bone. Stirrup (Stapes)Vibrations pass from the anvil to this bone. Key Terms: Semicircular CanalsContains receptors to help with balance. Cochlea- Bony, snail shaped tube that is lines with receptor to respond to sound. Auditory NerveConducts impulses to the brainstem. Odors get trapped in the nasal mucous. Receptor cells have cilia (hair-like structures) that send signals to the brain. The brain then deciphers what the scent is. Taste buds along with the salivary glands help with taste, however they do not work alone. The olfactory system helps with the sense of taste. The skin has many types of receptors, light pressure and heavy pressure, temperature, and pain receptors. All of these receptors use the peripheral nervous system to relay the information to the central nervous system.