Chapter 14: Nervous System Guided Notes (A-day) Nervous System Overview Major Function: Control the body's and. Divided into the Nervous System (CNS=Brain and Spinal Cord) and the Nervous System (PNS=Cranial and Spinal Nerves; the rest of the body). Organs/Structures Neurons (See Figure 1) Description & Functions Parts: Cell Body: Contains and. Dendrites: Cell extensions that information. Axons: messages to other cells. Myelin Sheath: Covers axons to signal transfer. Connecting Points: - The junction between two neurons, a neuron and a muscle fiber, or a neuron and a gland. Synaptic Terminals- extensions at the end of the axons that release. Neurotransmitters- messages released from vesicles by the synaptic terminals Receptors- Proteins that the neurotransmitters bind to and receive signals from, Sensory Receptors: Collect information from the outside world and from processes inside the body. ( Ex- in eyes or in the skin. Sensory Neurons: Transmit information from the receptors to the brain and spinal cord for processing. Motor Neurons: Transmit signals to effectors ( or ). : Connect sensory and motor neurons and make local connections to the brain and spinal cord. Nerve Fibers (aka nerves) Nerves Bundles of. Afferent Nerves: Sending signals the CNS. Efferent Nerves: Sending signals the CNS. Nerve Impulse Membrane Potential: Difference in across a cell membrane. Resting Potential: Membrane potential when no signal is being transmitted. Action Potential: Significant change in that leads to a signal being transmitted. (Nerve impulse occurs)
CNS: CENTRAL NERVOUS SYSTEM (Brain & Spinal Cord) Brain (Basic Structure) Description: Part of the CNS. Found in the cavity Cerebrum (Brain) Function: Help to - nerve signals to control the body's action. Meninges: Membranes around the. (See Figure 2) (See Figure 3) Cerebral Cortex: The layer of nervous tissue in the brain. Frontal Lobe: Site for and speech. Lobe: Sensory Input. (temperature, pressure, touch, muscle control, etc). Also interprets. Temporal Lobe: Center for hearing,, and language input. Lobe: Primary area for vision. Cerebellum (Brain) (See Figure 4) Description: Located below and behind the Highly Folded Function: Coordinates muscle action Responsible for. Receives impulses from muscles,, joints, eyes,, and other brain centers. Diencephalon (Brain) (See Figure 5) Description: Located between the and. Two parts: Thalamus and Hypothalamus Thalamus: Receives incoming sensory signals Affects memory, emotion, and motivation
Hypothalamus: Helps maintain homeostasis. Hormone production Affects memory, emotion, and motivation Brainstem (Brain) Description: Leads from to cord Three parts: Midbrain, Pons, and Medulla Midbrain: Receives and signals. : Communications between cerebral hemispheres and cerebrum. Medulla Oblongata: Control center for heart rate, respiration rate, etc. Spinal Cord Description: A column of tissue It has an outer sheath of matter and a rigid inner core of matter Function: It's purpose is to transmit signals between the and of the body Cerebrospinal Fluid Cerebrospinal fluid circulates through central canal in the spinal cord and of the brain -This gives cells while taking away -It is also a cushion for the brain and spinal cord Gray Matter consists of cell bodies and unmyelinated axons PNS: PERIPHERAL NERVOUS SYSTEM (Cranial Nerves, Spinal Nerves & Autonomic Nervous System) Cranial Nerves Description, Location & Number: Attached to the brain arranged symmetrically on each side of the brain Function: Provide input and motor control. Olfactory Nerve: Sensory input, carries impulses for smell to the Optic Nerve: sensory input, carries impulses for Oculomotor Nerve: conducts motor impulses to 4 of 6 muscles of the Trochlear Nerve: conducts motor impulses to control superior oblique muscle of the Trigeminal Nerve: sensory & motor fibers, provides sensory input from Abducens Nerve: conducts motor impulses to the lateral rectus muscle of the Vestibulocochlear Nerve (Acoustic): sensory input for and Glossopharyngeal Nerve: sensory and motor fibers provide general sense of
Vagus Nerve: sensory and motor fibers and is the longest of the cranial nerves.the fibers innervate platal and pharyngeal muscles and branch to the heart,lungs,stomach,and intestines. Accessory Nerve: movement of and Hypoglossal Nerve: controls muscles of the Spinal Nerves Description, Location & Number: pairs of nerves distributed along the length of the spinal cord. Function: They send impulses to the Dorsal/Sensory Roots: composed of afferent fibers carrying impulses to the cord Ventral Roots: contains motor fibers carrying impulses to muscles and organs Cervical Spinal Nerves: Thoracic Spinal Nerves: Lumbar Spinal Nerves: Sacral Spinal Nerves: Coccygeal Spinal Nerves: pairs pairs pairs pairs pair ANS: AUTONOMIC NERVOUS SYSTEM (Part of Peripheral Nervous System) Autonomic Nervous System Transmits signals which regulate the internal environment by controlling smooth and cardiac muscles in the gastrointestinal, cardiovascular, excretory, and endocrine systems Sympathetic Division: Causes the heart to beat faster and adrenaline to be secreted when activated. Also called-. Parasympathetic Division: Slows the heartbeat and digestion when activated. Pathology/Disorders of the Nervous System Alzheimer s Disease progressive, disease of the brain that is characterized by loss of and other cognitive. Encephalitis Meningitis Epilepsy inflammation of the. of the membranes that surround the and. brain disorder involving repeated of any type.
Multiple Sclerosis chronic, potentially debilitating disease that affects the and. Parkinson s Disease Stroke progressive disorder caused by of nerve cells in the part of the brain that. of brain tissue that occurs when the does not get enough and. SENSE ORGANS The Ear Overview: The site of and (balance) Three distinct divisions- external, middle, and inner External Ear: Includes Auricle(pinna), External Acoustic Meatus(auditory canal), and the Tympanic Membrane( ). Middle Ear: Contains Malleus, Incus, and Stapes; is lined with. Inner Ear: Contains, Vestibule, and Semicircular Canal. Pathology of the Ear Hearing Loss: Meniere s Disease: Otitis Media: inflammation or infection of any part of the,,or. Tinnitus: sensation of or sounds in or ears. The Eye Function:The eye sight. Orbit: contains the eyeball; cavity is lined with that the eye. Muscles of the Eye: short muscles provide and movement. Eyelids: protect from intense, particles, and. Conjunctiva: acts as covering and keeps and moist. Lacrimal Apparatus:, and tears.
Eyeball Function: The of vision. Sclera: The layer of the eyeball. (whites of your eyes) Cornea: Transparent portion of the eye; bends light rays and helps focus them on the. : Vascular membrane that prevents internal reflection of light. Ciliary Body: muscle that governs the convexity of the lens. Iris: portion of the eyeball; regulates the amount of light. Retina: Translates light waves into nerve impulses. : Sharpens the focus of light on the retina. Pathology of the Eye Cataract: Clouding of the eye's. Conjunctivitis ( ): Inflammation of the conjunctiva, the tissue that lines the inside of the and helps keep the eyelid and the eyeballs moist. Glaucoma: Group of eye diseases characterized by intraocular pressure. : Incurable eye disease that affects more than 10 million Americans.
Figure 1: Anatomy of a Neuron Brain Structure Figure 2:Hemispheres Figure 3: Cerebrum
Figure 4: Cerebellum Figure 5: Dicephalon Figure 6: Brainstem
Figure 7: Nervous System Breakdown