Bio 30 Alberta Diploma Final Review Exam Question And Answers !!!

The Nervous System - ANS A system of the body that coordinated and regulates the activities of the body. There is communication within your internal environment and between you and the external environment. Incoming stimuli are sensed and outgoing responses are sent by neural messages from the brain and spinal cord. This system along with the Endocrine system keep the body systems regulated to ensure homeostasis. Negative Feedback - ANS To reverse a current trend. Positive Feedback - ANS Amplifies a current trend. Parts of the nervous system - ANS Nervous system -central nervous system (decision maker) :brain and spinal cord -peripheral nervous system (feeds into and out of the can) :sensory pathway :motor pathway ~somatic pathway (voluntary-under conscious control) ~autonomic pathway (involuntary-unconscious control) sympathetic (stimulators-speeds you up) parasympathetic (restores to normal-restores balance) Sympathetic traits - ANS Dilated pupils Increased heart rate Increased respiration Inhibits digestion Relaxes bladder and bowels Adrenaline response Parasympathetic Traits - ANS Constricts pupils Decreases heart rate Decreases respiration Stimulates digestion Contracts bladder and bowels Types of cells in nervous system - ANS Neurons Glial Cells Neurons - ANS Function units of the nervous system (conduct nerve impulses). Glial Cells - ANS Non-conducting Important for support and metabolism of nerve cells. Nourish neurons, remove wastes, and defend against infection. Provide a supporting framework for all nervous system tissue. Types of neurons - ANS Sensory neuron Motor neuron Interneuron Sensory neuron - ANS Connects a sensory receptor to the central nervous system Aka afferent neurons. Conducts nerve impulses from sense organs to the brain and spinal cord. Neuron that carries impulses to the central nervous system. Motor neurons - ANS Connects the central nervous system to a muscle or a gland. Aka efferent neurons. Neuron that carries impulses from the central nervous system to an effector. Conducts nerve impulses from CNS to muscle fiber or glands. Interneuron - ANS Connects two or more neurons. Aka association neurons. Found in cns Relays information from one interneuron to another. A neuron of he central nervous system that connects with sensory, motor, and other interneuron Ls to integrate sensory input with motor output. Nerves - ANS Individual neurons organized into tissues. Dendrites - ANS Short branching terminals that receive nerve impulses from other neurons or sensory receptors, and relay impulse to cell body. Cell Body - ANS Contains the nucleus and is site of metabolic reactions. Also processes info from dendrites. Axon - ANS A neuron typically has one axon, which conducts impulses away from the cell body. Terminal end branches into many fibres. Myelin Sheath - ANS Inner layer of Schwann cells. A glistening white coat of fatty protein that acts as insulation for the neurons. Speeds up nerve transmission by preventing loss of ions. Provide insulation. Prevent loss of signal down axon. Damaged myelin results in a loss of signal down the axon. Mylenation improves the speed of nerve impulse conduction. Nodes of Ranvier - ANS Regularly occurring gaps between the sections of myelin sheath along the axon. Nerve impulses jump from one node to another=faster nerve transmission. Gaps between myelin sheaths which increases nerve transmission by causing nerve impulses to jump from one node to another. Reflexes - ANS Involuntary responses to certain stimuli. Schwann Cells - ANS Type of glial cell that produces the myelin sheath In CNS, myelinated neurons doen what is known as white matter, and unmyelinated neurons form grey matter. Neurilemma - ANS All nerve fibres found within the PNS have a thin outer membrane called the neurilemma. Outer membrane of nerve fibres in PNS that are formed by Schwann cells and promote regeneration of changed axons. Reflex Arc - ANS Simple connections of neurons that explain reflexive behaviours. Use few neurons to transmit message=rapid response. A reflex that does not require the brain. Interneuron sends message back on the motor neuron at the same time as it sends the message to the brain Reflexes may be innate or acquired. Reflexes are autonomic responses to certain stimuli and are not under conscious control (involuntary). The pathway that a nerve impulse takes is called a reflex arc. Components of Reflex Stc - ANS Stimulus's. Receptor-highly specific, receive stimuli. sensory pathway Modulator/Regulator-selects appropriate response (spinal cord to brain). motor pathway Effector-carries out the response (muscle or gland). Action How the reflex arc functions - ANS 1. Sensory organs (receptors) detect dangerous stimuli. 2. Impulse is passed from the sensory organ to a sensory neuron. 3. Sensory neuron transfers the impulse to the Interneuron in the spinal cord. 4. The interneuron links the sensory to the motor neuron. 5. The motor neuron takes the impulse to the effector. 6. The effector (usually a muscle) reacts. 7. Simultaneously interneurons send the signal up to the brain for interpretation. Myelinated Neurons - ANS Myelination improves the speed of nerve impulse conduction. Action Potential - ANS The voltage difference across a nerve cell membrane when the nerve is excited (40mV). Resting Potential - ANS Voltage difference across a nerve membrane when it is not transmitting a nerve impulse (70 mV). Maintaining Resting Potential - ANS Caused by an uneven distribution of positively charged ions across the membrane. Set up and maintained by a Sodium-Potassium pump. 3 Na+ are pumped out of the cell, 2 K+ ions are pumped into the cell. Resting membrane is said to be charged and is called a polarized membrane. These positive ions want to move with their concentration gradient by diffusion. Sodium moves out faster than potassium moves in leaving a "relative" negative charge inside the cell. There is a higher concentration of potassium ions (K+) inside of the cell and a higher concentration of sodium ions (Na+) outside of the cell. The cell is polarized. Polarized membrane - ANS Resting membrane is said to be charged and is called a polarized membrane. Action Potential process - ANS A nerve impulse is an action potential. When a neuron receives a stimulus it becomes more permeable to sodium than potassium. Na+ gates are opened while K+ gates close. Positive ions flood into the cell making it positive. This rapid inflow is referred to as depolarization. After the impulse, the Na+ channels close and the K+ channels open. This is called repolarization. The flow of potassium ions out of the cell (with their concentration gradient) restores the resting potential. The potassium gates close relatively slowly which makes the inside of the neuron slightly more negative than resting potential (hyperpolarization.