11.1 Textbook Questions PDF

11.1 TEXTBOOK QUESTIONS 1)​ Define homeostasis. Homeostasis is the state of dynamic equilibrium within the body 2)​ Explain why the nervous system is critical for maintaining homeostasis The nervous system regulates homeostasis by rapidly controlling all the bodily functions 3)​ Create a...

11.1 TEXTBOOK QUESTIONS 1)​ Define homeostasis. Homeostasis is the state of dynamic equilibrium within the body 2)​ Explain why the nervous system is critical for maintaining homeostasis The nervous system regulates homeostasis by rapidly controlling all the bodily functions 3)​ Create a table to identify the different systems in the nervous system and explain the structure and function of each. Central nervous system- consists of the brain (gathers information like thoughts, emotions, actions, etc, and sends it to the central nervous system) and spinal cord (sends information from the brain, controls reflex activities) Peripheral nervous system- consists of sensory and motor neurons. Sensory neurons are afferent, meaning they send information from the sensory organs back to the central nervous system and brain. While motor neurons are different, meaning they send information from the central nervous system down to the muscles and glands. Motor neurons can be divided into 2 divisions: somatic division (controls voluntary movement) and autonomic division (controls involuntary movement) 4)​ Compare the basic function of neurons and glial cells. Neurons are the basic building blocks of the nervous system and conduct nerve impulses. Glial cells do not conduct impulses, but rather provide structural and metabolic support 5)​ List the three types of neurons, and identify their primary functions. Interneurons-Are found in the central nervous system, collect and process information and send them to the peripheral nervous system Sensory neuron- Gather information from sensory organs and send it back to CNS Motor neurons- Send information from CNS to muscles and glands 6)​ Identify the basic neural pathway that is involved as you dodge a wayward tennis ball. Compare this pathway with a withdrawal reflex. The 5 basic steps of a reflex arc are as follows: First a sensory receptor in your eyes processes information and sends it through your sensory neuron to the CNS. In the CNS, your interneuron quickly processes this information and sends it through your motor neuron to a effector (muscle or glad) that will then move your body to dodge the tennis ball. 7)​ Draw a neuron, label its basic structures, and identify their functions.  Dendrites- short terminal branches that receive information from other neurons or the CNS and send them to the cell body Cell body- contains nucleus, site of metabolic reactions, sends information to axon. Axon- extension of cytoplasm, sends information to synapses through gaps, can also form branches into other neurons 8)​ Describe the structure of a myelinated neuron. The myelin sheath is a fatty protective layer over the axon that is composed of schwann cells and contain gaps known as the nodes of ranriver 9)​ Explain what the resting membrane potential is, and why it is significant to the functioning of neurons. Resting potential is the voltage difference across a nerve cell membrane at -70mV when it is not stimulated or transmitting an impulse 10)​ Identify and explain the three factors that contribute to the resting membrane potential. Some factors that contribute to the resting potential are the different concentrations of ions in and out of the cell membrane, the sodium-potassium pumps which return the cell to its resting state by exchanging 3 sodium ions out of the cell for every 2 potassium ions into the cell, and the leakiness of some of the potassium gates as they transfer potassium ions in a slower manner. 11)​ Explain the difference between depolarization of a neuron and an action potential Action potential is the rapid, temporary change in electrical potential across a membrane from negative to positive and back to negative. While depolarization is the stage during action potential where the inside of the membrane becomes more positive than the outside due to the intake of sodium ions through the sodium ion gates. 12)​ Describe the "all-or-none" response. The all or none response means that the action potential happens completely or not at all 13)​Describe the process of repolarization in the neuron, and explain its importance in the transmission of a neural impulse. When a neuron becomes depolarized the K+ gates open allowing the inside to return to its negative state relative to the outside, however because the ions are not in its original position in the membrane, sodium-potassium pumps are used to move sodium ions out of the membrane and potassium ions back into the membrane in a 3:2 ratio sodium to potassium. 14)​ Summarize the events that occur as an impulse is propagated along the length of the neuron. Resting membrane potential reaches threshold, then sodium gates propagate opening one after the other allowing sodium ions to move into the membrane causing the inside to become overall positive resulting in depolarization. Then the Na gates shut which allows the K gates to open allowing the inside of the membrane to return to its negative state (repolarization). However because the ions are now at the wrong side of the membrane, Sodium potassium pumps transfer the ions back into there original position. The refractory period is a short amount of time immediately after a action potential where a neuron cannot respond to another stimulus. 15)​ Summarize the events involved in impulse transmission from the presynaptic neuron to the postsynaptic neuron. Once the action potential reaches the end of the axon terminal and into the presynaptic membrane, calcium gates open allowing neurotransmitters to enter into the synaptic vesicles. Which are then ejected into the post synaptic membrane where the neurotransmitters bind onto receptors allowing them to send electrical signals by opening or closing the ion channels 16)​Identify the function of neurotransmitters in the nervous system. Neurotransmitters carry chemical messages or signals from one neuron to another 17)​ Compare the excitatory and inhibitory effects of neurotransmitters on the postsynaptic membrane. Excitatory neurotransmitters depolarize the postsynaptic neuron by making the inside of the membrane more positive, bringing it closer to the action potential threshold Inhibitory neurotransmitters hyperpolarize the postsynaptic neuron by making the inside of the membrane more negative, brining it away from the action potential threshold 18)​ Compare and relate the functions of acetylcholine and cholinesterase. ACh is a natural occurring neurotransmitter that plays a role in brain functions like memory, and body functions like muscle contractions to move. Cholinesterase inhibitors function to decrease the breakdown of acetylcholine. They are used in treatments of alhzimers