Name__Katelyn Devries_ Unit 9 Worksheet – Membrane Potentials Each answer is worth 1 point (20 points total) To complete this worksheet, select: Chapter 12: Nervous Tissue Animations Introduction to Membrane Potentials 1. Describe the neuron function. Neurons act to facilitate the transfer of data amongst the body’s cells sustaining homeostasis 2. Contrast graded potentials and action potentials. Graded potentials are electrical signals that have variable amplitude, are localized, and travel short distances along the membrane.
7. Describe the process involved in the movement of ions through these channels. 8. When nerve cells are at rest, there is an unequal amount of positive and negative charges on either side of a nerve cell membrane. This charge difference is called an electrical potential.
(Calcium ions) are stored in the Sarcoplasmic reticulum. 4. The cause for the release of Calcium is the depolarization of the T-tubules. (Acetylcholine enters the synaptic cleft gap and opens the chemically gated sodium channel that starts an action potential spreading down the sarcolemma of the myofibril. This will cause an action potential to spread down to the T- tubules and “electrical chemical signals = shocks” the sarcoplasmic reticulum into releasing calcium ions.
Neurons, electrically excitable cells, respond to chemical and mechanical stimuli by producing small changes in the resting membrane potential (measured in mV) called graded potentials. Graded potentials, if large enough, may produce an action potential. Action potentials are generated when the resting membrane potential (usually -70 mV to -55 mV) at the axon hillock is depolarized above threshold (usually-55 mV) by depolarizing graded potentials. Action Potential An action potential is a large change in membrane potential. It is used to communicate over large distances.
What is a voltage-gated sodium ion channel? What is it made of? What is its function? A voltage-gated sodium ion channel allows for sodium ions to travel across the cell membrane. Voltage-gated sodium ion channels are made of amino acids and are necessary for the initiation and propagation of action potentials.
c) How does one nerve cell communicate with another? - Nerve cells communicate with one another through neurotransmitters. 2. a) Explain what neurotransmitters are? - Neurotransmitters are chemical messengers that cross the synaptic gaps between neurons. When released by the sending neuron, neurotransmitters travel across the synapse and bind to receptor sites on the receiving neuron, thereby influencing where that neuron will generate a neural impulse.
The electrocardiogram measures? The electrical activity of the heart. B 2. In the atria, the depolarizing phase of the action potential creates? The P-Wave.
Dependent Variable-membrane potentials 2. Independent Variable-voltage 3. Controlled Variables-frequency of stimulation, type of neuron Experiment 2: Effect of Frequency of Stimulation on Action Potential Generation 1. Dependent Variable-membrane potential 2. Independent Variable-frequency of stimulation
Distribution and constituent of water Distribution and constituent of water P3 – describe the distribution and constituents of body fluids M2 – explain functions of the constituents of body fluids This report will describe and explain the distribution and constituents of water. I will also be explaining the functions of three components of fluid in the human body, which are the constituents, water and solutes. Intracellular fluid is found within a cell and make up 55% of the total body water. ‘Intracellular fluid contains water and dissolved solutes and proteins. The solutes are called electrolytes, which maintain healthy bodily functions.
(Goodsell, D, 2009) ATP is used in many ways; to power muscles, making sure that enzymes perform accurate reactions, to heat our bodies. Roughly a third of ATP made by our cells is used to power the sodium- potassium pump. The sodium- potassium pump is found within our cellular membranes, this is where it is in charge of generating a gradient of ions. It is continuously pumping sodium ions out of the cell and potassium ions into the cell; this is all powered by ATP. For every ATP that is broken down, it moves 3 sodium ions out and then 2 potassium ions in.