Cell and Neurophysiology Week 1 Study Guide KEY (SP24) PDF

Cell and Neurophysiology Week 1 Study Guide KEY Name: Course: PHSL 3051 Term: Professor: Hannah Thompson Email: [email protected] Office: 6-125 Jackson Hall Week 1 Reading List: Topics Textbook Pages (1st Edition) Textbook Pages (2nd Edition) Lab 1: Diffusion 28-32, 133 – 136 31 – 34, 134-136 Intro t...

Cell and Neurophysiology Week 1 Study Guide KEY Name: Course: PHSL 3051 Term: Professor: Hannah Thompson Email: [email protected] Office: 6-125 Jackson Hall Week 1 Reading List: Topics Textbook Pages (1st Edition) Textbook Pages (2nd Edition) Lab 1: Diffusion 28-32, 133 – 136 31 – 34, 134-136 Intro to Human Physiology 1-18 1-19 Intro to the Nervous System 188 – 196, 238 – 244 190 – 199, 243 - 249 PowerPoint presentations, class notes, and lab lectures/worksheets can be found on Canvas. Cell & Neuro Week 1: 1 Table of Contents Class 1: Introduction to Human Physiology I. Pre-Class 1: Intro to Human Phys ……………………………………………………………………. p.3-4 II. Class 1: Intro to Human Phys …………………………………………………………………………… p. 5-7 Class 2: Introduction to the Nervous System I. Pre-Class 2: Intro the Nervous System …………………………….……………………………. p.8-10 II. Class 2: Intro to the Nervous System ……………………………………………………………. p.11-14 Cell & Neuro Week 1: 2 Pre-Class 1: Intro to Human Physiology Learning objectives: Describe the interrelationships between molecules, cells, tissues, organs, and organ systems in the human body. Explain the five key themes in physiology: homeostasis, integration, communication, mechanism of action, and structure-function relationships. Provide an example of each. 1. In your own words, define what human physiology is. Human physiology is the study of how the human body and its parts function. 2. In your own words, describe the following levels of organization and how these levels relate to one another: Molecular Level The molecular level consists of all molecules, which are groups of atoms bound together. Cellular Level The cellular level consists of cells, which are the basic unit of life. Many different molecules come together to form a cell and its parts (i.e., organelles, cytoplasm, etc.). Tissue Level Tissues are made up of a group of similar cells that come together to perform specific functions. In the human body, there are four types of tissues: muscle, neural, epithelial, and connective. Organ System Level Organs themselves are made of two or more tissues that come together to perform specific function(s). Organ systems are composed more than one organ coming together to perform specific function (i.e., the stomach and pancreas are part of the digestive system). Cell & Neuro Week 1: 3 3. Define each key theme of physiology and provide an example of each. Homeostasis Homeostasis is the maintenance of a relatively stable internal environment. Recall that the internal environment refers to the extracellular fluid which includes the interstitial fluid (fluid in between cells) and plasma (fluid compartment of blood). Homeostasis is a central theme in human physiology and we’ll talk about many different mechanisms by which the body maintains homeostasis. A few examples: Plasma glucose levels are tightly regulated. When plasma glucose levels are too high, the body releases insulin. When plasma glucose levels are too low, the body releases glucagon. When the temperature of the internal environment is too high, our body will sweat, and blood vessels will dilate which will result in heat loss. When the temperature of the internal environment is too low, individuals may shiver. When blood pressure increases, the body will dilate blood vessels and decrease heart rate. When blood pressure decreases, blood vessels will constrict and heart rate will increase. Integration Integration describes when any different cells, tissues or organs come together to form a specific function. Integration is necessary to maintain homeostasis. Some examples include: The central nervous system, cardiovascular system, kidneys and adrenal glands all come together to regulate blood pressure. The central nervous system and musculoskeletal systems come together to regulate movement. Digestion and absorption of food involves the mouth, esophagus, pancreas, liver, gallbladder, small intestine, large intestine and anus. Communication To perform physiological functions, cells, tissues and organs must communicate with one another. Communication can occur over long or short distances. Some examples include: Cardiac muscle cells are able to transmit electrical signals with one another through the presence of gap junctions Hormones are produced by specific cell types and move from the cell into the blood. Then, hormones are able to circulate in the blood until it reaches its target tissue and binds to its receptor. Cell & Neuro Week 1: 4 Mechanism of Action Mechanism of action refers to how a physiological process occurs. Some examples include: At the synapse, the presynaptic neuron releases neurotransmitters which bind to ligand gated ion channels. Ligand ion channels then open, allowing ions to move down their electrochemical gradient and a postsynaptic potential is generated. The pancreas regulates blood glucose levels through the release of the hormone insulin. Insulin binds to its target tissues present in skeletal muscle, fat (adipose) tissue and liver to decreases plasma glucose levels. Structure-Function Relationships Structure, or how a cell/tissue/organ is organized and function, or physiological role/purpose are closely related. Some examples include: Type 1 Alveolar cells in the lungs facilitate diffusion of gases from alveoli into the lungs. Type 1 alveolar cells are also very long, thin and flat which minimizes the distance gases must diffuse. Neurons are considered functionally polarized. The presence of transduction channels at sensory receptors of sensory neurons allow sensory receptors to transduce stimuli. The structure of a transduction channel determines which type stimulus the transduction channel transduces. The more dendrites a neuron has, the greater the amount of input signals a neuron can receive. Cell & Neuro Week 1: 5 Class 1: Intro to Human Physiology Learning objectives: Diagram the body plan, showing the various organ systems and their interrelationships with one another and with the external environment. Describe the main components of a feedback system. Compare and contrast negative and positive feedback and feedforward systems and give an example of each in the human body. What are these types of systems designed to do? Define what set point is and how this related to homeostasis. Overview 1. In the diagram below, label the intracellular fluid, extracellular fluid, and plasma. Intracellular fluid Plasma Interstitial Fluid 2. Which fluid components make up the internal environment? Interstitial fluid and plasma Cell & Neuro Week 1: 6 3. Identify whether the molecule described is part of the cell’s external environment or internal environment. Explain how you came to your conclusion. a. Glucose found within the plasma. The internal environment. Plasma is one of the two components of the internal environment along with interstitial fluid. b. Glucose found within the urine in the urinary bladder. Fluids in the lungs, gut and urinary system are part of the external environment. The urinary bladder stores urine made by the kidneys. Urine is then moved from the bladder outside of the body through the urethra. Therefore glucose in the urine is considered part of the external environment. 4. Below is an example of the reflex arc known as the swallowing reflex. 1. After swallowing a bite of food, the food stretches the soft pallet which is in the back of the mouth. 2. These physical changes caused by food hitting the soft pallet trigger mechanoreceptors (receptors sensitive to changes in length). 3. Afferent sensory neurons send signals to the central brain. 4. The brain sends a message to skeletal muscle present in the esophagus through efferent nerves which causes the soft pallet to elevate, the glottis to close, and the opening of the upper esophageal sphincter. 5. Food can move deeper in the esophagus/into the stomach and the back of the mouth is cleared. The soft pallet, glottis, and upper esophageal sphincter return to their original positions. Identify the following in this reflex arc: Stimulus: Food stretching the soft pallet Receptor: Mechanoreceptors Afferent Pathway: Afferent sensory neurons Integrating Center: The Brain Efferent Pathway: Efferent motor neurons Effector(s): Soft pallet, glottis, upper esophageal sphincter Response(s): Food is moved further down the esophagus and into the stomach until the mouth is cleared, decreasing the degree of stretch of the soft pallet. What kind of feedback is being described by this mechanism? (Positive or negative), why? This is an example of a negative feedback because the response (clearing of the mouth which decreases the stretch of the soft pallet) opposes the stimulus (stretching of soft pallet). Cell & Neuro Week 1: 7 5. Consider the following scenarios. Identify whether these situations are examples of positive feedback, negative feedback, or a feedforward mechanism and explain why. a. You are heading to the gym for your regular workout. Before even beginning to exercise, you notice that your heart rate increases. Feedforward mechanism. Your body is undergoing a change in anticipation of an event (exercise). b. You are waiting for the bus on a cold, winter day. You notice you begin to shiver and feel yourself getting a little bit warmer. Negative feedback. The response (shivering, which increases body temperature) opposes the stimulus (decreased body temperature). c. A newborn begins nursing; milk production continues until the newborn stops nursing. Positive feedback. The initial stimulus of nursing causes even more milk to be produced. Therefore, the initial stimulus reinforces the response. An outside factor (the newborn no longer nursing) is required to stop this feedback loop. Cell & Neuro Week 1: 8 Pre-Class 2: Intro to the Nervous System Learning objectives: Describe the main components of the central nervous system and peripheral nervous system and their general function. Describe the structure and function of the different components of a neuron: dendrites, soma, and axon. Summarize the main functions of the following parts of the brain: brainstem (pons, medulla oblongata, midbrain), diencephalon (thalamus, hypothalamus, pineal gland (epithalamus), pituitary gland), cerebellum and cerebrum (cortex and basal nuclei). 1. Match the organ to the central (C ) or peripheral (P) nervous system. C: Brain P: Cranial Nerves P: Peripheral Nerves C: Spinal Cord 2. In your own words, what is the major function of the central nervous system? The central nervous system is responsible for receiving input signals, integrating the input information and sending output signals to the rest of the body. 3. What is the major function of the peripheral nervous system? To convey sensory information to the central nervous system and output information FROM the central nervous system. 4. What are the two major branches of the peripheral nervous system? 1. Efferent Division 2. Afferent Division Cell & Neuro Week 1: 9 5. What are the three branches of the autonomic nervous system? 1. Sympathetic nervous system 2. Parasympathetic nervous system 3. Enteric nervous system 6. In the diagram, identify and label the following structures: nucleus, cell body, dendrites, axon, and axon terminal. Nucleus Cell Body Dendrites Myelin Sheath Axon Axon Terminal Cell & Neuro Week 1: 10 Describe the major function of the following regions of the brain: Cerebrum: The cerebrum is responsible for regulating voluntary actions, conscious activity and the processing/perception of sensory information. The cerebrum is also responsible for activities that require very high levels of cognition such as coordinating and initiating movement. Brainstem: The brainstem includes the control centers for respiration and heart rate and is a major regulator of subconscious activity and reflexes. Cerebellum: The cerebellum is responsible for controlling movement, posture, balance and motor learning. Hypothalamus: The hypothalamus is a major regulator of homeostasis (H for homeostasis!) Thalamus: The thalamus is the final relay center of sensory information and plays a critical role in sensory perception. Cell & Neuro Week 1: 11 Class 2: Intro to the Nervous System Learning objectives: Differentiate between the afferent division and efferent division of the peripheral nervous system and describe the general function and direction of information flow for each Compare and contrast the morphology of sensory neurons (unipolar) with that of motor neurons and interneurons (multipolar). Describe the direction of signal transmission in these different cell types. Describe the organization of the spinal cord with respect to the function of the dorsal and ventral roots and their relationship to the efferent and afferent divisions of the peripheral nervous system. Explain how the size and proportion of gray and white matter differ at different levels of the spinal cord (i.e., lumbar, vs. thoracic vs. cervical). 1. What kind of information is conveyed through the afferent division of the peripheral nervous system? Sensory information 2. What kind of information is conveyed through the efferent division of the peripheral nervous system? Motor information 3. What are the three major types of senses? Describe what each sense is. (1) Somatic: Somatic senses are senses that we are consciously aware of. Somatic senses include senses such as touch, pain, etc. (2) Visceral: Visceral senses are senses that we are not consciously aware of and include things such as blood gas levels, blood pH, blood pressure, etc. (3) Special senses: Special senses are senses that are difficult to categorize as “visceral” or “somatic”. The special senses includes taste, hearing, vision, equilibrium and smell. 4. What are the two major types of motor output? Describe both types of output. (1) Somatic: Somatic motor output leads to actions that you have conscious control of. More specifically, somatic motor output goes to skeletal or voluntary muscle. (2) Visceral: Visceral motor output goes to all other organs/tissues outside of skeletal muscle and leads in actions that you have no conscious control over. Cell & Neuro Week 1: 12 5. Complete the diagram below to describe the general flow of information between the peripheral and central nervous systems. 6. Identify whether the neuron is unipolar (U) or multipolar (M) U: Sensory neuron M: Motor neuron M: Interneuron 7. Label white matter, gray matter, dorsal root, ventral root, dorsal horn ventral horn, and dorsal root ganglion on the image below. Also, make sure to indicate the posterior (dorsal) and anterior (ventral) sides of the spinal cord. Cell & Neuro Week 1: 13 8. What is grey matter? What is it made of and what is its general function? Grey matter is made up of the cell bodies of neurons and synapses. There main function of grey matter is to process information/integrate information. 9. What is white matter? What is it made of and what is its general function? White matter is made up the myelinated axons of neurons. The main function of white matter is to transmit signals between neurons. 10. What is the difference between a neuron and a nerve? A neuron is a single cell. A nerve is the collection of myelinated axons in the peripheral nervous system. 11. What are ganglia? Where are ganglia found? Ganglia refers to a collection of cell bodies and synapses in the peripheral nervous system. 12. What type of information is conveyed through ascending tracts? Sensory information 13. What kind of information is conveyed through descending tracts? Motor information Cell & Neuro Week 1: 14 14. Complete the following table with the correct information about the 31 pairs of spinal nerves. How many pairs of nerves are there? Which parts of the body do these nerves innervate? 8 Head, neck, shoulders, arms, hands 12 Chest, upper abdomen 5 Lower abdomen, hips, legs 5 Genitals, lower digestive tract 1 Skin lying above the tailbone Cervical Thoracic Lumbar Sacral Coccygeal 15. Below is a cross-section of a thoracic spinal cord. Notice how small the ventral horns are. What might this tell you about the function of the thoracic spinal cord? Information in the dorsal side of the spinal cord is largely sensory information and information found in the ventral side of the spinal cord is largely motor. The ventral horns therefore convey motor information. The ventral horns are very small and can therefore suggest that there is not a lot of motor output to the thorax/upper abdomen. This makes sense because the thorax houses our lungs and our heart and these organs do not undergo complex movements. Cell & Neuro Week 1: 15