Study with the several resources on Docsity
Earn points by helping other students or get them with a premium plan
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Community
Ask the community for help and clear up your study doubts
Discover the best universities in your country according to Docsity users
Free resources
Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors
This document delves into the intricacies of human physiology, exploring key concepts such as the role of calcium ions in cardiac function, the mechanisms of sensory receptors, and the regulation of blood glucose levels. It provides a detailed explanation of the nervous system, including the structure and function of the spinal cord, sensory neurons, and the role of neurotransmitters. The document also covers the endocrine system, highlighting the importance of hormones like insulin and glucagon in maintaining homeostasis. It further explores the process of erythropoiesis and the function of white blood cells in the immune response. This comprehensive guide is ideal for students seeking a deeper understanding of the human body's complex systems.
Typology: Assignments
1 / 18
This page cannot be seen from the preview
Don't miss anything!
Human Anatomy and Physiology Hafsa Azhar Student ID: 3621313 Athabasca University Human Anatomy and Physiology ( BIOL 235 ) Tutor Ckroeker Assessment 2 11 , April ,
Answer the following short question Question 1 With regards to effort and load, describe the main difference between a lever operating with a mechanical advantage versus a lever operating at a mechanical disadvantage. When observing lever systems, we will see three key components: the fulcrum (fixed point), the effort (cause of movement), and the load (resistance). The way these components are arranged determines whether the lever operates with a mechanical advantage or disadvantage. In a lever operating with a mechanical advantage, the load is positioned closer to the fulcrum while the effort is applied farther from the fulcrum. This arrangement results in a shorter lever arm on the load side compared to the effort side. Consequently, a smaller moment of force is required to overcome the resistance of the load, enabling the load to be moved with greater ease. Conversely, in a lever operating at a mechanical disadvantage, the load is farther from the fulcrum while the effort is applied closer to the fulcrum. This configuration leads to a longer lever arm on the load side compared to the effort side. As a result, a greater moment of force is needed to move the load, making it more difficult to overcome the resistance. Understanding this relationship between the arrangement of load and effort relative to the fulcrum provides insight into why levers can either amplify or diminish the force required to move a load.. (Derrickson & Tortora, 2017, p. 3 44 ). Question 2 Name and describe the locations and actions of the muscles typically used in breathing. The thoracic muscles play a vital role in the process of breathing. These muscles are responsible for altering the size of the thoracic cavity, facilitating the inhalation and exhalation of air. By adjusting the dimensions of the thoracic cavity, these muscles enable the rhythmic expansion and contraction necessary for breathing to take place.
At rest, K+ channels are open to some degree, allowing K+ ions to move out of the cell along their concentration gradient, contributing to the negative charge inside the cell. The Na+/K+ pump actively transports K+ ions into the cell, against their concentration gradient, contributing to the high intracellular concentration of K+. Sodium (Na+): Na+ is the primary extracellular cation, meaning it is found in higher concentrations outside the cell compared to inside. The concentration of Na+ ions is kept low inside the cell by the activity of the Na+/K+ pump, which actively transports Na+ ions out of the cell. The Na+/K+ pump exchanges 3 Na+ ions out of the cell for every 2 K+ ions transported into the cell, helping to establish and maintain the concentration gradients for both ions. This active transport process requires energy in the form of ATP hydrolysis, making it metabolically driven.. (Kandel, E. R., Schwartz, J. H., & Jessell, T. M., 1991 , p. 26 ). Question 4 Describe the difference between spatial and temporal summation in a postsynaptic neuron. Spatial is summation of postsynaptic potentials in response to a stimulus, which occurs at different locations in the membrane at the same time.Each little message (synaptic input) to the cell might not be strong enough to make it fire. But if lots of messages arrive at the same time from different places on the cell, they add up to a big enough signal. This combined signal travels to a special spot on the cell called the trigger zone. If the combined signal is strong enough there, it makes the cell fire an action potential. So, spatial summation is like lots of little messages coming together to make a big one that triggers the cell to fire. (Derrickson & Tortora, 2017, p. 449 ). Temporal summation is summation of postsynaptic potentials in response to a stimulus that occur at the same location in the membrane but at different times. Each individual synaptic input may be sub-threshold on its own , but if they occur close enough in time , their effects can sum together .Temporal summation depends on the timing and frequency of synaptic inputs from a single.It depends on the timing and frequency of synaptic inputs from the single pre- synaptic neuron. (Kandel et al ,2013, p.686).
Question 5 Describe the gross external and cross-sectional anatomy of the spinal cord. When examining the spinal cord externally, one immediately notices its distinctive enlargements: the cervical enlargement, spanning from C4 to T1, and the lumbar enlargement, extending from T9 to T12. These expansions serve as vital hubs for nerve pathways, with the cervical enlargement orchestrating the intricate movements of the upper limbs, while the lumbar enlargement commands the mobility and sensation of the lower limbs. Above the lumbar enlargement, the tapering conus medullaris gracefully concludes its journey between the vertebrae L1 and L2, giving rise to the filum terminale—an extension of the spinal cord's delicate pia mater. This filamentous anchor not only secures the spinal cord but also integrates with the arachnoid and dura mater, firmly anchoring the spinal cord to the coccyx. Internally, the spinal cord reveals a meticulous arrangement of white and gray matter. The white matter comprises bundles of myelinated axons, segregated into right and left sides by two prominent grooves: the anterior median fissure and the posterior median sulcus. Enclosed within this white matter, the gray matter forms a distinct H-shaped pattern, with the gray commissure serving as its crossbar. Nestled within the gray commissure lies the central canal, a slender passageway extending the spinal cord's entire length, filled with cerebrospinal fluid. An anterior/ventral white commissure bridges the right and left sides of the spinal cord's white matter anteriorly, ensuring seamless communication between neural pathways. Within the gray matter, neuronal bodies cluster into nuclei, subdividing the gray matter into functional regions known as horns. The posterior/dorsal horns house incoming sensory neuron axons, while the anterior/ventral horns host somatic motor nuclei. Between these horns lie the lateral gray horns, housing autonomic motor nuclei, vital for regulating involuntary bodily functions. This intricate architecture epitomizes the spinal cord's role as a conduit for sensory input and motor output, seamlessly integrating neural signals to orchestrate complex bodily movements and responses. (Derrickson & Tortora, 2017, p. 462,464,465). Question 6 Describe the role of all components of a crossed extensor reflex. A crossed extensor reflex initiates a flexor reflex that causes you to withdraw the limb. The crossed extensor reflex to help maintain your balance. For example, stepping on a tack stimulates the sensory receptor of a pain-sensitive neuron in the foot. (Derrickson & Tortora, 2017, p. 485 ).
threatening or position sense stimulus, in one limb.
The hypothalamus and pituitary gland are pivotal players in the endocrine system. Nestled beneath the thalamus, the hypothalamus is a diminutive yet influential segment of the brain. Below it lies the pituitary gland, which comprises two distinct lobes: the anterior and posterior lobes. Through both a direct neural connection and a blood network, the hypothalamus communicates with the anterior lobe, thereby orchestrating the gland's hormonal activities. Within the hypothalamus, various hormones are synthesized, which the pituitary gland dutifully transports to target organs, ensuring precise regulation and coordination within the body. (Derrickson & Tortora, 2017, p. 511 ). Question 9 Explain why the sympathetic division of the ANS has more widespread and longer-lasting effects than the parasympathetic division. The sympathetic division of the autonomic nervous system (ANS) has more widespread and longer-lasting effects than the parasympathetic division. The sympathetic division also has longer affects due to its response to neurotransmitters. Acetylcholinesterase is able to quickly inactivate acetylcholine, A single sympathetic preganglionic fiber has many axon branches and may synapse with over 20 postganglionic neurons. Sympathetic postganglionic neurons branch extensively, activating multiple tissues simultaneously. Norepinephrine and epinephrine released by sympathetic neurons degrade more slowly than acetylcholine released by parasympathetic neurons, prolonging sympathetic effects. The adrenal medulla releases epinephrine into the bloodstream in response to sympathetic stimulation, amplifying sympathetic effects throughout the body. There are more visceral receptors for norepinephrine and epinephrine compared to acetylcholine, allowing the sympathetic division to affect a wider range of target tissues. These factors collectively contribute to the broader and longer-lasting effects of the sympathetic division compared to the parasympathetic division. Parasympathetic preganglionic fibers only synapse with four or five post synaptic neurons. Each of these post synaptic neurons only supply a single visceral effector, allowing parasympathetic responses to be localized to a single effector. (Derrickson & Tortora, 2017, p. 527,540,541,561). Question 10
Compare and contrast the overall responses of the sympathetic and parasympathetic divisions, including specific effects at various visceral effectors. Although the sympathetic and parasympathetic divisions collaborate to maintain equilibrium, they usually operate in contrasting manners. This equilibrium, known as autonomic tone, is crucial for overall bodily function. Typically, the sympathetic nervous system is associated with the "fight or flight" response, while the parasympathetic system governs the "rest and digest" functions.
(Derrickson & Tortora, 2017, p. 541,542,561 ) Question 11 A viral infection has damaged a patient’s tectospinal tract. What signs of this damage probably helped the physicians diagnose the problem? The tectospinal tract plays a vital role in translating sensory cues into rapid, reflexive movements of the head, eyes and trunk. It enables the body to swiftly orient towards sudden visual or auditory stimuli, like a flash of lightning or a loud bang. When this pathway is compromised, evident signs emerge: a lack of response to abrupt stimuli and difficulty in tracking moving objects with the eyes. Such impairments can have serious consequences, as the ability to reflexively dodge potential threats is compromised. For instance, if a baseball hurtles towards someone's head, even with warnings to move, the delayed response due to tectospinal tract damage increases the risk of injury. (Derrickson & Tortora, 2017, p. 567,568 ) Question 12 List the six types of sensory receptors, as classified based on the type of stimulus they detect, and describe the stimuli each responds to. Name the three types of sensory receptors categorized based on their location, identify the origin of stimuli that activate them, and describe the nature of the stimuli that cause their excitation. Six types of sensory receptors based on stimuli: Mechanoreceptors: Detect deformation, stretching, or bending of cells, blood vessels, and internal organs. They provide sensations of touch, pressure, vibration, proprioception, hearing, and equilibrium. Thermoreceptors: Detect changes in temperature, internal or external. Nociceptors: Respond to painful stimuli resulting from chemical or physical damage. Photoreceptors: Detect light striking the retina. Chemoreceptors: Detect chemicals in the mouth, nose, and body fluids, providing taste and smell. Osmoreceptors: Sense osmotic pressure of body fluids, potentially alerting the body to dangerous situations like bleeding. Three types of sensory receptors based on location: Exteroceptors: Located on or near the body's surface, sensitive to stimuli from outside the body, conveying sensations of visual, smell, taste, touch, pressure, vibration, thermal, and pain. Interoceptors: Found in blood vessels, visceral organs, and the nervous system, providing information about the internal environment, sometimes perceived consciously as pain or pressure.
Proprioceptors: Located in muscles, tendons, joints, and the inner ear, providing information about body position, muscle length and tension, joint position and motion, as well as balance. (Derrickson & Tortora, 2017, p. 551,573 ) Question 13 Describe the process of image formation on the retina, and contrast light and dark adaptation. Include the role of the rods and cones in your description. Three distinct processes must be understood to explain how clear images form on the retina;
Explain the mechanism by which a deficiency of gonadotropin-releasing hormone (GnRh) will lead to in fertility in both a male and a female. Gonadotropin-releasing hormone (GnRH) is crucial for regulating reproductive functions in both males and females. Produced by specialized nerve cells in the hypothalamus, GnRH controls the ovarian and uterine cycles. It travels through the bloodstream to the pituitary gland, where it prompts the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Once released, LH and FSH act on the ovaries and testes to initiate and maintain reproductive processes. In females, FSH stimulates follicular growth, while LH further develops the ovarian follicle. Together, these hormones prompt the secretion of estrogen and progesterone from the ovarian follicles, regulating the female reproductive system, supporting pregnancy, and preparing the mammary gland for lactation. In males, FSH and LH stimulate the testes to produce sperm and testosterone, essential for the development of male reproductive tissue and the expression of male sex characteristics. Estrogen primarily dominates ovarian hormone production before ovulation, while progesterone and estrogen are secreted post-ovulation by the corpus luteum. The hypothalamus governs the secretion of GnRH, so any damage or trauma to it can disrupt this process. Without adequate GnRH signaling, LH and FSH production is halted, leading to potential infertility. In females, this disruption can manifest as amenorrhea and a decline in estrogen and progesterone levels. In males, it can result in reduced sperm production and testosterone secretion. Damage to the hypothalamus can thus impair the entire reproductive system, affecting hormone production and fertility in both sexes.(Derrickson & Tortora, 2017, p.658,659) Question 16 Describe how insulin affects liver and adipose cells, as well as the feedback loop involving insulin, eating, and blood-glucose levels By using a negative feedback system, the body balances the secretion of insulin and glucagon to keep your blood sugar at a normal level. Insulin is released when your blood sugar goes to high, and glucagon is released if it goes too low. High levels of blood glucose inhibit the release of glucagon and stimulate secretion of insulin by beta cells found in the pancreatic islets. Insulin acts on many body cells by causing accelerated diffusion of glucose into cells, turning glucose into glycogen faster, increasing the uptake of amino acids by cells and increasing protein synthesis. Insulin also speeds up the synthesis of fatty acids which slows the conversion of glycogen to glucose. It also slows the formation of glucose from lactic acid and amino acids. When eating, especially if eating in access, insulin increases the uptake of circulating fatty acids and enhances triglyceride synthesis. This leads to the accumulation of adipose tissue and can cause an increase of it throughout the body.
(Tortora &Derrickson, 2017, p. 652) (Gastaldelli, Gaggini, & DeFronzo, 2017 , p. 652,653 ) Question 17 A patient appears to have an infection but is not sure if the infection is bacterial, viral, fungal, or parasitic. Which blood test should be ordered and how would the causative agent of the infection be determined? When a patient presents with an infection, doctors often order a differential white blood cell count, commonly known as a 'diff'. This test counts each of the five types of white blood cells in the bloodstream. An elevated white blood cell count typically indicates inflammation or infection. Each type of white blood cell serves a unique function in the body's immune response. By quantifying each type, doctors gain valuable insight into the nature of the infection. For instance, neutrophils are the first responders to bacterial infections, while lymphocytes play a crucial role in combating viral infections. Eosinophils are involved in allergic reactions and parasitic infections, while basophils release inflammatory mediators. Monocytes help to engulf and digest pathogens. By analyzing the differential count, doctors can tailor treatment strategies more effectively, targeting the specific type of infection based on the predominant white blood cell count. This comprehensive approach enhances diagnostic accuracy and improves patient outcomes. (Tortora &Derrickson, 2017, p. 709) Question 18 Describe the negative feedback loop that controls the rate of erythropoiesis. Under what circumstances would you expect the rate of erythropoiesis to increase? How would it be possible to tell if the rate of erythropoiesis is elevated? Erythropoiesis, the process of red blood cell (RBC) production, initiates in the red bone marrow with precursor cells known as proerythroblasts. This crucial process is tightly regulated by a negative feedback loop, triggered by hypoxia, or insufficient oxygen levels. When hypoxia is detected, the kidneys respond by releasing erythropoietin into the bloodstream, stimulating the maturation of proerythroblasts into reticulocytes. Consequently, there is an increase in the number of reticulocytes in the blood and subsequently, a higher count of circulating RBCs. This surge in RBC production ensures enhanced oxygen delivery to body tissues, restoring homeostasis. Instances triggering heightened erythropoiesis include low oxygen levels at high altitudes and various forms of anemia, such as those resulting from nutritional deficiencies. Assessing erythropoiesis levels typically requires a blood test, as elevated levels may signify conditions like
160 beats/minute, stroke volume will decrease due to the short time frame the heart has to refill. At such a fast rate, end diastolic volume (EDV), the volume of blood that fills the ventricles at the end of diastole, decreases. Preload (the degree of stretch on the heart before it contracts) is directly proportional to the EDV. Less filling time equals a lower EDV which means the heart may contract before the ventricles are equally filled.If the heart cannot compensate and continues to have reduced preload cardiac performance may be affected over time. (Tortora &Derrickson, 2017, p. 720)
References Tortora, G., & Derrickson, B. (2017). Principles of anatomy and physiology (15th ed.). Wiley. Moore, K. L., Dalley, A. F., & Agur, A. M. R. (201 4 ). Clinically Oriented Anatomy ( 7 th ed.). Wolters Kluwer. Kandel, E. R., Schwartz, J. H., & Jessell, T. M. (1991). Principles of Neural Science (3rd ed.). McGraw-Hill. Kandel, E. R., Schwartz, J. H., Jessell, T. M., Siegelbaum, S. A., & Hudspeth, A. J. (2013). Principles of Neural Science (5th ed.). McGraw-Hill. Learning, L. (n.d.). Biology for majors II. Retrieved October 31, 2022, from https://courses.lumenlearning.com/wm-biology2/chapter/vestibular-information/
