SEHS Test Chapter A.1.1 Inter-system communication Flashcards
(22 cards)
Explain the Central Nervous System?
The Central Nervous System (CNS), consisting of the brain and spinal cord, functions as the body’s primary control centre. It processes sensory input, formulates appropriate responses, and sends instructions to effectors such as muscles and glands. The brain is responsible for regulating higher-order functions including thought, memory, emotions, and voluntary movement, while the spinal cord serves as a vital communication pathway between the brain and the rest of the body. Working in close partnership with the Peripheral Nervous System (PNS), the CNS ensures coordinated and efficient responses to internal and external stimuli. To maintain its function and integrity, the CNS is protected by the skull, vertebral column, and cerebrospinal fluid, which act as physical barriers and cushioning systems to prevent damage.
Explain the Peripheral Nervous System?
The Peripheral Nervous System (PNS) comprises all the nerves located outside the brain and spinal cord. Its primary role is to link the Central Nervous System (CNS) to the rest of the body, including muscles, organs, and sensory structures such as the skin. The PNS contains sensory neurons, which transmit information from the body to the CNS, and motor neurons, which deliver commands from the CNS to effectors. It is divided into two major components: the somatic nervous system, which controls voluntary movements like walking or writing, and the autonomic nervous system, which regulates involuntary functions such as heart rate, breathing, and digestion. The autonomic system is further divided into the sympathetic division, responsible for activating the “fight or flight” response, and the parasympathetic division, which promotes “rest and digest” functions. Overall, the PNS plays a critical role in maintaining homeostasis and enabling the body to react appropriately to internal and external changes.
Explain the Autonomic Nervous System Division?
The Autonomic Nervous System is a subdivision of the Peripheral Nervous System responsible for regulating involuntary physiological functions, such as heart rate, breathing, digestion, and gland activity. These processes occur automatically, without conscious effort, ensuring the body maintains internal stability. The ANS is made up of two main branches: the sympathetic and parasympathetic nervous systems. The sympathetic system activates the “fight or flight” response during times of stress or danger, increasing heart rate, expanding airways, and redirecting blood flow to muscles. In contrast, the parasympathetic system promotes the “rest and digest” response, slowing the heart rate and enhancing digestive activity to conserve and restore energy. These two systems work in balance to maintain homeostasis and enable the body to respond appropriately to changing internal and external conditions.
Explain the brain and spinal cord
The brain and spinal cord form the two primary components of the Central Nervous System (CNS), which is responsible for controlling most bodily functions. The brain oversees complex processes such as thought, memory, emotion, voluntary movement, and decision-making. It is securely protected by the skull and cushioned by fluid, which acts as a shock absorber to reduce the risk of injury. The spinal cord is a vital communication pathway, made up of nerve tissue that extends from the brain down the vertebral column. It transmits messages to and from the brain, enabling both voluntary actions and reflexes. Enclosed by the vertebrae, the spinal cord is also protected from damage. Together, the brain and spinal cord coordinate essential life functions, from basic survival tasks like breathing to more advanced responses such as reacting to threats.
Explain the parasympathetic Nervous System
The parasympathetic nervous system is a division of the autonomic nervous system, which regulates involuntary bodily functions. Its primary role is to return the body to a state of rest and recovery following periods of stress or heightened activity. Commonly referred to as the “rest and digest” system, it slows the heart rate, reduces breathing rate, stimulates digestion, and promotes energy conservation. For instance, it increases saliva production, enhances nutrient absorption, and supports internal healing processes. The parasympathetic system works in direct opposition to the sympathetic nervous system, which activates the “fight or flight” response. Together, they maintain homeostasis by ensuring the body can appropriately respond to both stress and relaxation.
What are Proprioceptors?
Proprioceptors are specialised sensory receptors located in muscles, tendons, and joints that provide the brain and spinal cord with continuous information about body position, movement, and balance. They allow individuals to sense the position of their limbs without needing to look, enabling smooth and coordinated movement. For example, proprioceptors make it possible to walk without watching your feet or maintain balance while standing on one leg. This sense, known as proprioception, is essential in activities that require precision, such as sport and dance, where accurate timing, posture, and quick reactions are critical. By constantly monitoring changes in muscle length and joint position, proprioceptors play a key role in enhancing coordination, improving posture, and supporting effective movement control.
What are Chemoreceptors?
Chemoreceptors are specialised sensory receptors that detect chemical changes within the body and external environment. They are primarily located in blood vessels, the nasal cavity, and taste buds. In the circulatory system, chemoreceptors monitor levels of oxygen, carbon dioxide, and blood pH, sending signals to the brain to regulate vital functions such as breathing rate and heart rate. For example, during physical activity, a drop in oxygen or a rise in carbon dioxide triggers chemoreceptors to signal the respiratory centres to increase breathing. In the nose and mouth, chemoreceptors enable the detection of smells and tastes by responding to chemical stimuli. Overall, chemoreceptors play a vital role in maintaining homeostasis by ensuring the body responds appropriately to internal and external chemical changes.
What are Baroreceptors?
Baroreceptors are specialised sensory receptors responsible for detecting changes in blood pressure. They are primarily located in the walls of major arteries, such as the aorta and the carotid arteries near the heart and neck. When blood pressure increases or decreases, baroreceptors send signals to the brain, particularly the medulla oblongata, which responds by adjusting heart rate and the diameter of blood vessels to stabilise blood pressure. This process is essential for maintaining homeostasis and ensuring that vital organs receive a constant supply of oxygen and nutrients. For instance, if blood pressure drops suddenly, baroreceptors trigger an increase in heart rate and cause blood vessels to constrict, helping to restore normal pressure levels. Baroreceptors operate automatically and continuously, playing a critical role in protecting the body from rapid or dangerous fluctuations in blood pressure.
Explain the Endocrine System
The endocrine system is a network of glands that secrete hormones directly into the bloodstream to regulate and coordinate key bodily functions. These hormones act as chemical messengers, influencing processes such as growth, metabolism, mood, and reproduction. Major glands within the endocrine system include the pituitary gland, thyroid gland, adrenal glands, pancreas, and the ovaries or testes. The pituitary gland is often referred to as the “master gland” because it regulates the activity of many other endocrine glands. Once released, hormones travel through the bloodstream to specific target organs or tissues, where they trigger precise physiological responses. The endocrine system works closely with the nervous system to maintain homeostasis and ensure the body functions efficiently and responds appropriately to internal and external changes.
What are hormones and how are they released?
Hormones are chemical messengers produced by endocrine glands that travel through the bloodstream to specific target organs or tissues. They play a crucial role in regulating a wide range of physiological processes, including growth, metabolism, stress response, and reproduction. Each hormone binds to receptors on its target cells, triggering precise effects that help maintain the body’s internal balance, known as homeostasis. The release of hormones is tightly regulated by the pituitary gland and feedback mechanisms that detect changes within the body. For example, when blood glucose levels rise, the pancreas secretes insulin, which facilitates the uptake of glucose by cells, thereby lowering blood sugar to a normal range. This precise control ensures that the body responds appropriately to internal fluctuations and external demands.
What is Ephinephrine and Norepinephrine?
Epinephrine and norepinephrine are hormones and neurotransmitters produced by the adrenal glands, specifically in the adrenal medulla. They play a vital role in the body’s acute stress response, commonly known as the “fight or flight” reaction. Epinephrine, also called adrenaline, increases heart rate, dilates airways, and boosts blood flow to muscles, preparing the body for rapid action. Norepinephrine, or noradrenaline, works alongside epinephrine by increasing blood pressure and narrowing blood vessels to direct blood to essential organs. Both hormones help the body respond quickly to stressful or dangerous situations by increasing alertness and energy availability. Their release is controlled by the sympathetic nervous system.
Explain the Nervous System
The nervous system is a complex network that controls and coordinates all the activities of the body. It is divided into two main parts: the Central Nervous System (CNS), which includes the brain and spinal cord, and the Peripheral Nervous System (PNS), which consists of all the nerves outside the CNS. The nervous system receives sensory information from both the internal and external environments, processes this information, and sends out appropriate responses to muscles and glands. It enables voluntary actions like movement as well as involuntary functions such as breathing and heartbeat. The nervous system also plays a key role in regulating emotions, memory, and thought processes. Overall, it ensures the body can respond quickly and effectively to changes, maintaining homeostasis and survival.
How does the hypothalamus function?
The hypothalamus is a small but crucial region of the brain that serves as a link between the nervous system and the endocrine system. It regulates essential bodily functions such as body temperature, hunger, thirst, and sleep. The hypothalamus controls the pituitary gland by sending signals that trigger the release of hormones, which then influence other endocrine glands throughout the body. It plays a vital role in maintaining homeostasis by balancing hormone levels and coordinating various physiological processes. The hypothalamus constantly responds to internal and external changes to keep the body’s environment stable. Because of its regulatory functions, it is fundamental in managing stress, growth, and reproductive processes.
How does the pituitary gland function?
The pituitary gland is often called the “master gland” because it regulates the activity of many other endocrine glands in the body. It is located just below the brain and is directly connected to the hypothalamus, which controls its function. The pituitary gland secretes various hormones that influence key processes such as growth, metabolism, and reproduction. It sends signals to glands like the thyroid, adrenal glands, and ovaries or testes to stimulate hormone production. By responding to instructions from the hypothalamus, the pituitary helps maintain homeostasis and ensures the body’s internal environment remains balanced. Its hormones also regulate vital functions including water balance and the body’s response to stress.
How does the pineal gland function?
The pineal gland is a small endocrine gland located deep within the brain that produces the hormone melatonin. Melatonin is essential for regulating the sleep-wake cycle, also known as the circadian rhythm, by signalling to the body when it is time to feel awake or sleepy. The pineal gland responds to light information received from the eyes, increasing melatonin production in darkness and decreasing it in light. This process helps regulate daily patterns of sleep and alertness, ensuring the body’s internal clock stays aligned with the external environment. Additionally, the pineal gland influences seasonal biological rhythms in some animals. Overall, it plays a key role in maintaining synchronisation between the body’s physiological functions and environmental cues.
How does the thyroid gland function?
The thyroid gland, located in the neck, produces the hormones thyroxine (T4) and triiodothyronine (T3), which are vital for regulating the body’s metabolism. These hormones control how the body converts energy and influence growth, development, and the rate at which cells function. The thyroid’s hormone production is regulated by signals from the pituitary gland, which adjusts hormone release based on the body’s needs. Proper functioning of the thyroid ensures stable energy levels and helps maintain body temperature. An imbalance in thyroid hormone levels, whether too much or too little, can lead to significant health issues and affect overall energy and metabolism. Thus, the thyroid plays a crucial role in maintaining the body’s metabolic balance.
How does the parathyroid gland function?
The parathyroid glands are four small glands located behind the thyroid gland in the neck that produce parathyroid hormone (PTH). PTH plays a crucial role in regulating calcium levels in the blood and bones. When blood calcium levels drop, PTH signals the bones to release calcium into the bloodstream and instructs the kidneys to reduce calcium loss through urine. It also increases calcium absorption from the intestines by activating vitamin D. Maintaining calcium balance is essential for muscle contraction, nerve function, and maintaining strong bones. The parathyroid glands automatically regulate calcium levels to support these vital bodily functions and overall health.
Explain the adrenal glands
The adrenal glands are two small glands situated on top of each kidney that produce several essential hormones, including adrenaline (epinephrine) and cortisol. Adrenaline plays a key role in the body’s “fight or flight” response by increasing heart rate and boosting energy levels to help the body react quickly to stress. Cortisol is involved in regulating metabolism, reducing inflammation, and managing the body’s response to long-term stress. Additionally, the adrenal glands secrete aldosterone, a hormone that helps control blood pressure by regulating the balance of salt and water in the body. Together, these hormones enable the body to respond effectively to stress and maintain important physiological functions. The adrenal glands are therefore vital for both immediate and ongoing regulation of the body’s internal environment.
Explain the process of the thymus
The thymus is a small gland located behind the breastbone that plays a vital role in the immune system. It produces hormones that stimulate the development and maturation of T-cells, which are essential white blood cells responsible for fighting infections. The thymus is most active during childhood and adolescence, after which it gradually decreases in size and activity. Mature T-cells leave the thymus and enter the bloodstream to help protect the body against viruses and bacteria. This gland is crucial for building a strong immune defense early in life. Although it shrinks with age, the thymus’s role in developing immunity during youth has lasting effects on the body’s ability to fight disease.
Explain the pancreas
The pancreas is a gland located behind the stomach that performs both digestive and endocrine functions. It produces digestive enzymes that aid in breaking down food in the small intestine, facilitating nutrient absorption. The pancreas also secretes important hormones such as insulin and glucagon into the bloodstream to regulate blood sugar levels. Insulin lowers blood glucose by enabling cells to absorb and use it for energy, while glucagon raises blood sugar when levels are too low. Together, these hormones maintain blood sugar balance, which is essential for proper energy supply to the body. Overall, the pancreas plays a critical role in regulating metabolism and ensuring the body’s energy needs are met.
What are the differences between ovaries and testes?
The ovaries and testes are the primary reproductive glands in females and males, respectively. The ovaries, located in the pelvis, produce eggs (ova) and secrete hormones such as estrogen and progesterone, which regulate the menstrual cycle and female sexual development. The testes, found in the scrotum, produce sperm continuously and release the hormone testosterone, which controls male sexual development. Both glands are essential for reproduction and the production of hormones that influence secondary sexual characteristics, like body hair growth and voice changes. The ovaries release one egg each month during the menstrual cycle, while the testes produce millions of sperm daily. Together, these organs play a vital role in enabling reproduction and regulating sexual development.
Explain the Sympathetic Nervous System
The sympathetic nervous system is a division of the autonomic nervous system that prepares the body for rapid, intense physical activity, often described as the “fight or flight” response. When activated, it increases heart rate, dilates airways, and redirects blood flow to the muscles, providing the body with more oxygen and energy to respond to a threat or stress. It also triggers the release of adrenaline (epinephrine) from the adrenal glands, which enhances these effects. Additionally, the sympathetic system inhibits non-essential functions like digestion to prioritize energy use for immediate survival. This system works automatically and rapidly to help the body react effectively to emergencies. Overall, the sympathetic nervous system is crucial for managing acute stress and ensuring quick physical responses.
