![]() The Cardiovascular System (sometimes called the circulatory system) consists of the heart, blood vessels, and lymphatics. The heart provides the power to move the blood and the vascular system represents the network of branching conduit vessels through which the blood flows. This network brings life-sustaining oxygen and nutrients to the body's cells, removes metabolic waste products, and carries hormones from one part of the body to the other. Right off the bat, what immediately catches my interest about this system is the heart. On a mechanical level, this mystical love pump is capable of greater reliability than some of the best pumps ever built by humans and can easily withstand 80 to 100 years of continuous service without ever stopping for repairs. Its output is also fully adjustable on demand, over a range of about 5 to 25 liters of blood per minute. On another level, the heart is an important organ of perception. Both recent and ancient wisdom invites us to think of the heart as an organ of sensitive perception and integration. In our therapeutics class on cardiovascular wellness, Betzy spoke about the heart's connection to both our nervous and endocrine systems and its ability to perceive electromagnetic fields (what small people call - vibes) from people, animals, plants and the environment. Betzy compared the cardiovascular system to an internal tree of life, that connects and responds to our external world as well as internal needs. Unfortunately, in our modern life it's challenging to get the same amount of movement and time spent outdoors that our ancestors did. We are a society that predominately lives in our heads rather than our bodies and we are far more sedentary and indoor dwelling and head centered than we evolved to be. Additionally, our culture doesn't support strong community ties, love for the natural world and connection - even to our closest loved ones. When we don't exercise our intuitive faculties or emotional ones either, we start to lose our strength and vitality. It's no wonder that the cardiovascular disease is the most common serious, life-threatening illness we face worldwide. As with any muscle, lack of use leads to deterioration, inflexibility and lack of responsiveness - the opposite of vitality and resilient health. Let's take a closer look at the inner workings of this system to gain some more insight into what it's all about. Blood: Did you know that 7-8% of human body weight is from blood? In adults, this amounts to 4.5-6 quarts of blood. This essential fluid carries out the critical functions of transporting oxygen and nutrients to our cells and getting rid of carbon dioxide, ammonia, and other waste products. In addition, it plays a vital role in our immune system and in maintaining a relatively constant body temperature. Blood is a highly specialized tissue composed of more than 4,000 different kinds of components. Four of the most important ones are red cells, white cells, platelets, and plasma. All humans produce these blood components--there are no populational or regional differences. Red blood cells transport oxygen and carbon dioxide to and from body tissues. They contain hemoglobin, the oxygen carrying substance that gives blood its red color. These cells have an average lifespan of 120 days and are released by bone marrow. White blood cells participate in the body’s defense and immune systems. These five types of cells are classified as granulocytes and agranulocytes. Platelets are small, colorless, disk-shaped cytoplasmic fragments spit from cells in bone marrow. These fragments have a lifespan of about ten days and perform three vital functions which includes initiating contraction of damaged blood vessels to minimize blood loss, forming hemostatic plugs in injured blood vessels and with plasma, providing materials that accelerate blood coagulation. Plasma is the clear, straw-colored liquid portion of blood that remains after red blood cells, white blood cells, platelets and other cellular components are removed. It is the largest component of human blood, comprising about 55 percent, and contains water, salts, enzymes, antibodies and other proteins. The Pulmonary and Systemic Circuits: The above diagram shows the general structure of the entire cardiovascular system. Note that the heart is pumping blood through the lungs (the pulmonary circuit) and through the rest of the body to all the cells (the systemic circuit) simultaneously. Each circuit has its own set of blood vessels. Let’s follow the pulmonary circuit first:
The system circuit serves the rest of the body. When blood enters the left ventricle, it begins the systemic circuit, which takes it to the rest of the body.
Arteries, Arterioles, Capillaries, Venules, and Veins- Who are they? As described in the pulmonary and systemic circuits, when blood leaves the heart it is pumped into large, muscular, thick-walled arteries. Arteries transport blood away from the heart. The larger arteries have a thick layer of muscles because they must be able to withstand the high pressure generated by the heart. Arteries branch again and again, so the farther the blood moves from the heart, the smaller in diameter the arteries become. Eventually the blood reaches the smallest arteries, called arterioles (literally, “little arteries”). The largest artery in the body, the aorta, is about 2.5 centimeters (roughly 1 inch) wide. In contract, arterioles have a diameter of 0.3 millimeter or less, about the width of a piece of thread. By the time blood throws through the arterioles, blood pressure has fallen considerably. Consequently, arterioles can be simpler in structure. Arterioles connect to the smallest blood vessels, called capillaries. Capillaries are thin-walled vessels that average only about one-hundredth of a millimeter in diameter- not much wider than the red blood cells that travel through them. In fact, they are so narrow that red blood cells often have to pass through them in single file or even bend to squeeze through them. From the capillaries, blood flows back to the heart through venules (small veins) and veins. LIke the walls of arteries, the walls of veins consist of three layers of tissue. However, the outer two layers of the walls of veins are much thinner than those of arteries. Veins also have a larger lumen (are larger in diameter) than arteries. The anatomical differences between arteries and veins reflect their functional differences. As blood moves through the cardiovascular system, the blood pressure becomes lower and lower. The pressure in veins is only a small fracture of the pressure in arteries, so veins do not need nearly as much wall strength (provided by muscle and connective tissue) as arteries. In addition to their transport function, veins serve as a blood volume reservoir for the entire cardiovascular system. Nearly two-thirds of all the blood in your body is in your veins. Very cool! The Hepatic Portal System The hepatic portal system is the system of veins comprising the hepatic portal vein and its tributaries. This system is responsible for directing blood from parts of the gastrointestinal tract to the liver. Substances absorbed in the small intensive travel first to the liver for processing before continuing to the heart. Not all of the gastrointestinal tract is part of this system but overall it extends from about the lower portion of the esophagus to the upper part of the anal canal. It also includes venous drainage from the spleen and pancreas. Blood pressure is the force that blood exerts on the wall of a blood vessel as a result of the pumping action of the heart. Blood pressure is not the same in all blood vessels (or people for that matter - like this bizarre dude in the picture above). heh. When health professionals measure your blood pressure they are assessing only the pressure in your main arteries. From a clinical standpoint, blood pressure gives valuable clues about the relative volume of blood in the vessels, the condition or stiffness of the arteries, and the overall efficiency of the cardiovascular system. Trends in blood pressure over time are a useful indicator of cardiovascular health. Blood pressure higher than normal is called hypertension and is a significant risk factor for cardiovascular disease. The greater pressure, the greater the strain on the cardiovascular system. Blood vessels react to the pounding by becoming hardened and scarred, which makes them less able to stretch during systole. Hypertension also places a greater strain on the heart, because the work it must do is directly proportional to the arterial pressure against which it must pump. Smoking, a sedentary lifestyle, obesity, heredity, persistent emotional stress, heavy alcohol consumption and other factors can increase the risk of hypertension. How this all relates to Herbal Medicine:
As with so many aspects of human health, the basic approach to both prevention and management of cardiovascular issues or disease is undertaking appropriate exercise, mind-body balance, and diet - with herbs to support more specific aspects of health health, as needed. Regular cardio exercise strengthens the function of the heart while meditation, breathwork and exercises with a mind-body component like yoga and tai chi have been shown to reduce heart-damaging stress and slow or even reverse heart disease. Heart tonics with plants like rose, hawthorn, rooibos, hibiscus, linden and cacao have all been shown to be beneficial, with broad-reaching cardiovascular benefits. A heart healthy diet full of berries, leafy greens and vegetables is a powerful component of strong cardiovascular health. Remember kids, it's never too late to:
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I’m running on a trail in a nature reserve outside of Montpelier after a long day working on my feet. My stomach rumbles with hunger and my lips feel parched from not drinking enough water. There’s a strong breeze in the air and I have goose bumps on my arm as my body hasn’t warmed up to the jogging yet. As I come around a turn in the trail, I hear a tree cracking above my head that distracts my attention. I look up to see what made the sound and then slip on a rock and start to fall forward. My body responds by recoiling and I slide and catch my fall by landing on my feet and hustling out of the way of a large branch falling from the tree above. Whhhattttt a system! My nervous system has my back. It's a dynamic, split-second acting, brilliant living presence within me that is constantly receiving input from all kinds of sources and sorting through large amounts of information on a moment to moment basis, including data stored in my memory banks about the meaning of these sounds and sensations and other stimuli. My luscious nervous system integrates this seemingly unrelated information quickly and this allows me to react in time. Let’s take a look at this extraordinary part of our body. The nervous system receives information from our senses. Then it integrates the different pieces of information from many different sources and makes sense of it as a whole. Instantaneously it sifts through mountains of data and comes up with a plan or course of action. What’s so fascinating to me is that all this is going on automatically without requiring my attention or even my conscious decision making. However, the nervous system can bring selected information to the level of my conscious awareness. In conjunction with the endocrine system, the nervous system works to support allostasis and allows us to feel emotions, be aware of ourselves and exert conscious control over the extraordinary diversity of our physical movements and experiences. The nervous system consists of the central nervous system and the peripheral nervous system. The central nervous system consists of the brain and the spinal cord. This system receives, processes, stores and transfers information. The peripheral nervous system represents components of the nervous system that lie outside the central nervous system. See picture below. The peripheral nervous system has two functional subdivisions: the sensory division of the peripheral nervous system (see yellow side of diagram) carries information to the brain and spinal cord and the motor division (see purple side of diagram) carries information from the central nervous system. The motor division of the peripheral nervous system is further subdivided as you can see in the diagram above. The somatic division controls skeletal muscles while the autonomic division controls smooth muscles, cardiac muscles and glands. Additionally, the autonomic division has two subdivisions called the sympathetic and parasympathetic divisions. These two parts work antagonistically to slow us down to rest and digest or fire us up to accomplish our mission in the world or escape from a falling tree. While the sympathetic and parasympathetic oppose each other, they essentially work together to accomplish the automatic, subconscious goal of allostasis. The sympathetic division of the autonomic nervous system arouses the body. Preganglionic motor neurons of the sympathetic division originate in the thoracic and lumbar regions of the spinal cord. Many of them attach to a chain of sympathetic ganglia that lie alongside the spinal cord. Because the sympathetic division is are well connected to each other, the sympathetic division tends to produce a unified response in all organs at once, transmitting signals that prepare the body for emergencies and situations requiring high levels of mental alertness or physical activity. This could include fighting or running away from danger (“flight or fight”) and even play or sexual activity. The sympathetic division is in charge of increasing heart rate and respiration, raising blood pressure, dilating the pupils and other effects that help you detect and respond quickly to changes in your environment. In addition, the sympathetic division also reduces blood flow to organs that do not help you cope with an immediate emergency, such as the intestines and kidneys and this division inhibits less important body functions such as digestion and production of saliva. This is why it’s common to get a dry mouth during highly stressful moments. See my drawing below for a visual of the divisions of the autonomic nervous system. The parasympathetic division predominates during relaxation. Preganglionic neurons of this division originate either in the brain or from the sacral region of the spinal cord. The ganglia where the preganglionic neurons synapse with the postganglionic neurons is generally some distance from the central nervous system and may even be in the target organ itself. The parasympathetic division predominates in situations in which one is relaxed. This division transmits signals that lower heart rate and respiration, increase digestion, permit defecation and urination, and exerts calming, restorative effects that counteract the fight or flight stimulation of the sympathetic division. Curiously, parasympathetic nerves are also responsible for the vasodilation that causes erections in the penis and swelling of the labia and erection of the clitoris in the vagina. Overall, it appears that the actions of the sympathetic and parasympathetic divisions oppose each other work. But their seemingly antagonistic actions work together to accomplish the automatic, subconscious maintenance of allostasis. Both systems are intimately involved in the feedback loops that help to make allostasis happen. As we’ve looked at, the nervous system coordinates all body functions, enabling a person to adapt to changes in internal and external environments and thus maintain allostasis. This system has two main types of cells - neurons, that act as conducting cells and neuroglia, that act as supporting cells. Our dear neuron is the basic unit of the nervous system. This highly skilled and specialized conductor cell receives and transmits electrochemical nerve impulses. Let’s take a look at the various parts of this mystical unit. Axons and dendrites are threadlike nerve fibers that extend from the central cell body and transmit signals. In particular, the axons conduct nerve impulses away from cell bodies and are covered in a white, fatty segmented covering called a myelin sheath. Dendrites on the other hand are short, thick, branched extensions of the cell body that receive impulses from other cells and conduct information on toward the cell body. Neurons receive information in the form of electrochemical information from other neurons at the cell body. If the incoming information is of the right kind and is strong enough, the neuron responds by generating an electrical impulse of its own where the dendrite joins the axon. The impulse is then transmitted from one end of the axon to the other, bypassing the cell body. The impulse stimulates synaptic vesicles in the presynaptic axon terminal. A neurotransmitter substance is released and diffuses to bind to specific receptors. This stimulates or inhibits stimulation of the postsynaptic neuron. The reflex arc is the transmission of sensory impulses to a motor neuron via the dorsal root. The motor neuron delivers the impulse to where it needs to go - a muscle or gland, which then produces an immediate response. All this happens in an instant. Incredible! Reflection:
Because the nervous system is so complex and controls so many bodily functions, disorders of the nervous system can be particularly debilitating. Trauma, infections, and brain tumors can cause major injury as well as disorders of neural and synaptic transmission like Parkinson’s disease, a progressive, degenerative disorder that strikes nearly 50,000 people a year in North America, most over age 55. Symptoms include stiff joints and muscle tremors in the hands and feet. Eventually people with Parkinson’s lose mobility; they may also become mentally impaired. My father died this past November after battling this disease for nine years. It was a grueling and devastating decline and it's been hard but interesting to read more about it during this unit. Parkinson's is caused by the degeneration of dopamine-releasing neurons in the area of the midbrain that coordinates muscle movement. The shortage of dopamine impairs the ability to perform smooth, coordinated motions. My father was prescribed L-dopa, a drug that the body converts into dopamine, but this does not slow the loss of neurons. Even taking the medication for years my father rapidly lost his ability to feed himself, walk and eventually talk. It was heart breaking to watch him want to do things but his body wouldn’t respond. I could almost see the lack of electrical impulse. Watching my father suffer for so long and feeling powerless to do anything about it is one of the reasons I decided to delve deeper into my interest in and love for herbal medicine. I wish I had known that American Skullcap could have eased his symptoms and that there are many other herbs that support the neural brain forest that is rich with memories, emotions, dreams and desires not to mention all the control center systems that I mentioned previously. Our brain controls how we see the world, taste our food, hear music, smell aromas and absorb the wonder of the earth around us. The brain and nervous system ecosystem should not be taken for granted. As we discussed before, neurotransmitters are the substances responsible for transmitting electrical impulses across the neural synapses. When their job is done, enzymes break down the neurotransmitters. Reuptake inhibitors (including the well-known antidepressant selective serotonin reuptake inhibitors SSRIs) inhibit the breakdown of specific neurotransmitters so that more of those neurotransmitters will be present in the body. Neurotransmitters do a wide range of things, and an excess or deficiency of them plays a role in many different diseases. Acetylcholine (ACh) is a major transmitter for basic body functions including contraction and control of muscles. Low ACh levels are associated with Alzheimer’s, dementia and Parkinson’s. I was delighted to discover many of our mint-family brain-boosting herbs like sage, rosemary, lemon balm, and mint for example boost ACh levels by inhibiting the enzyme that breaks it down. I also strongly believe that diet, lifestyle and well-being have an even greater effect as the foundations of health and vitality when it comes to brain health. My father spent a lot of his life extremely stressed out. He also ate very poorly and didn’t exercise and often felt distant from his family and community. Quality food, exercise, community, meditation - these are all important ways to support ourselves on so many levels including strong brain health. Additionally, our brain requires voluminous blood flow to function properly. Blood delivers essential nutrients, including oxygen and glucose, shuttles out our waste and transports hormones. Oxidation and inflammation in the body inhibit blood flow and create blockages in the neural roadways. Some damage may not become obvious until one’s later years, as issues can take decades to accumulate. Herbalism offers us an alternative to the anti-inflammatory drugs so commonly prescribed as well as eating quality food, keeping stress levels down, getting enough sleep and exercise. Other herbs to consider: Indians have revered Gotu Kola as a memory and brain tonic for at least 2,500 years and Ginkgo, turmeric, berries (especially blueberries) and green tea have all been revered for their antioxidant ways. Bacopa (the Ayurvedic creeping water plant) promotes memory and focus and holy basil, ashwagandha, reishi, lemon balm and rhodiola have all been renowned for their antistress, adaptogenic effects. I was having such a hard time caring for myself while caring for my father when he was sick that it was really challenging for me to begin bringing in herbal remedies for him. I try not to be hard on myself about the things I could have done and how much more I could have been there for him. I did the best I could. I feel grateful to have been by his side the last few days of his life, spritzing rose water on his face, swabbing his mouth with fresh water and relighting the sage smudge in the corner of the room - small but potent forms of love medicine offerings. Perhaps someday I’ll be able to offer some herbs to others struggling with similarly demonic nervous system disorders. Ufffffff. Circadian rhythms are physical, mental and behavioral changes that occur based on a 24 hour cycle. This cycle is attuned primarily to light and darkness in a organism's environment and are found in most living things, including animals, plants and many tiny microbes. The "master clock" that controls circadian rhythms consists of a group of nerve cells in the brain called the suprachiasmatic nucleus, or SCN. The SCN contains about 20,000 nerve cells and is located in the hypothalamus, an area of the brain just above where the optic nerves from the eyes cross. Circadian rhythms are important in determining human sleep patterns. The body's master clock, or SCN, controls the production of melatonin, a hormone that makes you sleepy. Since it is located just above the optic nerves, which relay information from the eyes to the brain, the SCN receives information about incoming light. When there is less light—like at night—the SCN tells the brain to make more melatonin so you get drowsy. Circadian rhythms can influence sleep-wake cycles, hormone release, body temperature and other important bodily functions. They have been linked to various sleep disorders, such as insomnia. Abnormal circadian rhythms have also been associated with obesity, diabetes, depression, bipolar disorder and seasonal affective disorder. Lifestyle and herbal musings: Stress is a major factor in disruption of sleep and the production of melatonin. There are sedative herbs at night or stress-relieving herbs that can be taken during the day that can help but it's important to try to reduce the stressor directly. Sometimes one's life situation can't be changed and thus finding more relaxing time for oneself can be crucial - meditation, yoga, daytime exercise, or an evening wind-down ritual of reading and sipping tea can really help. Stimulants can make some people restless and more apt to wake up during the night or struggle to fall asleep. Coffee, chocolate, yerba mate, soda and tea are obvious late-night no-nos. There are other remedies that don't contain caffeine that can be overly simulating, such as B vitamins, stimulant adaptogens, blood pressure medications, antidepressants, dementia medications, antihistamines, glucosamines, and statins. Alcohol can initially sedate but ultimately prevents deep sleep. Late-night eating can wreak havoc on a good night's sleep, especially when digestion and liver involvement kick in a few hours after you eat. Try to stop eating at least four hours before bedtime and avoid large, heavy, fatty, sugary meals in the evening. Exercise, unplugging before bed and developing a sleep ritual are all great ways to improve one's sleep. Some herbal sleep aids include valerian, california poppy, skullcap, passionflower, chamomile, hops, blue vervain, wood betony and wild lettuce. The endocrine system is a collection of specialized cells, tissues, and glands that produce and secrete circulating chemical messenger molecules called hormones. Most hormones are secreted by endocrine glands - ductless organs that secrete their products into interstitial fluid, lymph, and blood. Hormones are bloodborne units of information, just as nerve impulses are units of information carried in nerves. Some hormones participate in feedback control loops regulating various bodily functions. We need these hormones to maintain allostasis. Other hormones produce specific effects, such as contractions of the uterus during childbirth, growth during childhood and the exciting development of sexual characteristics at puberty. We need specific hormones to be able to carry out each of these very specific functions. The endocrine system differs from the nervous system in that hormones of the endocrine system reach nearly every living cell (through circulation in the blood), each hormone acts only on certain cells (with target cells that have the appropriate receptor) and endocrine control tends to be slower than nervous system control. Due to these differences it’s understandable why the reflexes that prompt us to avoid a hot surface are controlled by the nervous system and that endocrine communication is highly effective for longer-term controls such as regulating blood pressure or the production of red blood cells. Hormones are generally classified into two basic categories based on their structure and mechanism of action: Steroid hormones are structurally related to cholesterol. They are all synthesized from cholesterol and all are lipid soluble. Nonsteroid hormones consist of, or at least partly derived from the amino acid building blocks of protein. In general, they are water soluble. The differences in lipid solubility explain most of the important differences in how the two categories of hormones work. Steroid hormones usually enter the cell, bind to an intracellular receptor and activate genes that produce new proteins. Nonsteroid hormones generally bind to receptors on the cell’s surface. Their binding either opens or closes cell membrane ion channels or activates enzymes within the cell. Negative and Positive Feedback Loops Feedback loops can enhance or buffer changes that occur in a system. Positive feedback loops enhance or amplify changes, this tends to move a system away from its equilibrium state and make it more unstable. Negative feedbacks tend to dampen or buffer changes; this tends to hold a system to some equilibrium state making it more stable. As messenger molecules, some hormones participate in internal allostatic control mechanisms and control vital physiological processes. It is essential to regulate carefully the rate at which each hormone is secreted so that its concentration in blood is just right to carry out its intended function. In a negative feedback loop involving a hormone, the endocrine gland is the control center and the hormone represents the pathway between the control center and the hormone’s target cells, tissues or organs. A negative feedback loop involving an endocrine gland and a hormone is a stable, self-adjusting mechanism for maintaining homeostasis of the controlled variable, because any change in the controlled variable sets in motion a response that reverses that change. Not all negative feedback loops are as simple as the one I described. In some cases the real control center is the brain, which activates an endocrine gland via nerves. The effect is the same. Additionally, a few hormones are secreted in response to specific environmental cues or for particular purposes such as puberty. This type of secretion is not part of a negative feedback loop. The pituitary gland- is a small endocrine gland located beneath the hypothalamus and connected to it by a stalk of tissue. The hypothalamus also produces hormones and monitors the pituitary gland. The pituitary gland is sometimes called “the master gland” because it secretes eight different hormones and regulates many of the other endocrine glands. The hypothalamus creates neuron cell bodies that make either antidiuretic hormones (ADH) or oxytocin - both nonsteroid hormones - and then sends the hormones down the axon for storage endings in the pituitary. ADH acts on the kidneys to regulate water balance and oxytocin causes uterine contractions and milk ejection in pregnant and lactating women. In both sexes, oxytocin contributes to feelings of sexual satisfaction. The anterior pituitary produces six key hormones:
Thyroid - The thyroid and parathyroid glands are anatomically linked. The thyroid gland is situated just below the larynx at the front of the trachea and the two lobes of the thyroid gland wrap part of the way around the trachea. The four small parathyroid glands are embedded in the back of the thyroid. The thyroid and parathyroid glands are both functionally linked- they help regulate calcium balance. In addition, the thyroid has a separate and important role in controlling metabolism. The thyroid gland produces two very similar hormones called thyroxine (T4) and triiodothyronine (T3). They’re identical except that thyroxine contains four molecules of iodine whereas T3 contains only three. The thyroid gland secretes mainly thyroxine but eventually most of it is converted to the more active T3 form of the hormone in the blood. These thyroid hormones regulate metabolism. Calcitonin, the other main hormone of the thyroid gland is produced by a separate group of thyroid cells. Calcitonin decreases the rate of bone resorption by inhibiting the activity of osteoclasts. It also stimulates the uptake of calcium by bone. The parathyroid glands produce only one hormone, parathyroid hormone which removes calcium and phosphate from bone, increases absorption of calcium by the digestive tract and causes the kidneys to retain calcium and excrete phosphate. Adrenal Glands- are two small endocrine organs located just above the kidneys. Each gland has an outer layer, the adrenal cortex, and an inner core, the adrenal medulla. The adrenal cortex produces small amounts of the sex hormones estrogen and testosterone and two classes of steroid hormones called glucocorticoids and mineralocorticoids. The adrenal cortex produces a group of glucocorticoids with nearly identical structures. Cortisol accounts for approximately 95% of these glucocorticoids. The other hormones produced by the adrenal cortex are the mineralocorticoids, the most abundant of which is aldosterone. The adrenal medulla produces nonsteroid hormones epinephrine (adrenaline) and norepinephrine (noradrenaline). These hormones play roles in metabolism and controlling blood pressure and heart activity. Pineal - The pineal gland is a pea-sized gland located deep within the brain, in the roof of the third ventricle. Its name derives from the fact that it is shaped like a small pine cone (hehe). More than 200 million years ago our pineal gland was photosensitive area or “third eye” located near the skin’s surface. Although it is now shielded from the sun by our thick skull, it still retains its photosensitivity because it receives input directly from the eyes via the optic nerve and nerve pathways in the brain. The pineal gland secretes the hormone melatonin in a cyclic manner coupled to the daily cycle of light and dark. Melatonin is sometimes called the “hormone of darkness” because its rate of secretion rises nearly 10 fold at night and then falls again during the daylight. Its secretion appears to be regulated by the absence or presence of visual cues. During the day, nerve impulses from the retina inhibit its release. AND we are just beginning to understand what melatonin does… Notes on the role of the pancreatic endocrine cells in the regulation of blood glucose: Within the pancreas, clusters of cells called the pancreatic islets produce and secret three hormones - glucagon, insulin, and somatostatin. Glucagon raises blood glucose levels, insulin lowers blood glucose levels, and somatostatin appears to inhibit the secretion of glucagon and insulin. Overall thoughts on the Endocrine System and its connection to Herbal Medicine: I’m fascinated by the thyroid. This organ plays an important role in determining our body temperature; the way we digest, metabolize and assimilate food; our body’s ability to make good-quality connective tissue, hair, skin and nails; and our mood. Thyroid fluctuations can affect many things including menopausal symptoms, fertility, and overall vitality. Your body can tilt towards hypothyroidism (underactive/low thyroid) or hyperthyroidism (overactive/high thyroid). Hypothyroidism is the most common thyroid imbalance in which things slow to nearly a halt resulting in colder body temperatures, weight gain, depression, sluggishness, poor digestion, brain fog, hair loss, dull skin, and horizontal ridges in the fingernails, among other things. It can look like anemia. Hyperthyroidism is characterized by an overdrive - you might feel like a hot furnace, become rail-thin, toss and turn at night, and feel extremely agitated and anxious. It wears on the whole body and can even make your eyes bug out in advance cases. Even though more and more people - particularly women - have thyroid imbalances, it’s hard to find good information about how to take care of the thyroid holistically. It’s important to get a full thyroid panel completed if you suspect issues. This will give you a better idea of what’s going on as well as rule out issues like anemia and lyme disease. Knowing exactly where you stand can help drive appropriate therapies. Herbal and lifestyle approaches to thyroid issues excel at addressing imbalances and are less apt to have negative side effects like some of the thyroid-focused supplements and pharmaceuticals. Also many underlying causes of thyroid problems relate to stress, grief, autoimmune disease, diet, a sedentary lifestyle, toxins and and emotional connections - consider the possible aggravating factors. Herbs that assist hypothyroid issues are iodine, kelp, selenium, ashwagandha, bacopa and guggul, and tyrosine. Avoid eating excessive amounts if you tend toward hyperthyroid disease. Lemon balm, motherwort and bugleweed are frequently used for hyperthyroid disease. Preliminary research suggests that these herbs inhibit parathyroid functions through a variety of mechanisms including binding to TSH receptors, inhibiting thyroid hormone production and preventing thyroid hormone conversion from T4 to T3. It’s interesting to me that lemon balm and motherwort are commonly used for conditions similar to hyperthyroid disease: insomnia, anxiety, agitation and stress-related cardiac overdrive including panic attacks and palpitations. Vitamin B, magnesium and bitters tend to be beneficial for healthy thyroid function regardless of whether your thyroid needs a boost or needs to be taken down a notch. |
AuthorThe adventures, studies, and musings of a student at the Vermont Center for Integrative Herbalism.
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