Holistic Physiology: Movin’ & Groovin’
Posted on November 26th, 2016 to Blog
Movin’ and Groovin’ Badge
- Describe the layers of the skin and the functions of each layer
- Focus: epidermis & its five layers, dermis and matrix, subcutaneous tissue
Our skin is a remarkable system of protection that is composed of multiple layers with a variety of functions. The skin is composed of three layers, the Epidermis, the Dermis, and the Hypodermis.
Let’s begin by looking at the five layers of the Epidermis, which is our external protective barrier. We should point out the difference between “thick skin” which is composed of all five layers and covers the palms of our hands and the soles of our feet, and “thin skin” which is everything else and is only made up of four layers.
Stratum corneum – “horny layer” like “horny toad” (i.e. armored) this is the outermost layer of dead keratinocyte cells that protect us from environmental threats.
Stratum lucidum – “clear layer” The next layer is composed of a few layers of clear, flat, dead keratinocyte cells. This is layer that is missing in our “thin skin”.
Stratum granulosum – “Granular layer” contain living keratinocytes that are constantly making new cells that are moving up through the layers of the epidermis. The closer they get to the surface, the further they get from the blood and eventually they die and serve only as a protective barrier.
Stratum spinosum – “Spiny layer” – these cells contain filaments which help them hold together. At this level we are getting closer to the site of cell reproduction. The deeper you go, the younger the tissue. Important to note that the Epidermis is avascular, which means blood does not flow to these layers. This means that nutrition for the cells must come from below, pushes the old cells up and out.
Stratum basale – “Basal layer” is a single layer of columnar cells where new cell production occurs. This layer connects the epidermis to the dermis.
“Come, Let’s Get Sun Burned” is a fun mnemonic device to remember the names of each layer of the epidermis.
The Dermis is the middle layer between the epidermis and the hypodermis. This layer is made up of thicker connective tissue that holds all the blood vessels, nerves, hair follicles, collagen and sweat glands.
The Hypodermis lies beneath the Dermis and is composed primarily of adipose tissue (fat) and sweat glands. This layer of fat keeps us warm, provides a form of energy storage, and is essential for the production of Vitamin D.
- Describe the accessory structures of the skin and the functions of each
- Focus: list appendages, differentiate between sebaceous & sweat glands & apocrine v. eccrine glands
Our integumentary system is not just our skin, but our skin appendages which include our hair, nails, sweat glands, and sebaceous (oil) glands. Each strand of hair is simply a tube of epidermal cells that is continually pushing new cells upward and outward. Our nails grow in the same fashion, generating new keratinocyte cells at the root of the nail, pushing older cells outward.
We have up to 3 million sweat glands, also referred to as sudoriferous glands, displaced throughout the body. Sweat glands are either known as eccrine sweat glands or apocrine sweat glands.
Eccrine glands are simple coiled tubes that are more abundant, found in our palms, forehead, and soles of our feet. They are responsible for regulating body temperature by bringing water to the surface of our skin where it evaporates and cools us down. The Apocrine glands are numbered only about 2,000 and are found only in the armpits and pubic region. The Apocrine glands secrete a combination of sweat, protein, and fats that when consumed by bacteria creates the characteristic body odor.
Sebaceous glands and the oil producing glands which are attached to hair follicles. The purpose of this oil is to keep our skin soft and moisturized. It also helps keep our skin waterproof and protects us against bacteria and fungi. Most people are aware the of sebaceous glands of sheep, the source of lanolin and cholecalciferol (Vitamin D-3).
- List and describe the functions of bones
Bones are quite literally the framework that holds us together. There are typically 206 bones in a healthy human body and they enable us to do everything from simply walking around town to protecting our brain from serious head trauma. Because they are often compared to the framework of a building, the most common misunderstanding people have about bones is the idea that they are completely stiff and rigid, made of minerals, so they must be lifeless tubes of rock. Of course, nothing is further from the truth. Bones are specialized living tissue that need to be dense and strong but at the same time flexible and able to reconstitute itself upon breakage. Bones also play an important role in the storage of essential minerals, particularly calcium, which our muscles must have in order to function. Without a plentiful store of calcium to draw upon, we would literally grind to a halt.
- Discuss the process of bone formation and remodeling
- Focus: explain osteocytes, osteoblasts, osteoclasts and their roles in remodeling + the hormones in play
Our bones are essentially made of a dense, smooth layer of compact bone surrounding a porous, spongy bone tissue. The outer layer of our bones is known as cortical bone which make up about 80% of the mass of our bones. They are stores of calcium phosphate, known as calcium hydroxyapatite and other minerals that are also required for healthy neurotransmitter function. Inside our bones is trabecular bone, also known as spongy bone, where bone marrow is found. There are two kinds of bone marrow: yellow bone marrow which is made of fat, and red bone marrow which is where the generation of new blood cells takes place, known as hematopoeisis. When we are born most of our bones are filled with red bone marrow, but as we age the red bone marrow gets replaced with yellow marrow until only a small portion of our bones contain red bone marrow. As a side note, this points out the importance of using “blood building” herbs and foods such as Dang Gui, Rehmannia, Molasses, Beets, especially as we age. Ideally, we would start a healthy maintenance of our bones and blood by nourishing the pregnant mother before she is even pregnant, but then when the baby is born it is essential to allow the entirety of the blood to flow from the placenta into the newborn child before cutting the umbilical cord. Bastyr University has an article on the subject here: http://www.bastyr.edu/news/health-tips-spotlight-1/2014/06/whats-hurry-benefits-waiting-cut-umbilical-cord-after-birth
The structural integrity of the bones are held together by osteons, the weight bearing tubes that are filled with collagen fibers (lamellae) that run in a criss cross pattern. This cross pattern is what provides the weight bearing capacity of our bones. Inside these osteons are channels that allow blood vessels to run through them. It is essential for blood to flow to the bone because it is living tissue which contains specialized cells that need nutrients in order to continually remodel bones. Let’s take a look at the various cells involved in this process.
Osteocytes are the permanent resident cells that are found within the osteons. They are activated when the hormones calcitonin and parathyroid hormone detect low levels of calcium in the blood. If calcium is more needed, the osteocytes will respond to the hormonal signals to retrieve more calcium from the bone and bring it to where it is needed.
Osteoblasts are the bone making cells that “produce enzymes and osteoid, a mixture of collagen and other proteins to which hydroxyapatite binds” (Silverthorn, 743). They are stimulated by the thyroid hormone calcitonin, again demonstrating and important relationship between the thyroid and the health of our skeletal structure. On the other side of the coin are Osteoclasts, which are the bone breakers; they break down the bone matrix to allow for resorption of the minerals.
Through this ongoing process, the osteocytes sense stress, perhaps they detect a microscopic fracture. This triggers the release of osteoclasts which then release collagen digesting enzymes and an acidic hydrogen ion mixture that dissolves the hydroxyapatite. This process releases these components back into the blood where they can be used for other purposes. Once the osteoclasts have done their job, they go through apoptosis (programmed cell death), but before doing so they trigger the release of the osteoblasts to come in and remodel the bone. This is why it is so important for our bones to have regular stress put upon them; it actually strengthens them by encouraging this system of bone remodeling to take place.
- Describe the function and structure of skeletal, cardiac muscle, and smooth muscle
Although our bones are incredibly important, they would cease to function were it not for our skeletal muscles. Skeletal muscle is what enables us to move our bodies. Skeletal muscle surrounds bones (usually) and is attached to bone via tendons. However, not all skeletal muscle is connected to bone. Some skeletal muscle such as the obliques are connected to flat tendons; this is referred to as aponeurosis. The control we have over these muscles can be classed as voluntary, meaning we use our free will to move these muscles in order to carry out certain actions (walking, etc.) The skeletal muscle cells are unusual in that they are elongated with multiple nuclei throughout the edge of the cell. Skeletal muscle is striated, meaning the muscle is striped in bundles of fiber.
The Cardiac muscle is specialized muscle tissue so it is categorized as its own type. This muscle is exclusive to the heart and is involuntary in its control, meaning we do not have to consciously think about beating our heart, it will beat whether or not we actively move the muscle. The cardiac muscle cells are branched with 1 or 2 nuclei. Cardiac muscle is also striated.
Smooth muscle surround hollow organs such as the stomach, instestines, bowel, etc.. Blood vessels are hollow in the sense that they are hollow so that blood may flow through them. Smooth muscle is in the walls of our hollow organs and blood vessels. These muscles are important because they help our stomach to digest, pump blood through our veins, essentially anything that involved movement. Smooth muscle control is also involuntary, therefore we do not have to consciously put effort into digesting our food. The smooth muscle cells are described as almond shaped and have only 1 nuclei in the middle of the cell.
Describe how muscles contract and relax
- Focus: explain the role of sarcomeres, calcium, actin and myosin in muscular contraction
The sarcomere is the functional unit of muscle fiber that actually enables a muscle to contract. This means it is the actual protein complex that is doing the work of movement. The striation on skeletal muscle fibers are actually the arrangement of myofilaments of actin and myosin. Actin filaments, together with Myosins, are responsible for a variety of cell movements. According to The Cell: A Molecular Approach. 2nd Edition: “interactions of actin and myosin are responsible not only for muscle contraction but also for a variety of movements of nonmuscle cells”.
Read more here: http://www.ncbi.nlm.nih.gov/books/NBK9961/
According to the Rensselaer Polytechnic Institute: “Myosins are a large superfamily of motor proteins that move along actin filaments, while hydrolyzing ATP. About 20 classes of myosin have been distinguished on the basis of the sequence of amino acids in their ATP-hydrolyzing motor domains. The different classes of myosin also differ in structure of their tail domains. Tail domains have various functions in different myosin classes, including dimerization and other protein-protein interactions”.
If we remember back to our discussion on ATP, we will recall that ATP (adenosine triphosphate) is broken down to generate mechanical energy in the body. This is yet another reason why it is important to nourish our mitochondria with nutritious foods and Qi building herbs. We can visualize these little Myosin proteins as being supercharged when we provide them with the right foods, herbs, and supplements.
Our friend calcium plays a crucial role in this process, like it does in so many other processes. According to The Cell: A Molecular Approach. 2nd Edition:
“The contraction of skeletal muscle is triggered by nerve impulses, which stimulate the release of Ca2+ from the sarcoplasmic reticulum—a specialized network of internal membranes, similar to the endoplasmic reticulum, that stores high concentrations of Ca2+ ions. The release of Ca2+ from the sarcoplasmic reticulum increases the concentration of Ca2+ in the cytosol from approximately 10-7 to 10-5 M. The increased Ca2+ concentration signals muscle contraction via the action of two accessory proteins bound to the actin filaments: tropomyosin and troposin”.
Here we can see how maintaining proper levels of calcium is so important for both nervous system and musculoskeletal system. Not only is it essential that we have enough calcium present in the blood for the action potential to take place and trigger muscular contraction, but it is also critical that we have enough of all the other nutrient co-factors that ensure the proper transport of calcium. Without the proper co-factors we can take calcium all day and the calcium will not go where it is needed. This problem is twofold: 1) because the calcium is being deposited into the arteries, increasing our chances of cardiovascular disease, and 2) because our tissues and bones are unable to make use of that calcium, leading to muscle cramping, spasms, osteoporosis, etc. It is critical that we eat a vast array of mineral rich foods and good quality fats to ensure we are getting not just calcium, but also Magnesium, Potassium, Chloride, Vitamin D, Vitamin K-2, and many others.
- Explain the importance of a nerve supply and exercise in keeping muscles healthy
- Focus: neuromuscular junction’s role in muscle stimulation (you will need to use OpenStax for this question)
A nerve supply is critical if we want to be able to move our muscles and feel what is happening to us. Dr. Doron Sher writes: “The sensory nerves supply the joint itself as well as the skin over the knee. Many muscles have both motor and sensory functions”. http://www.kneedoctor.com.au/Learn-about-the-knee/knee-nerve-supply-nerves-supplies-joint-feeling-movement-sensation-strength
Our blood vessels supply our muscles with nutrients that are required for proper functioning. Without a proper supply of nutrients our muscles will be unable to contract. This will cause cramping and eventually our vascular tissue will be completely unable to stimulate muscular contractions. This can be seen when a person is suffering from dehydration. Not only do they need water, but they also need to resupply their electrolytes to nourish their nervous system and muscles. Some of these nutrients include calcium, magnesium, potassium, B vitamins, and more.
All of these communications that take place between muscles and nervous system occur at the neuromuscular junction (NMJ) and would not be possible without the steady supply of nutrients described above. The NMJ is where a motor neuron comes into close contact with a skeletal muscle cell. It is here where a complex chemistry of communication is taking place. The exchange of calcium ions alters the electrical impulse on the neuron and releases neurotransmitters across the synaptic cleft, where they are absorbed into ligand-gated channels with receptors. This transmission of chemical information is what allows movement to take place.
- Explain the importance of this module’s material in the study of herbal medicine
Clearly, a fundamental understanding of the bodies integumentary system is critical if we are to work with clients and have a comprehensive grasp on the science that is behind the protocol we are recommending. The better we are able to understand these complex ideas, the better we are able to convey they in a simple and easy to understand fashion for our clients and future students.
Of course having a strong skeleton is key. We must have a strong foundation before anything else. This is why it is essential that we start the nourishment of a human being even before conception by nourishing the mother and bringing out the best genetic potential in her (and the father) epigenetic makeups. By choosing the healthiest foods and the most specific herbs for the persons constitution, we can bring healthy children into the world with strong foundations.
It gets more difficult as we age to counteract problem that have been decades in the making, so it is important to communicate to our clients that they did not get their problem overnight and that it may take a long time to see improvement. We have to take into account whether or not our client has taken or is taking drugs and what potential nutrient deficiencies have arisen because of said drugs. In the case of osteoporosis for example, if a woman does not have access to quality foods or chooses to eat poor quality foods throughout her life she may become prone to low thyroid function, as well as osteoporosis.
It is quite true that malnutrition is the root of all disease. A lack of rich sea vegetables in the diet may potentially lead to an iodine deficiency, which then will reduce the amount of calcitonin the thyroid releases. This will greatly diminish the amount of osteoblasts that are able to generate new bone growth, thus osteoporosis. It makes sense that women would be more likely to experience nutrient deficiencies, considering they undergo blood loss on a regular basis. This, coupled with the lack of birth choices, lack of information, lack of critical thinking skills, and the poor food choices of 21st century civilization, can yield increased rates of anemia, low thyroid, bone loss, etc.