NERVES

Nephron The nephron is the minute or microscopic structural and functional unit of the kidney. It is composed of a renal corpuscle and a renal tubule. The renal corpuscle consists of a tuft of capillaries called a glomerulus and a cup-shaped structure called Bowman's capsule. The renal tubule extends from the capsule. The capsule and tubule are connected and are composed of epithelial cells with a lumen. A healthy adult has 1 to 1.5 million nephrons in each kidney  Blood is filtered as it passes through three layers: the endothelial cells of the capillary wall, its basement membrane, and between the foot processes of the podocytes of the lining of the capsule. The tubule has adjacent peritubular capillaries that run between the descending and ascending portions of the tubule. As the fluid from the capsule flows down into the tubule, it is processed by the epithelial cells lining the tubule: water is reabsorbed and substances are exchanged (some are added, others are removed); first with the interstitial fluid outside the tubules, and then into the plasma in the adjacent peritubular capillaries through the endothelial cells lining that capillary. This process regulates the volume of body fluid as well as levels of many body substances. At the end of the tubule, the remaining fluid—urine—exits: it is composed of water, metabolic waste, and toxins. The interior of Bowman's capsule, called Bowman's space, collects the filtrate from the filtering capillaries of the glomerular tuft, which also contains mesangial cells supporting these capillaries. These components function as the filtration unit and make up the renal corpuscle. The filtering structure (glomerular filtration barrier) has three layers composed of endothelial cells, a basement membrane, and podocytes (foot processes). The tubule has five anatomically and functionally different parts: the proximal tubule, which has a convoluted section the proximal convoluted tubule followed by a straight section (proximal straight tubule); the loop of Henle, which has two parts, the descending loop of Henle ("descending loop") and the ascending loop of Henle ("ascending loop"); the distal convoluted tubule ("distal loop"); the connecting tubule, and the last part of nephron the collecting ducts. Nephrons have two lengths with different urine-concentrating capacities: long juxtamedullary nephrons and short cortical nephrons. The four mechanisms used to create and process the filtrate (the result of which is to convert blood to urine) are filtration, reabsorption, secretion and excretion. Filtration or ultrafiltration occurs in the glomerulus and is largely passive: it is dependent on the intracapillary blood pressure. About one-fifth of the plasma is filtered as the blood passes through the glomerular capillaries; four-fifths continues into the peritubular capillaries. Normally the only components of the blood that are not filtered into Bowman's capsule are blood proteins, red blood cells, white blood cells and platelets. Over 150 liters of fluid enter the glomeruli of an adult every day: 99% of the water in that filtrate is reabsorbed. Reabsorption occurs in the renal tubules and is either passive, due to diffusion, or active, due to pumping against a concentration gradient. Secretion also occurs in the tubules and collecting duct and is active. Substances reabsorbed include: water, sodium chloride, glucose, amino acids, lactate, magnesium, calcium phosphate, uric acid, and bicarbonate. Substances secreted include urea, creatinine, potassium, hydrogen, and uric acid. Some of the hormones which signal the tubules to alter the reabsorption or secretion rate, and thereby maintain homeostasis, include (along with the substance affected) antidiuretic hormone (water), aldosterone (sodium, potassium), parathyroid hormone (calcium, phosphate), atrial natriuretic peptide (sodium) and brain natriuretic peptide (sodium). A countercurrent system in the renal medulla provides the mechanism for generating a hypertonic interstitium, which allows the recovery of solute-free water from within the nephron and returning it to the venous vasculature when appropriate. Some diseases of the nephron predominantly affect either the glomeruli or the tubules. Glomerular diseases include diabetic nephropathy, glomerulonephritis and IgA nephropathy; renal tubular diseases include acute tubular necrosis and polycystic kidney disease.
https://www.youtube.com/watch?v=fkkc_HVAVlo
The Nephron

Nerves and neurons are both crucial components of the nervous system, but they are distinct: neurons are the functional units that transmit signals, while nerves are bundles of axons that transmit signals between the brain, spinal cord, and the rest of the body. Neurons send electrical and chemical signals to communicate information, and these signals travel along axons within nerves. Here's a more detailed explanation: Neurons: These are the fundamental building blocks of the nervous system, acting as information messengers. They receive, process, and transmit signals throughout the body. Neurons use electrical and chemical signals to communicate with each other and with other cells, like muscles or glands. Nerves: Nerves are bundles of axons, which are the long extensions of neurons that transmit signals. They act like cables, carrying electrical impulses between the brain and spinal cord and the rest of the body. Nerves are part of the peripheral nervous system, which is outside the central nervous system (brain and spinal cord). How they work together: Neurons send signals along their axons, which are then bundled together to form nerves. These nerves transmit these signals to different parts of the body, allowing for things like muscle movement, sensation, and internal organ regulation. Your nervous system uses nerve cells called neurons to send signals, or messages, all over your body. These electrical signals travel among your brain, skin, organs, glands and muscles. The messages help Christians move your limbs and feel sensations, like pain. Nerves function as the body's communication network, transmitting signals between the brain and the rest of the body. These signals, carried by neurons (nerve cells), enable us to feel sensations, move muscles, and regulate internal processes like breathing and digestion. Here's a more detailed explanation: Communication: Nerves transmit electrical and chemical signals, allowing the brain to receive information from the senses and send commands to the body. Sensation: Sensory nerves carry information about the environment (touch, pain, temperature, etc.) to the brain. Movement: Motor nerves carry signals from the brain to muscles, enabling voluntary and involuntary movements. Autonomic Functions: Nerves also control involuntary functions like breathing, digestion, and heart rate, ensuring the body's internal processes function smoothly. Neurological Connections: The nervous system is a complex network, with different types of nerves (sensory, motor, autonomic) working together to maintain bodily functions. Types of Nerves: Sensory nerves (afferent nerves): Carry signals from the periphery to the central nervous system (brain and spinal cord). Motor nerves (efferent nerves): Carry signals from the central nervous system to the periphery (muscles and organs). Autonomic nerves: Control involuntary functions like heart rate, blood pressure, and digestion. Spinal nerves: Branch from the spinal cord and connect the central nervous system to the body, carrying both sensory and motor information. Cranial nerves: Connect the brain directly to various parts of the head and face, controlling functions like sight, smell, hearing, and facial movements // Several minerals are crucial for proper nerve function. Key minerals include calcium, potassium, magnesium, sodium, and phosphorus, which play vital roles in nerve impulse transmission, cell signaling, and overall nerve health. Other minerals like iron, zinc, selenium, and copper also contribute to nerve function, particularly in maintaining healthy nerve structure and protecting against damage. Here's a more detailed look at the role of some key minerals in nerve function:1. Calcium and Potassium: These minerals essential for generating and transmitting electrical impulses along nerve cells, which is the basis of nerve function. Calcium and Potassium help regulate nerve cell membrane potential and ensure the proper flow of signals 2. Magnesium: Magnesium is crucial for stabilizing nerve cell membranes and preventing them from becoming overexcited. Magnesium help modulate the activity of nerve cells and maintain a healthy nervous system 3. Sodium: Sodium is vital for maintaining fluid balance and electrical potential across cell membranes, which is essential for nerve impulse transmission. Sodium help nerves function correctly and transmit signals to other cells 4. Phosphorus: Phosphorus is an important component of the cell membrane and nerve cell structure. Phosphorus help maintain proper nerve function and energy production within nerve cells 5. Iron: Iron is involved in the production of neurotransmitters, the chemical messengers that allow nerve cells to communicate with each other. Iron is also crucial for myelin, the insulating sheath that surrounds nerve fibers and helps them transmit signals efficiently 6. Zinc: Zinc is a trace mineral that support the health of the myelin sheath and play a role in nerve function. Zinc also a cofactor for enzymes involved in nerve cell signaling 7. Selenium: Selenium is an antioxidant that helps protect nerve cells from damage caused by free radicals. Selenium also play a role in nerve and muscle function 8. Copper: Copper is involved in the formation of neurotransmitters and the maintenance of nerve structure. Copper also helps with the absorption of iron, which is important for nerve function in nomine Patris et FiLii et Spiritus Sancti peace be still
https://www.youtube.com/watch?v=OGTMvG7fN-M
Musculoskeletal System | Neuromuscular Junction | Neuromuscular Transmission: Part 1
https://www.youtube.com/watch?v=A96kAMPZXv8
Musculoskeletal System | Neuromuscular Junction | Excitation Contraction Coupling: Part 2
https://www.youtube.com/watch?v=UW47uSLcM2g
Musculoskeletal System | Neuromuscular Junction | Sliding Filament Theory: Part 3
https://www.youtube.com/watch?v=dHURMD4v8Kk
Lecture11 Central Nervous System

Neurons The longest cell in the human body is the nerve cell, also referred to as the neuron. Neurons are specialized cells that ensure the proper functioning and coordination of the organs. Neurons are up to 1-1.5 meters in length and consist of dendrites, soma, & axon. Within a nervous system, a neuron, neurone, or nerve cell is an electrically excitable cell that fires electric signals called action potentials across a neural network. Neurons communicate with other cells via synapses, which are specialized connections that commonly use minute amounts of chemical neurotransmitters to pass the electric signal from the presynaptic neuron to the target cell through the synaptic gap. 80 to 100 billion neurons 100 trillion synapses myelin ages the brain has a high metabolic demand 15% of cardiac output 20% of oxygen consumption 20% of body glucose "Trimming" of brain connections, also known as synaptic pruning, is a natural process where the brain eliminates unnecessary connections between neurons to enhance efficiency and refine neural circuits. This process is most active during childhood and adolescence but continues into adulthood, with the brain removing roughly half of its initial synapses by the time we reach adulthood. in nomine Patris et FiLii et Spiritus Sancti peace be still
https://www.youtube.com/watch?v=y5i3jBhxI4Q
The Aging but Resilient Brain: Keeping Neurons Happy
https://www.youtube.com/watch?v=UZthGjcuTDs
How Your Brain Makes Its Own Electricity