Human Anatomy and Physiology: A Comprehensive Guide to the Body’s Systems
Posted on May 24, 2024 in Biology
Renin-angiotensin-aldosterone system (RAAS)
ECG (electrocardiogram)
Dental formula- I – 2/2 C – 1/1 P – 2/2 M – 3/3 = 16 x 2 = 32
The main components of the nephron are the glomerulus, the Bowman’s capsule or glomerular capsule, the proximal convoluted tubule, the loop of Henle, and the distal convoluted tubule.
Tidal volume is the amount of air that moves in or out of the lungs with each respiratory cycle.
Larynx is also known as voice box.
Lymph (clear, watery fluid) and lymphocytes (white blood cells) travel through the lymph vessels and into the lymph nodes where the lymphocytes destroy harmful substances.
The cardiac cycle is the performance of the human heart from the beginning of one heartbeat to the beginning of the next.
Micturition is a process where urine is expelled from the body.
Stomach: Your stomach creates digestive juices and breaks down food. It holds food until it is ready to empty into your small intestine.
Histology, also known as microscopic anatomy or microanatomy, is the branch of biology that studies the microscopic anatomy of biological tissues.
Auditory bones – malleus, incus, and stapes.
Contractile filament – A sarcomere is the basic contractile unit of a myocyte (muscle fibre). A sarcomere is composed of two main protein filaments (thin actin and thick myosin filaments) which are the active structures responsible for muscular contraction.
Part of brain: The adult brain is composed of the following 4 major parts- A. Cerebrum B. Cerebellum C. Diencephalon D. Brain Stem
Spermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testicle.
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What is the renin-angiotensin- aldosterone system (RAAS)?
The renin-angiotensin-aldosterone system (RAAS) is the system of hormones, proteins, enzymes and reactions that regulate your blood pressure and blood volume on a long-term basis.
It regulates your blood pressure by increasing sodium (salt) reabsorption, water reabsorption (retention) and vascular tone (the degree to which your blood vessels constrict, or narrow). The RAAS consists of three major substances, including: Renin (an enzyme)., Angiotensin II (a hormone)., Aldosterone (a hormone).
Enzymes are proteins that help trigger chemical reactions in your body. They build some substances and break others down. Hormones are chemicals that coordinate different functions in your body by carrying messages through your blood to your organs, muscles and other tissues. These signals tell your body what to do and when to do it.
CARDIAC CYCLES:
“A cardiac cycle include all the events associated within one heart beat” The normal heart beats in healthy adult is 75 beats/min and cardiac cycle last for 0.8 sec. In the cardiac cycle due to the pressure changes atria and ventricles alternately contract and relax, and blood flows from areas of higher blood pressure to areas of lower blood pressure. Cardiac cycle is described by the following phase:
1) Atrial systole- In this phase Atrial contraction is begins which is last about 0.1 sec at same time ventricle are relaxed. So, the Right and Left AV valves are open and Atria send blood into the relaxed ventricles,
Atrial systole pushes 25 ml of blood in to ventricles which already contain 105 ml blood so at the end of atrial systole means end of ventricle diastole Ventricles contain maximum blood volume which is 130 ml known as end-diastolic volume (EDV). In the ECG or EKG it is noted as P wave.
2. Ventricular systole: In this phase ventricles begin contraction which is last for 0.3 sec. • Pressure in ventricles rises due to contraction and shut the AV valves which is heard by “Lubb” Sound. For about 0.05 sec all four valve are closed which is known as isovolumetric contraction. Ventricular contraction pushes blood out of the ventricles and opens the both Semilunar valve and ejected 70 ml blood in to sorta and same amount of blood in to pulmonary trunk
What is the creatinine clearance test?
The creatinine clearance test is a test that checks your how well your kidneys are working. It allows your healthcare provider to see how much creatinine is in a sample of your pee (urine) and blood. The results of this test can lead to a diagnosis of kidney disease.
Creatinine is a waste product of creatine. Creatine is a chemical that your body uses to supply your muscles with energy. As your muscles use energy, they break down. This natural breakdown of muscle tissue causes creatinine to release into your bloodstream Your kidneys typically filter creatinine But, if your kidneys aren’t functioning correctly, you may have higher levels of creatinine in your body than you should.
The creatinine clearance test involves collecting your pee over a 24-hour period and having your blood drawn. Your provider uses these samples to see how much creatinine your kidneys filter over the 24-hour window.
The results of the test show your creatinine clearance. Creatinine clearance is one way to estimate your glomerular filtration rate (GFR), or how well your kidneys are filtering your blood. The GFR is the main number used by your provider to determine how well your kidneys are working.
Healthcare providers don’t use the creatinine clearance test as much as they once did because collecting pee over a 24- hour period is inconvenient. Instead, they usually use a blood test called the estimated glomerular filtration rate (eGFR) coupled with a urine test like urine albumin-creatinine ratio (uACR), which only involves peeing one time.
Composition of lymph
The lymphatic system comprises- Lymph plasma, lymph corpuscles, Lymphold organs
Lymph plasma- lymph is a interstitial fluid. It has similar mineral content as in plasma.
Lymph Corpuscles- Lymph corpuscles refer to the cellular component found in lymph particularly white blood cells.
Lymphoid organs-lymphoid organs are the structure in the body where lymphocytes are produced, stored and even active as a part of the immune system.
Respiratory system
Calculation steps for Total Lung volume/Minute Volume:
1. Tidal volume (VT)
Healthy adult doing 12 breaths in cach minute and with each inhalation and exhalation moving about 500 mL of air into and out of the lungs. The volume of one breath is called the tidal volume (VT).
2. Minute Ventilation (MV)
We are doing 12 breaths in each minute so the minute ventilation (MV) is the the total volume of air inhaled and exhaled in each minute.
Minute Ventilation (MV)
Tidal volume (VT) x 12
=500 mL/breath x 12 breaths/min=6 litres/min
In a typical adult, about 70% of the tidal volume (350 mL) actually reaches the respiratory zone of the respiratory system namely the respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli and participates in external respiration.
The other 30% (150 mL) remains in the conducting airways of the nose,pharynx, larynx, trachea, bronchi, bronchioles, and terminal bronchioles known as dead space because these part does not undergo respiratory exchange of gases
Not all of the minute ventilation can be used in gas exchange because some of it remains in the anatomic dead space.
3. Alveolar Votiation Rate
The sheeler ventilation rate is the volume of air per minute that actually reaches the respiratory zone.
in the example just given, alveolar ventilation rate would be 150 mL/besath x 12 terrath/min=4200 mL/min
4. Ispiratory Reserve Volume
When we do very deep breath, we can inhale more than 5
00 mL of air. This addional inhaled ar, called the inspiratory reserve volume which is about 3100mL in an average adult male and 1900 ml in an average adult female.
5. Expiratory Reserve Volume or Force Expiratory Volume
If inhalation follows forced exhalation we can more air in addition to the 500 mL of tidal volume which is 1200 mL in males and 700 mL in females is called the expiratory reserve volume or force expiratory volume.
ELECTROCARDIOGRAPHY: ECG
Electrocardiography (ECG or EKG from the German Elektrokardiogramm) is a transthoracic interpretation of the electrical activity of the heart over time captured
and externally recorded by skin electrodes. • It is a noninvasive recording produced by an electrocardiographic device. .
The ECG works mostly by detecting and amplifying the tiny electrical changes on the skin that are caused when the heart muscle “depolarizes” during each heart beat.
At rest, each heart muscle cell has a charge across its outer wall, or cell membrane. Reducing this charge towards zero is called de-polarization, which activates the mechanisms in the cell that cause it to contract
During each heartbeat a healthy heart will have an orderly progression of a wave of depolarization that is triggered by the cells in the sinoatrial node, spreads out through the atrium, passes through intrinsic conduction pathways” and then spreads all over the ventricles. This is detected as tiny rises and falls in the voltage between two electrodes placed either side of the heart which is displayed as a wavy line either on a screen or on paper. This display indicates the overall rhythm of the heart and weaknesses in different parts of the heart muscle.
Types of Nephron
There are two types of nephron: • Cortical nephron-These are the nephrons present within the cortex. These are short and comprise about 80% of the total nephrons. Juxtamedullary nephron-These have long loops of Henle and extend into the medulla. These are about 20%.
Functions of Nephron
The primary function of nephron is removing all waste products including the solid wastes, and other excess water from the blood, converting blood into the urine, reabsorption, secretion, and excretion of numerous substances. As the blood passes through the glomerulus with high pressure, the small molecules are moved into the glomerular capsules and travel through a winding series of tubules. The cell present in each tube absorbs different molecules excluding the glucose, water, and other beneficial molecules which are called as the ultrafiltrate. As the ultrafiltrate molecules travel down the tubules they become
Functions of lymph
It keeps the body cells moist. It transfers oxygen, hormones and nutrients to the different parts of the body and remove metabolic waste to the cell. It transports antibodies and lymphocytes to the blood. Maintaining the composition of the tissue fluid and volume of the blood. Absorption of fat from the small intestine occurs through lymphatic vessels.
Mechanism of Breathing
The air that we breathe in and out of the lungs varies in its pressure. So basically when there is a fall in air pressure the alveolar spaces fall and the air enters the lungs (inspiration) and as the pressure of the alveoli within exceeds the atmospheric pressure, the air is blown from the lungs (expiration). The flow rate of air is in proportion to the magnitude of the pressure difference.
The breathing mechanism involves two processes:
• Inspiration
• Expiration
Inspiration
In the process of inspiration, there would be a contraction of muscles attached to the ribs on the outer side which pulls out the ribs and results in the expansion of the chest cavity.
Later, the diaphragm, contracts, moves downwards and expands the chest cavity resulting in the contraction of the abdominal muscles.
The expansion of the chest cavity produces a partial vacuum which sucks air into the lungs and fills the expanded alveoli.
Mechanism Of Inspiration
• The process of intake of atmospheric air is known as inspiration. It is an active process.
• When the volume of the thoracic cavity increases and the air pressure decreases, inspiration takes place.
• Contraction of external intercostal muscles increases the volume of the thoracic cavity.
• Contraction of the diaphragm further increases the size of the thoracic activity. Simultaneously, the lungs expand.
• With the expansion of the lungs, the air pressure inside the lungs decreases.
• The pressure equalizes and the atmospheric air rushes inside the lungs.
by respectively left and right ventricles so the 60 ml of blood remains in the each ventricle out of 130 ml. This is known as ventricular ejection which last for 0.25 sec .Ventricular systole isovolumetric contraction + ventricular ejection -(0.05)+(0.25) 0.3 sec.
Function of Heart – 1. The heart’s primary function is to pump blood throughout the body. 2. It supplies oxygen and nutrients to the tissues and removes carbon dioxide and waste from the blood. 3. It also helps to maintain adequate blood pressure throughout the body. 4. Heart pumps the blood throughout the body, hence playing an important role in maintaining body temperature.
The pancreas is a mixed or heterocrine gland.
Oogenesis is the process of formation of female gametes.
Skin is made up of three layers, the epidermis, dermis, and the hypodermis.
A neuron has three main parts: dendrites, an axon, and a cell body or soma .
Your blood group is identified by antibodies and antigens in the blood .
O negative donors are often called ‘universal donors’ .
AB+ is the universal acceptor.
Hematopoiesis is blood cell production.
The clotting factors are Factor I (fibrinogen), Factor II (prothrombin), Factor III (tissue thromboplastin or tissue factor), Factor IV (ionized calcium), Factor V (labile factor or proaccelerin), Factor VII (stable factor or proconvertin), and Factor VIII (antihemophilic factor).
Mitochondria is called powerhouse of the cell.
Flexion refers to a movement that decreases the angle between two body parts.
The study of the structure of a plant or animal is called anatomy.
A surgical suture, also known as a stitch or stitches, is a medical device used to hold body tissues together and approximate wound edges after an injury or surgery.
The five parts of your axial skeleton include the bones in your skull, ossicles (small bones) of your middle ear, hyoid bone of your neck, vertebra (bones of your spine) and thoracic cage (ribcage).
Spleen is highly vascular lymphoid organ present in the body
Lymph nodes are small glandular structures located in the course of lymph vessels.
The process by which the formed elements of blood develop is called hemopoiesis or hematopoiesis.
The salivary glands in many vertebrates including mammals are exocrine glands that produce saliva through a system of ducts. Humans have three paired major salivary glands (parotid, submandibular, and sublingual), as well as hundreds of minor salivary glands.Function- Human salivary glands produce between 0.5 to 1.5 L of saliva daily, facilitating mastication, swallowing, and speech, lubricating the oral mucosa, and providing an aqueous medium for taste perception.
Function of brain- Thoughts and decisions. Memories and emotions. Movements (motor function), balance and coordination. Perception of various sensations including pain. Automatic behavior such as breathing, heart rate, sleep and temperature control. Regulation of organ function. Speech and language functions.
more and more hypertonic, which results in more amount of water to be extracted from the ultrafiltrate before it exits the nephrons.
Functions of Spleen- Spleen play an important role in the hematopoietic function in embryo. Spleen are also called graveyard of RBCs because it participate in the destruction of RBCs and other old blood cells.
Blood is a special type of fluid connective tissue which consisting of clear straw colored watery non- living fluid matrix (Plasma) and living blood cells (formed elements).Composition of blood — Blood plasma—plasma proteins, inorganic salts, nutrients, principally from digested foods, waste materials, hormones, gases. Formed elements— RBCs, WBCs, Platelets.
Blood Plasma is the straw colored fluid constituting nearly 55 percent of the blood. 90-92 percent of plasma is water and proteins contribute 6-8 percent of it.Plasma proteins— Albumins ,Globulins ,Fibrinogen.
Function of blood— Blood performs a number of functions, all concerned in one way or another with transporting substances, regulating blood levels of particular substances, or protecting the body. Transport— Transporting the oxygen and carbon dioxide from the lungs to other parts of organ. Transports the nutrients and wastes material from metabolic sites to eliminating sites. Transports hormones from the endocrine organs to their target organs. Regulation— It regulates the fluid volume by releasing the inorganic salts (Na+ , Ca2+, K+ , HCO3- etc.) and maintain the normal PH in body tissue. Maintain body temperature by absorbing and distributing heat throughout the body and to the skin surface to encourage heat loss. Protection— Prevent blood loss, when a blood vessel is damaged, platelets and plasma proteins initiate clot formation, halting blood loss. Prevent the infection by producing the antibodies and leukocytes cell, which help defend the body against foreign invaders such as bacteria and viruses
The function of the renal / urinary system is to eliminate wastes from the body, regulate blood volume and pressure, control levels of electrolytes and metabolites, and regulate blood pH.
6. Residual Volume
When we do force expiration not all amount of air go out some amount remain in anatomical dead space that is 1200 mL in male and 1100 mL in female which is known as residual volume.
7. Inspiratory capacity
Inspiratory capacity is the sum of tidal volume and inspiratory reserve volume (500 ml+3100 ml= 3600 mL. in males and 500 ml+1900 mL=2400 ml in females).
8. Functional residual capacity
Functional residual capacity is the sum of residual volume and expiratory reserve volume (1200 mL + 1200 mL -=2400 mL in males and 1100 mL + 700 mL= 1800 mL in females).
9. Vital capacity
Vital capacity is the sum of inspiratory reserve volume, tidal volume, and expiratory reserve volume (4800 mL in mates and 3100 mL in females).
10. Total lung capacity
Finally, total lung capacity is the sum of vital capacity and residual volume (4800 mL+1200 ml= 6000 mL in males and 3100 mL+1100 mL= 4200 ml in females).
Function of kidney– remove waste products from the body. remove drugs from the body. balance the body’s fluids.release hormones that regulate blood pressure. produce an active form of vitamin D that promotes strong, healthy bones. control the production of red blood cells.
