Lymph is the fluid that flows through the lymphatic system, a system composed of lymph vessels and intervening lymph nodes whose function, like the venous system, is to return fluid from the tissues to the central circulation. Interstitial fluid - the fluid, between the cells in all body tissues - enters the lymph capillaries; this lymphatic fluid is transported via progressively larger lymphatic vessels through lymph nodes, where substances are removed by tissue lymphocytes and circulating lymphocytes are added to the fluid, before emptying into the right or the left subclavian vein, where it mixes with central venous blood. Since the lymph is derived from the interstitial fluid, its composition continually changes as the blood and the surrounding cells continually exchange substances with the interstitial fluid, it is similar to blood plasma, the fluid component of blood. Lymph returns excess interstitial fluid to the bloodstream. Lymph transports fats from the digestive system to the blood via chylomicrons.
Bacteria may be transported to lymph nodes, where they are destroyed. Metastatic cancer cells can be transported via lymph; the word lymph is derived from the name of the ancient Roman deity of Lympha. Lymph has a not identical to that of blood plasma. Lymph that leaves a lymph node is richer in lymphocytes; the lymph formed in the human digestive system called chyle is rich in triglycerides, looks milky white because of its lipid content. Blood supplies nutrients and important metabolites to the cells of a tissue and collects back the waste products they produce, which requires exchange of respective constituents between the blood and tissue cells; this exchange is not direct, but instead occurs through an intermediary called interstitial fluid, which occupies the spaces between cells. As the blood and the surrounding cells continually add and remove substances from the interstitial fluid, its composition continually changes. Water and solutes can pass between the interstitial fluid and blood via diffusion across gaps in capillary walls called intercellular clefts.
Interstitial fluid forms at the arterial end of capillaries because of the higher pressure of blood compared to veins, most of it returns to its venous ends and venules. Thus, lymph when formed is a watery clear liquid with the same composition as the interstitial fluid. However, as it flows through the lymph nodes it comes in contact with blood, tends to accumulate more cells and proteins. Lymph returns excess interstitial fluid to the bloodstream. Lymph may bring them to lymph nodes, where they are destroyed. Metastatic cancer cells can be transported via lymph. Lymph transports fats from the digestive system to the blood via chylomicrons. Tubular vessels transport lymph back to the blood replacing the volume lost during the formation of the interstitial fluid; these channels are the lymphatic channels, or lymphatics. Unlike the cardiovascular system, the lymphatic system is not closed and has no central pump, or lymph heart. Lymph transport, therefore, is sporadic. Despite low pressure, lymph movement occurs due to peristalsis and compression during contraction of adjacent skeletal muscle and arterial pulsation.
Lymph that enters the lymph vessels from the interstitial spaces does not flow backwards along the vessels because of the presence of valves. If excessive hydrostatic pressure develops within the lymph vessels, some fluid can leak back into the interstitial spaces and contribute to formation of oedema. Flow of the lymph in the thoracic duct in an average resting person approximates 100ml per hour. Accompanied by another ~25ml per hour in other lymph vessels, total lymph flow in the body is about 4 to 5 liters per day; this can be elevated several fold while exercising. It is estimated. In 1907 the zoologist Ross Granville Harrison demonstrated the growth of frog nerve cell processes in a medium of clotted lymph, it is made up of lymph vessels. In 1913, E. Steinhardt, C. Israeli, R. A. Lambert grew vaccinia virus in fragments of tissue culture from guinea pig corneal grown in lymph
The pelvis is either the lower part of the trunk of the human body between the abdomen and the thighs or the skeleton embedded in it. The pelvic region of the trunk includes the bony pelvis, the pelvic cavity, the pelvic floor, below the pelvic cavity, the perineum, below the pelvic floor; the pelvic skeleton is formed in the area of the back, by the sacrum and the coccyx and anteriorly and to the left and right sides, by a pair of hip bones. The two hip bones connect the spine with the lower limbs, they are attached to the sacrum posteriorly, connected to each other anteriorly, joined with the two femurs at the hip joints. The gap enclosed by the bony pelvis, called the pelvic cavity, is the section of the body underneath the abdomen and consists of the reproductive organs and the rectum, while the pelvic floor at the base of the cavity assists in supporting the organs of the abdomen. In mammals, the bony pelvis has a gap in the middle larger in females than in males, their young pass through this gap.
The pelvic region of the trunk is the lower part of the trunk, between the thighs. It includes several structures: the bony pelvis, the pelvic cavity, the pelvic floor, the perineum; the bony pelvis is the part of the skeleton embedded in the pelvic region of the trunk. It is subdivided into the pelvic spine; the pelvic girdle is composed of the appendicular hip bones oriented in a ring, connects the pelvic region of the spine to the lower limbs. The pelvic spine consists of the coccyx; the pelvic cavity defined as a small part of the space enclosed by the bony pelvis, delimited by the pelvic brim above and the pelvic floor below. Each hip bone consists of 3 sections, ilium and pubis. During childhood, these sections are separate bones, joined by the triradiate cartilage. During puberty, they fuse together to form a single bone; the pelvic cavity is a body cavity, bounded by the bones of the pelvis and which contains reproductive organs and the rectum. A distinction is made between the lesser or true pelvis inferior to the terminal line, the greater or false pelvis above it.
The pelvic inlet or superior pelvic aperture, which leads into the lesser pelvis, is bordered by the promontory, the arcuate line of ilium, the iliopubic eminence, the pecten of the pubis, the upper part of the pubic symphysis. The pelvic outlet or inferior pelvic aperture is the region between the subpubic angle or pubic arch, the ischial tuberosities and the coccyx. Ligaments: obturator membrane, inguinal ligament Alternatively, the pelvis is divided into three planes: the inlet and outlet; the pelvic floor has two inherently conflicting functions: One is to close the pelvic and abdominal cavities and bear the load of the visceral organs. To achieve both these tasks, the pelvic floor is composed of several overlapping sheets of muscles and connective tissues; the pelvic diaphragm is composed of the coccygeus muscle. These arise between the symphysis and the ischial spine and converge on the coccyx and the anococcygeal ligament which spans between the tip of the coccyx and the anal hiatus; this leaves a slit for the urogenital openings.
Because of the width of the genital aperture, wider in females, a second closing mechanism is required. The urogenital diaphragm consists of the deep transverse perineal which arises from the inferior ischial and pubic rami and extends to the urogential hiatus; the urogenital diaphragm is reinforced posteriorly by the superficial transverse perineal. The external anal and urethral sphincters close the urethra; the former is surrounded by the bulbospongiosus which narrows the vaginal introitus in females and surrounds the corpus spongiosum in males. Ischiocavernosus clitoridis. Modern humans are to a large extent characterized by large brains; because the pelvis is vital to both locomotion and childbirth, natural selection has been confronted by two conflicting demands: a wide birth canal and locomotion efficiency, a conflict referred to as the "obstetrical dilemma". The female pelvis, or gynecoid pelvis, has evolved to its maximum width for childbirth—a wider pelvis would make women unable to walk.
In contrast, human male pelvises are not constrained by the need to give birth and therefore are more optimized for bipedal locomotion. The principal differences between male and female true and false pelvis include: The female pelvis is larger and broader than the male pelvis, taller and more compact; the female inlet is oval in shape, while the male sacral promontory projects further. The sides of the male pelvis converge from the inlet to the outlet, whereas the sides of the female pelvis are wider apart; the angle between
Organs are groups of tissues with similar functions. Plant and animal life relies on many organs. Organs are composed of main tissue, "sporadic" tissues, stroma; the main tissue is that, unique for the specific organ, such as the myocardium, the main tissue of the heart, while sporadic tissues include the nerves, blood vessels, connective tissues. The main tissues that make up an organ tend to have common embryologic origins, such as arising from the same germ layer. Functionally-related organs cooperate to form whole organ systems. Organs exist in most multicellular organisms. In single-celled organisms such as bacteria, the functional analogue of an organ is known as an organelle. In plants there are three main organs. A hollow organ is an internal organ that forms a hollow tube, or pouch such as the stomach, intestine, or bladder. In the study of anatomy, the term viscus is used to refer to an internal organ, viscera is the plural form. 79 organs have been identified in the human body. In biology, tissue is a cellular organizational level between complete organs.
A tissue is an ensemble of similar cells and their extracellular matrix from the same origin that together carry out a specific function. Organs are formed by the functional grouping together of multiple tissues; the study of human and animal tissues is known as histology or, in connection with disease, histopathology. For plants, the discipline is called plant morphology. Classical tools for studying tissues include the paraffin block in which tissue is embedded and sectioned, the histological stain, the optical microscope. In the last couple of decades, developments in electron microscopy, immunofluorescence, the use of frozen tissue sections have enhanced the detail that can be observed in tissues. With these tools, the classical appearances of tissues can be examined in health and disease, enabling considerable refinement of medical diagnosis and prognosis. Two or more organs working together in the execution of a specific body function form an organ system called a biological system or body system.
The functions of organ systems share significant overlap. For instance, the nervous and endocrine system both operate via the hypothalamus. For this reason, the two systems are studied as the neuroendocrine system; the same is true for the musculoskeletal system because of the relationship between the muscular and skeletal systems. Common organ system designations in plants includes the differentiation of root. All parts of the plant above ground, including the functionally distinct leaf and flower organs, may be classified together as the shoot organ system. Animals such as humans have a variety of organ systems; these specific systems are widely studied in human anatomy. Cardiovascular system: pumping and channeling blood to and from the body and lungs with heart and blood vessels. Digestive system: digestion and processing food with salivary glands, stomach, gallbladder, intestines, colon and anus. Endocrine system: communication within the body using hormones made by endocrine glands such as the hypothalamus, pituitary gland, pineal body or pineal gland, thyroid and adrenals, i.e. adrenal glands.
Excretory system: kidneys, ureters and urethra involved in fluid balance, electrolyte balance and excretion of urine. Lymphatic system: structures involved in the transfer of lymph between tissues and the blood stream, the lymph and the nodes and vessels that transport it including the Immune system: defending against disease-causing agents with leukocytes, adenoids and spleen. Integumentary system: skin and nails of mammals. Scales of fish and birds, feathers of birds. Muscular system: movement with muscles. Nervous system: collecting and processing information with brain, spinal cord and nerves. Reproductive system: the sex organs, such as ovaries, fallopian tubes, vulva, testes, vas deferens, seminal vesicles and penis. Respiratory system: the organs used for breathing, the pharynx, trachea, bronchi and diaphragm. Skeletal system: structural support and protection with bones, cartilage and tendons; the study of plant organs is referred to as plant morphology, rather than anatomy – as in animal systems.
Organs of plants can be divided into reproductive. Vegetative plant organs include roots and leaves; the reproductive organs are variable. In flowering plants, they are represented by the flower and fruit. In conifers, the organ that bears the reproductive structures is called a cone. In other divisions of plants, the reproductive organs are called strobili, in Lycopodiophyta, or gametophores in mosses; the vegetative organs are essential for maintaining the life of a plant. While there can be 11 organ systems in animals, there are far fewer in plants, where some perform the vital functions, such as photosynthesis, while the reproductive organs are essential in reproduction. However, if there is asexual vegetative reproduction, the vegetative organs are those that create the new generation of plants. Many societies have a system for organ donation, in which a living or deceased donor's organ is transplanted into a person with a failing organ; the transplantation of larger solid organs requires immunosuppression to prevent organ rejection or graft-versus-host disease.
There is considerable interest throughout the world in creating laboratory-grown or artificial organs. The English word "organ" dates back in reference to any musical instrument. By the late 14th
Internal obturator muscle
The internal obturator muscle or obturator internus muscle originates on the medial surface of the obturator membrane, the ischium near the membrane, the rim of the pubis. It exits the pelvic cavity through the lesser sciatic foramen; the internal obturator is situated within the lesser pelvis, at the back of the hip-joint. It functions to help laterally rotate femur with hip extension and abduct femur with hip flexion, as well as to steady the femoral head in the acetabulum, it arises from the inner surface of the antero-lateral wall of the pelvis, where it surrounds the greater part of the obturator foramen, being attached to the inferior pubic ramus and ischium, at the side to the inner surface of the hip bone below and behind the pelvic brim, reaching from the upper part of the greater sciatic foramen above and behind to the obturator foramen below and in front. It arises from the pelvic surface of the obturator membrane except in the posterior part, from the tendinous arch which completes the canal for the passage of the obturator vessels and nerve, to a slight extent from the obturator fascia, which covers the muscle.
The fibers converge toward the lesser sciatic foramen, end in four or five tendinous bands, which are found on the deep surface of the muscle. The tendon inserts on the greater trochanter of the proximal femur; the internal obturator muscle is innervated by the nerve to internal obturator. This bony surface is covered by smooth cartilage, separated from the tendon by a bursa, presents one or more ridges corresponding with the furrows between the tendinous bands; these bands leave the pelvis through the lesser sciatic foramen and unite into a single flattened tendon, which passes horizontally across the capsule of the hip-joint, after receiving the attachments of the superior and inferior gemellus muscles, is inserted into the forepart of the medial surface of the greater trochanter above the trochanteric fossa. A bursa and elongated in form, is found between the tendon and the capsule of the hip-joint; this article incorporates text in the public domain from page 477 of the 20th edition of Gray's Anatomy Anatomy photo:13:st-0407 at the SUNY Downstate Medical Center - "Gluteal Region: Muscles" Anatomy photo:43:st-0603 at the SUNY Downstate Medical Center - "The Female Pelvis: Muscles" Cross section image: pelvis/pelvis-e12-15—Plastination Laboratory at the Medical University of Vienna pelvis at The Anatomy Lesson by Wesley Norman perineum at The Anatomy Lesson by Wesley Norman Int.
J. Morphol. 25:95-98, 2007
The sigmoid colon is the part of the large intestine, closest to the rectum and anus. It forms a loop; the loop is shaped like a Greek letter sigma or Latin letter S. This part of the colon lies within the pelvis, but on account of its freedom of movement it is liable to be displaced into the abdominal cavity; the sigmoid colon begins at the superior aperture of the lesser pelvis, where it is continuous with the iliac colon, passes transversely across the front of the sacrum to the right side of the pelvis. It curves on itself and turns toward the left to reach the middle line at the level of the third piece of the sacrum, where it bends downward and ends in the rectum, its function is to expel gaseous waste from the gastrointestinal tract. The curving path it takes toward the anus allows it to store gas in the superior arched portion, enabling the colon to expel gas without excreting faeces simultaneously, it is surrounded by peritoneum, which forms a mesentery, which diminishes in length from the center toward the ends of the loop, where it disappears, so that the loop is fixed at its junctions with the iliac colon and rectum, but enjoys a considerable range of movement in its central portion.
Pelvic splanchnic nerves are the primary source for parasympathetic innervation. Lumbar splanchnic nerves provide sympathetic innervation via the inferior mesenteric ganglion. Behind the sigmoid colon are the external iliac vessels, obturator nerve, the left Piriformis, left sacral plexus of nerves. In front, it is separated from the bladder in the male, the uterus in the female, by some coils of the small intestine. Diverticulosis occurs in the sigmoid colon in association with increased intraluminal pressure and focal weakness in the colonic wall, it is a common cause of hematochezia. Volvulus occurs when a portion of the bowel twists around its mesentery, which can lead to obstruction and infarction. Volvulus in the elderly occurs in the sigmoid colon, whereas in infants and children it is more to occur in the midgut; this may correct itself spontaneously or the rotation may continue until the blood supply of the gut is cut off completely. This article incorporates text in the public domain from page 1182 of the 20th edition of Gray's Anatomy Anatomy figure: 37:06-07 at Human Anatomy Online, SUNY Downstate Medical Center - "The large intestine."
Superior & Inferior Mesenteric Artery at The Anatomy Lesson by Wesley Norman
Arcuate line of ilium
The arcuate line of the ilium is a smooth rounded border on the internal surface of the ilium. It is inferior to the iliac fossa and Iliacus muscle, it forms part of the border of the pelvic inlet. In combination with the pectineal line, it comprises the iliopectineal line; the arcuate line marks the border between the body and the wing of the ilium, running inferior and medial from the auricular surface to the area corresponding to the acetabulum, it indicates where weight is transferred from the sacroiliac joint to the hip joint. Anatomy photo:44:st-0704 at the SUNY Downstate Medical Center
Internal iliac lymph nodes
The internal iliac lymph nodes surround the internal iliac artery and its branches, receive the lymphatics corresponding to the distribution of the branches of it, i. e. they receive lymphatics from all the pelvic viscera, from the deeper parts of the perineum, including the membranous and cavernous portions of the urethra, from the buttock and back of the thigh. The internal iliac lymph nodes drain the superior half of the rectum, above the pectinate line, it does not receive lymph from the ovary or testis. External iliac lymph nodes pararectal lymph nodes This article incorporates text in the public domain from page 704 of the 20th edition of Gray's Anatomy