Anatomy & Physiology, GIZ-HYA
Human beings have long been curious about the way that things work, and that curiosity includes wondering about how we ourselves work. The fields of anatomy and physiology involve studying the structures of bodies and the way that those structures and bodies function.
Anatomy & Physiology Encyclopedia Articles By Title
Gizzard
Gizzard, in many birds, the hind part of the stomach, especially modified for grinding food. Located between the......
gland
gland, cell or tissue that removes specific substances from the blood, alters or concentrates them, and then either......
glans penis
glans penis, rounded, bulbous tip of the penis, the male reproductive organ. The glans forms the most sensitive......
glaucoma
glaucoma, disease caused by an increase in pressure within the eye as a result of blockage of the flow of aqueous......
Globulin
Globulin, one of the major classifications of proteins, which may be further divided into the euglobulins and the......
glottis
glottis, either the space between the vocal fold and arytenoid cartilage of one side of the larynx and those of......
Gluconeogenesis
Gluconeogenesis, formation in living cells of glucose and other carbohydrates from other classes of compounds.......
Glucose
Glucose, one of a group of carbohydrates known as simple sugars (monosaccharides). Glucose (from Greek glykys;......
Gluten
Gluten, a yellowish gray powdery mixture of water-insoluble proteins occurring in wheat and other cereal grains......
gluteus muscle
gluteus muscle, any of the large, fleshy muscles of the buttocks, stretching from the back portion of the pelvic......
Glycogen
Glycogen, white, amorphous, tasteless polysaccharide (C6H1005)n. It is the principal form in which carbohydrate......
Glycolipid
Glycolipid, any of a group of molecules consisting of a carbohydrate (sugar) moiety attached to a lipid (fat) backbone.......
glycolysis
glycolysis, sequence of 10 chemical reactions taking place in most cells that breaks down glucose, releasing energy......
Glycoside
Glycoside, any of a wide variety of naturally occurring substances in which a carbohydrate portion, consisting......
goitre
goitre, enlargement of the thyroid gland, resulting in a prominent swelling in the front of the neck. The normal......
Goitrogen
Goitrogen, substance that inhibits the synthesis of the thyroid hormones (thyroxine and triiodothyronine), thereby......
gonad
gonad, in zoology, primary reproductive gland that produces reproductive cells (gametes). In males the gonads are......
granulocyte
granulocyte, any of a group of white blood cells (leukocytes) that are characterized by the large number and chemical......
granulomatous thyroiditis
granulomatous thyroiditis, inflammatory disease of the thyroid gland, of unknown but presumably viral origin. It......
Graves disease
Graves disease, endocrine disorder that is the most common cause of hyperthyroidism (excess secretion of thyroid......
ground substance
ground substance, an amorphous gel-like substance present in the composition of the various connective tissues.......
Guanine
Guanine, an organic compound belonging to the purine group, a class of compounds with a characteristic two-ringed......
gum
gum, in anatomy, connective tissue covered with mucous membrane, attached to and surrounding the necks of the teeth......
gynecomastia
gynecomastia, enlargement of the breasts in the male, usually because of hormone imbalance. The growth and development......
hair
hair, in mammals, the characteristic threadlike outgrowths of the outer layer of the skin (epidermis) that form......
hamstring
hamstring, any of the three muscles at the back of the thigh that begin at the pelvis (specifically originating......
hand
hand, grasping organ at the end of the forelimb of certain vertebrates that exhibits great mobility and flexibility......
haptoglobin
haptoglobin, a colourless protein of the α-globulin fraction of human serum (liquid portion of blood plasma after......
Hashimoto disease
Hashimoto disease, a noninfectious form of inflammation of the thyroid gland (thyroiditis). Hashimoto disease is......
head
head, in human anatomy, the upper portion of the body, consisting of the skull with its coverings and contents,......
heart
heart, organ that serves as a pump to circulate the blood. It may be a straight tube, as in spiders and annelid......
heart rate
heart rate, the number of times the ventricles of the heart contract and relax (that is, beat) per minute or other......
heart sound
heart sound, audible rhythmic vibrations in the heart, typically heard through a stethoscope pressed to the chest......
heel
heel, in anatomy, back part of the human foot, below the ankle and behind the arch, and the corresponding part......
height
height, in anatomy, the measurement of the body from the base (usually the soles of the feet) to the top of the......
helper T cell
helper T cell, type of white blood cell that serves as a key mediator of immune function. Helper T cells play a......
hemagglutinin
hemagglutinin, any of a group of naturally occurring glycoproteins that cause red blood cells (erythrocytes) to......
hematology
hematology, branch of medical science concerned with the nature, function, and diseases of the blood. In the 17th......
Hemicellulose
Hemicellulose, any of a group of complex carbohydrates that, with other carbohydrates (e.g., pectins), surround......
Hemochromogen
Hemochromogen, compound of the iron-containing pigment heme with a protein or other substance. The hemochromogens......
hemocytoblast
hemocytoblast, generalized stem cell, from which, according to the monophyletic theory of blood cell formation,......
hemoglobin
hemoglobin, iron-containing protein in the blood of many animals—in the red blood cells (erythrocytes) of vertebrates—that......
hemolysis
hemolysis, breakdown or destruction of red blood cells so that the contained oxygen-carrying pigment hemoglobin......
heparin
heparin, anticoagulant drug that is used to prevent blood clots from forming during and after surgery and to treat......
hepatic vein
hepatic vein, any of a group of veins that transports blood from the liver to the inferior vena cava, which carries......
herd immunity
herd immunity, state in which a large proportion of a population is able to repel an infectious disease, thereby......
heterospecific mating
heterospecific mating, mating in which the man and woman have incompatible blood types, such that the woman may......
high-risk pregnancy
high-risk pregnancy, pregnancy in which the mother, the fetus, or the newborn has an elevated risk of experiencing......
hindbrain
hindbrain, region of the developing vertebrate brain that is composed of the medulla oblongata, the pons, and the......
Hip
Hip, in anatomy, the joint between the thighbone (femur) and the pelvis; also the area adjacent to this joint.......
hippocampus
hippocampus, region of the brain that is associated primarily with memory. The name hippocampus is derived from......
histogenesis
histogenesis, series of organized, integrated processes by which cells of the primary germ layers of an embryo......
Histone
Histone, type of protein that plays a critical role in the structural organization and regulation of DNA within......
Holliday junction
Holliday junction, cross-shaped structure that forms during the process of genetic recombination, when two double-stranded......
Homeostasis
Homeostasis, any self-regulating process by which biological systems tend to maintain stability while adjusting......
hoof
hoof, hard, flexible covering that protects the toes of ungulate mammals. Because all hoofed animals essentially......
Hormone
Hormone, organic substance secreted by plants and animals that functions in the regulation of physiological activities......
- Introduction
- Vertebrates, Endocrine, Neuroendocrine
- LH, ICSH, Endocrine
- Thyroid Gland, Metabolism, Hormone Production
- Parathyroid, Calcium, Parathormone
- Glucagon, Pancreas, Regulation
- Reproductive, Endocrine, Glands
- Endocrine Glands, Secretions, Hormone Functions
- Molting, Insects, Juveniles
- Plant Growth, Photosynthesis, Reproduction
- Growth Inhibitors
horn
horn, in zoology, either of the pair of hard processes that grow from the upper portion of the head of many hoofed......
hot flash
hot flash, symptom of declining estrogen levels associated with menopause that is characterized by a sensation......
How big can tortoises get?
Tortoises as a group vary significantly in size. Giant tortoises, specifically those found on the Aldabra Islands......
How Big Is the Giant Squid?
In the public consciousness, titanic conflicts between giant squids (genus Architeuthis) and sperm whales (Physeter......
How common are doppelgängers?
Perhaps you’ve heard the saying, “Everyone has a twin somewhere in the world.” Not a biological twin (although......
How do fish breathe?
Fish primarily breathe through gills, which are specialized organs that extract dissolved oxygen from water. The......
How do fish reproduce?
Fish reproduction is a fascinating process that varies significantly across different species. Most bony fishes......
How do fish sleep?
Fish enter a restful state marked by minimal movement and decreased responsiveness. During this time, they maintain......
How do frogs breathe?
Frogs have an adaptable respiratory system that allows them to breathe in multiple ways throughout their life cycle......
How do gills work?
Gills help aquatic animals breathe by allowing gases to move between water and blood. Their feathery, branched......
How do horses sleep?
Horses sleep both standing up and lying down. Most of their sleeping time is spent standing, which is crucial for......
How Do Monkeys and Apes Trim Their Fingernails?
Have you ever seen a monkey getting a manicure? Though that line sounds like the beginning of a bad joke, it actually......
How do penguins stay warm?
Penguins have a unique feather arrangement and body structure that provides excellent insulation. Their short,......
How do snakes swallow large prey?
Snakes have a unique and fascinating way of swallowing prey that is much larger than their own heads and even bodies.......
How Do We Know That Dinosaurs May Have Had Feathers?
Modern birds are living dinosaurs, having evolved from a line of theropod dinosaurs more than 150 million years......
How Does A Ventilator Work?
Mechanical ventilators have played an important, if controversial, role in the treatment of patients with severe......
How Does the Human Body Maintain Its Temperature?
People are mammals, and mammals are warm-blooded creatures, capable of maintaining a relatively constant internal......
How Is BMI Calculated?
BMI stands for “body mass index” and is an estimate of total body fat. BMI does not measure body fat directly,......
How long can whales hold their breath?
Whales can hold their breath for varying durations depending on the species, with some capable of staying submerged......
How long do chicken eggs take to hatch?
Chicken eggs typically take about 21 days to hatch. This is the time it takes for a fertilized egg to develop into......
How long does it take food to digest?
The process of food digestion typically takes between 24 and 72 hours. The precise length of time is determined......
How long does it take for rigor mortis to set in?
Rigor mortis sets in about two to six hours after death, starting in the smaller muscles of the body, such as those......
How many eyes does a spider have?
Spiders typically have eight eyes, although some species may have fewer. The number and arrangement of eyes can......
How many hearts does an octopus have?
An octopus has three hearts, facilitating efficient nutrient and oxygen delivery throughout its eight-armed body.......
How Many Legs Does a Caterpillar Have?
Caterpillars are the larval form of moths, butterflies, and skippers. Like all insects, they have three pairs of......
How many pints of blood does a human have?
A typical adult human has approximately 8 to 12 pints (about 4.5 to 6.8 liters) of blood circulating through their......
How many stomachs does a cow have?
Cows do not have four stomachs, as is sometimes thought. They have one stomach divided into four compartments—the......
How many teeth does a shark have?
The number of teeth a shark has is different for each species, but some can have more than 35,000 teeth in their......
How many tentacles does a jellyfish have?
Jellyfish are a diverse group of marine animals, and their tentacle count varies significantly across different......
How much does a human brain weigh?
The adult male human brain typically weighs between 1,300 grams and 1,400 grams (2.87 to 3.08 pounds), making up......
How much does an elephant weigh?
The short answer? A lot. The African bush elephant (Loxodonta africana), also known as the African savanna elephant,......
How Much Sleep Do You Need?
Sleep is a biological necessity, and sleep needs change throughout life. Newborns may need as many as 17 hours......
How tall are giraffes?
Giraffes are the tallest land animals. Males (bulls) may exceed 5.5 meters (18 feet) in height, and females (cows)......
How tall was T. rex?
If the Tyrannosaurus rex (T. rex)—the largest member of a group of theropod dinosaurs called tyrannosaurs—had stood......
How the First Surviving Quintuplets Became a Tourist Attraction
On May 28, 1934, a miracle happened. In a modest farmhouse in Corbeil, Ontario, Canada, parents Oliva and Elzire......
human aging
human aging, physiological changes that take place in the human body leading to senescence, the decline of biological......
human body
human body, the physical substance of the human organism, composed of living cells and extracellular materials......
human cardiovascular system
human cardiovascular system, organ system that conveys blood through vessels to and from all parts of the body,......
- Introduction
- Origin, Development & Function
- Heart Wall, Blood Flow, Circulation
- Coronary Arteries, Heart Valves, Blood Flow
- Electrocardiogram, Heartbeat, Circulation
- Arteries, Veins, Capillaries
- Arteries, Circulation, Blood Flow
- Pulse, Circulation, Blood Vessels
- Superior Vena Cava, Tributaries, Circulation
- Inferior Vena Cava, Tributaries, Circulation
- Capillaries, Circulation, Oxygenation
human development
human development, the process of growth and change that takes place between birth and maturity. Human growth is......
Human microbiome
Human microbiome, the full array of microorganisms (the microbiota) that live on and in humans and, more specifically,......
humerus
humerus, long bone of the upper limb or forelimb of land vertebrates that forms the shoulder joint above, where......
humour
humour, (from Latin “liquid,” or “fluid”), in early Western physiological theory, one of the four fluids of the......
hyaline cartilage
hyaline cartilage, type of connective tissue, glossy pearl-gray or blue-white in appearance and resilient, found......