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Transcript of Ancient Medicine-Wk2
* The nervous system integrates and monitors the countless actions occurring simultaneously throughout the entire human body; therefore, ever task a person accomplishes, no matter how menial, is a direct result of the components of the nervous system.
* these actions can be under voluntary control, like touching a computer key, or can occur without your direct knowledge, like digesting food, releasing enzymes from the pancreas, or other unconscious acts.
*The strong bones of your skull protect a vital organ - your brain. Your brain weighs only about three pounds, but it has many complicated tasks to perform.
* Your brain coordinates your movements, controls your breathing, and lets you feel hunger, pain, sadness, and happiness. All the information about the world around you and all the things you do are controlled by your brain through a system of nerves.
*Sensory nerves carry information to your brain from your five senses: sight, hearing, taste, smell, and touch. When the information from your sensory nerves reaches your brain, your brain sends messages of its own to the body.
*For example, if you smell dinner cooking, your brain may make you feel hungry. Or if you see a scary movie, your brain may make your heart beat faster. Nerves that bring messages from your brain to your organs and muscles are called motor nerves.
*All of the signals going to and from your brain travel through your spinal cord. Together, the brain and spinal cord are called the central nervous system.
* Your heart rate, breathing rate, blood pressure, and the way your pupils adjust to changing light are all involuntary functions, which means you have no control of over them. These and similar functions are under the control of you autonomic nervous system.
* Your parasympathetic nervous system is made of the paired vagus nerves, parts of other nerves in your brain, and some spinal nerves from your pelvic area. The parasympathetic nervous system brings your body to a resting state.
* For example, this system slows your heart and breathing rate, but it also increases the wave-like motions of your digestive system when you eat.
* On the other hand, the sympathetic nervous system does just the opposite. This system increases your heart rate, quickens your breathing rate, and prepares your body to fight or flee when you're excited or scared.
* As in many ancient societies, medicine and religion were intertwined in ancient Greece.
The God of Medicine
The God of Medicine cont.
The Nervous System
A Bundle of Nerves
* The ancient Greeks built temples in honor of Asclepius.
* The temples were part spa, part house of worship.
* Sick people went there to be cured and also to pray to Asclepius. Patients hoped that Asclepius would appear to them in a dream and administer a "dream drug" or a "dream surgery."
* People thought that gods could both cause and cure illness.
* The Greeks worshiped a god of healing named Asclepius.
* They prayed to him when they got sick or when epidemics of disease swept through Greek cities.
* According to Greek myth, Asclepius learned the art of healing from his father, the god Apollo.
* Asclepius's children included Hygeia (the goddess of health, cleanliness, and sanitation) and Panacea (the goddess of healing.)
* Asclepius's symbol was a snake coiled around a staff.
* Priests at the temples also treated patients with special diets, massage, and plant medicines.
* People believed that bathing in or drinking the waters would cure illness.
* The temple of Asclepius in Pergamum, modern-day Turkey, had a mineral spring at its center. One Roman writer described the curative powers of the water there:
"This spring was discovered by and belongs to the great miracle worker Asclepius, he who does everything for the healthy well-being of humankind, and for many it takes the place of drugs. For many who have bathed in it recovered their eyesight, while many by drinking were cured of chest ailments and regained vital breathing. For in some cases it cures their feet, while for others it cured some other part of the body."
The Father of Medicine
* Hippocrates was the most famous physician of ancient time. As a physician and professor of medicine in ancient Greece, he took a scientific approach to treating patients.
* Hippocrates was born on the Greek island of Cos. The island already had a temple to honor Asclepius. Hippocrates established a medical school as part of the temple complex.
* He taught medical students to carefully observe each patients' symptoms and to select an appropriate treatment.
Ancient Greece was home to famous writers, philosophers, scientists, and artists.
It was a center of learning in the ancient world. Not surprisingly, ancient Greece was also home to skilled doctors. Many modern traditions have their routes in ancient Greece.
* Legend says that Hippocrates made his students take a pledge. They had to promise to practice medicine in an ethical way.
* In fact, many ancient Greek doctors did take such an oath. We call it the Hippocratic oath, although Hippocrates probably didn't write it.
* In the oath, ancient Greeks swore to use medicine for good and not for harm.
*They promised never to give a poisonous drug to a patient. They also promised to respect patients' privacy. Modern doctors take a similar oath.
The Four Humors
* Like the ancient Chinese, the ancient Greeks thought that sickness resulted when the body was out of balance.
* Greek physicians thought that four humors, or fluids, controlled human health. These humors were phlegm, blood, yellow bile, and black bile.
* The fluids were part of a larger philosophy, or belief system. In this philosophy, each of the four humors was associated with a different natural substance, a specific moisture and temperature, a certain part of the body, and a certain season of the year.
To Cut Up
*Our modern medical term anatomy comes from ancient Greek words that mean "to cut up." The study of human anatomy involves dissecting, or cutting up, dead bodies.
* Anatomy is one of the first courses medical students take. Doctors must know the body is put together to diagnose and treat diseases.
* The Greek physician Herophilus was another anatomy pioneer. He started a medical school in Alexandria in Egypt. Although not officially part of Greece, the city was home to many ancient Greek scholars and scientists. At Alexandria, Herophilus wrote the first detailed description of the brain.
* He recognized the brain as the seat of intelligence. He described differences between two key parts of the brain, the cerebrum and the cerebellum. He suggested that nerves are involved in the senses.
* He also recognized the difference between arteries,which carry fresh, oxygen-rich blood away from the heart, and veins, which carry blood from body tissues back to the heart.
* They did not know how to keep wounds from becoming infected.
*They did not know much about the workings of the heart, the lungs, and other organs. Although Hippocrates took a scientific approach to medicine, his medical knowledge was very limited.
* He treated patients with plant remedies, wound dressings and minor surgeries. But he could not save everyone.
The Father of Medicine cont.
To Cut Up cont.
* Galen was born in Pergamum, modern-day Turkey. At the time, Pergamun was part of the Roman empire.
* Galen studied medicine in Alexandria. Then he returned to Pergamum. There, he learned a great deal about wounds and the insides of the human body by treating wounded gladiators.
* Galen moved to the city of Rome. He became the physician to Emperor Marcus Aurelius and his family. Along with his job, Galen continued his own medical research writing.
* He learned more about the human body by dissecting monkeys.
* Since monkeys and humans evolved from the same animal ancestors, their bodies are similar. Galen also studied human skeletons.
* Galen studied other animals too. In one experiment, he operated on a pig. He wanted to determine whether a nerve in the pig's neck controlled its breathing.
* He cut the nerve and pig kept breathing, but it was unable to squeal. So Galen realized that a comparable nerve in humans, the recurrent laryngeal nerve, controls speech.
Taking Your Pulse
* As part of the medical examination, Galen would take a patient's pulse. The pulse is the rhythmic expansion and contraction of a person's arteries.
* Female doctors were common in ancient Rome. Most of them focused on diseases specific to women.
The Endocrine System
* The endocrine system produces hormones that are instrumental in maintaining homeostasis and regulating reproduction and development.
* A hormone is a chemical messenger produced by a cell that effects specific change in the cellular activity of other cells.
* Endocrine glands secrete their hormones directly into the surrounding extracellular space. The hormones then diffuse into nearby capillaries and are transported throughout the body in the blood.
* Your kidneys lie at the very back of your abdominal wall, near your 12th rib. They're about an inch from both sides of your spine.
*The kidneys act as very selective filters of your blood. They remove extra water, slats, and other wastes, which leave your body as urine.
* Urine travels from the kidneys through the ureters, and is collected in the bladder. When your bladder gets full, you know it's time to head for the bathroom.
* This information helped other physicians when they operated on the human thyroid, a gland in the front of the neck. They knew to avoid cutting the recurrent laryngeal nerve. It is still called Galen's nerve.
* Ancient Indian surgeons probably invented cataract surgery. Sushruta wrote a long description of the technique.
* Celcus described a technique very similar to Sushruta's.
* In fact, the techniques are so similar that historians think the Roman learned about the technology from Indian doctors or from Indian medical books.
* An anatomist named Erasistratos worked with Herophilus at Alexandria and according to Celsus, a Roman writer, the two men even performed dissections on living people.
* Celsus, who lived several centuries after, condemned their experiments as cruel. He said that surgeons could look inside the bodies of people who were already severely wounded, such as accident victims and gladiators, instead of cutting up people on purpose.
* As cruel as the experiments were, they helped improve Greek medical knowledge. By studying anatomy, ancient Greek surgeons learned to do major surgery. They learned how to safely amputate limbs, repair hernias, and remove stones from the bladder.
* Hormones are chemical messengers that turn body function on or off.
* When your glands don't work properly, serious illnesses often result. For example, when the pancreas fails to produce a hormone called insulin, the level of sugar in the blood can rise dangerously, causing diabetes.
Chemical Messengers cont.
* His contributions to medicine later earned him the label "Father of Medicine".
* Hippocrates and other ancient Greek doctors didn't know enough about the working of the human body to treat serious illnesses; they did not know about germs or how germs caused disease.
* If your glands control so many delicate operations in your body, what controls your glands? The master gland of the endocrine system is your pituitary gland, located at the base of your brain.
* Just above the kidneys are the adrenal glands. The adrenal glands are part of the endocrine gland system and they secrete several hormones, including some steroid hormones.
* The ancient study of anatomy that began with Herophilus in Greece reached a peak with Galen in Rome.