Homeostasis and Clinical Blood Letting

Homeostasis

• Keloy’s blood sugar levels were high due to a disruption in his body’s ability to regulate blood sugar levels.
• The body's ability to regulate blood sugar is an example of a homeostatic mechanism.
• This means that the body is trying to maintain a stable internal environment, such as a normal blood sugar level.
• After visiting his doctor, Keloy was fitted with an insulin pump which helped regulate blood sugar levels.
• Swimming in cold water would cause the body to initiate mechanisms to maintain a stable internal body temperature.
• The body would likely shiver to produce heat and vasoconstrict to reduce heat loss.
• If a negative feedback mechanism did not return the value of a variable to its normal range, it would likely lead to disease or death.

Clinical Blood Letting

• Bloodletting developed as a form of medical treatment based on the ancient humoral theory.
• This theory states that the body is composed of four fluids (humors): blood, phlegm, yellow bile, and black bile.
• Disease was believed to result from a disruption in the balance of these fluids.
• It was thought an excess of one or more fluids could cause illness.
• Bloodletting was believed to restore the balance of fluids.
• It was commonly practiced by barbers in the past.
• It was often practiced by drawing blood from a patient through a vein.
• It was often practiced until the patient fainted or died.
• Bloodletting has since been deemed an ineffective and dangerous practice.
• Bloodletting is still used in some cases, like polycythemia.

Directional Terms

• Directional terms are used to describe the location of structures in the human body.
• Anterior: Means that the structure is in front of the body.
• Ventral: Means the same as anterior.
• Posterior: Means that the structure is at the back of the body.
• Dorsal: Means the same as posterior.
• Proximal: Means that the structure is closer to the midline of the body.
• Distal: Means that the structure is further away from the midline of the body.
• Medial: Means that the structure is closer to the midline of the body.
• Lateral: Means that the structure is further away from the midline of the body.
• Superficial: Means that the structure is closer to the surface of the body.
• Deep: Means that the structure is further from the surface of the body.

Type 2 Diabetes

• Type 2 Diabetes Mellitus (T2DM) is a metabolic disorder characterized by high blood sugar levels.
• It results from the body's inability to properly use insulin.
• Insulin is a hormone that regulates blood sugar levels.
• Insulin resistance occurs when the body's cells do not respond properly to insulin.
• T2DM is often associated with obesity.
• It can be managed by restricting food intake, especially carbohydrates and fats.
• It can be managed by increasing exercise.
• It can lead to complications such as frequent infections, vision changes, and fatigue.

Age vs. Endocrine System

• The endocrine system changes with age.
• Some endocrine glands produce less hormone as people age.
• This may be related to decreased physical activity in older adults.
• Growth hormone (GH) secretion declines with age, especially in those who do not exercise regularly.
• Melatonin secretion also decreases with age, which may affect sleep patterns.
• Thyroid hormone secretion decreases slightly with age.
• The kidneys of the elderly secrete less renin, reducing the ability to respond to decreases in blood pressure.
• Reproductive hormone secretion declines in elderly men, and women experience menopause.
• Thymosin secretion from the thymus gland decreases with age, reducing the immune system's effectiveness.
• Parathyroid hormone secretion increases to maintain blood calcium levels in elderly individuals.
• The ability to regulate blood glucose does not usually decrease with age.
• There is an age-related tendency to develop T2DM in those with a familial tendency.

Hyperthyroidism

• Hyperthyroidism is a condition caused by an overactive thyroid gland.
• The thyroid gland produces too much thyroid hormone.
• Common symptoms include excessive sweating, flushed appearance, rapid heartbeat, nervousness, difficulty concentrating, weakness, weight loss, and increased appetite.
• Graves' disease is a type of hyperthyroidism.
• It is caused by the immune system attacking the thyroid gland.
• It can be treated with medication, radioactive iodine therapy, or surgery.
• Removing part of the thyroid gland would reduce the production of thyroid hormone.
• This would help to control the symptoms of hyperthyroidism.