4.5.3 Hormonal Coordination in Humans Flashcards
4.5 Homeostasis and Response (19 cards)
What does the human endocrine system compose of?
It composes of many endocrine glands that release hormones directly into blood. The blood carries these hormones to the target organ.
How fast is the endocrine systems response, and how lasting is it?
It is a slow but long lasting one.
What is the pituitary gland also known as, and what does it do?
The master gland, and it secretes (releases) hormones that stimulate other glands, which cause them to release hormones and bring changes in the body
How is Blood Glucose Concentration controlled?
It is controlled by the pancreas (can mention if asked specifically).
If BGC is high, pancreas will release insulin so glucose moves into cells. Muscle and liver cells convert glucose to glycogen for storage.
If BGC is low, pancreas releases hormone glucagon, which binds at muscle and liver cells and makes them convert their glycogen back into glucose.
What is the BGC system called?
A negative feedback cycle
What is Type 1 Diabetes and what is the treatment for it?
It is usually genetic and occurs due to pancreas producing little or no insulin.
Raised BGC could cause death long term if not treated.
TREATMENT:
- Insulin Therapy: it is injected into blood directly during mealtimes to ensure bgc is controlled.
- Limit high carbohydrate intake: stops BGC from increasing rapidly
- Regular exercise: helps reduce BGC as glucose is taken into cells for energy
What is Type 2 Diabetes and what is the treatment for it?
Occurs due to body cells being unresponsive (resistant) to insulin.
Pancreas produces insulin but has no effect
Obesity is a risk factor for Type 2 Diabetes
TREATMENT:
- Limit high carbohydrate intake: stops bgc from increasing rapidly
- Regular exercise: helps reduce bgc as glucose is taken into cells for energy release
Compare hypoglycaemia ad hyperglycaemia.
Hypoglycaemia is a condition in which the level of glucose in blood drops far too low. This is usually around 4mmol/L. It can affect anyone, but is most common with people who have diabetes, who manually take insulin to lower blood sugar.
Hyperglycaemia is a condition in which the levels of glucose in blood exceed normal. This is usually around 125-180mg/dL. It can also affect anyone, but is much more common in those with type 1 or 2 diabetes, due to insufficient insulin or insulin resistance.
What is excretion?
It is the removal of metabolic waste from the body, which is any waste that has been made from a chemical reaction.
What organs are involved in excretion?
Kidneys: remove excess water, ions and urea from blood
Skin: removes water and ions by sweating
Lungs: it removes CO2 and releases water from the blood.
How is urea formed?
Proteins contain nitrogen, which when digested forms amino acids. In the liver, excessive AAs are deaminated to form ammonia, which is toxic, so is converted into urea. This is safely excreted.
What does the kidney do?
it is responsible for filtering your blood. Useful substances can be taken back into the blood by selective reabsorption (glucose, some ions, right amount of water), while urea, excess and unwanted ions and excess water is excreted in the form of urine.
What can the body control the water content of the blood with, and what is the process called?
The Kidney, Osmoregulation
How does osmoregulation occur?
Special cells in the hypothalamus of the brain detect the amount of water in the blood. They can then cause the pituitary gland to release a hormone called anti-diuretic hormone (ADH). This then travels to the kidney in the blood where it acts on the kidney tubules to reabsorb more water into the blood, which is achieved by making the collecting duct more permeable to water.
What happens if the kidney fails?
- Waste build up
- Ion control is lost
- Water control is lost
- Organ damage can occur which leads to death
How can you treat kidney failure?
Dialysis
Kidney Transplant
How does Dialysis work?
- Blood from patient enters th dialysis machine
- Waste products diffuse from the blood and into the dialysis fluid as there is a lower concentration of waste in the fluid.
- Glucose and ion concentration are the same in fluid as blood, stopping any diffusio nfrom happening
- Filtered blood is returned to the person
- Because mebrane is partially permeable, large molecules like proteuins will not be lost to the dialysis fluid.
Who are kidney transplants taken from?
They are taken from people who died suddenly (like car accidents) or from people who would like to donate one of their kidneys
