Nutrition and ageing Flashcards
What are macronutrients?
Nutrients that must be sinus especially daily and in relatively large amounts
What are micronutrients?
Nutrients that must be consumed in relatively small amounts
What are examples of macronutrients?
Proteins, carbohydrates and lipids
What are examples of micronutrients?
Vitamins and minerals
What are essential nutrients?
Nutrients that must be obtained from the diet
What are non essential nutrients?
Nutrients that are not required in the diet because they are produced by biochemical processes of the body
What is a nutrient?
Any substance in food that is used by the body to promote normal growth, maintenance and repair
When does the absorptive state occur?
The time of eating, digesting and absorbing nutrients
When does the post-absorptive state occur?
Time between meals
What are the characteristics of the absorptive state?
lasts 4 hours after a meal
- concentrations of nutrients increase as they are absorbed from the gut
What are the characteristics of the post-absorptive state?
body relies on stores of nutrients
- body woks to maintain homeostatic levels of nutrients
What are the three types of carbohydrates?
monosaccharides: glucose, fructose, galactose
disaccharides: sucrose, lactose, maltose
polysaccharides: dextrose, cellulose, starch, glycogen
What is the major hormone during the absorptive state?
Insulin
What is the major hormone during the post-absorptive state?
Glucagon
Why is regulation of blood glucose so important?
low blood sugar levels compromise normal brain function
- high blood sugar levels damage blood vessels and nerves
Diabetes mellitus type 1
inability to produce sufficient insulin
10% of diabetes cases
treated by self-monitoring of glucose and artificially injected insulin
Diabetes mellitus type 2
caused by a combination of genetic, lifestyle, and environmental factors.
What is BMI?
Body Mass Index (BMI) is a measurement that uses an individual’s height and weight to estimate body fat
What are the three things that causes the body to grow?
growth is driven by genetics (the blueprint for potential)
hormones (the regulators of growth processes)
nutrition (the fuel and building blocks)
What is hyperplasia?
the process by which an organ or tissue increases in size due to an increase in the number of its cells
What is hypertrophy?
the increase in the size of an organ or tissue due to the enlargement of its individual cells
What are some key changes in rates of height growth?
Infancy
Early Childhood (Ages 2-5)
Middle Childhood (Ages 6-Puberty)
Puberty
Late Adolescence (Post-Puberty)
What hormone is essential for bone and muscle growth?
Growth hormone is the key hormone for bone and muscle growth
What hormones are important for fetal growth?
Fetal growth is regulated by a combination of IGFs, hPL, insulin, thyroid hormones, cortisol, estrogen, and progesterone.
What does GH do?
Growth hormone is essential for overall growth and development, metabolic regulation, tissue repair, and the maintenance of muscle and bone health.
What are the key targets of GH?
Growth hormone targets multiple tissues, including the liver, bones, muscles, adipose tissue, kidneys, and immune cells.
What stops growth at the end of puberty?
puberty is primarily caused by the closure of growth plates, triggered by hormonal changes, particularly the rise in sex hormones (estrogen and testosterone)
What is Hayflick’s limit?
refers to the finite number of divisions that normal somatic cells can undergo before entering senescence, primarily due to telomere shortening.
What is a telomere?
is a specialised structure located at the ends of linear chromosomes.
What does a telomere do?
essential for maintaining chromosome stability, protecting chromosome ends, and regulating cell division.
What happens to telomeres and how are they repaired?
Telomeres naturally shorten with each cell division, leading to cellular senescence once they reach a critical length
What are free radicals?
Free radicals are unstable, highly reactive molecules that can cause significant cellular damage if not adequately controlled by the body’s antioxidant defenses.
