Lecture 22 Flashcards
What controls our hunger and tells us to stop eating when we have enough?
Brain receptors Liver Stomach and intestines Small intestine Fatty tissue External cues
What do nutrients supply energy for?
For muscle contraction
Body temperature
Active transport
DNA replication…
How do nutrients act as building blocks?
For complex molecules such as muscle proteins, cell membranes, DNA, hormones. enzymes etc
How are nutrients stored?
Glycogen in liver and muscle
Triglyceride in adipose tissue
What is protein useful for?
Essential for growth and repair of body tissues cell, especially tissue
What are fats useful for?
An energy source and a valuable source of fat soluble vitamins, brain and cell wall construction
What are carbohydrates useful for?
Our bodies’ main source of energy essential for brain metabolism
What are minerals useful for?
Inorganic elements necessary to normal body processes
What are vitamins useful for?
Play an important part in many chemical processes in the body
What is water needed?
Essential to out normal body function with 60% of the human body made up of it
What are examples of fatty acids that needs to be ingested since they cannot be synthesized?
Linoleic acid, linolenic acid, arachidonic acid
How many amino acids are needed for protein synthesis?
22
How many of the required amino acids can be synthesized from carbohydrate precursors?
11
What are the 9 essential amino acids that can only be obtained from diet?
Histidine, isoleucine, leucine, tryptophan, lysine, methionine, phenylalanine, threonine, valine
How much of our diet consists of carbohydrates, fats and proteins?
57% carbs (bread, potatoes, fruit, cereals)
30% fats (dairy products, oils)
13% proteins (soy, pulses, beans, yoghurt, eggs, meat, poultry, fish)
What is the energy yield per gram for carbs, fats and proteins?
Carbs 4kcals
Fats 9kcals
Proteins 4 kcals
What type of cells in the brain are sensitive to blood glucose?
Glucoreceptors of hypothalamic cells
What do the chemoreceptors in the stomach do?
Sensitive to small amounts of food dissolved in fluid
- send signals to brain saying “filling up”
What does the hormone cholecystokinin do?
CCK released from mucousal cell layer of duodenum
Says stop eating
What does adipose tissue release into the bloodstream?
leptin
What do hypothalamic receptors detect from to sense fullness?
leptin
What are the two centers for feeding?
Hypothalamus contains “on” and “off” switch for feeding
On = Lateral region of hypothalamus
Off = ventromedial region of hypothalamus
What is Ghrelin made by?
Stomach cells
What is PYY 3-36 made by?
Intestinal cells
What is ghrelin?
hormone for hunger
What is PYY 3-36?
Potent inhibitor of appetite
- stimulating neurons by binding to receptors called NPY Y2.
What could contribute to today’s obesity rates?
Reduced sensitivity to PYY 3-36
