Endocrine Deck 4 Flashcards
what is energy expenditure determined by?
resting (basal) metabolic processes (energy needed in a physically inactive state)
White adipose fat
most abundant in the body
responsible for many of the functions of fat
found deep within the body (visceral fat) and in the periphery as subcutaneous fat. Increases in visceral fat predominantly around the intra-abdominal cavity (belly fat) are associated with increased complications such as cardiovascular and diabetes mellitus risk.
what are some of the key functions of fat
storage of excess calories as an energy reserve. Adipokines (hormones and cytokines) released by adipocytes (fat cells) also regulate metabolism and activate immune processes.
Excesses of white fat cause dysregulation of these multiple adipokines
aging and fat
With aging, gonadal and growth hormone naturally declines, resulting in an increase in visceral fat in men, while in women, decreases in estrogen (usually due to menopause) and growth hormone contribute to increases in visceral fat.
White fat can become __________ __________
Beige fat
Beige fat is
an energy-expending type of fat
Brown fat
is considered a good fat and primarily regulates energy usage, particularly maintenance of warmth in newborns, and usage peaks around puberty. Brown fat expends energy like beige fat. The amount of brown fat decreases with age but continues to remain metabolically active and is stimulated with exposure to cold weather
Brown fat is located in
upper torso in the neck and clavicular area
The more active the brown fat the…..
lower the BMI and body fat percentage
What type of fat do leaner individuals have more of
Brown fat
Body weight and fat stores are regulated by the
central and peripheral nervous system
From periphery to metabolism… (orexigenic)
afferent signals from the periphery regarding food needs and fuel use -> CNS -> orexigenic neurons in hypothalamus stimulated ->decreased metabolism and mechanisms to increase calories by promoting appetite and stimulation of eating
From periphery to metabolism (anorexigenic)
afferent signals from the periphery regarding food needs and fuel use -> CNS ->anorexigenic neurons in hypothalamus stimulated -> , increase metabolism and suppress appetite and eating.
how do signals lead to overeating
The hypothalamus also connects with areas of the cortex that are associated with memory, pleasure, and reward, and these areas can be activated by food and the feeling of satiety. Activation of these areas can override physiologic intake and energy expenditure stimuli leading to overeating, or the desire for only certain foods
what is leptin?
a key hormone that is primarily secreted by white fat adipocytes; its role is to send signals to the brain regarding the adequacy of energy reserves.
