Hormonal regulation of metabolism Flashcards
what tissues are for fuel storage
- liver and muscle: carbohydrates; glycogen
- adipose: lipids; triglycerides
- tissue and blood proteins: protein (no other storage form)
what is the fuel usage time line
after 8 hr; liver glycogen is depleted
after 24 hr; TGs provide energy for all tissues except for the brain and RBC; protein degradation provides glucose for brain
Several days: OAA depleted as shunted for gluconeogenesis; AcCoA builds up as FA’s oxidized; Ketone bodies used as alternative fuel.
what insures brain function
glucagon; releases fuel from liver glycogen and adipose tryglycerides.
Epinephrine targets
adipose, liver and muscle
what are longer term metabolic control hormones
- Cortisol
- Thyroid hormone
- Leptin
- Adiponectin
- first is steroid hormone
- second behaves like steroid hormone
- last two made by adipose tissue and are protein hormones
as fat stores increase adiponectin ___ whereas as fat stores increase leptin increases
decreases
what does stress trigger
cortisol secretion; responds to hypothalmic/pituitary signals Hypothalamus secretes CRH into portal system, anterior pituitary secretes ACTH into systemic circulation, adrenal cortex responds with secretion of cortisol.
Where does ACTH come from
a large precursor protein: made by a gene called Pro oplomelanocortin (POMC) gene
What are features of cortisol
fuel mobilizer, elevates blood glucose, mobilizes fat, inc muscle protein catabolism, is well known for its anti inflammatory effects
what is cushings syndrome
excess cortisol; weight gain of upper body and trunk, skin changes inc darkening of the skin and easy bruising, excess hair growth/acne in women, personality changes/mood swings and fatigue.
what is addisons disease
cortisol deficiency; changes in BP or heart rate, chronic diarreah, darkening of the skin, paleness, extreme weakness and fatigue. Loss of apetite and mouth lesions on the buccal mucosa
what happens if you have hyporthyroidism
cold sensitive, weight gain, fatigue, constipation, depression, brittle hair, and nails
congenital hypothyroidism: cretinism
what is hyperthyroidism
heat sensitive, weight loss, exopthalmia, insomnia, diarrehea, tremor
what is leptin
the “set point” hormone. when it gets knocked out you are hungry all the time. as fat tissue biulds up, more leptin produced to shut off hunger response
what kind of receptor does leptin use
“orphan” receptor:
what does leptin and insulin inhibit
production of oriexgenic neuropeptide Y which is a neurotransmitter that activates hunger response.
leptin and insulin activate:
anorexigenic peptides which are derived from proopiomelanocortin (POMC)