-
Concept that cells perform certain metabolic pathways based on what tissue/organ they're a part of
Compartmentalization
-
3 ways in which nutrients are utilized after intake
- catabolized for energy
- substrates for new molecules
- stored for energy
-
3 types of carbs our bodies use
- glucose (for energy)
- glycogen (for storing energy)
- polysaccharides (for glycoproteins on cell membranes)
-
Proteins which carry triglcyerides around in blood
HDL, LDL
-
Where are FAs & monoglycerides absorbed?
GI tract
-
After being absorbed in GI tract, what happens to FAs & monoglycerides? (3 steps)
- Reassembled into triglycerides by epithelial cells
- TGs get carried around in blood by lipoproteins
- TGs in capillaries broken down by LPL into FAs & monoglycerides
-
Enzyme which breaks TGs into FAs & monoglycerides
Lipoprotein lipase (LPL)
-
FAs are lipids which are used for:
energy & synthesis of phospholipids
-
Energy expended per unit of time
Metabolic rate
-
Rate of energy expenditure of a person awake, resting, lying down, and fasted for 12 hours
Basal metabolic rate (BMR)
-
Why is BMR measurement useful?
Measures minimum energy expenditure necessary to maintain body functions
-
Energy output is made up of ___ (~ 60%) + ____ (~40%)
-
When would someone have a positive energy balance?
When energy intake > energy ouput. This causes weight gain.
-
When would someone have a negative energy balance?
When energy intake < energy output. This causes weight loss.
-
Intake of food causes less energy output; nutrients absorbed or stored
Absorptive state
-
3-4 hours after eating; stored nutrients are broken down & used; glucose spared for nervous system (brain)
Post-absorptive state
-
Glycogen is made up of _____ _____
phosphorylated glucose
-
Breakdown of glycogen in muscle cells vs in liver cells
- In muscle cells produces glucose-6-phosphate which can't leave muscle cell
- In liver cells, glucose-6-phosphate is broken down by glucose-6-phosphatase (removes phosphate group) so glucose can leave liver & enter blood
-
Food metabolism regulation by: (3)
- Hormones (insulin during absorption & glucagon during post-absorption)
- Epinephrine (sympathetic nervous system) (minor)
-
Normal blood glucose range
70-100 mg/dL
-
Insulin secreted by
Beta cells of pancreas
-
Metabolism hormone which promotes synthesis of energy storage molecs (anabolic rxns)
Insulin
-
Secretion of insulin increased by (2)
- Increased concentration of glucose, AAs, or GIPs in blood
- Also stimulated by parasympathetic nervous system
-
Hormone secreted by cells in the wall of the GI tract which prepares body for transitions to absorptive state by triggering insulin secretion in advance
GIP (Gluose-dependent insulinotropic peptide)
-
Secretion of insulin decreased by (2)
- Decrease in bs
- Sympathetic nervous system (epinephrine)
-
Actions of insulin: (3)
- Anabolism to store energy (synthesis of glycogen & TGs)
- Increase glucose uptake by cells
- Decrease catabolism
-
Peptide hormone which is secreted from alpha cells of pancreas
Glucagon
-
Metabolism hormone which promotes breakdown of energy stores so they can be used; mainly by utilizing FAs so that glucose is spared for nervous system
Glucagon
-
Secretion of glucagon is triggered by:
- Low bs
- Epinephrine (sympathetic nervous system)
-
Actions of glucagon
- Catabolism of glycogen (glycogenolysis) & TGs (lipolysis)
- Gluconeogenesis (from glycogen)
-
Sympathetic nervous system is
fight or flight response
-
Parasympathetic nervous system is
returns things to normal
-
The _____ nervous system suppresses insulin release & stimulates glucagon release
Sympathetic autonomic nervous system
-
Autonomic nervous system consists of: (2)
- Sympathetic ANS
- Parasympathetic ANS
-
Growth hormone, Insulin-like growth factors (IGF aka somatomedins), Insulin, Thyroid hormones, Sex hormones are all hormones that affect
growth
-
Term for increase in cell size
Hypertrophy
-
Term for increase in cell number
Hyperplasia
-
Metabolic actions which help growth (5)
- Fat breakdown
- Gluconeogenesis in liver
- Release of IGF
- "Glucose sparing" (keep it in blood instead of cells)
- Uptake AA into cells
- (these are all similar actions of glucagon)
-
Concept of "glucose sparing"
Increase of blood glucose instead of going into fat & muscle cells
-
GH works mostly via ____ by stimulating it's release from liver & other cells
IGF (somatomedins)
-
IGFs effect target cells as ___ or as ____
hormone or paracrine
-
___ ___ regulate GH secretion and include 2 types:
- Tropic hormones
- GH Releasing Hormone (GHRH)
- GH Inhibiting Hormone (GHIH)
-
How do tropic hormones regulate GH secretion? (ie where)
GHRH or GHIH from hypothalamus inhibits GH release from anterior pituitary
-
2 hormones which are required (ie permissive) for GH actions
insulin, thyroid hormones
-
Hormone which inhibits growth but is still permissive for GH secretion
Glucocorticoids
-
___ : lipophilic (bind to nuclear receptors & cause increased transcription), control BMR, if there's little then more energy is stored, are required for epinephrine receptor expression (so are permissive for sympathetic nervous system)
thyroid hormones
-
During stress more __ and __ are secreted to mobilize energy stores. Also bp is ___
- Epinephrine, glucocorticoid (ie increased sympathetic nervous system activity)
- maintained
-
Thyroid concentration:
____ concentrations increase ___ ___
____ concentrations increase ___ ___
- High; energy mobilization
- Low; energy storage
-
Cortisol is anabolic or catabolic? How does it affect immune system? How is it controlled?
- catabolic
- suppresses it
- by tropic hormones
-
Thermal energy through electromagnetic waves
(body heat --> air ---> walls)
Radiation
-
Thermal energy through contact
Conduction
-
Heat transfer by mvmt of fluid or air
Convection
-
Central thermoreceptors are found in ____ and peripheral thermoreceptors are found mostly in ___
- hypothalamus (where thermoregulatory center is located)
- skin
-
Thermoneutral zone is aka and the range is:
- room temp
- 20-30 C (77-86 F)
-
Increase or decrease in vessels to alter body temp
Vasoconstriction/vasodilation
-
2 heat-generating mechanisms
- Shivering thermogenesis
- Nonshivering thermogenesis
-
Growth Hormone v. Cortisol
- Growth Hormone
- • Stimulates energy store breakdown
- • Stimulates glucose sparing
- • Supports growth actions (ieprotein synthesis)
- • Controls insulin-like growth factors (IGFs) which promote growth
- Cortisol
- • Stimulates energy store breakdown
- • Stimulates glucose sparing
- • Very few actions that support growth
- • Actually increases protein breakdown
- • No IGF signaling
|
|
