Upgrade to remove ads
Only $35.99/year

Digestive Physiology Pt. 3

Terms in this set (73)

Carbohydrates make ___________________
ATP
Glucose is converted to _________________ for short storage and _________________ for long-term storage
glycogen
fat
_______________________ make protein
amino acids
Excess amino acids are ____________________ or _________________________
burned as energy
stored as fat
_______________________ leave intestine by the lymphatic vessels and contain cholesterol, triglycerides, and phospholipids
Chylomicrons
_______________________________ converts triglycerides into glycerol and fatty acids
Lipase
What 2 ways is excess cholesterol secreted?
1. bile
2. blood
_____________________ brings cholesterol from liver to most cells
LDL
_______________ transports cholesterol out of plasma
HDL
Abnormal plasma levels of lipids increases risk of ________________ and ____________________ disease
atherosclerosis and coronary heart disease
Proteins can be used to make ATP through the ______________________ of amino acids. The byproduct, ammonia, is converted to ____________.
deamination
urea
Lipolysis
breakdown of fat
Fatty acids undergo ___________________ to produce acetyl CoA
beta-oxidation
Excess acetyl CoA becomes ______________________ which can lead to _______________________
ketone bodies
ketoacidosis
What are some of the hormones that can influence metabolism?
neuropeptide and hypothalamic hormones
thyroid hormones
hormones of the cortisol pathway
growth hormone
epinephrine
Bod temperature balances ____________________, _________________ and _____________
heat production
gain
loss
What are some examples of heat input (gain?)
Internal heat production - metabolism, shivering thermogenesis, waste heat - exercise
External heat input - radiant heat gain, conductive heat gain
What are some examples of heat output (loss)?
conductive heat loss
radiant heat loss
convective heat loss
evaporative heat loss
__________________________________ generates enough heat to maintain body temperature in the thermoneutral zone
Normal metabolism
Thermoneutral zone
36.5 - 37.5 degrees C
If we are above the thermoneutral zone, must compensate for _________________
heat gain
If we are __________________ the thermoneutral zone, must compensate for heat loss.
below
The termoregulatory center is in the ____________________ while __________________ are in the skin and anterior hypothalamus.
hypothalamus
thermoreceptors
Alterations in ________________________ conserve or release heat and involved the sympathetic cholinergic neurons
cutaneous blood flow
What are some responses to minimize heat loss?
1. vasoconstriction of cutaneous blood vessels
2. lack of sweating
3. behavioral responses - add clothes, curling up, stand near heat source
What are some responses to maximize heat production?
1. shivering thermogenesis
2. nonshivering thermogenesis
3. behavioral response - increased voluntary activity
What are some responses to maximize heat loss?
1. vasodilation of cutaneous blood vessels
2. increased sweating
3. behavioral responses - fans, immersion in water, seek shade, remove clothes
What are some responses to minimize heat production?
1. diminished food intake
2. behavioral response - decreased physical activity.
What are some examples of physiological regulation of the body's thermostat?
circadian rhythm
menstrual cycle variations
postmenopausal hot flashes
fever
What are some examples of pathological conditions that impact the body's thermostat?
1. hyperthermia - heat exhaustion, heat stroke, malignant hyperthermia
2. hypothermia
The pancreas secretes __________________ and __________________-
insulin and glucagon
What are the Islets of Langerhans and what do they secrete?
Beta cells - insulin
Alpha cells - glucagon
D cells - somatostatin
The ______________________ ratio regulates metabolism
insulin-to-glucagon
In the fed state, _______________ dominates
insulin
In the fasting state, ____________________ dominates
glucagon
When is a fed state and insulin dominating, what increases?
Glucose oxidation
glycogen synthesis
fat synthesis
protein synthesis
Plasma insulin concentration begins to rise before the plasma _________________ concentration
glucose
In a fasted state, when glucagon dominates, what increases?
glycogenolysis
gluconeogenesis
ketogenesis
What is the Half-life of insulin?
5 minutes
What two hormones are antagonistic to insulin?
growth hormone
cortisol
What factors affect release of insulin?
plasma glucose > 100
parasympathetic activity
feedforward effects of GI hormones
increased plasma amino acids
What factor inhibits insulin secretion?
sympathetic activity
What is the origin of the adrenal catecholamines?
adrenal medulla
What is the half-life of adrenal catecholamines?
2 minutes
What is the onset and duration of action of adrenal catecholamines?
rapid and brief
Insulin binds to _______________________________ which activated insulin-receptor substrates
tyrosine kinase receptor
What are the 4 ways insulin lowers plasma glucose?
1. increases glucose transport into most insulin-sensitive cells
2. enhances utilization and storage of glucose
3. enhances utilization of amino acids
4. promotes fat synthesis
In the absence of insulin, there are no _______________________ in the cell membrane
GLUT4 transporters
In the fed state, insulin signals the cells to insert ______________________ into the membrane to allow __________________ to enter the cell.
GLUT4 transporters
glucose
In the fasted state, the hepatocyte makes glucose and transports it out into the blood, using ___________________________
GLUT2 transporter
In the fed state, the glucose concentration gradient _______________ and glucose enters the hepatocyte.
reverses
In which cell does glucagon originate?
Alpha cells in pancreas
What is the half-life of glucagon?
4-6 minutes
What factors increase glucagon release?
plasma glucose <65-70
increased blood amino acid
Glucagon is generally ________________________ to insulin
antagonistic
Glucagon prevents hypoglycemia by stimulating _______________________ and _____________________
glycogenolysis and gluconeogenesis
The ____________________ is the primary target of glucagon
liver
Diabetes mellitus
abnormally elevated plasma glucose concentrations or hyperglycemia
What are some systems impacted by diabetes?
blood vessels, eyes, kidneys, and nervous system
Type 1 diabetes
insulin deficiency from autoimmune destruction of beta cells
Type 2 diabetes
insulin-resistant diabetes
If the blood glucose is 100-125 after 8 hours of fasting, what condition does the pt. have?
prediabetes
If the blood glucose is greater than 125 after 8 hours of fasting, what condition does the pt. have?
diabetes
For the glucose tolerance test, what range is indicative of diabetes? prediabetes?
Diabetes = >200
Prediabetes = 140-199
What is commonly evaluated to differentiate between a type 1 and type 2 diabetic?
C-peptide values
What findings are expected after a 2 hour glucose tolerance test for someone with Type 1 diabetes?
Absent C-peptide
No/normal insulin levels
What findings are expected after a 2 hour glucose tolerance test for someone with Type 2 diabetes?
High C-peptide
No/normal insulin levels
Type 1 DM have a genetic predisposition that is sometimes preceded by ______________________ often in childhood
viral infection
Without insulin cells, there is an increase in metabolism of _____________________, ___________________, ____________________, and ___________________
Protein, fat, glucose, and brain
An increase in brain metabolism results in ______________________________
polyphagia
Diabetes Type 2 account for ______________% of all cases of diabetes
90
What is the first therapy for DM 2
exercise and weight loss
What are some of the actions of medications for diabetes type 2?
1. stimulate beta-cell secretion of insulin
2. slow digestion or absorption of carbohydrates
3. inhibit hepatic glucose output
4. make target tissues more responsive to insulin
5. promote glucose excretion in urine
6. mimic endogenous hormones
Other sets by this creator