Thursday, Oct 28 Part III of course We will first go over the exam' Regulation of Internal States

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Thursday, Oct 28 Part III of courseWe will
first go over the exam.Regulation of Internal
States
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• Types of Hormones
• Reproductive hormones control the menstrual
  cycle, child birth, breast feeding (activational
  effects). Organizational effects instruct the
  body to develop as male or female.
• Homeostatic hormones maintain internal bodily
  environment relevant to life itself the balance
  of sugars, proteins, carbohydrates, salt and
  water in the bloodstream and all body cells
  (activational effects that cells can respond to
  from early life)
• Stress Hormones control behavioral and
  physiological responses to stress (best
  understood re. activational effects)

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Brain must regulate 3 primary internal states-
temperature- water balance- nutrient and energy
supply (food)Homeostatic control - maintains at
relatively constant values within an optimal
range
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Homeostatic control - maintains at relatively
constant values within an optimal rangeIdeal
values - the set pointsMaintained by-
negative feedback systems- redundant controls-
behavioral actions
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Hunger, Eating, and Body Weight RegulationFood
intake--gt Digestion --gtdelivery of energy and
nutrients to the body for use and
storageImmediate use Glucose, amino acids,
nutrientsStored forms Glycogen (quick use
stored form of glucose)ProteinsFats
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Glucose- the brains primary source of energy-
primary source for cells of body- in body cells
(not brain), insulin is necessary for glucose to
enter cellLiver is the primary reservoir for
glucose and its stored form, glycogen.Liver is
the short-term carbohydrate reservoir.Adipose
tissue (fat) is the long term energy reservoir.
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Energy utilization is controlled by 2 hormones
from the pancreas Insulin Glucagon
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Role of insulin 1) aids use of glucose 2)
promotes conversion of blood-borne useable fuels
to stored forms (glucose to glycogen and fat
amino acids to protein) 3) aids storage of
glycogen in liver and muscle fat in adipose
tissue proteins in muscle
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Role of Glucagon 1) stimulates conversion of
glycogen into glucose 2) promotes release of
fatty acids from storage in adipose tissue 3)
aids in conversion of fatty acids to useable
energy (ketones) for muscles
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Feedback system for control of glucose and
glycogen levelsFood in digestive tract--gt
available glucose--gt glucose in blood --gt brain
reads levelsand gets info. from the vagus nerve
from liverTells pancreas to secrete insulin--gt
tells liver to convert glucose to glycogen
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Food in digestive tract--gt available glucose--gt
glucose in blood --gt brain reads levelsTells
pancreas to secrete insulin--gt tells liver to
convert glucose to glycogenGlucose levels in
blood fall --gt brains reads and tells pancreas to
secrete glucagonTells liver to convert glycogen
to glucose
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Glucostat - feedback control system for glucose
Brain centers that contain glucose
detectors1. Brainstem - medulla and pons -
process information from vagus nerve coming from
the liver analyze the glucose levels in the
surrounding tissue2. Hypothalamus
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Brain centers that contain glucose detectors1.
Brainstem - medulla and pons - process
information from vagus nerve coming from the
liver analyze the glucose levels in the
surrounding tissue2. Hypothalamus - several
areas contain glucose detectors and other
relevant detectors also process information from
other sources3. Circumventricular organs
(lining of ventricles)
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Information about body status is signalled by
1) stomach and gut (cholecystokinin) 2) liver -
vagus nerve 3) blood - glucose and several
hormones4) fat cells - leptin
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Diseases related to glucose regulation1.
Diabetes mellitus (type 1 diabetes) early
childhood onsetPancreas stop producing
insulin.Brain can use glucose from diet but body
cannot.Excess glucose in blood cannot be stored
goes to kidneys for removal increases thirst
to help, but dehydration may result.Excess
glucose can damage tissues like kidneys, retina,
peripheral nerves also results from decreased
blood flow acidosis.
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Diseases related to glucose regulation1. Type
2 Diabetes loss of response to insulin (insulin
resistance) as well as reduced insulin
releasemajority of cases occur in overweight or
obese individualsSimilar complications.Dietary
change and exercise can reverse the condition.
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• Pancreatic hormones and fat
• insulin promotes storage of glucose into
  glycogen and fatty acids into fat
• glucagon promotes conversion of glycogen to
  glucose and fat to fatty acids
• Regulatory systems are quite complex with respect
  to energy utilization, storage , and
  appetite/satiation signals.