Priorities: An Organization Chart of the Body

1
Chapter 4

• Priorities An Organization Chart of the Body

2
Organization

• Cells
• Tissues
• Organs
• Organ Systems
• The Body

3
Specialized Functions

• Digestive System food in solid waste out
• Respiratory System gas exchange, O2 in CO2 out
• Excretory System Nitrogen and other soluble
  waste out, water ion and blood pressure balance
• Immune System protection from invaders

4
Specialized Functions Cont.

• Circulatory System Delivering things around the
  body
• Reproductive System A priority of the species
• Nervous System Controls the endocrine system and
  expresses its priority

5
Priorities

• One individual (function) is more important than
  another
• Discrimination
• Priorities are necessary because resources are
  limited and circumstances change

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Change Requires Adjustment

• Gravity
• Food and water
• Temperature
• Danger
• etc

7
Expression of Priorities
Access to blood, access to resources
8
Sensitivity to Blood Flow

• Brain acutely sensitive
• Heart
• Kidney
• Digestive system
• Skin

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Controlling Priorities
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Barriers of the Body

• The interfaces with the outside world
• Exchange of atoms, molecules and heat
• Lungs
• Skin
• Digestive System

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The Lungs
Gas Exchange

• A passive bag with a large blood supply
• When skeletal muscles expand the chest, air is
  sucked in to the lungs

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Diffusion

• A corollary of Mother Natures chaos rule
• Everything goes down hill
• From a high concentration to a low concentration
• Concentration is the number of molecules (or
  ions) of a certain type per volume of water

13
Control of Breathing

• The Brain controls how often the Chest is
  expanded and How much the chest is expanded
• Information in H concentration, also acute
  stress override
• Information out Motor nerves to the Diaphragm
  and intercostal muscles
• The Brain must tell you to breath, every time

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Airways

• The autonomic nervous system (part of the brain)
  controls the opening and closing of the airways
  and the flow of blood to the lungs
• Parasympathetic (calm times) closes airways and
  reduces blood flow
• Sympathetic (acute stress) opens airways and
  increases blood flow

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Skin

• The surface of the body
• Constant replacement and damage repair
• Heat exchange, large variations in blood flow
• Molecules can also pass into the blood through
  the skin eg. drugs, toxic molecules

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Skin
Heat Exchange and water conservation also effects
blood pressure
Parasympathetic more blood Sympathetic less
blood
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Digestive System

• Digestion Big molecules into little molecules
• Absorption Taking the little molecules and ions
  into the body.
• Inside the digestive system is outside the body

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A Captured water Environment
Compartmentalized Esophagus Stomach Small
intestine Large intestine
Nutrient acquisition
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Control of Digestion

• Parasympathetic Increase movement, secretions,
  and blood flow
• Sympathetic Decrease movement, secretions and
  blood flow
• The changes in blood flow are very large
• Priority of digestion is very low

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The Liver and Kidney

• LiverAdjusting the molecular composition of the
  blood
• Kidney Water and ion balance

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The Liver
Blood containing nutrients taken into the blood
at the small intestine goes directly to the liver
through the hepatic portal vein Capillary bed
Capillary
bed
Small intestine (in)
Liver (out)
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Liver

• Nutrients that enter the blood at the small
  intestine must get out of circulation in the
  liver before entering general circulation
• The liver has the first opportunity to store
• The liver also has the first exposure to drugs
  and toxic compounds

23
Control of Liver

• Parasympathetic promotes storage and increased
  flow of blood from the small intestine to the
  liver
• Sympathetic Removes from storage and reduces
  blood flow from the small intestine to the liver
• Almost all hormones
• Liver Storage and Molecular Processing
• Blood also enters the liver from general
  circulation
• Nutrients enter the general circulation in the
  liver
• Molecules in general circulation are removed for
  reprocessing
• Many serum proteins and fats are made in the
  liver and released into circulation (eg. steroid
  binding proteins and cholesterol)

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BalanceIons and water
Ion concentration Blood Pressure
The ion concentrations of the blood must be just
right The more water in the body, the higher the
blood pressure The kidney controls the loss of
water and ions from the body
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Pressure and Volume

• When blood volume increases, blood pressure
  increases
• If you put in or remove ions from the body you
  must save or loose water to maintain
  concentrations just right
• The most important ion in this game is Na
• H20 mover faster and easier than Na

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Kidney
The kidney filters out water, small molecules and
ions from the blood and returns just the right
amount to the blood
Ion, water and blood pressure balance
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Control of the Kidney

• Parasympathetic Increases blood flow to the
  kidney and increases urine volume
• Sympathetic Reduces blood flow to the kidney
  and decreases urine volume
• Hormones
• Antidiuretic Hormone (ADH) from the pituitary
  increases water recovery
• Mineralocorticoid from the adrenal increases ion
  recovery

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Storage

• We live in a world of feast and famine
• We store when nutrients are available and remove
  from storage when not available
• All tissues except for the brain store to some
  extent
• The liver stores sugar for the brain

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Storage Tissues for the general Body
In addition to the liver

• Muscle amino acid storage
• Fat Fat
• Bone Calcium (Ca)

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Skeletal Muscle
Almost 50 of all of the protein in the body is
in the musculature
Amino acid storage Movement, Heatgeneration
Movement of the skeleton is the only way that the
brain can act on the world Generation of heat is
a by-product of movement Makes you warm blooded
31
Skeletal Muscles

• Composed of thousands of individual fibers that
  shorten when sent a signal by a nerve
• Each fiber is controlled by a single motor nerve
• One motor nerve can control many fibers
• There are two types of fibers
• Tonic deals with gravity
• Phasic Deals with movement

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Skeletal Muscle continued

• Most muscles are composed of a mixture of both
  types of fibers.
• Most muscles carry out both functions movement
  and posture (gravity)
• Tonic fibers work more because gravity is always
  present
• The two types of fibers respond to some signals
  differently

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Control of muscle

• Both respond to signals from their motor nerve by
  shortening
• Sympathetic nervous system and adrenalin
• Phasic more efficient
• Tonic less efficient
• If you are in danger you dont want posture
• getting in the way!!!

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Hormonal Control

• Glucocorticoids Shifts muscle into net
  degradation of proteins to provide amino acid
  carbon for making sugar in the liver and kidney-
  Phasic fibers more sensitive than tonic because
  they work less
• Insulin Allows the fibers to take up sugar and
  amino acids- Tonic fibers more sensitive because
  they work more

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Other Hormones

• Thyroid hormone increases production and use of
  energy
• Growth hormone Builds up muscle
• Testosterone Makes exercise more useful in
  building up muscle

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Fat Cells
Contains very little water so it is light weight
and has a very low catacity to transfer heat
(good insulation)
Fat is a light weight way of storing energy
because it does not require water. OIL AND WATER
DONT MIX!
37
Control of Fat Cells

• Insulin Up take of nutrients- converts sugar to
  fat
• Adrenaline release fat into circulation
• Many Drugs mobilize fat

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Distribution of Fat in the Body
Are you a good fat or a bad fat?
Oil and water dont mix so fat must be packaged
in a charged protein coat to move in the blood
LDL
HDL
High Density Lipoprotein Low Density Lipoprotein
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Bone
Rigid structure against gravity what muscles
move All blood cells are born in the marrow of
bones Storage of Calcium (Ca)
40
Control of Bone

• Glucocorticoids Demineralizes bone-More use less
  sensitive, less use more sensitive
• Calcitonin From thyroid gland Ca out of bone
• Parathyroid hormone From parathyroid gland Ca
  into bone storage

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Cells of the Blood
Red Blood Cells No nucleus, A membrane bag
containing hemoglobin and an enzyme carbonic
anhydrase (CO2 H2O
H2CO3) White Blood cells Cells of the immune
system
Both Red and White Blood Cells are Born in the
Bone Marrow
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Control of Blood Cells

• Red Blood Cells Erythropoietin control how fast
  they are made
• White Blood Cells
• Insulin controls the uptake of nutrients
• Glucocorticoids suppress
• Cytokines the chemical messages of the immune
  system (many effects)

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Reproduction
A priority of the species Very expensive,
especially to the female Mother Nature built
the compulsion to do it into the brain
44
Change is Stress

• Stress requires adjustments
• Priorities are expressed in response to stress
• Gravity
• Starvation
• Cold
• Danger/anger

45
Drugs influence Priorities

• Coffee
• Nicotine and cocaine
• Alcohol
• Antihistamines
• Birth control pills
• Etc.