Description
Bio 129 Chap. 4 continued & 5 09/19/2016
Control of Breathing
∙ The brain controls how often the chest is expanded and how much the chest expands
∙ H positive concentration is the information in as well as acute stress override
∙ Information out: motor nerves to the diaphragm and intercostal muscles
∙ The brain must tell you to breath every time
∙ When you hyperventilate you are getting rid of carbon dioxide so you can breath longer (makes you feel like you don’t need to
breath)
Airways
∙ The autonomic nervous system controls the opening and closing of the airways and the flow of blood to the lungs
∙ Parasympathetic (calm) closes airways and reduces blood flow ∙ Sympathetic (acute stress) opens airways and increases blood flow ∙ Immune protection
Skin
∙ Surface of the body If you want to learn more check out What is light microscopy used for?
∙ Constantly being damaged and replaced
∙ Heat exchange, large variations in blood flow
∙ Blood flow helps maintain body temperature
∙ Blushing is blood going to the surface of the body
∙ Molecules can also pass into the blood through the skin (drugs & toxic molecules)
∙ Immune protection
Digestive System
∙ Big molecules into little molecules and ions into the body ∙ Big carbohydrates turn into sugars (this begins in your mouth) ∙ Absorption is taking the little molecules and ions into the body ∙ Inside the digestive system is outside the body
We also discuss several other topics like What are the mature bone cells?
Don't forget about the age old question of What happened in nat turner’s rebellion?
∙ Immune protection
∙ This is a captured environment outside of the blood A “Captured” Water Environment
∙ Compartmentalized
∙ Esophagus
∙ Stomach
∙ Small intestine
∙ Large intestine- takes a lot of water from digestion Control of Digestion
∙ Parasympathetic- increases movement, secretions, and blood flow ∙ Sympathetic- decreases movement, secretion and blood flow ∙ The changes in blood flow are very large
∙ Priority of digestion is very low
The Liver and Kidney
∙ Liver- adjusting the molecular composition of the blood o Most molecules that enter the water of the body will pass through the liver eventually
o Blood that contains nutrients taken into the blood at the small intestine goes directly to the liver through the hepatic portal veinWe also discuss several other topics like Who is john maynard smith?
o Liver has first opportunity to store
o It also has the first exposure to drugs and toxic compounds o More immune protection
o Parasympathetic promotes storage and increased flow of blood from the small intestine to the liver
o Sympathetic removes from storage and reduces blood flow from the small intestine
∙ Kidney- water and ion balance
Pressure and Volume
∙ When blood volume increases, blood pressure increases ∙ If you add or remove ions from the body you must save or lose water to maintain concentrations “just right”
∙ The most important ion in this game is Na
∙ H2O moves faster and easier than Na+
Control of the Kidney
∙ Parasympathetic increases blood flow to the kidney and increases urine volume We also discuss several other topics like What is the scientific study of interactions between organics and their environment?
∙ Water follows salt
∙ Sympathetic reduces blood flow to the kidney and decreases urine volume
∙ Hormones
o ADH increases water recovery
o Mineralocorticoids increases ion recovery
Storage
∙ We live in a world of feast and famine
∙ We store nutrients once they’re available and remove from storage when they aren’t
∙ All tissues except for the brain store to some extent ∙ The liver stores sugar for the brain
∙ Muscle stores amino acids
∙ Fat tissue stores fat molecules
∙ Bone stores calcium
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 2 types of fibers
o Tonic- deals with gravity
o Phasic- deals with movement
Control of Muscle
∙ Both respond to signals from their motor nerve by shortening ∙ Sympathetic nervous system and adrenalin If you want to learn more check out What is the impact of globalization on society?
o Makes phasic more efficient
o Makes tonic less efficient
∙ If you’re in danger you don’t want posture getting in the way Hormonal Control
∙ Glucocorticoids: shifts muscle into net degradation of proteins to provide amino acid carbon for making sugar in the liver and kidney o Phasic fibers are more sensitive than tonic because they work less
∙ Insulin: allows the fibers to take up sugar and amino acids o Tonic fibers more sensitive because they work more Other Hormones
∙ Thyroid: increases production and use of energy ∙ Growth hormone: builds up muscle (comes from brain) ∙ Testosterone: makes exercise more useful in building up muscle Fat Cells: Energy Storage and Insulation
∙ Insulin: uptake of nutrients and converts sugar to fat ∙ Adrenaline: release fatty acids into circulation
∙ Many drugs mobilize fatty acids
∙ Fat also produces hormones
o Adiponectin, leptin, cytokines
o Obesity
o Diabetes (type 2 is more common- insulin resistant, the muscle is responsible for this)
o Atheroscelrosis
Distribution of Fat in the Body
∙ Oil and water DON’T mix so fat mst be packaged in a charged protein coat to move in the blood
Control of Bone
∙ Glucocorticoids: demineralizes bone
o More use=less sensitive
o Less use=more sensitive
∙ Calcitonin: from thyroid gland
o Ca++ out of bone
∙ Parathyroid hormone: from parathyroid gland
o Ca++ into bone (storage)
Control of Blood Cells
∙ Red blood cells: erythropoietin controls how fast hey are made in bone marrow
∙ White blood cells
o Insulin controls the uptake of nutrients
o Glucocorticoids suppress
o Cytokines: the chemical messages of the immune system (many effects)
Change in Stress
∙ Stress requires adjustments
∙ Priorities are expressed in response to stress
o Gravity
o Starvation
o Cold
o Danger/anger
Drugs Influence Priorities
∙ Coffee
∙ Nicotine and cocaine
∙ Alcohol
∙ Antihistamines
∙ BC
Chapter 5: A Question of Pressure
It’s different with solids, liquids, and gas
Gravity
∙ Is the major problem of circulation, which is made worse because we walk up-right
∙ Gravity is pressure on gas: it compresses
∙ Water compresses gas
Cardiovascular System
∙ Heart: four-chambered muscular pump
∙ Blood Vessels: paths through which blood can flow ∙ Purpose: to distribute resources around the body
∙ Lymphatics: a drain returning excess extracellular water to the blood
The Rhythm of the Heart
∙ Heart: a pump that contracts and relaxes rhythmically o Relaxed- blood enters the heart
o Contraction- pushes blood out of the heart
∙ Heart cells have an intrinsic rhythm
o Artial cells- 70 beats/min
o Ventricle cells- 30 beats/min
∙ Left atria: the pacemaker
∙ The heart delivers ions, molecules and heat around the body Control of the Heart
∙ W/o any input from the brain the heart will contract to the rhythm of the pacemaker
∙ The autonomic nervous system can alter the rate and strength of contraction
o Parasympathetic- slower, weaker
o Sympathetic- faster, stronger
Blood Pressure
∙ 120/60 (example)
∙ For blood to move, the pressure generated by the heart must exceed the back pressure in the system
∙ The difference between the “top” and “bottom” numbers is the pressure to do the work of moving the blood
∙ P=VxR
∙ V=P/R
∙ Resistance is how open/closed an artery is
Local Volume Control
∙ By opening and closing arteries the brain can change the volume of blood going to different places in the body
o Acute stress
o Temperature regulation
o Digestion
o Immune/Inflammatory reactions: volume can leave circulation (swelling and congestion)
∙ Amount of water in body can change
∙ Concentration of ions must be maintained
∙ Na+ is the most important ion for volume control
∙ Low salt diets
Kidney
∙ Filters out water, ions, and small molecules from circulation and returns the “right amount: of each to circulation
∙ Generally, all small molecules such as sugars and amino acids are returned
∙ Return water and ions (b/c this must be balanced)