Download - Chapter 5 – 6 Homeostasis
CHAPTER 5 – 6 HOMEOSTASIS
Section 1: Feedback LoopsSection 2: Circulatory SystemSection 3: Respiratory SystemSection 4: Immune System
SECTION 1: FEEDBACK SYSTEMS
BACKGROUND 1. Organisms use feedback systems to
maintain internal balance and respond to changing conditions.
a. Two Types: Negative Feedback Positive Feedback
TYPES OF FEEDBACK SYSTEMS1. Used to return the body to normal
conditions.2. There is a ‘set point’ for many values
in the bodya. Temperatureb. pH of bloodc. Blood pressured. Water and salt balance
3. When the body moves away from the ‘set point’, something will happen to get it back to normal.
4. Very similar to how a thermostat works in your house
MAINTAINING INTERNAL CONDITIONS5. Examples of Negative feedback loops
a. Carbon dioxide & Breathing rate Increased CO2 makes the blood acidic – body
responds to return to normalb. Exercise
Carbon dioxide levels increase as cells work harder
Respiratory system responds by stimulating diaphragm to contract more rapidly
Breathing rate increases, more CO2 is released from body, blood pH returns to normal
Involuntary regulatory system
SET POINTNormal
blood pH is 7.4 – 7.6
Exercise Requires O2
and Produces CO2
High level of CO2 (low pH)
in blood detected by
brain
Brain sends signal to lungs &
diaphragm
Breathing rate increases
Extra CO2 is removed and
more O2 taken in
MAINTAINING INTERNAL CONDITIONS
c. Hyperventilation Occurs when carbon dioxide is lost more rapidly
than it is produced Caused by:
FeverAspirin poisoningAnxiety
Hyperventilation causes blood pH to become too basic* How does breathing into a paper bag help this condition?
SET POINTNormal
blood pH is 7.4 – 7.6
Hyperventilation - too much CO2 released (pH increases)
Breathe into paper bag
Extra O2 is released and some CO2 is
taken in
CO2 decreases blood pH
POSITIVE FEEDBACK1. Organisms use positive feedback to
complete a critical process quickly in order to get back to normal
a. Keeps moving in a cycle until completed Blood clotting Labor
b. Similar to the “vicious cycle”
BLOOD CLOTTING2. Examples
a. Blood Clotting Clotting proteins (factor proteins) respond to the
scene and pile up to create a clot These proteins signal more factor proteins,
which signal even more There are many different types of factor proteins
for different types of wounds Process continues until clot is made and
bleeding has stopped.
BLEEDING
Clotting proteins (factor) respond
Signal more proteins to
respond
Bleeding Stops
SECTION 2: CIRCULATORY SYSTEM
CIRCULATORY SYSTEM ANATOMY1. Three main parts:
a. Bloodb. Heartc. Blood vessels
CIRCULATORY SYSTEM ANATOMY1. Importance of Blood
a. Red blood cells (Erythrocytes)b. Contains hemoglobin - Carries dissolved
gasses Protein found in red blood cells Oxygen binds to hemoglobin and is transported
to all tissues of the bodyc. White blood cells (Leukocytes)
Defend the body against diseased. Platelets
Involved in blood clottinge. Plasma
Liquid part of the blood Makes up about 55% of the total blood volume
HEART A muscular organ that pumps blood
throughout the body. Pumps about 5L of blood a minute. It beats an average of 100,000 times a
day It pumps about 200,000 gallons of blood
a day. It is about the size of your fist. It has four chambers or “rooms” that
hold blood. Pacemaker
small bundle of cells that controls the rhythm of the heart.
HEART ANATOMY1. The atria (atrium) are chambers that
receive blood returning to the heart.
HEART ANATOMY2. Below the atria are the ventricles
which are thick walled chambers that pump blood away from the heart.
HEART ANATOMY3. Series of valves prevent blood from
going backward
http://www.pbs.org/wgbh/nova/body/map-human-heart.html
HEART ANATOMY4. Heart Beat:
a. Lub sound: Tricuspid and Mitral valve close:
heart contracting, pushing bloodb. Dub sound: Pulmonary and Aortic valves
close: heart fills with blood—pause takes longer
c. Heart murmur—one valve doesn’t close completely
http://depts.washington.edu/physdx/heart/demo.html
Why do we show half of the heart as blue and the other half as red?
BLOOD FLOW1. The Heart pumps the oxygen rich
blood throughout the body in ARTERIES2. Oxygen Poor blood is pumped back to
the heart in VEINS
*There is one exception to thisrule!
BLOOD FLOW
3. The path of blood:a. Heartb. Arteryc. Arteriolesd. Capillariese. Venulesf. Veinsg. Heart
BLOOD FLOW3. Pulmonary Circuit:
Venules↓
Veins (Superior Vena Cava from above the heart and Inferior Vena Cava from below
the heart)↓
Heart (deoxygenated blood)↓
LUNGS
BLOOD FLOW
RBC
Lung cell
Lung cell
Lung cell
Lung cell
AlveoliHigh in O2
Take in CO2
RBCHigh in CO2
Take in O2
O2
CO2
o How do O2 particles move into RBC and CO2 particles into the Alveoli?• diffusion (no energy)
o The blood is now oxygenated and moves back to the heart.
BLOOD FLOW4. Systemic Circuit:
Heart (Oxygenated Blood from lungs)↓
Aorta↓
Arterioles↓
Capillaries
CELLS CLOSE TO BLOOD POOL
What is exchanged at the capillaries? - Oxygen- Carbon
dioxide- Nutrients- Hormones
BLOOD FLOW5. The heart itself cannot get nutrients
and oxygen from its own chambers. Why?
a. It’s too thick for diffusion to work. It must rely on coronary arteries—lie in grooves that spiral around the heart.
HEART DISEASE1. Kills one million
people a year2. Atherosclerosis
a. Heart disease caused by narrowing of the arteries
b. Cholesterol plaques build up inside arteries
c. Causes abnormal blood flow
HEART DISEASEd. An obstruction to any of these coronary
arteries would require bypass surgery to restore proper blood flow
HEART DISEASE3. Blood Pressure -
Pressure exerted by the blood on the walls of blood vessels
HEART DISEASE4. Heart attack
a. Occurs when the arteries that deliver oxygen to the heart become blocked.
b. Usually occurs in the coronary arteriesc. Heart cells begin to die after 4 – 6 hours
without blood
HEART ATTACK Risk Factors
High cholesterolHigh blood
pressureSmokingFamily historyDiabetes
Prevention Early diagnosis of
heart diseaseTreatment of high
blood pressureRegular medical
checkupsHealthy dietRegular exercise
ECG (ELECTROCARDIOGRAM) MACHINES
Measure electrical pulses in the heart.
ELECTROCARDIOGRAM
SECTION 3: THE RESPIRATORY SYSTEM
ANATOMY OF THE RESPIRATORY SYSTEM1. Lungs
a. Made of 5 lobesb. Connects with the
external environment through the trachea (wind pipe)
c. Inhale Oxygen
d. Exhale Carbon dioxide
Without oxygen, your body can not obtain enough energy from food to survive!
Carbon dioxide waste is toxic to cells and must be removed!
ANATOMY OF THE RESPIRATORY SYSTEM2. Nose
a. Air is warmed, moistened, and cleaned
3. Larynxa. Contains vocal
cords 4. Trachea (windpipe)
a. Tube lined with cilia (hair-like structures) that sweep debris out of trachea
ANATOMY OF THE RESPIRATORY SYSTEM5. Bronchioles
Branches leading to each lobe of the lungs
6. Alveoli Smallest lung
compartment Oxygen and carbon
dioxide diffuse across thin walls called alveolar membranes
RESPIRATORY DISEASE Asthma – when bronchioles of the lungs
become constricted because of sensitivity to certain stimuli.
- The constriction makes it difficult for oxygen to
reach the blood.Emphysema – caused by cigarette smoke - lung tissue loses its elasticity and it
becomes more difficult for lungs to expand and take in air
Lung cancer – carcinogens from cigarette smoke cause cancerous tumors to grow on lung tissue.
SECTION 4IMMUNESYSTEM
WHAT IS A VIRUS? Pathogen-causes disease Infect cells and use the cell to make
more viruses
ARE VIRUSES ALIVE? No!
Do not growCan not reproduce without a host cellNot made of cells
NONSPECIFIC DEFENSE Doesn’t have to recognize a specific
invaderSkinMucusSalivaTearsSweatHair
SPECIFIC LINE OF DEFENSEUsing antibodies to target a specific
pathogen.Ex: if you’ve had the chicken pox, you have
antibodies ready to go in case you get infected again.
They PLAN an ATTACK on a TARGET
The BloodMobileCirculatory System
Respiratory System
Immune System
Urinary System
Digestive System
Right ventricle
lungs White blood cells
liver Small intestine
RBC oxygen antibodies kidneysheart Carbon
dioxideWBC
nutrients
WRITING YOUR MATERIALS AND METHODS!
Physiology Lab
Write this in your notes:
Vital Sign to Measure
Tools to Use What to measure Normal Range (Resting)
Write this in your notes:
Vital Sign to Measure
Tools to Use What to measure Normal Range (Resting)
Breathing Rate
Stopwatch # of breaths in 15 sec. (x4) About 12 breaths per minute
Heart Rate
Stopwatch -Find carotid or radial artery-# of beats in 15 sec. (x4)
60 – 100 beats per minute
Blood Pressure
Sphygmoman-ometer (Cuff)
Stethoscope
-Systolic Pressure (first beat, top #) – Maximum pressure in brachial artery-Diastolic Pressure (last beat, bottom #) – Pressure between heart beats when heart is filling with blood
120/80
Materials
StethoscopeSphygmomanometer
Blood pressure cuffStopwatch
Methods
1. Measure your resting breathing rate. a. Count the number of breaths for 15 sec and
multiply by 4.b. Normal BR is about 12 breaths per minute.
Methods
2. Measure your resting heart rate (pulse).a. Find your carotid artery on your neck or your
radial artery on your wrist.b. Count the number of beats for 15 sec and multiply
by 4.c. Normal HR is 60-100 beats per minute.
Methods
3. Measure your resting blood pressure.a. Wrap the cuff around your upper arm.b. Put the stethoscope on inner elbow.c. Pump cuff to 180 mm Hg.d. SLOWLY release the pressure, then listen carefully
for the first beat. (You are listening to the Korotkoff sounds.)
1) This is your systolic pressure (top number).1) The maximum pressure in your brachial artery
Methods
e. Keep listening until you hear the last beat.
1) This is your diastolic pressure (bottom number).
a. The pressure between heart beats – the heart is relaxed and is filling with blood.
f. Normal BP is 120/80.
Methods
4. Record results on table.5. Exercise-run up and down the stairs 5
times, repeat steps 1-3 and record on table.