Respiratory System

As always, copy everything in RED and any pictures you are told to.

What is Respiration?

 Cellular respiration = producing energy (ATP) from the breakdown of molecules in food in the presence of oxygen  Respiration = oxygen and carbon dioxide are exchanged between cells, blood, and air in the lungs  What does CPR stand for?- cardiopulmonary resuscitation breathing combined with chest compressions (rescue

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Human Respiratory System

Function: exchange oxygen and carbon dioxide Structures: – Nose: filters air as it enters the body – – – – passes air and food Larynx: “voice box ” = vocal cords (two folds of elastic tissue) Trachea: “windpipe” • Epiglottis covers entrance of trachea when you swallow Bronchi: large passageways leading air to each lung • Bronchioles are branches from bronchi in each – lung Lungs: gas exchange • bronchioles and wrapped in capillaries

Section 37-3 Figure 37-14 The Respiratory System

Nose Mouth Epiglottis Pharynx Larynx Trachea Lung Bronchus Bronchioles Bronchiole Alveoli Diaphragm Edge of pleural membrane Capillaries

Gas Exchange

   350 million alveoli in a healthy lung Increase surface area for gas exchange across capillaries – Oxygen in alveoli diffuses across capillaries into blood – Carbon dioxide in blood diffuses across capillaries into alveoli Very efficient gas exchange – Inhaled air contains 21% oxygen and 0.04% carbon dioxide – Exhaled air contains 15% oxygen and 4% carbon dioxide

Section 37-3 Figure 37-15 Gas Exchange in the Lungs

Alveoli Bronchiole Capillary

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Breathing

The movement of air into and out of the lungs At the bottom of the chest cavity is a large flat muscle = diaphragm The lungs are sealed in two sacs = pleural membranes – – When you breathe in (inhale), the diaphragm contracts and expands the volume of the chest cavity, creating a partial vacuum in the pleural membranes, allowing atmospheric pressure to fill the lungs with air When you breathe out (exhale), the diaphragm relaxes and decreases the volume of the chest cavity, increasing the pressure in the chest cavity and forcing air out of the pleural membranes

Section 37-3 Figure 37-16 The Mechanics of Breathing

Air inhaled Rib cage rises Diaphragm Air exhaled Rib cage descends Diaphragm

Inhalation Exhalation

How breathing is controlled

 Although you can voluntarily hold your breath, eventually your body will “force” you to breathe  Breathing is controlled in the medulla oblongata in the brain, which is part of the autonomic nervous system  Cells monitor the amount of carbon dioxide in the blood and as it increases, nerve impulses cause the diaphragm to contract bringing air into the lungs

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Tobacco creates problems

Smoking tobacco damages and eventually destroys the protective system by paralyzing cilia and trapping mucus in airways  Tobacco contains: – – – Nicotine = addictive, stimulate drug that increases the heart rate and blood pressure Carbon monoxide = blood poisonous gas that blocks the transport of oxygen by hemoglobin in the Tar = carcinogen (causes cancer)

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Respiratory diseases caused by smoking

Chronic bronchitis = bronchi become swollen and clogged with mucus, so constant coughing to try and force the particles out Emphysema = difficult respiratory disease due to loss of elasticity of lung tissue making breathing very Lung cancer = deadly because it spreads to other parts of body Heart disease = work harder narrowing of blood vessels increases blood pressure and makes the heart

Circulatory System

Circulation and Respiration

   Each breath brings oxygen rich air into your body Your cells need that oxygen Your heart delivers oxygen to your cells  Working together, your circulatory and respiratory systems supply cells throughout the body with the nutrients and oxygen that they need to stay alive!

Function

 The circulatory system transports substances including oxygen to changing demands , nutrients and wastes to and from cells responding by diffusion (from high to low concentration along concentration gradient).

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Structure

Humans have a closed circulatory system.

– Blood is pumped through a system of vessels (In an open system, blood flows in vessels and sinuses/gills) Sometimes the circulatory system is also called the “cardiovascular system” because: – Cardio = heart – Vascular = vessels The human circulatory system consists of: – The heart – A series of blood vessels – Blood that flows through them

The Heart

       Located near the center of your chest A hollow organ about the size of your fist composed of cardiac muscle .

Enclosed in a protective sac of tissue called the pericardium Inside there are two thin layers of epithelial and connective tissue Contractions of the myocardium, a thick cardiac muscle, pump blood through the circulatory system The heart contracts about 72 times a minute Each contraction pumps about 70 mL of blood

  Septum, or wall, separates the right side from the left side preventing mixing of oxygen-rich blood and oxygen-poor blood Flaps of connective tissue called valves divide each side into 2 chambers: totaling 4 chambers – Upper chambers receive blood = atrium – Lower chambers pump blood out of heart = ventricle

Heart

Types of Circulation

 Pulmonary circulation = from right side of the heart to lungs where carbon dioxide leaves the blood and oxygen is absorbed  Systemic circulation = from left side of the heart to organs – Coronary circulation = through heart tissue

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Pulmonary Circulation

The right side of the heart pumps blood from the heart to the lungs In the lungs, carbon dioxide leaves the blood while oxygen is absorbed.

The oxygen-rich blood goes into the left side of the heart

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Systemic Circulation

The oxygen-rich blood from the left side of the heart is pumped to the rest of the body Oxygen-poor blood returns to the right side of the heart This blood is oxygen-poor because the cells absorbed the oxygen and released carbon dioxide into the blood The oxygen-poor blood is ready for another trip to the lungs to get oxygen again

Section 37-1 Figure 37-2 The Circulatory System

Capillaries of head and arms Superior vena cava Aorta Pulmonary artery Capillaries of Pulmonary vein right lung Inferior vena cava Capillaries of left lung Capillaries of abdominal organs and legs

Blood Flow through the heart

 Blood leaves the heart in arteries, and blood returns to heart in veins.         Oxygenated blood returns from the lungs through the pulmonary veins to the left atrium.

Oxygenated blood is pumped from the left atrium through the mitral valve to the left ventricle.

Oxygenated blood leaves the left ventricle through the aortic valve to the aorta, which is the largest artery of your body.

The aorta branches into various arteries pumping blood through your body.

Deoxygenated blood returns from the top of your body through the superior vena cava and from the bottom of your body through the inferior vena cava to the right atrium. Deoxygenated blood is pumped from the right atrium through the tricuspid valve to the right ventricle.

Deoxygenated blood leaves the right ventricle through the pulmonary valve to the pulmonary arteries.

The pulmonary arteries pump blood to the lungs to absorb oxygen and release carbon dioxide.

Heart circulation animation: http://www.nhlbi.nih.gov/health/dci/Diseases/hhw/hhw_pumping.html

The Path of Blood– KNOW THIS!!!

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Valves

Blood enters into the atria of the heart, separated from the ventricles by valves, preventing back-flow of blood keeping the blood flowing in one direction When the atria contract, the valves open and blood flows into the ventricles When the ventricles contract, the valves close preventing blood from flowing back into the atria and blood flows out of the heart At the exits of the ventricles, there are valves that prevent blood from flowing back into the heart  The “lub-dup” sound of your heart is caused by the closing of the heart’s valves. The “lub” is when the ventricles contract and blood being forced against the artioventricular or A-V (tricuspid or mitral) valves. The “dup” is the blood being forced against the semilunar (aortic or pulmonary) valves.

Figure 37-3 The Structures of the Heart Section 37-1 Superior Vena Cava

Large vein that brings oxygen-poor blood from the upper part of the body to the right atrium

Aorta

Brings oxygen-rich blood from the left ventricle to the rest of the body

Pulmonary Veins

Bring oxygen-rich blood from each of the lungs to the left atrium

Pulmonary Valve

Prevents blood from flowing back into the right ventricle after it has entered the pulmonary artery

Tricuspid Valve Right Atrium

Prevents blood from flowing back into the right atrium after it has entered the right ventricle

Inferior Vena Cava

Vein that brings oxygen-poor blood from the lower part of the body to the right atrium

Right Ventricle Pulmonary Arteries

Bring oxygen-poor blood to the lungs

Left Atrium Aortic Valve

Prevents blood from flowing back into the left ventricle after it has entered the aorta

Mitral Valve

Prevents blood from flowing back into the left atrium after it has entered the left ventricle

Left Ventricle Septum

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Heartbeat

There are two muscle contractions in the heart: – The atria – The ventricles Each contraction begins in a small group of cardiac muscle cells in the right atrium that stimulate the rest of the muscle cells = sinoatrial node (SA node) Since the sinoatrial node sets the pace for the heart it is also called “the pacemaker” The impulse spreads from the pacemaker through fibers in the atria to the atrioventricular node (AV node) and through fibers in the ventricles   When the atria contract, blood flows into the ventricles When the ventricle contract, blood flows out of the heart

Blood vessels

 Blood circulates in one direction and it is moved by the pumping of the heart  As blood flows through the circulatory system, it moves through three types of blood vessels: – Arteries – Capillaries – Veins

   Large vessels that carry blood away from the heart to tissues of the body Except for the pulmonary arteries, all arteries carry oxygen-rich blood.

Arteries have thick walls of elastic connective tissue, contractible smooth muscle, and epithelial cells that help them withstand the powerful pressure produced when the heart contracts and pushes blood into the arteries.

Arteries

Capillaries

  The smallest of the blood vessels connecting arteries and veins Walls are one cell thick allowing for easier diffusion of nutrients and oxygen from capillaries to body cells and wastes and carbon dioxide from body cells to capillaries

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Veins

Return blood to the heart Veins have walls of connective tissue and smooth muscle Large veins contain valves that keep blood flowing towards the heart Many veins are located near skeletal muscles, so when the muscles contract, they help force blood through the veins, even against gravity Exercise helps prevent accumulation of blood in limbs and stretching veins out of shape

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Blood Pressure

The heart produces pressure when it contracts.

The force of blood on the arteries’ walls = blood pressure Blood pressure decreases when the heart relaxes, but there must always be some pressure to keep the blood flowing Doctors measure blood pressure with a sphygmomanometer recording two numbers – Systolic pressure = force felt in arteries when ventricles contract – Diastolic pressure = force of blood felt in arteries when ventricles relax Average adult’s blood pressure = 120/80

High Blood Pressure

   Also known as Hypertension Forces heart to work harder, which may weaken or damage the heart muscle and vessels More likely to develop heart disease and increased risk of heart attack and stroke

Heart Attack

 A medical emergency  Coronary arteries (supplying heart blood) bring oxygen and nutrients to the heart muscle itself  Blockage of coronary artery may damage or kill part of heart muscle (myocardium) due to lack of oxygen = heart attack – Symptoms include: chest pain/pressure, feeling of heartburn/indigestion, sudden dizziness, or brief loss of consciousness

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Stroke

Blood clots may break free from vessels and get stuck in a blood vessel leading to a part of the brain = stroke Brain cells relying on that vessel may begin to die from lack of oxygen and brain function in that region may be lost Strokes can also occur when a weakened artery in the brain burst, flooding the area with blood

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Prevention

Cardiovascular diseases are easy to prevent: – Exercise – increases respiratory system’s efficiency – Weight control – reduces body fat and stress – Sensible diet heart disease – low in saturated fat reduces risk of – Not smoking – reduces risk of heart disease