Circulatory and

Respiratory System

Honors BiologyPowerpoint #4

Unit 8 – Chapter 37

Circulatory System

Circulatory System• Structures: oHeart, Blood vessels, blood

• Functions: oBrings oxygen, nutrients and

hormones to cellsoFights infectionoRegulates body temperature.

Heart• Made of cardiac

muscle • Beats on average 65-

85 beats per minute• Pumps to circulate

blood throughout the body

Take your heart Rate

Blood Vessels:• Carry blood to cells• Lined with smooth muscle tissue • Three kinds:

1. Arteries2. Capillaries3. Veins

Arteries (carries blood away)

• Carry oxygenated blood from the heart to the rest of the body.

Capillaries• Branch off of the Arteries• The smallest of the blood vessels

o some have diameters as small as 1 red blood cell• Takes blood to cells

Veins• Takes deoxygenated blood from

the capillaries back to the heart

Veins• Have valves to prevent backflow because

not receiving pressure from heart• Muscles help pump blood back to heart

through the veins

Varicose veins

Blood• The human

body has 4-6 liters of blood

• Blood:o45% of blood is

Cellso55% of blood is

plasma

Blood Cells: 3 kinds• Red Blood Cells: transports

oxygen, contain hemoglobin (gives them color)

• White Blood Cells (leukocytes): attack foreign substances or organisms.

• Platelets: stick to broken blood vessels to stop bleeding when you are cut

Plasma • 90% water• 10% other materials:

oDissolved gases o SaltsoNutrientso EnzymesoHormonesoWaste products

Blood Flow in the

Heart

Upper body

The Heart• The human heart has four chambersoLeft and right ventricleoLeft and right atrium

• The left side of the heart pumps oxygenated blood to the body

• The right side of the heart pumps

deoxygenated blood to the lungs

Right Atrium

Right Atrium

Left Atrium

Left Ventricle

1) The right atrium receives deoxygenated blood from the body

through the superior and inferior vena cava.

2) The right atrium pumps blood through the tricuspid (AV) valve and into the right ventricle

3) Right Ventricle Contracts and pushes blood through pulmonary valve towards

lungs

4) Blood is pushed through the pulmonary arteries to the lungs to

receive oxygen

5) Oxygenated blood returns to the left atrium from the lungs through

the pulmonary veins

6) Blood passes through the bicuspid (mitral) valve into the

left ventricle.

7) Contraction of Left ventricle pumps blood through aortic

valve to the aorta

8)Blood travels through aorta and then to all regions of the body where it feeds cells with

oxygen picked up from the lungs and nutrients from the digestive tract.

Blood Pressure• Blood pressure is a measure of the

force exerted by the blood on the wall of the arteries.oAn example is 120/80 (systolic

pressure/diastolic pressure.• Systolic pressure is the result of the

contraction of the ventricles (normal 110-140)• Diastolic pressure is during the ventricle

relaxation (normal 70-90)

Disorders of the Circulatory System:

Coronary artery disease – Atherosclerosis

• Plaque buildup blocks arteries, reducing, or even stopping blood flow

• Plaques can break off, causing heart attack or stroke

Cause: Damaged arteries are ‘invaded’ by bad LDL cholesterol. White blood cells try to digest the LDL. Ultimately, a jumble of cholesterol and cells is accumulated.Risk Factors: Smoking, high blood pressure, high LDL cholesterol, diabetes

Disorders of the Circulatory System

• Heart Attack– Myocardial Infarction (MI)

= Death of cardiac muscle cells

Cause: Plaque dislodges, blocking an artery to the heart muscle. Cardiac muscle cells are starved for oxygen and die. After, scar tissue forms where cells died, therefore reduces the functionality of heart.Severity of a heart attack depends on size and area supplied by the artery.

Risk Factors: Smoking, high blood pressure, high LDL cholesterol, diabetes

Disorders of the Circulatory System

• Stroke=Death of cells in the brain.

Cause: A blood vessel in the brain is blocked (by dislodged plaque, or bursts, starving the cells of oxygenA stroke can have many different symptoms, including: numbness, vision changes, speech changes, or confusion.

Risk Factors: Smoking, high blood pressure, high LDL cholesterol, diabetes

Disorders of the Circulatory System

• Arrhythmia= Irregular / skipped heart beat

Cause: The heart uses electrical signals created in the SA node in the right atria, to begin a heartbeat. The conduction of these signals, or irregular firing of the SA node, can cause arrhythmias. Atrial arrhythmias are less dangerous than ventricular arrhythmias.

Risk Factors: Generally random, but factors are stimulants (such as caffeine), fevers, stress, or genetic disorders.

Disorders of the Circulatory System

• High blood pressure - HypertensionDiastolic pressure over 90

Why it is dangerous: Excessive pressure can cause the arteries to thicken, and blood vessels to weaken and rupture. This can lead to heart failure, stroke, kidney failure, loss of sight when vessels in eyes burst.

Risk Factors: Genetics, overweight, limited physical activity, smoking, alcohol consumption, certain medications

Virtual Cardiology Lab

Respiratory System• Function:

Bringing Oxygen into the body, and removing carbon dioxide and water vapor.

Respiratory System• What gases are in our

atmosphere?78% Nitrogen21% Oxygen1% Argon

Respiratory System• Structures: • Nose • Pharynx• larynx • trachea • bronchi • bronchioles • lungs

Nose, pharynx, larynx, trachea, bronchi,

bronchioles, lungs

NosePharynx

TracheaLarynx

LungBronchi

Bronchioles

Respiratory System• What is the job of the

nose?: • Cilia (small hairs) filter out

dirt• Moistens and warms the air

you breathe

Respiratory SystemPharynx• Part of both

respiratory & digestive systems

• Aids in swallowing

• Houses the tonsils

Larynx• Generates

sound• Contains

vocal chords

• vocal chords video

Trachea

Tracheotomy

Bronchi/bronchioles

Inside of lungs

Respiratory System• Inhalation:

o Rib muscles and diaphragm contract

o Rib cage expandso Lung volume increaseso Air pressure in lungs

decreaseso Air flows into lungs

Respiratory System

• Exhalation:o Rib

muscles/diaphragm relax

o Rib cage becomes smaller

o Air pressure in lungs increases

o Air flows out of lungs

Respiratory System• Diaphragm:

oDome shaped muscle

o Located at base of rib cage

Smallest Part of Lung= Alveoli

• Alveoli: air sacks where gas is exchanged• Surface area of a tennis court

Oxygen and Carbon Dioxide

• Exchanged in the lungs though: Diffusion

• The process by which materials move from an area of:oHigh concentration to an area of low concentration

Asthma

Lung Cancer

Non-smoker vs. smoker