Body Systems

CirculatoryLymphatic &Respiratory

Hierarchy of structure in Animals

The Human Body

• The human body is composed of many systems– Circulatory - Immune– Respiratory - Digestive– Muscular - Nervous– Skeletal - Reproductive– Lymphatic - Endocrine– Excretory

Function of The Circulatory System- Moves oxygen from the lungs to all the body

cells- Moves carbon dioxide from the body cells to

the lungs- Moves nutrients from the small intestine to

the body cells- Moves waste materials from the body cells to

the kidneys and skin

Main Parts of the Circulatory System

Heart – the pump

Blood – fluid in which materials are transported

Vessels – Tubes to carry the blood

The Heart

• Composed of cardiac muscle tissue, nerve tissue and connective tissue

• Frequency of heart beat depends on your physical activity level and other factors (stress, general health, etc)

• Did you know…– Your circulatory system

is about 60,000 miles long

– Your heart beats more than 2.5 billion times in the average lifetime

– the human heart creates enough pressure when it pumps out to the body to squirt blood 30 feet.

The Blood

• Blood is a type of connective tissue that circulates through your body, it consists of 4 components:– Red Blood Cells (RBC)– White Blood Cells (WBC)– Platelets– Plasma

Did you know…- It takes about

20 seconds for a RBC to circulate the entire body

The Vessels- There are 3 types of blood vessels:

arteries, veins, and capillaries- Arteries carry blood away. Because the

heart generates a lot of pressure when pumping blood through the body the walls of the arteries are thicker than the other vessels

- Veins carry blood toward the heart. - arteries and veins are linked together by

capillaries- Capillaries is where the gas exchange

occurs. Oxygen from the lungs diffuses from the blood to the surrounding tissues and Co2 and other wastes pass from the body to the blood to be carried out for disposal

Circulatory System

Path of Blood •blood is collected in the atria via veins

•atria walls contract, blood is pumped from the atria to the ventricles via opened atrio-ventricular valves •semi-lunar valves are closed to prevent blood from flowing to arteries while the ventricle fills up with blood

•ventricle walls contract, causing rise in blood pressure

•high blood pressure cause atrio-ventricular valves to close to prevent back flow of blood to atria

•high blood pressure also cause semi-lunar valves to open to allow blood to be pumped from ventricles to arteries

•as blood leaves ventricles, pressure inside the ventricles drop and ventricles stop contracting•the semi-lunar valves close to prevent back flow of blood from arteries to ventricles

The Lymphatic System

Function of The Lymphatic System

• The lymphatic system aids the immune system in destroying pathogens and filtering waste.

• To remove excess fluid, waste, debris, dead blood cells, pathogens, cancer cells, and toxins from these cells and the tissue spaces between them.

• The lymphatic system also works with the circulatory system to deliver nutrients, oxygen, and hormones from the blood to the cells that make up the tissues of the body.

Lymphatic System and Circulatory System Working Together

• Lymph originates as plasma (fluid portion of blood)

• Some of this plasma leaves blood stream and flows into the surrounding tissues (called interstitial fluid).

• Interstitial fluid delivers nutrients to the cells and takes up cell waste

• 90 percent of this tissue fluid flows back through the circulatory system, 10 percent of the fluid is left behind and is now known as lymph

• Lymphatic system is designed so lymph only flows upwards (from the extremities), where it is filtered through lymph nodes on its way towards the neck where it re-enters the bloodstream

Respiratory System

Main Parts of the Respiratory System• Trachea

– Tube that takes air from the back of the throat down to the lungs

• Bronchi (sing. bronchus)– As the trachea approaches the lungs it splits into

two bronchi, one bronchus leads to each lung• Alveoli (sing. alveolus)

– Tiny air sac surrounded by blood vessels– Lungs contain millions of these– Where gas exchange occurs

Gas Exchange

• O2 and CO2 have only to diffuse through 2 thin walls: capillaries and alveoli

• O2 that we breathe in diffuses from the alveoli into the blood stream and CO2 leaves the blood stream through the alveoli and the air we breathe out

Gas Exchange

• Alveoli are tiny sacs that fill with air to allow diffusion of gas• Many (millions of) alveoli provide a large total surface area for greater absorption • A thin, single layer of flattened cells are on the wall of each alveolus to

decrease the distance that gases need to diffuse across• A dense network of capillaries (tiny blood vessels) surrounding the

alveolus to remove CO2 from brought into from rest of body and to transport O2 to rest of the body

– Hemoglobin, the protein found in red blood cells, pick up O2 from the alveoli to transport to the rest of the body

Breathing• Involves the diaphragm (a

large sheet of muscle underneath the lungs) and the muscles between the ribs.

• Is an involuntary process that we can override while talking but only temporarily.

• It is controlled by a part of the human brain that detects the concentration of CO2 in our blood

Air Pathway• air enters through the nostrils (air is filtered by nose hair) ↓• nasal cavity (air is warmed, humidified, and sampled for odors) ↓ pharynx ↓ larynx ↓ trachea (aka windpipe)

↓ bronchi (there are 2, each leads to 1 lung) ↓

bronchioles ↓

alveoli (clusters of air sacs with very large surface area, surrounded by capillaries), oxygenated blood moves towards the heart, via the pulmonary vein and gets pumped into the left atrium

Class/Homework1. What is the system that aids in the destruction of pathogens from the

bloodstream?2. What system does the lymphatic system work with to access the lymph

nodes?3. Do lymph nodes regenerate?4. What occurs as you inhale?5. What is the muscle that contracts and shortens upon breathing?6. Explain how diffusion is involved in gas exchange.7. What are the three main parts of the respiratory system and what is

there function?• Questions (Nelson Text book)

– Pg 87 #1,2,5-7– Pg 95 #1-4