3.2 – Human Organs & Systems

Circulatory, Digestive, Respiratory, Nervous, Skeletal, Muscular, Immune, Endocrine,

Reproductive, Urinary, Integumentary

Cell Tissue Organ

Organs contain all 4 types of tissue in order to function properly: Epithelial Muscle Nervous Connective

Stomach organ

Some cells have more organelles than others ex: muscle cells are packed

with mitochondria, WBC are packed with lysosomes, etc.

Together, specialized cells form tissues that perform special functions

Tissues form organs that are part of a system organs work together so the

organism can survive

Organelle Cell Tissue Organ System

Example: the Circulatory System Consists of the heart, arteries, veins, & blood

cells: RBC, WBC, platelets, etc. tissues: all 4 (E, M, N, C) organs: heart, blood vessels system: circulatory

All function to transport nutrients, gases, and wastes to and from cells in the body

Humans Have 11 Organ Systems!

Circulatory Respiratory Digestive Urinary Skeletal Muscular

Nervous Immune Endocrine Reproductive Integumentary

Main Function of Each System

1. Circulatory System transports blood, nutrients, gases & wastes2. Respiratory System controls breathing and exchanges gases in the lungs3. Digestive System takes in food, breaks it down, absorbs nutrients and removes waste4. Urinary System removes liquid wastes5. Nervous System detects changes in the environment and sends signals to parts of the

body to respond6. Skeletal System supports, protects, & works with muscles to move parts of the body7. Muscular System works with bones to move parts of the body8. Immune System defends against infection9. Endocrine System makes & releases hormones to keep systems working properly10. Reproductive System produces offspring11. Integumentary System creates a waterproof barrier around body (skin, hair, nails)

Circulatory System Picks up and transports oxygen & nutrients to cells Carries wastes to kidneys for elimination from the body Heart contractions produce pressure so that blood can

move around the body Heart valves close after blood is pushed through them

to prevent blood from flowing backwards Arteries carry oxygenated blood Veins carry deoxygenated blood and wastes like CO2

that need to be removed from body remember the exception! (explained in the video)

artery = away from heart vein = towards heart

See Figure 3.20A on p. 100

Blood flows through the 4 chambers of the heart & through the lungs before being dispersed through the body

Remember…

Blood in the Heart & Lungs Blood returning from

the body is deoxygenated carries CO2 waste

from cellular respiration

Blood returning from the lungs is oxygenated bright red due to the

high O2 content See Figure 3.20B on p. 100

The Path of Blood in the BodyBlood from body: Vena cava Right atrium Right ventricle Pulmonary arteries Lungs Pulmonary veins Left atrium Left ventricle Aorta Blood circulates to body

Capillaries These are networks

of very thin blood vessels (1 epithelial cell thick!)

They deliver oxygen & nutrients and pick up waste materials from tissues in every organ in the body

Trace the path of blood with your finger, starting at one point and returning to it

KAP-ill-air-eez

Quiz time!1. Name the 2 major functions of the circulatory

system.

2. Name the 4 main chambers of the heart.

3. What do the valves in the heart do?

4. With a partner, explain the path that blood takes through the body from your fingertip or your toe, back to that same body part.

5. What are capillaries? What do they do?

The Same, but DifferentRead the top half of p. 101. Then with a partner, answer

the following questions. 1. a) What is the difference between an open and closed system with regards to circulation? b) Give an example of an animal that would have an open system, and one that would have a closed one.

2. How is a fish’s heart different from a human’s?

3. a) How many chambers does an amphibian’s heart have? b) What does this mean then?

Respiratory System Consists of the lungs & airways Responsible for gas exchange (O2 in, CO2 out) Is connected to the circulatory system so that it can

exchange gases in the blood (through capillaries) The diaphragm is a muscle that contracts when you

breathe allows room for your lungs to expand so they can take in air rib cage moves up & out, causing air to be pulled into your

body through your nose or mouth

Use Your Nose! The air your breathe in

passes by epithelial cells in your nasal cavity cells have tiny, hair-like

projections called cilia they also secrete mucus

Both cilia & mucus keep foreign particles like allergens, bacteria, and toxins out of your body

Pharynx Trachea Bronchi Air moves from the

pharynx (throat) to your trachea a small flap called the

epiglottis opens and closes so no food ends up in the trachea

From the trachea, the single pipe splits into two, called bronchi each bronchi goes to

a lung

Bronchi Bronchioles Alveoli Bronchi then branch out into smaller tubes

called bronchioles bronchioles are embedded within the lung tissue

Bronchioles divide into tiny sacs called alveoli Capillaries surround the alveoli

it is here that gas exchange takes place

See Figure 3.26 on p. 104

Alveoli Tiny clusters of air sacs in

the lung (sing. = alveolus)

have a very thin epithelial layer

gases can cross, but bacteria and other harmful substances cannot

O2 and CO2 are exchanged with blood in the capillaries O2 to RBC from alveoli CO2 to alveoli from RBC

RBCs contain hemoglobin, which binds O2 so that it can be carried through the body

Alveoli are the tiny heroes of the respiratory system!

Alveoli Mouth When your diaphragm &

chest muscles relax, you exhale CO2 in the alveoli is

released into the air in the opposite way O2 came in

When CO2 levels get too high, breathing rate increases so CO2 can be expelled quicker

The Same, but Different… again Birds, reptiles, & amphibians have lungs just

like humans do these creatures have an effective gas exchange

system, but it is different than ours Instead of alveoli, fish have gills Read over Figure 3.28 on p. 105

and summarize with a classmate how gills perform gas exchange just like alveoli in humans

Quiz… yahoo!!1. Trace the path of a breath of air in through

your nose and out through your mouth.2. Why should you always breathe in through

your nose?3. What is the structure in the lung where gas

exchange takes place? Name 2 gases that are exchanged with blood in capillaries here.

4. Why does your breathing rate increase when you’re exercising?

Digestive System Mechanically &

chemically breaks down food so the body can use nutrients

The major organs are the stomach, liver, pancreas, and intestines

See Figure 3.14A on p. 97

Mouth Teeth break down food into smaller pieces Enzymes (protein) in saliva begin chemical digestion Swallowed food passes through the pharynx to the

esophagusEsophagus Is a muscular tube that contracts &

relaxes to push chunks of food down to the stomach Waves of muscle contraction is

called peristalsis

Mouth Pharynx Esophagus

Contains liquids called gastric juices that chemically break down the food more are highly acidic

Stomach muscles mix the contents, which continues the mechanical breakdown of food churning action of stomach & gastric

juices cause food to break down into a liquid

Food is pushed into small intestine

Stomach

Small Intestine Divided into 3 sections:

1. duodenum where the rest of digestion takes place

2. jejunum3. ileum where absorption

of nutrients takes place Pancreas, liver, and gall bladder release digestive enzymes

into the duodenum via small tubes called ducts Walls of the small intestine are covered with little projections

called villi (& microvilli) they increase the surface area so that more nutrients and water can be

absorbed into the bloodstream

See Figure 3.15 on p. 98See Figure 3.16 on

p. 98

Large Intestine Includes the colon, rectum, & anus (oh geez)

Absorbs water, vitamins salts from digested food achieved by bacteria in the

gut like E.coli Remaining (undigested)

food is eliminated as feces

Sooooo… let’s recap The path of a meal from start

to finish: mouth pharynx

esophagus stomach small intestine large intestine

Weird facts: it takes 24 to 33 hrs for a

meal to go from beginning to end of this system

the small intestine is between 6 – 10 m in an adult

Quizzy, quizzy…1. Identify the structures A. – E.2. Name 3 organs that help digest

food that enters the small intestine.3. Name the 3 sections of the small

intestine.4. Give 4 organs in the digestive

system that chemically break down food and explain how each occurs.

5. Which part of the digestive systems mechanically breaks down food?

Urinary (Excretory) System Composed of the

kidneys, ureter, bladder, urethra, and blood vessels

Eliminates liquid wastes from the body

Interacts closely with the circulatory & digestive systems

Kidneys: Liquid Waste’s Last Stop As blood passes through the kidneys, it is

filtered and wastes are removed Remember nephrons? Those are the tiny

structures within the kidneys that do the filtering

Urine forms from excess water and unneeded salts in the blood (called urea)

Urine is stored in the bladder and then excreted through the urethra

Nephrons

Urine trouble if you don’t know the answers to these questions!

1. Name the 4 major structures that compose the urinary system.

2. How is the urinary system different from the digestive system?

3. What tiny structure in the kidney is responsible for filtering blood of its wastes?