Human Anatomy and Body Systems

Did you know?• Every square inch of the human body has about 19 million

skin cells.

• Every hour about 1 billion cells in the human body must be

replaced.

• The average human head has about 100,000 hairs.

• The circulatory system of arteries, veins, and capillaries is

about 60,000 miles long.

• The heart beats more than 2.5 billion times in an average

lifetime.

• There are about 9,000 taste buds on the surface of the

tongue, in the throat, and on the roof of the mouth.

• The strongest muscle in the body is the tongue.

• The human heart creates enough pressure when it pumps

out to the body to squirt blood 30 feet.

More!!

• You blink over 10,000,000 times a year.

• The human brain weighs about 3 pounds.

• It takes about 20 seconds for a red blood cell to circle

the whole body.

• Only 10% of the population are left handed.

• One fourth of the bones in your body are in your feet.

• Children tend to grow faster in the spring.

• The most sensitive finger on the human hand is the

index finger.

• More men are color-blind than women.

• More people have brown eyes than any other color.

The Amazing Human Body

• Why are bodies asymmetrical?

• Human Body – Nat Geo

Levels of Organization

Remember, the human body is organized in several

levels, from the simplest to the most complex. . .

Cells – the basic unit of life

Tissues – clusters of cells performing a similar

function

Organs – made of tissues that perform one

specific function

Organ Systems – groups of organs that perform

a specific purpose in the human body

***The purpose of the organ systems is for the human

body to maintain homeostasis.

Division of Labor & The First Level

Within multi-cellular organisms there is division of labor.

Division of labor means that the work (labor) of keeping

the organism alive is divided (division) among the

different parts of the body.

Each part has a job to do and as each part does its special

job, it works in harmony with all the other parts.

The arrangement of specialized parts within a living thing is

sometimes referred to as levels of organization. Cells of course,

are the first level of organization.

Second Level: Tissues

There are four basic/major types of tissues in the human body:

1. Muscle tissue

2. nerve tissue

3. connective tissue

4. epithelial tissue

Blood cells in your body are part of blood tissue, a liquid tissue

responsible for transporting food and oxygen throughout the

body.

Tissues are the second level of organization.

Types of Tissues

1. Connective tissue -

connects and supports

parts of the body. Blood,

fat, ligaments, cartilage,

bones, and tendons are

all connective tissues.

2. Nerve tissue carries

messages back and forth

between the brain and every

other part of the body. The

brain, spinal cord, and

nerves are made up of

nerve tissue.

3. Epithelial tissue covers

and lines the surfaces of your

body and organs, inside and

out. They primarily serve as

protective barriers. Skin is one

example.

4. Muscle tissue can

contract, or shorten.

Because of this, muscle

tissue makes parts of your

body move.

Level Three: OrgansWhen a bunch of different types of tissues work together,

they form an organ.

Level Four: Organ Systems

Each organ in your body is

part of an organ system, a

group of organs that

work together to perform

a major function.

For example, your heart is

part of your circulatory

system, which carries

oxygen and other

materials throughout your

body. Besides the heart,

blood vessels are organs

that work in your circulatory

system.

2. The nervous system

detects and interprets

information from the

environment outside the body

and from within the body;

controls most body functions.

3. The immune system fights

disease.

4. The excretory system

removes wastes.

5. The endocrine system

controls many body processes

by means of chemicals, like

hormones.

6. The muscular system

enables the body to move;

moves food through the

digestive system, and keeps

the heart beating.

7. The skeletal system

supports and protects the

body, and works with the

muscular system to allow

movement; makes and stores

blood cells and stores some

other materials.

8. The digestive system

takes food into the body,

breaks the food down into

smaller particles, and absorbs

the digested materials.

9. The respiratory system

takes oxygen into the body

and eliminates carbon

dioxide.

10. The reproductive

system produces sex cells

that can unite with other

sex cells to create offspring;

controls male and female

characteristics.

Let’s Review….

• 1st Level: Cells working together form

• 4th Level: Organ Systems, which work

together to form

• 2nd Level: Tissues, which can form

• 3rd Level: Organs, which work together

to form

• 5th Level: Organisms!

Scavenger Hunt

• Your task: Find every body system

• Fill in your chart

The Human Body Systems

The human body systems are as follows:

-- nervous system -- integumentary system

-- respiratory system -- digestive system

-- excretory system -- skeletal system

-- muscular system -- circulatory system

-- endocrine system -- immune system

The Digestive System

Purpose: to convert food particles into simpler

micromolecules that can be absorbed into the

bloodstream and used by the body

Major Organs and their Functions:

Mouth – to chew and grind up food

-- saliva also begins the chemical breakdown

Esophagus – pipe connecting mouth to stomach

Stomach – secretes an extraordinarily strong acid (pH = 2) that

leads to breakdown of food

-- once the food is broken down in the stomach and

mixed with digestive juices, it is called chyme

Pancreas – produces the hormone insulin that regulates

blood sugar levels

-- also help neutralize stomach acid

Liver – produces bile, which breaks down fats in foods

Gallbladder – pouch-like organ that stores bile for future use

Small Intestine – after digestion is complete, the chyme

enters the small intestine where it is absorbed into the

bloodstream

-- the chyme is propelled along by folded surfaces

called villi, on the intestine

Large Intestine – removes water from the chyme and gets the

waste ready for excretion

The Digestive System

The Excretory System

Purpose: to rid the body of wastes, including excess water

and salts

Major Organs and Their Functions

Kidneys – the main organs of the excretory system

-- waste-laden blood enters the kidney and the kidney

filters out urea, excess water and other waste

products, which eventually travel out of the kidney as

urine

-- eventually they travel through the ureter to the

urinary bladder

Rectum – solid (food) waste travels out of the body through

the rectum

Skin – sweat glands remove excess water and salts from the

body

Lungs – expel the waste gas carbon dioxide

The Excretory System

The Respiratory SystemPurpose: to provide the body with a fresh supply of oxygen

for cellular respiration and remove the waste product carbon

dioxide

Major Organs and Their Functions

Nose – internal entry and exit point for air

Pharynx – serves as a passage way for both air and food at

the back of the throat

Larynx – your “voicebox”, as air passes over your vocal

chords, you speak

Trachea – the “windpipe”, or what connects your pharynx to

your lungs

-- a piece of skin, called the epiglottis, covers the

trachea when you swallow, preventing food from

entering

Bronchi – the two large passageways that lead from the

trachea to your lungs (one for each lung)

-- the bronchi are further subdivided into bronchioles

-- eventually, the further subdivisions lead to tiny air

sacs called alveoli

-- alveoli are in clusters, like grapes

-- capillaries surrounding each alveolus is where

the exchange of gases with the blood occurs

The diaphragm is the muscle that causes you to breath

-- hiccups are involuntary contractions of the

diaphragm

The Respiratory System

The Circulatory System

Purpose: to deliver oxygenated blood to the various cells and

organ systems in your body so they can undergo cellular

respiration

Major Organs and Their Functions

Heart – the major muscle of the circulatory system

-- pumps blood through its four chambers (two

ventricles and two atria)

-- pumps deoxygenated blood into the lungs, where it

gets oxygenated, returned to the heart, and then

pumped out through the aorta to the rest of the body

-- valve regulate the flow of blood between the

chambers

Arteries – carry blood away from the heart and to the major

organs of the body

Veins – carry blood back to the heart away from the major

organs of the body

Capillaries – small blood vessels where gas exchange occurs

Blood – the cells that flow through the circulatory system

-- red blood cells contain hemoglobin, an iron-rich

protein that carries oxygen

-- white blood cells function in the immune system

-- platelets help in blood clotting

Spleen – helps to filter out toxins in the blood

The Circulatory System

The Nervous SystemPurpose: to coordinate the body’s response to changes in its

internal and external environment

Major Organs and Their Functions

Brain – control center of the body, where all processes are

relayed through

-- consists of cerebrum (controls though and senses)

and cerebellum (controls motor functions)

Spinal Cord – sends instructions from the brain to the rest of

the body and vice versa

-- any organism with a major nerve cord is classified as

a chordate

Nerves – conduct impulses to muscle cells throughout the

body

Nervous System

Diagram of a Nerve Cell

The Endocrine SystemPurpose: to control growth, development, metabolism and

reproduction through the production and secretion of

hormones

Major Organs

-- hypothalamus

-- pituitary gland

-- thyroid

-- parathyroid

-- adrenal glands

-- pancreas

-- testes

-- ovaries

The Endocrine SystemPurpose: to control growth, development, metabolism and

reproduction through the production and secretion of

hormones

Major Organs and their functions:

-- hypothalamus – a collection of cells in the lower part of the

brain that is the main link between the endocrine and nervous systems

-- pituitary gland – the most important part of this system, it

makes hormones that controls the other glands in the endocrine system

-- pancreas – produces insulin to maintain steady sugar levels

in the body

-- testes – in males, produce hormones such as testosterone

-- ovaries – in females, produce eggs and hormones

The Skeletal SystemPurpose: to provide structure and support to the human

body

Bones are where new blood cells are generated (in the

marrow), and require the mineral calcium for strength

Major Bones of the Human Body

-- femur (thigh bone) -- humerus (upper arm)

-- radius and ulna (lower arm) -- cranium (skull)

-- sternum (breastbone) -- clavicle (shoulder blade)

-- fibula and tibia (calf) -- vertebrae (back)

-- scalpula (shoulder) -- pelvic bone

-- coccyx (tail bone) -- phalanges (fingers/toes)

The Skeletal SystemMajor Bones of the Human Body (207 bones)

Skeletal can be divided into 2 major parts:

Axial skeleton – head and truck, composed of 80 bones

The Skeletal System

Major Bones of the Human

Body (207 bones)

Skeletal can be divided into 2

major parts:

Appendicular skeleton – lower

portion of the body, involved

in locomotion. Made of 126

bones.

The Skeletal System

The Muscular System

Purpose: works with the skeletal and nervous system to

produce movement, also helps to circulate blood through the

human body and provides heat to keep the body warm.

-- muscle cells are fibrous

-- muscle contractions can be voluntary or involuntary

-- consists of cardiac, smooth and skeletal muscles

-- nervous system controls it

Major Muscles in the Human Body

-- biceps -- triceps -- deltoids

-- glutes -- hamstrings

The Muscular System

Major Muscles groups in the Human Body

-- biceps and triceps – helps to control shoulder and elbow

-- abdominal – sitting up, posture

-- hamstring – walking, standing up

Image of the Muscular System

The Integumentary System

Purpose: to remove infectious diseases and other pathogens

from the human body

Major Organs and Their Functions

Skin –the skin is the body’s first line of defense

Epidermis – top layer of skin. Its purpose is to protect, absorb

nutrients and maintain homeostasis

Dermis – middle layer of skin, gives the skin its elasticity

Hypodermis – innermost layer, and the thickest. Stores fat.

Integumentary System

The Immune System

Purpose: to protect the body from disease

Major Organs and Their Functions

Skin- first layer of protect from foreign agents

Bone Marrow – (not technically an organ)all blood cells are

derived from bone marrow

Spleen – filters the blood, within the spleen are specialized

cells, such as T and B cells that fight infections

Lymph Nodes – located throughout the body and help fight

infection

Immune System

Body System Function Organs and their functions

Circulatory

Respiratory

Skeletal

Muscular

Digestive

Human Body Systems

Body System Function Organs and their functions

Excretory

Immune

Integumentary

Nervous

Endocrine

Human Body Systems