Human Body Systems

SubtitleBody systems work together and depend on one another

How Is the Body Organized? Cells

Tissues

Organs

Organ Systems

Cells • The smallest unit of life• Individual cells in multicellular organisms tend to

be specialized.• Specialized cells are uniquely suited to perform a

particular function.

Nerve CellBlood CellBone Cell

Tissues

A group of cells that work together to perform a specific function in the body ex: many muscle cells join to make up muscle tissue

M u s c l e c e l l s

Come together to make

Organ Two or more tissues working together to perform a specific job. Ex: brain, stomach, intestine, heart, lungs, skin, earsIn order for the heart to work, blood tissue, muscle tissue, and nerve tissues work together.

Organ SystemDifferent organs working together to perform a particular job make up an organ system

there are 11 organ systems in the human body:

Skin/IntegumentaryCardiovascular/CirculatoryMuscularSkeletalNervousRespiratoryDigestiveUrinaryReproductiveLymphatic/ImmuneEndocrine (hormones)

bones + cartilage + ligaments +

joints= Skeletal

System

Integumentary System

• Skin, nails, & hair –The largest organ of the human body.–Skin covers the body & prevents water loss–Protects against injuries & infections

Muscular System• There are about 600 muscles in the body.• Muscles work with bones for movement.• Muscles work by contracting and relaxing.• Body has three types of muscles:

– Skeletal muscle

– Smooth muscle

– Cardiac muscle

Skeletal System

The skeletal system–Provides shape and support–Allows the body to move–Protects the internal organs–Produces blood cells

Cardiovascular SystemThe cardiovascular system • Consists of heart, blood vessels, &

blood• Carries nutrients and oxygen to cells• Removes waste from the cells

Respiratory SystemThe respiratory system• Moves oxygen from outside into the

body• Removes carbon dioxide from the

body• Nose, pharynx, trachea, bronchi, and

lungs are all organs of respiratory system

Digestive system

• The digestive system – Breaks down food into nutrients (digestion)– Absorbs nutrients into blood stream

(absorption)– Eliminates waste from the body– Starts at the mouth and ends at anus

Urinary SystemThe urinary system • Collects liquid waste produced by the

cells• Removes the waste from the body

(excretion)• Filtering waste produces urine.• The two kidneys, ureters, urinary bladder,

and urethra, are the organs of urinary system.

Kidney

Ureter

Bladder

Nervous System The nervous system• Consists of the brain, spinal cord,

and neurons• Receives information about inside &

outside of the body• Responds to the received

information• Helps maintain homeostasis

Human body temp:37 C (98.6 F)

Immune System

• Immune system defends the body against pathogens (bacteria & viruses)

• The cells of the immune system recognize the different kind of pathogen and destroy them.

Endocrine System

The endocrine system • controls the body’s daily activities • Controls growth and development• Produces chemicals named

hormones• Hormones order organs what to do

Reproductive System

• The male and female reproductive system produce sex cells and sex hormones.

• Female reproductive system nourishes the developing fetus and gives birth.