Human body

Human Body

Organ System Overview

Nervous System

• Mental and physical activity and many aspects of homeostasis are controlled

by the nervous system.

• The central nervous system (CNS) includes the brain and spinal cord.

• Main divisions of the brain include the cerebrum-largest portion- and the

brain stem (cerebellum)

Integumentary System

• The integumentary system consists of the skin, hair, and nails, acts as a

barrier to protect the body from the outside world. It also functions to

retain body fluids, protects against disease, eliminates waste products, and

regulate body temperature.

Muscular System

• A muscle is a tissue in a coordinated fashion and includes muscle tissue,

which can contract blood vessels, nerves, and connective tissue.

• The human body has three types of muscle tissues: skeletal, smooth, and

cardiac.

Endocrine System

• Consists of glands that transmit chemical messengers throughout the body called hormones

• A gland is an organ that consists of cells that secrete materials into other regions of the body. There are two types of glands: exocrine and endocrine.

• Hormones are compounds that are secreted in small amounts into the blood stream and that influence the activity of distant cells.

• Amino acid base hormones – proteins amino acids adrenaline

• Steroid hormones—estrogen and testosterone

Immune System

• The immune system is the body system that fights off infection and

pathogens.

• Many other tissues and systems help the immune system.

• Skin is a physical barrier to infection.

• Mucous membranes trap pathogens entering the body.

• The circulatory system transports immune cells.

• Some viral diseases can be prevented with vaccines.

Respiratory System

• The respiratory and circulatory systems bring oxygen and nutrients to the

cells.

• The respiratory system is where gas exchange occurs.

– picks up oxygen from inhaled air

– expels carbon dioxide and water

Circulatory System

• Two fluids move through the circulatory system: blood and lymph

• Blood, heart, and blood vessels form the cardiovascular system.

• Lymph, lymph nodes, and lymph vessel form the Lymphatic system.

• The cardiovascular system and lymphatic system collectively make up the

circulatory system.

Digestive System

• Your digestive system is uniquely designed to turn the food you eat into nutrients, which the body uses for energy, growth and cell repair.

1. Ingest the food

2. Transport the food

3. Digest the food into smaller usable components.

4. Absorb the necessary nutrients into the bloodstream.

5. Expel the waste products from the body.

Composed of two separate categories of organs:

digestive organs

accessory digestive organs.

Collectively make up the gastrointestinal (GI) tract.

Also called the digestive tract or alimentary canal.

Reproductive System

• The human reproductive system produces, stores, nourishes, and transports

functional male and female gametes.

– Sperm

– Ovum

– Fertilization produces a zygote.

• The reproductive system also produces sex hormones that affect the structure and

function of other systems.

Female Male

Excretory System

• The excretory system is the system of an organism's body that performs the

function of excretion, the bodily process of discharging wastes.

• The Excretory system is responsible for the elimination of wastes produced

by homeostasis

Skeletal System

The adult human body consists of approximately 206 bones, which are organized into an internal framework called the skeleton.

The human skeleton is composed of two parts:

1. Axial Skeleton—which is composed of bones from the skull, ribs, spine, and sternum

2. Appendicular Skeleton—which is composed of the bones from the arms and legs, along with the scapula, clavicle, and pelvis