Unit Six

6.1 Human Body Systems

Vocabulary:

Arteries: vessels in the circulatory system that carry blood away from the heart

Bladder: Saclike structure that stores urine until it can be released

Blood vessel: An artery, vein, or capillary that carries blood to and from the heart and body tissues

Capillaries: Smallest vessel in the circulatory system; site of nutrient and gas exchange between blood and body cells

Chemical digestion: Process that breaks large food molecules into smaller molecules that can be taken in by cells

Circulatory system: Organ system that transports needed substances throughout the body and carries away wastes

Diaphragm: Large domed muscle that separates chest and abdomen and plays a major role in breathing

Digestion: Process of breaking down food into a form the body can use

Digestive system: Organ system that breaks down food into substances the body can use, and absorbs these substances

Egg: Female sex cell

Endocrine system: System of organs that controls body activities through chemical messengers (hormones)

Enzyme: A protein in the body that helps control a chemical reaction, such as digestion

Esophagus: Tube that carries food from the mouth to the stomach

Excretory system: Organ system that removes wastes from the body

Feedback mechanism: Positive or negative response to a stimuli; example: pain

Gall bladder: A sac that stores bile

Glands: Specialized organs that make substances (hormones) that control and regulate body processes

Heart: organ that pumps blood throughout the body

Homeostasis: Keeping conditions constant in the body

Hormone: A chemical released by a gland; controls a specific body function

Insulin: A hormone that is produced by a group of specialized cells in the pancreas and that lowers blood glucose levels

Integumentary System: System that covers the human body, basic organ is skin in the human body.

Kidneys: Organ in the urinary system that filters waste from the blood

Large intestine: Part of the digestive system where water is absorbed from solid waste

Liver: Organ in the digestive system that produces bile and enzymes, breaks down toxins and wastes

Lungs: Pair of organs in respiratory system, where carbon dioxide and oxygen are exchanged

Mechanical digestion: Process of breaking food into smaller pieces by chewing and mashing

Muscles: Elongated tissues that allow for contractions or relaxations to cause movement

Muscular system: All the muscles of the body, especially those involved in movement

Nephron: Tiny filters in the kidney that remove liquid wastes from blood

Nervous system: System of nerve cells and tissues that regulates the actions and responses of the body

Neuron: Nerve cell, sends messages through the nervous system

Ovaries: Female sex organs in which egg cells are produced

Pancreas: Organ in the digestive system and endocrine system; makes enzymes that help in the breakdown of carbohydrates, and that help regulate blood sugar levels

Rectum: Final section of the large intestine, ending in the anus

Reflex: An animal’s automatic response to a stimulus, such as jerking away from a hot surface

Reproductive System: Organ system involved in creating a new organism

Respiratory system: Organ system that takes oxygen into the body and releases carbon dioxide and water

Skeletal system: Bones and cartilage that support a vertebrate’s body

Small intestine: Organ in the digestive system that completes digestion and absorbs nutrients

Sperm: Male sex cell, produced in the testes

Stomach: Part of the digestive system, where food is stored and partially digested before it enters the small intestine

Testes: Male reproductive organs that produce sperm

Ureters: Tubes that pass urine from the kidney to the urinary bladder

Urethra: Tube that passes urine from the bladder to outside the body

Uterus: Organ in a female mammal in which fertilized eggs develop into young

Vein: Vessel that carries blood toward the heart

Ventricles: Two lower chambers of the heart

Virus: Disease causing, non-living particle, reproduces only in living cells