Unit 5 Human Body Systems

esophagus

A muscular tube that connects the mouth to the stomach.

pharynx

throat; passageway for food to the esophagus and air to the larynx

Larynx

voice box; passageway for air moving from pharynx to trachea; contains vocal cords

Trachea

Allows air to pass to and from lungs

Bronchi

The passages that direct air into the lungs

Bronchioles

smallest branches of the bronchi

alveoli

tiny sacs of lung tissue specialized for the movement of gases between air and blood

gas exchange

the process by which oxygen is transported to cells and carbon dioxide is transported from cells

Capillaries

Microscopic vessel through which exchanges take place between the blood and cells of the body

Aorta

Largest artery in the body

vena cava

largest vein in the body

Atria

upper chambers of the heart, where blood ENTERS

Ventricles

the two lower chambers of the heart, and they pump blood OUT to the lungs and body.

pulmonary vein

carries oxygenated blood from the lungs to the heart

pulmonary artery

Carries deoxygentated blood from the heart to the lungs

stomach

large muscular sac that continues the mechanical and chemical digestion of food

small intestine

Digestive organ where most chemical digestion and absorption of food takes place

Villi

Fingerlike extensions of the intestinal mucosa that increase the surface area for absorption

large intestine

The last section of the digestive system, where water is absorbed from food and the remaining material is eliminated from the body

Rectum

A short tube at the end of the large intestine where waste material is compressed into a solid form before being eliminated

Liver

produces bile

Pancreas

Regulates the level of sugar in the blood by secreting insulin and glucagon

galbladder

stores bile

skeletal muscle

A muscle that is attached to the bones of the skeleton and provides the force that moves the bones.

blood

Connective tissue made of plasma, erythrocytes, leukocytes, and platelets.

Bones

provide a resting ground for muscles and protection of vital organs

Ligaments

Connect bone to bone

Tendons

Connect muscle to bone

Cerebrum

Area of the brain responsible for all voluntary activities of the body

Cerebellum

A large structure of the hindbrain that controls fine motor skills.

brain stem

Connection to spinal cord. Filters information flow between peripheral nervous system and the rest of the brain.

Reflex Arc

A relatively direct connection between a sensory neuron and a motor neuron that allows an extremely rapid response to a stimulus, often without conscious brain involvement.

sensory neurons

neurons that carry incoming information from the sensory receptors to the brain and spinal cord

Relay neurons

These connect the sensory neurons to the motor or other relay neurons. They have short dendrites and short axons.

motor neurons

neurons that carry outgoing information from the brain and spinal cord to the muscles and glands

Dendrites

Branchlike parts of a neuron that are specialized to receive information.

Axon

the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands

Neurotransmitters

chemical messengers that cross the synaptic gaps between neurons

Synapse

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron

Insulin

A hormone produced by the pancreas or taken as a medication by many diabetics

myelin sheath

A layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next.

Glucagon

A protein hormone secreted by pancreatic endocrine cells that raises blood glucose levels; an antagonistic hormone to insulin.

Glucose

the form of sugar that circulates in the blood and provides the major source of energy for body tissues. When its level is low, we feel hunger.

diabetes type 1

No insulin is produced. Either born with it or developed at a young age

diabetes type 2

A chronic condition where the body does not use insulin properly and becomes insulin resistant.

frontal lobe

A region of the cerebral cortex that has specialized areas for movement, abstract thinking, planning, memory, and judgement

occipital lobe

A region of the cerebral cortex that processes visual information

parietal lobe

A region of the cerebral cortex whose functions include processing information about touch.

temporal lobe

A region of the cerebral cortex responsible for hearing and language.

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

cellular respiration

Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen

Respiration

Inhalation and exhalation of air.