Apologia Biology, 2nd Edition, Module 13

Vertebrae

Segments of bone or some other hard substance that are arranged into a backbone.

Notochord

A rod of tough, flexible material that runs the length of a creature's body, providing the majority of its support.

Endoskeleton

A skeleton on the inside of a creature's body, typically composed of bone or cartilage.

Bone Marrow

A soft tissue inside the bone that produces bone cells.

Axial Skeleton

The portion of the skeleton that supports and protects the head, neck, and trunk.

Appendicular Skeleton

The portion of the skeleton that attaches to the axial skeleton and has the limbs attached to it.

Closed Circulatory System

A circulatory system in which the oxygen-carrying blood cells never leave the blood vessels.

Arteries

Blood vessels that carry blood away from the heart.

Capillaries

Tiny, thin-walled blood vessels that allow the exchange of gases and nutrients between the blood and the cells of the body.

Veins

Blood vessels that carry blood back to the heart.

Olfactory Lobes

The lobes of a brain that receive signals from receptors in the nose.

Cerebrum

The lobes of the brain that integrate sensory information and coordinate the creature's response to that information.

Optic Lobes

The lobes of a brain that receive signals from the receptors in the eyes

Cerebellum

The lobe that controls involuntary actions and refines muscle movement.

Medulla Oblongata

The lobes that coordinate vital functions, such as those of the circulatory and respiratory systems, and transport signals from the brain to the spinal cord.

Internal Fertilization

The process by which the male places sperm inside the female's body, where the eggs are fertilized.

External Fertilization

The process by which the female lays eggs and the male fertilizes them once they are outside of the female.

Oviparous Development

Development that occurs in an egg that is hatched outside the female's body.

Ovoviviparous Development

Development that occurs in an egg that is hatched inside the female's body.

Viviparous Development

Development that occurs inside the female, allowing the offspring to gain nutrients and vital substances from the mother through a placenta.

Anadromous

A life cycle in which creatures are hatched in fresh water, migrate to salt water as adults, and then go back to fresh water in order to reproduce.

Bile

A mixture of salt and phospholipids that aids in the breakdown of fat.

Atrium

A heart chamber that receives blood.

Ventricle

A heart chamber from which blood is pumped out.

Ectothermic

Lacking an internal mechanism for regulating body heat.

Hibernation

A state of extremely low metabolism and respiration, accompanied by lower-than-normal body temperatures