Year 9 Biology – Skeleton, Muscles & Excretion

A set of vocabulary flashcards covering bones, muscles, joints, and excretory system terms for Year 9 Biology revision.

Skeleton

The body’s framework of bones that provides support, protection, shape and a surface for muscle attachment.

Axial Skeleton

The part of the skeleton consisting of the skull, vertebral column, and rib cage.

Appendicular Skeleton

The part of the skeleton made up of the limbs and girdles (shoulder and pelvic).

Femur

The thigh bone; the longest and strongest bone in the human body.

Tibia

The larger, weight-bearing bone of the lower leg, commonly called the shinbone.

Pelvis

The basin-shaped bony structure that supports the spine and houses organs of the lower abdomen.

Humerus

The bone of the upper arm that runs from the shoulder to the elbow.

Vertebrae

Individual bones that make up the spine, protecting the spinal cord.

Cranium

The portion of the skull that encloses and protects the brain.

Sternum

The flat bone in the centre of the chest to which the ribs attach anteriorly.

Rib Cage

The set of ribs that protects the heart and lungs and assists breathing.

Phalanges

The bones of the fingers and toes.

Metacarpals

The five long bones in the hand located between the wrist and the fingers.

Metatarsals

The long bones in the foot located between the tarsals and the phalanges.

Tarsals

The seven ankle bones that connect the foot to the lower leg.

Joint

A point where two or more bones meet, allowing movement.

Tendon

Strong, fibrous connective tissue that attaches muscle to bone.

Ligament

Tough connective tissue that connects bone to bone at a joint.

Cartilage

Flexible connective tissue that reduces friction and absorbs shock at joints.

Antagonistic Pair

Two muscles that work opposite each other; as one contracts, the other relaxes (e.g., biceps and triceps).

Biceps

The muscle on the front of the upper arm that flexes the elbow.

Triceps

The muscle on the back of the upper arm that extends the elbow.

Skeletal Muscle

Voluntary muscle attached to bones and responsible for body movement.

Cardiac Muscle

Involuntary, striated muscle found only in the heart and responsible for pumping blood.

Smooth Muscle

Involuntary, non-striated muscle found in walls of internal organs such as the intestines and blood vessels.

Voluntary Muscle

Muscle whose movement is consciously controlled (primarily skeletal muscle).

Involuntary Muscle

Muscle that works automatically without conscious control (cardiac and smooth muscle).

Flexion

A bending movement that decreases the angle between two body parts.

Extension

A straightening movement that increases the angle between body parts.

Calcium

The mineral stored in bones that provides hardness and is essential for muscle contraction and nerve function.

Kidney

An excretory organ that filters blood to produce urine and maintain water and salt balance.

Nephron

The microscopic filtering unit of the kidney where blood filtration and urine formation occur.

Ureter

The tube that carries urine from a kidney to the bladder.

Bladder

The muscular sac that stores urine before it is expelled from the body.

Urethra

The tube through which urine leaves the body from the bladder.

Excretion

The removal of metabolic wastes (such as urea, excess water, and salts) from the body.

Urine

The liquid waste produced by the kidneys, containing urea, water, salts, and other dissolved substances.

Hinge joint

Back and forth movement

Saddle joint

Allows movement back and forth in 2 different directions

Ball and socket

Allows full rotation movement

Pivot