Biology Study Notes: Cells and Human Body Systems

Vocabulary practice flashcards covering cell organelles, the digestive system, the respiratory system, the circulatory system, the nervous system, and the muscular system.

Cell membrane

Controls what enters and leaves the cell.

Cytoplasm

Jelly-like material where many cell reactions happen.

Nucleus

Contains DNA and controls the cell’s activities.

Mitochondria

Release energy from glucose during cellular respiration.

Ribosomes

Make proteins.

Rough endoplasmic reticulum (rough ER)

Has ribosomes; helps make and transport proteins.

Smooth endoplasmic reticulum (smooth ER)

Makes lipids and helps process some substances.

Golgi apparatus

Modifies, sorts and packages proteins and lipids.

Vacuole

Stores water, nutrients or waste; plant cells often have a large central vacuole.

Chloroplasts

Organelles in plant cells that absorb light for photosynthesis.

Cell wall

Structure in plant cells that supports and strengthens the cell.

Salivary glands

Produce saliva, which contains enzymes such as amylase.

Peristalsis

Muscular waves that move food along the digestive tract.

Liver

Produces bile, which helps break large fat droplets into smaller droplets.

Gallbladder

Stores and releases bile.

Pancreas

Releases digestive enzymes and bicarbonate into the small intestine.

Duodenum

First part of the small intestine; receives bile and pancreatic juices.

Jejunum and ileum

Parts of the small intestine where much nutrient absorption occurs.

Villi

Tiny finger-like projections that increase the small intestine’s surface area for absorption.

Microvilli

Even smaller projections on cells that increase surface area further.

Lacteal

A small lymph vessel in a villus that absorbs many digested fats.

Large intestine (colon)

Absorbs water and salts and forms faeces.

Pharynx

Passageway carrying air from the nose or mouth towards the larynx.

Larynx

Contains the vocal cords and connects the pharynx to the trachea.

Trachea

Windpipe that carries air towards the lungs and is supported by cartilage rings.

Bronchi

Two main branches from the trachea, one leading to each lung.

Bronchioles

Smaller airways that branch through the lungs.

Alveoli

Tiny air sacs where oxygen and carbon dioxide are exchanged with the blood.

Diaphragm

Muscle beneath the lungs that contracts and flattens during inhalation.

Intercostal muscles

Muscles between the ribs that help move the chest during breathing.

Right atrium

Heart chamber that receives oxygen-poor blood from the body.

Right ventricle

Heart chamber that pumps oxygen-poor blood to the lungs.

Left atrium

Heart chamber that receives oxygen-rich blood from the lungs.

Left ventricle

Heart chamber that pumps oxygen-rich blood around the body; has a thick muscular wall.

Septum

Wall separating the right and left sides of the heart.

Aorta

Carries oxygen-rich blood from the left ventricle to the body.

Venae cavae

Return oxygen-poor blood from the body to the right atrium.

Pulmonary artery

Carries oxygen-poor blood from the right ventricle to the lungs.

Pulmonary veins

Carry oxygen-rich blood from the lungs to the left atrium.

Arteries

Carry blood away from the heart; usually have thick, elastic walls.

Veins

Carry blood towards the heart; often have valves.

Capillaries

Very thin vessels where substances are exchanged with tissues.

Platelets

Blood components that help blood clot.

Plasma

Liquid part of blood that transports cells and dissolved substances.

Cerebrum

Part of the brain responsible for thinking, memory, interpreting senses and voluntary movement.

Cerebellum

Part of the brain responsible for balance, posture and coordination.

Brainstem

Part of the brain that controls automatic functions such as breathing and heart rate.

Neuron

A specialised nerve cell that carries messages.

Dendrites

Receive signals from other cells.

Axon

Carries a nerve impulse away from the cell body.

Myelin sheath

Insulates some axons and helps signals travel faster.

Synapse

Small gap where a signal is passed from one cell to another, often using chemicals.

Sensory neuron

Carries information from receptors towards the central nervous system.

Relay neuron

Connects neurons within the central nervous system.

Motor neuron

Carries signals from the central nervous system to a muscle or gland.

Central nervous system (CNS)

Division of the nervous system consisting of the brain and spinal cord.

Peripheral nervous system (PNS)

Division of the nervous system consisting of nerves outside the brain and spinal cord.

Skeletal muscle

Usually voluntary; attached to bones and moves the skeleton.

Smooth muscle

Involuntary; found in walls of organs such as the intestines and blood vessels.

Cardiac muscle

Involuntary muscle found only in the heart.

Tendon

Connects muscle to bone.

Ligament

Connects bone to bone.

Antagonistic pair

Two muscles that work opposite each other; one contracts while the other relaxes.