Cell Biology and Human Body Systems Flashcards

Comprehensive vocabulary flashcards covering cell organelles, specialized cells, cellular processes, plant tissues, and human organ systems.

Organelle

A specialised structure inside a cell that performs a specific job to help the cell function properly.

Nucleus

The control centre of the cell that contains DNA which contains genetic information for new cells and tells the cell what to do.

Cell Membrane

A thin and flexible semi-permeable layer that surrounds the cell and controls what goes in and out.

Cell Wall

A strong, rigid outer layer that surrounds the cell membrane in plant cells, fungi, and some bacteria. It gives the cell shape, strength, and protection. Provides support for the cell and provides resilience from water changes.

Ribosome

Tiny organelles which synthesise proteins. Found free or attached to the rough ER.

Mitochondria

The organelles where cellular respiration occurs. Respiration uses glucose and oxygen to make energy/ATP. Has a folded surface to maximise surface area for respiration to take place.

Cytoplasm

A jelly-like substance inside the cell that supports and cushions all of the organelles contained and where chemical reactions happen.

Chloroplasts

Green structures in plant cells where photosynthesis happens - where plants manufacture glucose. Stacked compartments to maximise surface area.

Vacuoles

Storage spaces in cells that hold water, food, or waste. Plant cells usually have one large vacuole.

Guard Cells

Pair of cells surrounding stomata. Contain a large vacuole and cell walls of different thickness. Ample water = vacuole full = cells both have a bean shape = open stoma. Low water = shape is thin = closed the stoma preventing water loss.

Root Hair Cells

Specialised cells found on the surface of roots. They have long, thin extensions that increase the surface area to help the plant absorb more water and minerals from the soil.

Red Blood Cells

Cells that carry oxygen around the body using a protein called haemoglobin. They have no nucleus so they can carry more haemoglobin and oxygen and they have a hollowed out biconcave shape to increase the surface area.

Nerve Cells

Long, thin cells that send messages between the brain and body (also called neurons). Long so they can send messages across long distances. Multiple dendrites to allow them to make many connections.

Specialised cells

Cells that have a specific job in the body and a structure suited to that job. For example, red blood cells carry oxygen, and nerve cells send messages.

Muscle cells

An elongated cell that can contract to allow movement. They have lots of mitochondria to provide the energy needed for this work.

Organism

Any living thing - it can be as simple as one cell or as complex as a human.

Tissue

A group of the same type of cells working together to do a specific job.

Organ

A structure made up of different tissues that work together to perform a job (e.g. heart, brain).

Cell

The basic building block of all living things.

System

A group of organs working together to carry out a major function in the body (e.g. digestive system).

Cell Theory

Three main ideas about cells: 1. All living things are made of cells. 2. Cells are the basic units of life. 3. All cells come from existing cells.

Unicellular

Means it is only made up of one cell. And that one cell does all the functions of life (like eating, moving, reproducing etc.).

Multicellular

Means the organism is made up of many cells. This means those cells usually have specialised jobs (like skin cells, muscle cells etc.).

Xylem

A plant tissue made of dead, hollow cells that form long tubes. It transports water from the roots to the leaves and helps support the plant.

Transpiration

The process where water evaporates from the leaves of a plant (through stomata), creating a suction pull that helps draw more water up from the roots.

Circulatory system

The body system that moves blood around the body, delivering oxygen and nutrients to cells and removing waste products like carbon dioxide.

Valves

One way gate-like structures inside the heart and veins that prevent blood from flowing backward, ensuring it moves in the right direction.

Arteries

Blood vessels that carry oxygen-rich blood away from the heart to the body's tissues. They have muscular, elastic walls that carry blood under high pressure.

Veins

Blood vessels that carry oxygen-poor blood back toward the heart at low pressure. They have thinner walls and often have valves to stop backflow.

Capillaries

Tiny, thin blood vessels where exchange happens between blood and body cells - oxygen and nutrients pass out, and waste moves in.

Respiratory system

The body system responsible for bringing oxygen into the body and removing carbon dioxide. It includes the lungs and airways and works closely with the circulatory system.

Bronchus

Two large tubes that branch off from the trachea - one going into each lung. They carry air into the lungs.

Bronchiole

Smaller branches of the bronchi inside the lungs. They spread air throughout the lung and lead to the alveoli.

Trachea

The main airway that carries air from the nose/mouth down toward the lungs. It connects to the bronchi. Contains c shaped rings of cartilage to keep it open.

Alveoli

Tiny air sacs at the end of the bronchioles. This is where gas exchange happens - oxygen enters the blood and carbon dioxide leaves the blood. High surface area and good blood supply.

Larynx

A part of the throat that contains the vocal cords. It helps you speak and is located between the pharynx and trachea.

Pharynx

A passage behind the nose and mouth that leads to both the trachea (airway) and oesophagus (food pipe). It's part of both the respiratory and digestive systems.

Diaphragm

A large, dome-shaped muscle under the lungs that helps you breathe. When it contracts (moves down), your lungs fill with air. When it relaxes (moves up), air is pushed out.

Oesophagus

A muscular tube that connects the mouth to the stomach. It moves food down using wave-like muscle movements called peristalsis.

Stomach

A stretchy, muscular organ that stores food and breaks it down using strong acids and enzymes to turn it into a liquid mixture.

Liver

A large organ that makes bile (a fluid that helps digest fats), stores nutrients, and removes toxins from the blood.

Pancreas

An organ that produces digestive juices to help break down proteins, fats, and carbs. It also helps control blood sugar.

Small intestine

A long, narrow tube where most digestion and nutrient absorption happens. It's lined with tiny finger-like villi to absorb nutrients into the blood.

Large intestine

A wider, shorter tube that absorbs water and minerals from food waste and turns the rest into solid waste (faeces).

Rectum

The final part of the large intestine that stores solid waste until it's ready to leave the body.

Anus

The opening at the end of the digestive system where waste exits the body.

Bones

Hard, strong structures that make up the skeleton. They support the body, protect organs, store minerals, and help with movement.

Muscles

Soft tissues that can contract (shorten) and relax to create movement in the body. Muscles work in pairs and are attached to bones.

Joints

Places where two or more bones meet. Joints allow the body to move and bend in different directions (like knees, elbows, and shoulders).

Tendons

Strong, stretchy cords that connect muscles to bones. They help move the bones when muscles contract.

Ligaments

Tough bands of tissue that connect bones to other bones at joints. They keep the joints stable and prevent too much movement.

Cartilage

Strong flexible connective tissue. Supports structures, cushions joints.

Respiration

The process where cells break down glucose (sugar) using oxygen to release energy. This energy is used for everything a cell needs to do to stay alive.

Photosynthesis

The process where plants use sunlight, carbon dioxide, and water to make their own food (glucose) and release oxygen. It happens in the chloroplasts of plant cells.