SCIENCE TEST CELLS AND SYSTEMS TERM 2

Oesophagus

Tube from mouth to stomach; uses peristalsis.

Stomach

Breaks down protein into amino acids.

Small Intestine

Breaks down carbs and fats; absorbs nutrients.

Large Intestine

Absorbs water and vitamins; houses helpful bacteria.

Liver

Makes bile, stores nutrients, breaks down toxins.

Gall Bladder

Stores bile for fat digestion.

Pancreas

Makes enzymes and insulin to help digestion and blood sugar control.

Lungs

Breathe in oxygen, breathe out carbon dioxide and water.

Trachea

Windpipe; carries air to lungs.

Bronchi

Tubes that lead into the lungs.

Alveoli

Alveoli are tiny air sacs in the lungs where oxygen enters the blood and carbon dioxide is removed through gas exchange.

Diaphragm

Muscle under lungs that helps with breathing.

Respiration

Glucose + Oxygen → Carbon dioxide + Water + Energy

Heart

Pumps blood around the body using two circuits.

Capillaries

Tiny vessels where nutrients and gases are exchanged.

Red blood cells

Carry oxygen around the body.

White blood cells

Fight infections and disease.

Platelets

Help blood clot.

Plasma

Watery part of blood carrying everything else.

Skeleton

Supports and protects the body; helps us move.

Compact bone

Strong outer layer of bone.

Spongy bone

Light inner bone with marrow.

Hinge joint

Movement in one direction (e.g. knee).

Ball and socket joint

Rotating movement (e.g. shoulder).

Pivot joint

Turning movement (e.g. neck).

Saddle joint

Movement in two directions (e.g. thumb).

Cartilage

Cushions joints and stops bones rubbing.

Ligaments

Connect bones to each other.

Tendons

Connect muscles to bones.

Synovial fluid

Lubricates joints.

Excretion

Removal of waste products made by the body.

Skin

Sweats out water, salts, and waste.

Kidneys

Filter blood and remove urea.

Urinary tract

Kidneys → Ureters → Bladder → Urethra.

Urine

Mostly water; contains urea and other waste.

High blood pressure

Can damage kidney filtering.

Kidney stones

Hard crystals that may block kidney tubes.

Urinary tract infection

Caused by bacteria like E. coli entering urethra.

Cells

Building blocks of life

Eyepiece (Ocular lens)

The lens you look through, usually magnifies 10×.

Objective lenses

Different lenses (low, medium, high power) that zoom in on the specimen.

Stage

Flat surface where you place the slide.

Stage clips

Hold the slide in place.

Light source

Shines light through the specimen so you can see it.

Arm

Used to carry the microscope.

Base

Bottom of the microscope; supports it.

Coarse focus knob

Moves stage up/down a lot to focus on low power.

Fine focus knob

Makes small adjustments for a clearer image, used on high power.

Cell wall

Only in plant cells; provides shape and support.

Unicellular (single cellular)

One cell does everything (e.g., bacteria, amoeba).

Multicellular

Many cells work together and are specialized (e.g., humans, plants, animals).

Organelle

e.g., mitochondria.

Cell

Basic unit of life.

Tissue

Group of similar cells, e.g., muscle.

Organ

e.g., heart, lungs.

Organ system

e.g., circulatory system.

Organism

Whole living thing.

Role of the Digestive System

Breaks down food into nutrients the body can absorb and gets rid of undigested waste.

Mechanical Digestion

Physical breakdown of food.

Chemical Digestion

Enzymes & acids break food into molecules.

Mouth

Chews food (mechanical), saliva starts digestion (chemical).

Esophagus

Pushes food to stomach using peristalsis (muscle movement).

Stomach

Churns food, adds gastric juices and acid.

Small intestine

Absorbs nutrients into bloodstream.

Large intestine

Absorbs water and forms feces.

Rectum & Anus

Stores and removes waste.

Liver

Produces bile (breaks down fat).

Gallbladder

Stores bile.

Small intestine villi

Absorb nutrients → pass into capillaries → carried by blood to body cells.

Role of the Respiratory System

Brings oxygen in and removes carbon dioxide.

Pathway of Air

Nose/Mouth - Air enters, filtered; Trachea - Windpipe; Bronchi - Two tubes entering lungs; Bronchioles - Smaller air tubes; Alveoli - Tiny air sacs where gas exchange happens; Diaphragm - Muscle below lungs, controls breathing.

Cilia and mucus

Trap dust and germs, prevent infections and protect lungs.

Oxygen from alveoli

Diffuses into capillaries.

CO₂ movement

Moves from blood into alveoli to be exhaled.

Heart Structure

4 chambers: Right atrium, Right ventricle, Left atrium, Left ventricle; Valves prevent backflow.

Pulmonary Pathway

Heart → Lungs → Heart; Picks up oxygen.

Systemic Pathway

Heart → Body → Heart; Delivers oxygen to body.

Deoxygenated Blood

Low oxygen, more CO₂; Dark red/blue; Found in the right side of heart, veins.

Oxygenated Blood

Lots of oxygen; Bright red; Found in the left side of heart, arteries.

Red Blood Cells

Carry oxygen using hemoglobin; Made in bone marrow.

Arteries

Carry blood away from heart; Thick muscular walls for high pressure.

Veins

Carry blood to the heart; Thinner walls, valves to stop backflow.

Capillaries

Exchange gases & nutrients; 1-cell thick walls for easy diffusion.

Purpose of the Skeleton

Support body shape; Protect internal organs; Help with movement; Make blood cells (in bone marrow).

Fixed Joint

No movement; Example: Skull.

Gliding Joint

Slides over each other; Example: Wrists, ankles.

Skull

Location: Head.

Clavicle

Location: Collarbone.

Ribs

Location: Chest cage.

Spine

Location: Backbone.

Pelvis

Location: Hips.

Humerus

Location: Upper arm.

Radius

Location: Forearm (thumb side).

Ulna

Location: Forearm (pinky side).

Femur

Location: Thigh bone (largest bone).

Tibia

Location: Shin bone (front).

Fibula

Location: Next to tibia.

2 systems that distribute blood

Systemic circulation and pulmonary circulation. Systemic circulation sends oxygen-rich blood from the heart to the body, while pulmonary circulation sends oxygen-poor blood to the lungs and brings oxygen-rich blood back to the heart.

What happens to your respiratory system when you excercise?

You breathe faster and deeper to bring in more oxygen and remove carbon dioxide.

What happens to your circulatory system when you excercise?

Your heart beats faster to pump oxygen and nutrients to your muscles.