SBI3U Grade 11 Biology Body Systems Test

Biology Study Notes

Biological Systems:

1)  Biological Systems: Group of organs work together to perform a function

2)  Organ System: Group of 2 or more tissues working to do a task

3)  Tissues: Specialized cells doing a common function

4)  Cells: Basic unit of life

Respiratory: Gas exchange between organism and the environment

Circulatory: Transporting nutrients and other material to cells of the organism

Digestive: Breaks down food into smaller molecules so that it can be absorbed

Cellular Respiration:

Glucose + 6O2 -> 6CO2 + 6H2O + 36 ATP (energy for life)

Respiratory System


Basic requirements: Large resp. Surface: enough to meet requirements

Moist: dissolve gases

Exchange Methods: Simple Diffusion: short distances, concentration + -> low

Skin: capillaries under skin does gas exchange (worm)

Lungs: mammal vertebrate’s preferred mechanism

Human R System:


Nasal Cavity: Nostrils; take air in

Oral Cavity: Mouth; take air in

Nasal Passages: Thin bone turbinate cleans; mucus, moistens air

Pharynx: Trachea/Esophagus, connects mouth to larynx/esophagus

Epiglottis: Flap: prevents food from falling into trachea

Glottis: Opening of the windpipe.

Larynx: Two fold structure, holds voice box, large space, muscles contract closing gap between chords, causing different vibrations hence sound

Trachea: Tube supported by half circle cartilage, air transported

Bronchi: Passageway 1/lung, Trachea into bronchioles

Bronchioles: Network of finer tubes; bronchus to alveoli, moistens with mucus

Alveoli: thin grape sacks with film and capillaries, site of gas exchange through simple diffusion or facilitated diffusion (with help of protein push)

Diaphragm: muscle layer, separates stomach and lung, contracts during inhalation

Lungs: Deep into body, surrounded with pleura, land vertebrates, left lung 2 lobes


1)  Diaphragm: muscle contracts to make room for lung space

2)  Intercostal muscles: contracts to push ribs outwards to make more room


-Air pressure is the force exerted on a surface by molecules

-Under 2 vessels, air pressure tries to get an equilibrium

-As volume increases, air pressure decreases

-As volume decreases, air pressure increases

-Air molecules move around to try to achieve equilibrium

-Ribs+diaphragm expand

-increased volume (thoratic cavity)

-air pressure in lung low, air rushes in

-Ribs+diaphragm relax

-decreased volume

-air pressure in lung increases, air races out

External Respiration: blood and alveoli

-Adjacent to alveoli are capillaries

-blood in hemoglobin with iron attracts to oxygen and transports around

Internal Respiration

-Oxygen diffuses from blood, into cell

-Same but opposite with carbon dioxide

Cellular Respiration

-Uses oxygen to chemically react with glucose to make ATP

-CO2 and water as byproducts

Lung Capacity- Amount of air your lung can hold outside of normal breathing rates

Tidal Volume: amount intake during normal movement

Inspiratory Reserve Volume: any additional volume of air intake during inhalation

Expiratory Reserve Volume: any additional volume of air that can be forced out beyond regular or tidal expiration

Vital Capacity: Total of gas in and out

Residue Volume: amount of air that remains in the passage way after full expiration. Never leaves system

Respiratory Efficiency: Rate at which oxygen can be transferred

Brain Medulla controls breathing rates

Cardiovascular System

Five Functions

1)  Transports oxygen

2)  Removes wastes

3)  Transports nutrients

4)  Temperature regulation

5)  Disease fighting cells and hormones

Blood Vessels: Transports blood from one place to another

Heart: the pump

Blood: Medium used to carry around the body


Deoxygenated blood = blood without oxygen

Oxygenated blood = blood with oxygen

Red blood cells (w/o nucleus) carries hemoglobin in the centre, consisting of an iron ion that attracts to oxygen molecules.

Blood Vessels

Arteries: carry oxygenated blood away from heart

-Strong thick muscular wall

-Elastic and stretchy

In heart, Pulmonary Arteries take deoxygenated blood out.

Veins: returns deoxygenated blood to heart

-Thin, smooth, walls

-Contains one way valves to prevent backflow

-In heart, Arteries and Veins switch roles

-Lowest pressure

In heart, Pulmonary Veins bring oxygenated blood in.

Capillaries: smallest vessels, one cell thick, used for gas exchange

Sphincter: muscle that controls the flow of blood in the capillary bed.

Heart -> Arteries -> Arterioles (smaller arteries) -> Capillaries -> Venules (smaller veins) -> Veins -> heart.

Blood: transports gases and nutrients

(Red Blood Cells, White Blood Cells and Platelets are formed components of Blood)

1)  Red Blood Cells: Oxygen, Carbon dioxide, nutrients 1%

2)  White Blood cells: fight off foreign agents 1%

3)  Platelets: help blood clot  8%

4)  Plasma: water, help blood flow 90%


Coronary Circulation: Pathway Inside heart

Pulmonary Circulation: Pathway between heart and lung

Systemic Circulation: Pathway between heart and body

Heart: muscle organ left side of chest cavity under sternum


Atria: collecting blood when they return

-Both contracts at the same time

-Right atrium receives blood from body

-Left atrium receives blood from lung

Ventricles: contracts at the same time

-Right ventricle pumps blood through arteries to lung

-Left ventricle pumps through Aorta to body

-thick walls to resist gravity

Atrioventricular valves

-leads into ventricles

-Right = tricspid valve

-Left = bicuspid valve

Semilunar Valves

-Gateway to pulmonary artery and Aorta

-Aortic and pulmonary valve

-prevents backflow

Order of Heart cycle

Inferior Vena Cava

Right Atrium

Tricuspid Valve

Right Ventricle

Pulmonary Semilunar Valve

Pulmonary Artery


Pulmonary Vein

Left Atrium

Bicuspid Valve

Left Ventricle

Aortic Semilunar Valve



Cardiac Cycle: pumping and filling of blood in the heart, takes 0.8 seconds


-Atria contracts, pumping blood to right side

-Ventricles contract and push blood out of heart, atria starts to refill

-Right ventricle contracts and blood moves to the lung

-Left ventricle contracts and blood moves out.


-Blood flows into the atria

Electric conduction

SA Node: right of atria near top

-controls rate of heart: influenced by brain or hormones

-receives signals from brain, and sends it to AV node

Internodal Pathway

-Path between SA and AV node

AV Node

-connects to the Perkinje fibres and bundle of HIS to contract ventricle

-Delays to ensure Atria is empty and that ventricles contract together

Bundle of HIS

-Muscle tissue

Perkinje Fibres

-Wall of ventricles

-triggers actual contraction.

ECG- Electrocardiogram


-Pwave: contraction of Atria

-QRS: contraction of Ventricles

-Twave: rest phase

Cardiac Output: volume of blood pumped in 1 min. ~5L/min

Stroke Volume: mL of blood pumped per beat

Vo2 Max: maximum amount of oxygen that can be taken in through working muscles

Blood Pressure– force exerted by blood onto the vessel walls, measured with sphygmomanometer

Systolic Pressure

-pressure during contraction of heart

Diastole Pressure

-pressure during relaxation of heart

Hypertension: high blood pressure due to genetics/fat/diet/aging

Coronary Artery Disease: plaque build up in blood vessels (Atherosclerosis)

Angina: not enough oxygen to blood going through veins

-heart muscles suffocate, and get damaged

-over damage results in heart attack

Mycardial Infarction (heart attack): blood clot, not enough oxygen to heart, muscle death.

Digestion System

For breaking down food into smaller molecules so they can be diffused and absorbed into the body in a 24-33 hour process through Mechanical and chemical digestion.


Mouth– grinds food

Tongue– keeps food in place, taste, move food to rear of mouth and creates ball of food

Uvula– ball like structure, prevent entrance to pharynx when we swallow

Saliva Glands (Parotid, Sublingual, Submandibular): excretes saliva

-neutralizes PH to 7 with buffers

-Antibacterial agent

-salivary amalyse to break carbs


-Mucin protects mouth lining

Esophagus: tub lubricated with mucin

-muscle and mucin help push food down through peristalsis

-Peristalsis involves circular and longitudinal smooth muscles that surround the digestive tract and to move food the circular muscles over a food mass relaxes while the longitudinal muscles immediately in front of it contracts and the circular muscles immediately behind the food mass then contracts while the longitudinal relax as muscular regions relax and contract food is pushed along.

Stomach: Inner folds called Ruggae increase surface area

Gastric Glands release Gastric Juice (acid of ph 2)

-Kills bacteria

-Breaks cell matrix that glues cells together

Pyloric Sphincter opens way out the stomach

-Churns food into Chyme fluid to be taken out

-Elasticity helps it expand

Cardiac Orfice opens to the stomach

Small Intestine:

Duodenum: Opening of small intestine (first 30cm)

-Most folds, villi, and microvilli to absorb nutrients

-Intestinal juices chemically continue to break down food

Jejenum: meters long.

-Breaks own protein and carbs

Illeum: contains fewer and smaller villi, absorbs rest of nutrients

Large Intestine: absorbs water and minerals

-Caecum: closed end of large intestine

-Appendix: hangs separately to kill off disease

-Colon: main part of intestine (transverse, Ascending, descending)

Rectum: canal leading to anus (opening for feces to be excreted)

Macronutrients: large quantities, large molecules into sub units.

-Carbohydrates: sugars

-Lipids: fats

-Proteins: meat

Mechanical Digestion

-Mouth, jaw, tongue, teeth

-Break into smaller particles

-Help increase surface area for absorption

Chemical Digestion

-Acids, enzymes act on food and changes them into new substances

Hydrolysis: breaks down protein, carb, and fats

-adds an H2O molecule reacting to break chains of molecules

Enzymes: enzymes speed up by cutting these chains apart

-substrate specific: only work on certain molecules

-makes molecules small enough to diffuse

-Proteases: stomach: breaks protein

-Lipases: small intestine: breaks Lipases

Carbohydrases: Everywhere: breaks carbs

Salivary Amylase: mouth breaks carbs

-Pepsin: stomach: breaks protein

-Sensitive to high temperatures and PH level (e.g. Stomach)

-ions, helper enzymes, vitamines help enzymes do the right thing

-No enzymes in large intestine (water absorbed there)

Liver: produces bile to help break fat

-Lipase activated by bile salts

Pancreas: produces enzymes

-enzyme to neutralize chyme in duodenum small intestine

Gall Bladder

-stores bile salts



-Female rats have urinary aperture behind the vaginal orifice, a depression in the vulva

-Male rats have large scrotal sacs of testes covered in prepuce (skin surrounding penis). The end of penis has urogenital orifice to let out urine and sperm

Pericardium: thin layer surrounding the heart

-Rats have glycogen to transform waste

-Rats have no gall bladder to store bile

-Stomach outer margin is Greater Curvature, inner margin is called Lesser Curvature

Spleen destroys old blood cells and also stores blood when there’s too much

-Pancreas produces insulin for regulating glucose metabolism


-2 External Nares

-2 Tympani (eardrums)

-2 Internal Nares (in the mouth)

-Vomerine teeth in the middle, maxillary teeth on the side

-Urine from Kidney > Ureter > Kidney, then out through the cloaca

-Male frogs are smaller in size with thick, larger thumb pads.

-Nictitating membrane is the third eyelid