Module 3- Exchange and Transport

Section 1: Exchange and Transport S

What do cells exchange with their environment?

• Oxygen

• Glucose

• Carbon Dioxide

• Urea

Do smaller animals have a higher or lower surface area?

Higher

How does diffusion happen in a single celled organism?

Directly across the cell surface membrane

Why is diffusion faster in single celled organisms?

Small distances to travel

How would you describe the surface area to volume ratio of a larger animal?

Low

Whay is it difficult to exchange enough substances in a animal?

They have a higher metabolic rate and use up oxygen and glucose faster

What are the features of most exchange surfaces?

• Large Surface Area

• Thin

• Good Blood Supply and Ventilation

How are root hair cells adapted for function?

Have long hairs which stick out into the soil with each branch covered in millions of microscopic hairs

What do root hair cells microscopic hairs do?

The roots have a large surface area which increases the rate of absorption of water and mineral ions

How is the Alveoli adapted to its function?

A thin layer of alveolur epithelium cells

Surrounded by a large capillary network

Why is the thin layer of alveolur epithelium cells in beneficial?

Decreases the distance which O2 and CO2 diffuse over

How does gas exchange work?

O2 Diffuses out of the alveolur space into the blood and Co2 diffuses in the opposite direction

How is the large capillary network beneficial to the alveolus?

Each alveolus has its own blood supply which constantly takes oxygen away from the alveoli and brings more carbon dioxide

What do the good supply of blood and vetilation help maintain in the lungs?

Maintain concentration gradient of O2 and Co2

How are fish gills adapted to its function?

• Large network of capillaries

• Well ventilated

How are fish well ventilated and how does this increase rate of reaction?

Constant flow of water

Maintains a concentration gradient of oxygen

What is the pathway of air in mammals?

Trachea

Bronchi

Bronchus

Bronchioles

Alveoli

What work together to move air in and out of mammals?

Ribcage

Intercostal muscles

Diaphragm

What is the function of Goblet cells?

Secret mucus

Where are goblet cells found?

Line the airways

What do the goblet cells mucus do?

Traps microorganisms and dust particles in the inhaled air stopping them reaching the alveoli

What do the cillia do?

Moves mucus upward away from the alveoli towards the throat

Where are cillia found

Surface of cells lining the airways

What do cillia prevent?

Lung infections

What is the function of elastic fibres in the walls of the trachea, bronchi, bronchioles and alveoli?

Help the process of breathing out

What happens to the elastic fibres when breathing in?

They stretch and recoil to help push air out

What do smooth muscle in the walls of the trachea, bronchi, bronchioles and alveoli do?

Allows their diameter to be controlled

What happens to the smooth muscle during excercise?

Relaxes making the tubes wider

What do rings of cartilage in the walls of the trachea do?

Provide support

Prevent collapsing when the pressure drops

What shape cartilage does the trachea have?

Large C shaped pieces

Does the trachea have Smooth muscle ?

YES

Does the trachea have elastic fibres?

YES

Does the trachea have Goblet cells

YES

What is the epithelium like in the trachea?

Cilliated

What is the bronchi cartilage like?

Smaller pieces

Does the bronchi have smooth muscle?

YES

Does the larger bronchiole have smooth muscle?

YES

Does the smaller bronchiole have smooth muscle?

YES

Does the smaller bronchiole have smooth muscle?

YES

Does the smallest bronchiole have smooth muscle?

NO

Does the alveoli have smooth muscle?

NO

What is the larger bronchiole cartilage like?

Doesnt have any

What is the smaller bronchiole cartilage like?

Doesnt have any

What is the smallest bronchiole cartilage liek?

Doesnt have any

What is the alveoli cartilage like?

Doesnt have any

Do the trachea, bronchi, larger smaller and smaller bronchi and alveoli have elestic fibres?

YES

Does the larger bronchiole have goblet cells?

YES

Does the smaller bronchiole have goblet cells?

NO

Does the smallest bronchiole have goblet cells?

NO

Does the alveoli have goblet cells?

NO

What are the bronchi epithelium cells like?

Cilliated

What are the larger bronchiole epithelium cells like?

Cilliated

What are the smaller bronchiole epithelium cells like?

Cilliayed

What are the smallest bronchiole epithelium cells like?

No cillia

What are the larger alveoli epithelium cells like?

No cillia

What happens to the external intercostal and diapragm during inspiration?

Contract

During inspiration how does the ribcage move?

Upwards and outwards

How does the diaphragm move in inspiration?

Flattens and increases volume

What happens when the thorax volume increases?

The lung pressure decreases

What can inspiration be described as?

An active process requiring energy

What happens to the external intercostal muscles and diaphragm during expiration?

Relax

How does the ribcage move during expiration?

Downwards and inwards

What happens to the diaphragm during expiration?

Becomes curved

What happens to the thorax during expiration what does this do to pressure?

Decreases

Increases the air pressure

What is normal expiration?

A passive procuess

What is tidal volume?

Volume of air in each breath

What is the vital capacity?

Maximum volume of air that can be breathed in or out

What is breathing rate?

Breaths taken usually in a minute

What is oxygen uptake?

Rate at which an organism uses up oxygen

How does a spirometer work?

1. Oxygen filled chamber with a moving lid

2. The person breathes through a tube connected to an oxygen chamber

3. The lid moves up and down

4. Theres movements can be recorded by a pen attached to the lid which writes on a rotating drum creating the spirometer trace

5. The soda lime in the tube absorbs the carbon dioxide

What is gaseous exchange in fish?

1. Water enters through its mouth and passes out through the gills

2. The gill has gilll filaments or primary lamellae giving a suface area for exchange which is then covered in secondary lamallea

3. The gill plates have lots of blood capillaries and thin surface area

4. Blood flows through the gill plates in one direction and water flows opposite direction

What is the gaseous exchange system of a fish known as?

Countercurrent

What is each gill in a fish supported by?

A gill arch

How are gills ventilated?

1. The fish opens its mouth whihc lowers the floor of the buccal cavity sucking water in

2. when its mouth is closed the floor of buccal caivty is raised focing water out across gill filaments

3. The operculum is forced open allowing water to leave the gills

What happens to the pressure when a fish opens its mouth?

The volume of the buccal cavity increases decreasing pressure in cavity

What happens to the pressure when a fish closes its mouth?

The volume of the buccal cavity decreases increasing pressure in cavity

What are insects air filled pipes called?

Tracheae

How does air move through an insect

1. Air moves into tracheae through spiracles

2. Oxygen travels down the concentration gradient towards the cells carbon dioxide moves down its own gradient to be releases

3. The tracheae branches to tracheole which have thin permeable walls and go to individual cells containing fluid for oxygen to dissolve in

4. Oxygen then dossolves from this fluid into body cells and carbon dioxide diffusing in the opposite direction

How do insects change the volume of their body?

Rhythmic abdominal movements

How can you dissect insects?

1. Attatch to a dissecting board

2. Cut and remove exoskeleton

3. Fill the abdomen with saline solution revealsing the tracheae

4. Examine under microscope

How can you dissect fish?

1. Place fish of dissection board

2. Push back operculum and remove gills

3. Look closely

What do mammals use to carry nutrients?

Blood

What type of circulatory system do fish have?

Single

What type of circulatory system do mammals have?

Double

How many times does blood pass the heart in a double circulatory system?

Twice

How does blood pass around the body in fish?

1. Heart pumps blood to the gills

2. Then through the rest on the body in a single circuit

How does blood pass around the body in mammals?

1. Right side pumps blood to the lungs

2. From the lungs it travels to the left of the heart which pumps to the rest of the body

3. When the blood returns to the heart it enters the right side

What circulatory system do verterbrates have?

Closed

How does blood travel in closed systems?

1. Heart pumps blood into arteries (branch out in capillaries)

2. Substances like oxygen and glucose diffuse from blood into capillaries into the body cells leaving the blood in the vessels

3. Veins take blood back to the heart

What trype of blood system do inverterbrates have?

Open

How does blood travel in an intertebrate

1. Heart contracts in a wave starting from mthe back and pumping the blood into a single main artery

2. The artery opens up into the body cavity

3. The blood flows around the insects organs gradually returning to the heart segments through valves

What does an insects circulatory system not do?

Supply it with blood

What do the hearts valves prevent it from?

Back flow

What do the atrioventricular valve link?

Artia and the Ventricles

What do the semi-lunar vavles link?

Ventricles

Pumonary Artery

How do valves prevent backflow?

• Only open one way (open or closed depends on relative pressure)

• If higher pressure is behind the valve its forced open

• If higher pressure in front on the valve it is forced shut

What is the cardiac sequence?

An ongoing sequence of contraction and relaxation keeping blood continously circulating

What is the first stage of the cardiac cycle?

The ventricles relax and the atria contract

What happens when the ventricles relax and the atria contract?

The volume decreases and the pressure increases pushing blood into the ventricle

Through what valve is blood pushed into the ventricle?

Antrioventricular valve