Chapter 6 - Distribution of Materials1 Distribution of Materials Outcome 2 Chapter 6 p128-173.

Chapter 6 - Distribution of Materials 1

Distribution of MaterialsOutcome 2

Chapter 6

p128-173


Blood - A Transporting Tissue

Blood is the link between the external environment and all the cells of the body.

The blood volume of an average adult male is between 5-6 litres.

Blood is made up of cells suspended in plasma, a straw coloured liquid.



Red Blood Cells (erythrocytes)

Blood appears red in colour due to the red blood cells.

They contain haemoglobin, an iron rich protein that combines readily with oxygen.

There is approximately 5.4 million rbc’s per mm3 of blood.



White Blood Cells (leucocytes)

The general function of white blood cells is to combat infection.

White blood cells are phagocytotic, which means they ingest bacteria and other foreign materials.

There are about 5000-7000 wbc’s per mm3 of blood.



Platelets

Blood contains about 250-500 thousand platelets of per mm3.

If there is damage to blood vessels, platelets initiate a chain of reactions that results in blood clotting.

Platelets are also involved in immune responses such as inflammation.


Survival Rate of Blood Cells

Mature red blood cells have no nuclei.

The membrane of a rbc breaks down after 120 days.

Dead rbc’s are discarded in the liver and spleen.

The body replaces rbc’s at a rate of 2.5 million per second.



White blood cells live for varying amounts of time.

Healthy wbc’s last for a few days.Wbc’s that fight infection only last for a few

hours.

Platelets only last for about a week.


Vessels That Carry Blood

Arteries Arteries are thick-walled vessels that carry

oxygenated blood away from the heart.

Eventually arteries branch into smaller and smaller arteries.

The smallest arteries are called arterioles and they enter muscle and tissue to supply oxygen.



Capillaries

Are microscopic vessels with walls that are one cell thick.

Nutrients and gases diffuse from the blood into tissue fluid that surrounds the cells of the body.



Veins Blood moves from the capillaries into venules,

which combine to form larger vessels called veins.

These vessels return deoxygenated blood back to the heart.

The pressure of blood in veins is lower than in arteries. Veins have muscles that surround them to help push the blood along back to the heart.


The Heart


The Heart

Blood must be continually on the move –

To collect oxygen from the lungs.To collect nutrients from the intestines.To transport nutrients and oxygen to all parts of

the body.To carry carbon dioxide and wastes away to

specialised waste removal organs.


The Heart

The heart can be thought as two pumps joined together.

The right side receives deoxygenated blood from the body and pumps it to the lungs.

The left side receives oxygenated blood from the lungs and pumps it to the whole body.


Main Structures of the Heart

Each side of the heart is separated by the septum.

Each side of the heart has 2 chambers, an atrium and ventricle. Blood enters the atrium and exits the ventricle.

Atriums have thin muscle lining, while ventricles have a thick lining. Why?



The right ventricle pumps blood to the lungs via the pulmonary artery.

Reverse blood flow is restricted by valves – folds of skin supported by elastic strands.Tricuspid valveBicuspid valveSemi-Lunar valve



Blood travels back from the lungs to the left side of the heart via the pulmonary vein.

It is then squeezed out of the left ventricle into the aorta to be sent to the body.


The Lymphatic System

As seen earlier, nutrients and oxygen diffuse from capillaries into tissue fluid between cells.

Some of these substances move back into the capillaries, most stays in the tissue spaces.

Excess tissue fluid is collected by a special series of vessels that make up the Lymphatic System.



Lymph capillaries are small vessels that transports tissue fluid (lymph) up to subclavian vein, where it is returned to the bloodstream.

Lymph is strained through lymph nodes where any bacteria and foreign material are destroyed and broken down.


Breathe or Die

During cellular respiration -

The carbon dioxide produced is a waste product and needs to be removed from the body.

If carbon dioxide is not removed – the life threatening condition of acidosis begins to develop.

Energy

Glucose + Oxygen Carbon Dioxide + Water


Breathe or Die

Circulating blood is the vehicle that transports carbon dioxide from the tissues to the lungs.

In blood, carbon dioxide is transported in three ways:

• As carbon dioxide dissolved in the plasma (about 8%)• Bound to haemoglobin in red blood cells (about 11%)• As bicarbonate ions in the plasma (81%)


The Respiratory System


The Respiratory System

Breathing In & Out – What Happens? p146


The Respiratory SystemStructure Function

•Pharynx

•Larynx

•Epiglottis

•Trachea

•Bronchus

•Bronchioles

•Lungs

•Alveolar Duct

•Alveoli


Nitrogenous Waste

When animals metabolise protein – nitrogen containing compounds are produced as wastes (fig 13.3).

These compounds must be removed or they will accumulate to damage tissue and cause death.

The elimination of nitrogenous wastes from an organism is called excretion.


Nitrogenous Waste

Different animals excrete different nitrogenous wastes.

Ammonia is toxic to cells and must be diluted and excreted with lots of water.

Uric Acid is least toxic and requires little water for excretion.

Urea is the main waste of humans and requires some water for removal.


Organs of Excretion

The Skin

An average adult has nearly 2 square metres of skin containing over 2.5 million sweat glands.

Sweat is a dilute solutions of salts which contains:

Sodium chloride Low levels of nitrogenous wastes


Organs of Excretion

The Liver

The liver is responsible for breaking down a number of substances in the body.

Bilirubin (by-product of dead rbc’s) Amino groups into ammonia Drugs and other chemicals

Once broken down the liver sends these substances to the kidneys for excretion.


Organs of Excretion

The Lungs

The lungs are internal structures shaped like a cavity or sac – with many pouches or lobes that increase the surface area.

Carbon dioxide is transported in the blood to the lungs where it diffuses into the lungs and is breathed out.


The Urinary System

Water concentration in the body must be regulated to ensure water gains and losses are balanced.

The urinary system plays a significant role in eliminating nitrogenous wastes from the body.

It does this by:

• Filtering blood• Removing the wastes• Producing urine


The Urinary System


The Kidneys

The kidneys play a major role in stabilising the internal environment of the body.

The kidneys filter the blood, remove wastes and produce urine.

The kidneys also excrete hormones, vitamins and maintain the balance of pH and salts in the body.


The Kidneys

Blood enters the kidney via the renal artery and leaves via the renal vein.

After filtration, wastes products (urine) exit the kidney via the ureter which is connected to the bladder.

The outer most layer of the kidney is the cortex. Beyond the cortex is a striated layer called the medulla.


The Kidneys

The functional unit of the kidney is called a nephron. Each kidney contains approximately 1 million nephrons.

The renal artery branches into smaller arterioles and capillaries which are surrounded by nephrons. These small clusters of blood vessels are called a glomerus.


The Kidneys

Waste materials are filtered from the blood in the glomerus.

High pressure formed in the capillaries squeezes the plasma out of the blood into the Bowman’s Capsule in the nephrons.

Substances such as water, glucose, amino acids, sodium chloride and phosphates are reabsorbed into the blood via active transport and diffusion.


The Kidneys

Urea and some water that isn’t reabsorbed (now urine), travels through the nephron to a collecting duct.

The collecting duct rejoins with others to form the ureter and sends the wastes off to the bladder for excretion.


When Kidneys Fail

A build up of waste products is toxic to the body.

If left to build up – death will occur within a few days.

When kidneys fail – an alternative way of removing wastes must be found.

Three such alternatives include:

• Kidney Dialysis Machine• Continuous Ambulatory Peritoneal Dialysis• Kidney Transplantation


Kidney Dialysis

Using a dialysis machine – blood is passed through a tube of semi permeable material called dialysis tubing.

The tubing passes through a dialysing fluid which removes wastes and balances water levels.

Dialysis needs to occur every three days and can take up to six hours.


Kidney Dialysis


Comparing Transport Systems in Animals


Comparing Excretory Systems in Animals


Transport in Plants – Vascular Plants

Larger plants such as ferns, pines and flowering plants are called vascular plants.

Vascular plants require special means for internal distribution of material.

Such plants have specialised transport tissue called vascular tissue.


Transport in plants

The two major components that are transported in plants are:

CarbohydratesWater and Dissolved Mineral Ions


Transport in Plants - Carbohydrates

Only cells containing chloroplasts can photosynthesise and produce carbohydrate in the form of sugars.

6H2O + 6CO2 C6H12O6 + 6O2

All other cells that don’t photosynthesise rely on a transport system to transport carbohydrate so they can survive.


Water Balance In Plants

Plants have an extensive root system to obtain water.

Water enters the roots by osmosis. Ions also enter the roots via a concentration gradient (active transport) and ATP is needed for this.

Once in the plant, the water and ions travel through the cortex and into the xylem tissue in the middle of the root.


Water Balance In Plants

The xylem transports water from the roots, through the stem and into the leaves of the plant.

The phloem runs parallel with the xylem and transports sugars and hormones around the plant.

Chapter 6 - Distribution of Materials1 Distribution of Materials Outcome 2 Chapter 6 p128-173.

Documents

Transcript of Chapter 6 - Distribution of Materials1 Distribution of Materials Outcome 2 Chapter 6 p128-173.