Biology module 2 & 3 (copy)

What are the two parts of the circulatory system?

pulmonary and systemic

What are some factors affecting the need for a transport system?

size, surface area : volume, metabolic activity level (warm/cold blooded)

What are the four main components of blood?

RBC, WBC, plasma, platelets

What are substances that are transported by blood plasma?

CO2, O2, hormones, proteins, urea, glucose, mineral ions

What is the function of the white blood cells?

engulf pathogens, produce antitoxins, produce antibodies

What is the function of platelets?

blood clotting

What is the function of the coronary arteries?

to supply the heart tissue with oxygen.

What are alveoli?

Air sacs that serve as the primary gaseous exchange surface which can recoil. Between 200-300 micrometres.

What are alveoli made of?

A thin epithelial layer, collagen and elastic fibers.

What are the Bronchi and what are they made of?

Divisions of the trachea supported by rings of cartilage, containing goblet cells and many mitochondria.

What are bronchioles?

Divisions of the bronchi.

what are bronchioles made of

Smooth muscle to restrict airflow to the lungs and no cartilage. Lined with a thin layer of ciliated epithelial cells.

What are ciliated epithelial cells?

Specialised cells with hair-like cilia lining in the trachea that waft bacteria-containing mucus up to the back of the throat.

What is countercurrent flow?

An adaptation for gaseous exchange in bony fish. Blood in the gill filaments and water moving over the gills flow in opposite directions, maintaining a steep oxygen concentration gradient.

What are elastic fibres?

Fibres of elastin that allow the alveoli to stretch as air is drawn in and recoil back to normal size, expelling air.

Where are elastic fibres found?

The trachea, bronchi and bronchioles.

What happens during expiration?

The diaphragm relaxes to form a dome. The external intercostal muscles relax, moving the ribs down and in. The volume of the thorax decreases and thoracic pressure becomes higher than air pressure. Air moves out of the trachea.

What happens during inspiration?

The diaphragm contracts and flattens and the external intercostal muscles contract, moving the ribs up and out. The volume of the thorax increases and thoracic pressure falls below air pressure. Air moves into the trachea.

What is the pleural cavity?

The space in-between the double membrane lungs are incased in, filled with pleural fluid.

What is a spirometer?

A device used to examine patterns of breathing and determine different aspects of lung volume.

What is a peak flow meter?

A device which measures the rate at which air can be expelled from the lungs

What is a vitalograph?

A more complicated version of a peak flow meter

When looking at a spirometer graph what does the trace going down mean?

A breath in

Why does the overall volume of gas go down in the tank?

The soda lime absorbs CO2, The O2 is used up by us

What is tidal capacity?

The volume of air that moves into and out of the lungs during a normal breath.

What is vital capacity?

The largest volume of air that can be breathed in following the strongest possible exhalation.

What is expiratory capacity?

The maximum volume of air exhaled after a normal inhalation.

What is inspiratory capacity?

The maximum volume of air inhaled after a normal exhalation.

What is inspiratory reserve volume?

The extra volume of air that can be inspired with maximum effort after normal inspiration.

What is expiratory reserve volume?

The extra volume of air that can be expired with maximum effort after normal expiration. (quiet)

What is residual volume?

The volume of air remaining in the lungs after a maximum exhalation.

What is pleural fluid?

It lubricates the lungs and adheres the outer walls of the lungs to the thoracic cavity so your lungs expand by water cohesion.

What are the important aspects of the nasal cavity?

Large SA and good blood supply- warms air.

Hairy lining- Traps dust and bacteria in mucus to prevent them from reaching lungs.

Moist surface- Increases humidity to reduce water evaporation in lungs.

What are gill filaments?

The main site of gaseous exchange in fish, over which water flows. They are found in large stacks, known as gill plates, and have gill lamellae which provide a large surface area for exchange.

What are gill lamellae?

The fine branches of the gill filaments.

What are gill plates?

Large stacks of gill filaments

What are gills?

The organs of gaseous exchange in fish. They are contained in a gill cavity and are made up of gill lamellae, gill filaments and gill plates.

What is the operculum?

A flap that covers the gills of bony fish. It protects the gills and helps to maintain a constant stream of water over them.

How is ventilation carried out in bony fish?

The buccal-opercular pump. Drawing water into the buccal cavity then pushing it through the gills.

What are goblet cells?

Specialised cells that secrete mucus onto the trachea lining. The mucus traps harmful substances and microorganisms, preventing their entry into the lungs.

When are internal intercostal muscles used?

During forced expiration.

What is smooth muscle for?

An involuntary muscle found in the walls of the trachea and bronchi. It constricts the lumen of the bronchi by contracting, reducing airflow to the lungs.

What are spiracles?

Small, external openings along the thorax and abdomen of insects, through which air enters, and air and water leaves.

What opens and closes the spiracles?

Spiracle sphincters open and close the spiracles to control gas exchange.

What type of circulatory system do insects have?

Open

What are 3 ways that insects carry out ventilation?

The tracheal system has flexible walls which can be squeezed with the flight muscles to ventilate.

In some insects wing movement alters thorax volume drawing air in and pushing it out.

Locust can alter their abdomen volume and coordinate it with their spiracles so air enters at the front and leaves at the back.

What is the trachea (mammals)?

The primary airway which carries air from the nasal cavity down into the chest. It is a tube supported by incomplete rings of cartilage.

What are tracheae (insects)?

Large tubes that run from the spiracles, into and along an insect’s body. They are supported by spirals of chitin.

What are tracheoles?

Divisions of the tracheae that run throughout the tissues of an insect, forming a complex network. They are the main site of gas exchange and are completely permeable to gases.

What is tracheal fluid?

A fluid found at the ends of the tracheoles. The amount of fluid affects the surface area available for gaseous exchange and water loss.

What are arteries?

Blood vessels which carry blood away from the heart at a high pressure.

What are arteries made of?

narrow lumen, thin elastic tissue, thick smooth muscle, thick collagen.

What are arterioles?

Blood vessels which distribute blood from arteries to capillaries.

What are cappilaries?

Blood vessels which allow for exchange of nutrients from blood to tissues.

What are capillaries made of?

narrow lumen, thin walls of flattened endothelial cells.

What are venules?

Blood vessels which distribute blood from capillaries to veins.

What are veins?

Blood vessels which carry blood back to the heart at a low pressure.

What are veins made of?

wide lumen, contain valves, thin walls of collagen, smooth muscle and elastic tissue.

What is affinity?

The tendency of one substance to bind with another substance.

What is the function of the tendinous chords?

Prevents atrioventricular valves from inverting.

Which ventricle pumps blood at a higher pressure?

Left

What makes the “lub“ sound of the heart beat?

AV valves closing

What makes the “dub“ sound of the heart beat?

SL valves closing

What are the three stages of the cardiac cycle?

Diastole, atrial systole, ventricular systole.

What happens during diastole?

Heart muscles relaxed, atria and ventricles fill with blood, AV valves open, SL valves closed, Elastic tissue causes ventricle walls to recoil.

What happens during atrial systole?

Atria contracted blood pushed into ventricles, AV vales open, SL valves closed.

What happens during ventricular systole?

Atria relaxed, ventricles contract, AV valves closed (tendinous chords), SL valves open, blood leaves ventricle.

What is the Bohr effect?

The loss of affinity of haemoglobin for oxygen as the partial pressure of carbon dioxide increases.

What type of muscle is found in the heart?

Myogenic

What is myogenic muscle?

cardiac muscle tissue that initiates its own contraction, without outside stimulation from nervous impulses.

What is fibrilation?

Uncoordinated contractions of the atria and ventricles, this causes inefficient pumping.

What controls the cardiac cycle?

The sino-atrial node

What does the sino-atrial node do?

Initiates a wave of electrical excitation

What is the order of the cardiac cycle?

SAN, Atria contract, AVN, bundle of his, purkyne fibres, ventricles contract

What is purkyne tissue?

Specialised cardiac muscle fibres which make up the bundle of His and conduct the wave of excitation through the septum, from the AVN down to the apex of the ventricles.

What is the bundle of his?

A collection of Purkyne fibres which run from the AVN down to the apex of the ventricles

What gradient does blood flow down?

Pressure gradient

What is an electrocardiogram?

A technique used to indirectly measure the spread of electrical activity through the heart by measuring tiny changes in the skin's electrical conductivity. This produces a trace which is used to detect abnormalities in heart rhythm.

What is the P wave?

atrial stimulation?

What is the QRS wave?

Ventricular stimulation?

What is the T wave?

Diastole

What is an ectopic heartbeat?

Additional heartbeats outside of the normal heart rhythm.

What is tachycardia?

A rapid resting heart rate (over 100 bpm)

What is bradycardia?

A slow resting heart rate (below 60 bpm)

What is atrial fibrillation?

An arrhythmia that involves the rapid contraction of the atria, preventing complete ventricular filling

What is ventricular fibrillation?

An arrhythmia that involves the rapid contraction of the ventricles, preventing blood from being pumped to the rest of the body.

What is carbonic anhydrase?

An enzyme that catalyses the reversible reaction between water and carbon dioxide to produce carbonic acid.

What is cardiac output?

The volume of blood pumped by the heart through the circulatory system in one minute.

What is the equation for cardiac output?

cardiac output = heart rate × stroke volume

What is chloride shift?

The process by which chloride ions move into the erythrocytes in exchange for hydrogen carbonate ions which diffuse out of the erythrocytes. This maintains the electrochemical equilibrium of the cell.

What is haemoglobin?

The red pigment found in erythrocytes that binds reversibly with four oxygen molecules to form oxyhaemoglobin.

What is a haem group?

The prosthetic group in haemaglobin containing Fe2+, allowing it to bind with one oxygen molecule.

What is haemoglobinic acid?

The product formed when haemoglobin accepts free hydrogen ions. This enables haemoglobin to act as a buffer, reducing changes in blood pH.

What is association?

Oxygen binding to haemoglobin to form oxyhaemoglobin

What is dissociation?

Oxygen being released from oxyhaemoglobin

What is partial pressure of oxygen?

The concentration of oxygen relative to other gases.

What is partial pressure of oxygen also known as?

Oxygen tension

What is conformational change?

When the first oxygen has bonded to a Hb which makes it easier for the other 3 to bind.

What is positive cooperaation?

When conformational change makes it easier for oxygen to associate or dissociate with haem groups.

At low partial pressures of oxygen it is difficult to bind to the Hb groups because…?

Of the tertiary structure