Unit 5 biology Flashcards
Name the pathway of air.
Nasal cavity, mouth, Pharynx, larynx, Trachea, bronchi, bronchioles, alveoli.
How many alveoli does an adult human have?
500-700 million
What is special about alveoli to allow gaseous exchange?
Their cells are one cell thick and contain squamous epithelial cells.
During inspiration, what happens to the diaphragm?
Contracts and flattens
During inspiration, what happens to the rib cage?
Moves upwards and outwards
During inspiration, what happens to the volume of the thoracic cavity?
Increases
During expiration, what happens to the diaphragm?
Pushes upwards and expands
During expiration, what happens to the rib cage?
Inwards and downwards
During expiration, what happens to the volume of the thoracic cavity?
Decreases
What is the process of mechanical ventilation?
- Air is pumped into the lungs by an endotracheal tube.
- This increases the pressure allowing air to flow inside of the airways.
- The pressure then drops to zero.
- Then the chest and lungs contract and push the air in the lungs out through passive expiration.
In the heart, what chamber is top left?
right atrium
In the heart, what chamber is top right?
Left atrium
In the heart, what chamber is bottom left?
right ventricle
In the heart, what chamber is bottom right?
left ventricle
What pumps blood into the right atrium?
Vena cava
What valve connects the right atrium to the right ventricle?
Tricuspid valve
Where does blood go when it reached the right ventricle?
Pulmonary artery
What pumps blood into the left atrium?
Pulmonary veins
What valve connects the left atrium to the left ventricle?
Bicuspid valve
Where does blood go after it has reached the left ventricle?
Aorta
What is the function of arteries?
Carry blood away from the heart
What is the function of veins?
Carry blood towards the heart
What is the function of capillaries?
Allows diffusion of gases and nutrients from blood into the body cells
What size walls do Arteries have?
Thick, muscular
What size walls do Veins have?
Thin muscular
What size walls do Capillaries have?
One cell thick
What is the size of arteries lumen?
Small
What is the size of veins lumen?
Large
What is the size of capillaries lumen?
Very small, only allows blood to pass through one cell at a time
What is the purpose of valves in veins?
Stop the backflow of blood.
What blood vessel are valves present in?
Veins
Describe the structure of arteries.
- Thick muscular wall
- Layer of elastic muscle
- Thin lumen
- High pressure
Describe the structure of veins.
- Wide lumen
- Valves
- Thin walls
Describe the structure of capillaries.
One cell thick
- They have an inner endothelial layer
They have an outer epithelial layer
Name the four valves in the heart and where they are located in the heart.
tricuspid valve: located between the right atrium and the right ventricle.
pulmonary valve: located between the right ventricle and the pulmonary artery.
mitral valve: located between the left atrium and the left ventricle.
aortic valve: located between the left ventricle and the aorta.
What is the role of valves?
Stop the backflow of blood
What does the term ‘myogenic’ mean?
Functioning in a rhythmic pattern
Describe the pathway of blood through the heart.
The right ventricle pumps the oxygen-poor blood to the lungs through the pulmonary valve. The left atrium receives oxygen-rich blood from the lungs and pumps it to the left ventricle through the mitral valve. The left ventricle pumps the oxygen-rich blood through the aortic valve out to the rest of the body.
Distinguish between the systemic and pulmonary circuits.
The systematic system pumps blood from the heart to the body and back. Pulmonary system pumps blood to the lungs and back from the heart.
Describe one cycle of the cardiac cycle and how pressure changes cause movement of blood.
One cycle is atrial systole which is when blood is pumped from the atria to the ventricles
Explain why the sinoatrial node is commonly referred to as a pacemaker.
It generates a series of electrical impulses that regulates the rhythm of the heart.
Describe how the cardiac cycle is controlled.
This is controlled by the cardiac conduction system and regulated by the medulla
Name the 4 main parts of a urinary system
- Kidney
- Ureter
- Bladder
- Urethra
Which arteriole that is linked to the Glomerulus is larger?
Afferent is larger than the efferent
What arteriole takes blood into the glomerulus?
Afferent
What arteriole takes blood out of the glomerulus?
Efferent
How is the proximal convoluted tubule adapted for rapid absorption?
- Large surface area due to microvilli
- Multiple mitochondria
What is osmoregulation?
active regulation of the water pressure of an organism’s body fluids
In the kidney, where is the blood filtered?
Cortex
What is the main role of the kidneys?
To remove urea from the blood.
What is ultrafiltration?
process in the kidney by which urea, salt, water and glucose etc. is extracted from the blood.
How does water move out of the loop of henle?
Osmosis
What is selective reabsorption?
the process whereby certain molecules are reabsorbed from the filtrate as they pass through the nephron.
What are the effects of ADH?
Makes the walls of the collecting duct permeable to water so more water move out by osmosis.
Where is ADH released from?
Pituitary gland
