Blood And Guts (Biology) Flashcards
Why do cells need energy
This is slightly different and some of the answers include growth, cell division, chemical reactions, movement (e.g. sperm) and absorbing materials
What is the cartilage
The trachea and bronchi, are held permanently open by incomplete rings of cartilage otherwise they would collapse, close, leading to suffocation
What is the cilia and mucus
The trachea and bronchi are lined with tiny hair-like cilia and glandular cells which secrete sticky mucus. Rhythmic beating of the cilia sweeps mucus containing trapped dust and germs upwards to the larynx from where it passes into the oesophagus. Germs are normally killed by acid of the stomach
Describe the breathing system
The lungs are a mammals organs of gas exchange. Air is taken in while carbon dioxide is removed. Air enters the body via the nose or mouth and passes over the larynx, trachea, bronchus, and bronchioles. These tiny tubes form a ‘bronchial tree’ with each branch narrowing and ending in tiny air sacs called alveoli. The alveoli are so numerous that they provide a large surface area for gas exchange and give the lungs a sponge-like texture
What is gas exchange
Blood arriving in a lung is deoxygenated (means low oxygen), when the body breathes in oxygen, the oxygen dissolves into the blood and is transported to different parts in the body. The deoxygenated blood contains carbon dioxide, releasing it when the body has exhaled.
What’s the important features of a respiratory surface.
- Alveoli present large surface area to absorb oxygen
- Alveolar surface is moist to allow oxygen to dissolve
- Alveolar lining is thin to allow oxygen to diffuse through into the blood easily
- Network of tiny blood vessels surrounds alveoli to pick up transport O
What happens when we inhale
Contraction of intercostal muscles pulls the rib cage out and up. At the same time, contraction of the diaphragm lowers (flattens) the floor of the chest cavity. The volume of the chest cavity is therefore increased (and so pressure is decreased) causing air to be inhaled.
What happens when we exhale
On relaxation of the intercostal muscles, the rib cage moves down and in. Relaxation of the diaphragm (back to its dome shape) causes a reduction in volume (and increase in pressure) of the chest cavity. Air is therefore exhaled
Why do animals need energy
Animals need food for a variety of reasons: growth, maintaining body heat, fighting disease and tissue repair.
Describe the animal transport and exchange systems
A large multicellular animal has a small surface area relative to its volume. Therefore it need additional absorbing areas to take in oxygen and food. In human beings, for example, alveoli in the lungs and villi in the small intestine greatly increase the surface area for the absorption of O and digested food.
What’s the mammalian circulatory system
He circulatory system consists of the heart (a muscular pump) and the blood vessels ( a system of tubes) which carry blood to all parts of the body
Describe the mammalian heart
The heart is divided into two separate sides. Each side has two hollow chambers: an atrium and a ventricle
What are the thee main types of blood vessels
Arteries
Veins
Capillaries
Describe the arteries.
Carry blood away from the heart
Describe the veins
Veins return blood to the heart
Describe the capillaries
They link arteries with veins
