The Human Organism Flashcards
What does A+ (A positive) blood indicate?
This red blood cell is in blood group A and has the Rhesus chemical on it.
Why is the Rhesus factor important?
For safe blood transfusions
What are the main blood groups?
A, B, AB, O
Describe red blood cells
- No nuclei (when mature)
- No mitochondria
- Biconcave shape (to give a larger surface area)
What are mature red blood cells called?
Blood corpuscles
What colour is haemoglobin?
Purple
What colour is oxyhaemoglobin?
Bright red
Describe lymphocytes
- Made in bone marrow
- Mature in lymphatic tissue
- Stored in spleen, lymph nodes, tonsils, adenoids and thymus gland
- Large round nucleus with very little cytoplasm
Structure of a monocyte
•Kidney-shaped nucleus
What is the need for a circulatory system?
To supply cells with all the materials they require
Benefits of a closed circulatory system
- Moves blood around the body faster
* Allows alterations in blood flow to different body organs
Why are animals with a closed circulatory system considered to be more active?
Blood is pumped around the body faster, allowing nutrients and oxygen to de distributed faster to the cells
Location of the heart
Located between the two lungs, slightly to the left-hand side of the thorax, just above the diaphragm
Structure of the heart
- Made of cardiac muscle
* Surrounded by double membrane called pericardium
Benefits of a double-circulation system
- Allows oxygenated and deoxygenated blood to be kept separate
- Ensures that the blood pressure is high enough to reach all parts of the body
Why does the aorta have thicker walls?
Blood entering the aorta is under high pressure due to the contraction of the left ventricle
What glands are associated with the digestive system?
- Salivary gland
- Liver
- Gall bladder
- Pancreas
What glands are associated with the digestive system?
- Salivary gland
- Liver
- Gall bladder
- Pancreas
What glands are associated with the digestive system?
- Salivary gland
- Liver
- Gall bladder
- Pancreas
Where is bile made and stored?
Made in the liver, stored in the gall bladder
What does the duodenum do?
Produces a range of digestive enzymes
What enters the duodenum?
The products of the pancreas and liver
What does sodium bicarbonate do in the pancreas?
Neutralises acid (chyme)
By what process is food absorbed?
Diffusion
Adaptations of villi for absorption
- Large numbers (increase surface area)
- Thin walls
- They have a rich blood supply to carry away water-soluble products
Adaptations of small intestine for absorption
- Has numerous villi and microvilli
- Walls of villi are thin
- It is very long
What are the four food groups?
- Cereals, bread and potatoes
- Fruit and vegetables
- Milk, cheese and yoghurt
- Meat, fish and poultry
To what vein do the venules in the villi lead to?
Hepatic portal vein
Location of the respiratory system
Thoracic cavity/Thorax
Why is breathing through the nose beneficial?
The nose filters, moistens and warms the air
Adaptations of alveoli
- Huge number of alveoli - huge surface area
- Thin wall
- Moist surface
- Enclosed in network of capillaries
What is the name of the process that occurs in gas exchange?
Diffusion
How is oxygen transported?
Oxygen combines with haemoglobin, to form oxyhaemoglobin.
Describe inhalation
- Diaphragm contracts
- Intercostal muscles contract
- Ribs move up and out
- Volume of thoracic cavity increases
- Pressure decreases
- Air rushes in
Describe exhalation
- Diaphragm relaxes
- Intercostal muscles relax
- Ribs move down and in
- Volume of thoracic cavity decreases
- Pressure increases
- Air is pulled out
How does exercise affect breathing?
Exercise increases the rate of respiration.
Describe Asthma
Symptoms: Breathlessness, Wheezy breathing
Cause: Allergens like pollen and dust
Prevention: Avoid allergens
Treatment: Inhalers
How does the brain control human breathing?
It monitors the levels of carbon dioxide in the blood that passes through it. The medulla oblongata controls this.
What is the controlling factor in gas exchange in animals and plants?
Carbon Dioxide
Describe the role of the skin in controlling body temperature in cold conditions
- Piloerection, which then traps a layer of warm air.
- Vasoconstriction, which reduces heat loss through skin.
- Shivering, which produces heat to raise temperature.
Main organs of excretion
Lungs, skin, kidneys
Location of kidneys
In the small of the back
Main processes in the kidneys
- Filtration (Cortex)
- Reabsorption (Cortex and Medulla)
- Secretion (Cortex)
How do the kidneys control blood pH?
They control the concentration of hydrogen ions in the blood
What does urine consist of?
Water, Urea and Salts
Functions of the kidneys
- Excretion
- Osmoregulation
- pH control of body fluids
