Coordination in humans Flashcards
Give two examples of homeostasis
Osmoregulation (body water content)
Thermoregulation (body temperature)
What is thermoregulation
Temperature regulation
Why is thermoregulation important?
Enzymes denature if temp too high
Cell membranes become fragile as temp rises
Diffusion rates rise with night temps and fall with lower temps
Liquids such as blood become more viscous (thicker) as temp falls
What controls thermoregulation
The hypothalamus
Protective functions of the skin
Tough water proof barriers between body and external environment
Regulates body temp
Contains sensory receptors to detect external environment changes
Protection from infection
What are the two main layers in the skin
The upper epidermis and lower dermis
What is the function of melanin
Absorbs ultraviolet light and protects the cells DNA from damage
Mammals and birds are what?
Endotherms
What can endotherms do
Maintain an internal environment that doesn’t change when external environmental temperatures change
Amphibians reptiles insects and fish are what
Ectotherms
Why can endotherms survive extreme temperatures better?
Temperature affects Ectotherms a lot more
Which animal will lose heat more quickly. A mouse or an elephant?
A mouse because it has a big surface area to volume ratio
What happens to sweat glands in the cold?
Sweat is not produced so sweat doesn’t move onto skin surface
What happens to sweat glands in hot temps
Sweat produced, water in sweat evaporates from the skin. This uses heat energy from the blood which will reduce heat energy and so cool you down
Why is it important for organism to control their internal environment?
So enzymes can control cell function and enzymes need specific conditions to work efficiently
Name two ways in which organisms achieve this coordination
Through hormonal control (endocrine control)
Through nervous control (nervous system)
What is the stimulus
Change in environment that triggers a reaction (eg a stimulus effects an endocrine gland to release a hormone)
What is the receptor
This receives the stimulus (e.g a receptor molecule on a cell membrane for a hormone)
What is the effector
The part of the organism that carries out the reaction to the stimulus (e.g a muscle or a gland)
What are glands?
Small structures responsible for making and secreting specific chemicals
What hormone is secreted by the pituitary gland in the brain?
A.D.H anti-diuretic hormone
Hormone for water regulation
What do the adrenal glands produce?
Adrenaline
Where are the adrenal glands?
Above the pancreas
What does pancreas secrete
Insulin
Controls blood sugar levels
What do the ovaries produce
Oestrogen and progesterone
What do the testis (singular) testes(plural) produce
Testosterone
How can you tell endocrine glands and exocrine glands apart?
Exocrine glands have tubes which secretes the hormones where as endocrine glands are just there.
ONE HAS A TUBE OR DUCT THAT LEADS/CONNECTS IT TO ANOTHER PART OF THE BODY
How do hormones work when they reach their target organs?
They lock onto receptor on their target cells. This triggers a reaction. Afterwards the hormones travel to the liver and are broken down
Explain how the adrenal gland can help an athlete running (e.g Ella because she’s a bloody pro)
Adrenaline is produced and passed into the blood, the breathing rate becomes quicker causing more oxygen to be taken in and more carbon dioxide removed. The heart beats faster so more oxygen is passed into the blood. This means that more respiration occurs and more energy ATP and glucose is released which increases blood sugar levels. This gives the athlete more energy and they can run faster and for longer.
What is homeostasis
Maintaining a constant internal environment
