Coordination in multicellular organsims Flashcards
(24 cards)
What are multicellular organisms?
A multi-cell organism with each cell being able to have one specific role.
What are unicellular organisms?
A one celled organism that does not have a specific role.
What is the role of the digestive system and how does it benefit cells?
The digestive system breaks food down into a useable form so that the body and cells can absorb the nutrients.
It has two types of digestions:
- Mechanical digestion (a physical change of the food)
- Chemical digestion (breaks complex substances into simpler chemicals to absorb. e.g. stomach acid)
What is the role of the Respiratory system and how does it benefit cells?
The respiratory system allows cellular respiration which is the series of chemical changes that take place in cells to release energy.
Oxygen + glucose = carbon dioxide + water + energy
What is the role of the circulatory system and how does it benefit cells?
The circulatory systems consists of the heart, blood vessels (arteries, veins, capillaries) ad blood. The heart pumps to keep blood moving which carries all the materials needed by the body and cells through blood vessels.
What is the role of the urinary system and how does it benefit cells?
The urinary system excretes (gets rid of any waste that your body has produced).
What is the role of the nervous system and how does it benefit cells?
the nervous system is a communication network that controls other systems of the body
There are two main parts to the nervous system:
Central Nervous System (CNS) = brain + spinal cord that receive and process information, then sends out messages to tell the body how to respond
Peripheral Nervous System (PNS) = nerves that carry messages to and from the CNS and the rest of the body
What is the role of the endocrine system and how does it benefit cells?
The endocrine system is a communication system that controls the internal environment of the body.
The endocrine system produces hormones which are chemical substances that act as messengers in the body.
How does the nervous system and endocrine system coordinate the other body systems?
The nervous systems controls all of the body systems using its two main parts, CNS and PNS while the endocrine system helps to regulate the body.
Describe and explain what the role of a sensory neuron is.
Sensory neurons bring information from receptors to the CNS
They connect a sense organ (e.g. nose, eyes, ears) to the CNS
They are long and have a cell body branching of the axon
Describe and explain what the role of a motor neuron is.
Motor neurons take signals from the CNS to a muscle or a gland
They are long and have a large body cell at one end with long dendrites branching of. They are slightly curved (a mix of an L and a c)
Describe and explain what the role of an interneuron (relay neuron) is.
Interneurons are found in the CNS
They connect sensory and motor neurons
They are short and have a small cell body at one end with many dendrites branching off it.
What is homeostasis?
Homeostasis is the process of the body maintaining a relatively constant internal environment.
Describe the two processes of homeostasis
Homeostasis has two processes.
The body detects a change where the brain then sends our a response to return the body back to normal. This is called negative feedback.
What does the thermoreceptors detect and where is it found?
Thermoreceptors are found in the skin and detect changes in temperature.
What is the structure of the eye and their roles?
Cornea - A touch clear covering over the iris and pupil that protects the eye and bends light as it passes through
Pupil - an opening that allows light to pass through the lens and into your eye
Aqueous Humor - A clear fluid that helps the cornea keep its rounded shape
Iris - A muscle that controls how much light enters the eye
Lens bands - refract light to help focus the light rays onto the photoreceptors in the retina
Lens - a clear flexible structure that make an image on the eye’s retina. The lens changes shape to focus on objects whether they are far away or close up
Vitreous Humor - A thick, clear jelly that helps give the eyeball its shape
Sclera - The thick, tough, white outer covering of the eyeball
Retina - The layer of light-sensitive cells at the back of the eye. It helps detect images focused on by the cornea and lens. It is also connect to the brain by the optic nerve
Blind spot - the place where the optic nerve leaves the retina. It has no light sensitive cells.
Optic nerve - the bundle of nerve fibers that carry information from the retina to the brain.
Tapetum - The colourful shiny material located behind the retina. Found in animals with good night vision. Reflects light back through the retina.
What is the structure of the ear and their roles.
There are three sections of the ear: Outer, middle, and inner.
Outer:
The pinna collects sounds and funnels then into the auditory canal
The auditory canal connects the outer ear with the eardrum.
The eardrum is the beginning of the middle ear and is made of a thin sheet of muscle and skin that vibrates in response to sounds.
The vibrations are passed to a set of three tiny bones.
The hammer, anvil and stirrup. They are also known as the ossicles. By the time sound reaches the stirrup it has been amplified to 30 times louder than at the eardrum.
The stirrup vibrates against the oval window (at the boundary between the middle and inner ear) which cause the vibrates to pass into a fluid filled tube called the cochlea
The fluid passes vibrations to a layer of tiny hairs which are connected to the auditory nerves. These are then sent to the brain and interpreted as sounds.
Above the cochlea are semicircular canals which helps us keep our balance.
Between the middle ear and the back of the throat is a tube called the Eustachian tube. It equalises the air pressure on both sides of the eardrums and also allows mucus to drain from the middle ear.
What is the role of osmoreceptors and where are they found?
Osmoreceptors regulate water levels in blood and are found in the brain and large arteries.
What is the role of mechanoreceptors and where are they found?
Mechanoreceptors are found in the skin and detect pressure and touch.
What is the role of cochlear cells and where are they found?
Cochlear cells are found in the inner ear and detect sound.
What is the role of photoreceptors and where are they found?
Photoreceptors are found in the retina in the eye and detect light.
What is the role of chemoreceptors and where are they found?
Chemoreceptors are found on the tongue and in the nose and detect chemicals.
What is the role of semicircular canals and where are they found?
Semicircular canals are found in the ear and detect changes in gravity.
What is positive feedback?
Positive feedback is when the body changes from normal to abnormal.
