Key Area 2 - Control And Communication Flashcards
What does the central nervous system consist of in mammals?
The brain and the spinal cord
How is the CNS connected to all other parts of the body?
By the nerves
Describe the function and the structure of the CEREBRUM
The large folded area of the brain which controls memory, personality and conscious thought
Describe the structure and function of the CEREBELLUM
Found at the rear of the brain behind the medulla and controls balance and coordination of movement
Describe the function of the MEDULLA
Controls heart and breathing rate
What are the two main functions of the CNS?
To process information received from the senses
To then co-ordinate the body’s response
Name the 3 receptors, their location in the body & their stimulus
- Photoreceptor , retina in eye , light
- Thermoreceptors , skin & hypothalamus , temperature
- Chemoreceptors , tongue & nose , chemicals
What are the 3 main types of neurons & what are their functions?
Sensory neurons - to carry impulses from the receptors to the CNS
Inter neurons - located in CNS, transmit electrical impulses from the sensory to motor neurons
Motor neurons - carry impulses from CNS to the effectors
What are neurones?
Specialised nerve cells which carry information, in the form of electrical nerve impulses, from the receptors to the CNS, and from the CNS to the effectors
What are the three parts each neurone consists of?
- Cell body ( containing cytoplasm and nucleus. The cell bodies are located in the brain and spinal cord)
- Fibres which carry impulses into the cell bodies
- Fibres carrying impulses away from the cell bodies
What is a synapse?
The gap between adjoining neurones.
What do nerve impulses arriving at a synapse cause?
Diffusion of a chemical substance (neurotransmitter), which crosses the gao and triggers off nerve impulses in the next neuron
What are the 4 main functions of the brain?
- Receives impulses from all sensory organs in the body (ears,eyes,mise,tongue & skin)
-Sends motor impulses to muscles and glands to control their function
Co-ordinates bodily activities
-Stores information (learning, memory, problem solving)
A reflex action is…? (REMEMBER: RAIP)
- Rapid
- Automatic
- Involuntary (cannot be ignored)
- Protective
Where do the nerve impulses pass through in a reflex action?
They pass through the spinal cord but not the brain, before a response is generated
Why do reflex actions work so quickly?
As they do not require conscious control from the brain, in order to protect the body from damage
Give 3 examples of reflex actions
Sneezing (causes violent expiration to blow out irritant material) Pupil reflex (controls light intensity, protecting retina from damage) Knee jerk (protects the tendon)
What makes up a reflex arc?
The structures involved and the nerve impulses responsible for reflex actions
Explain the process of a reflex arc being set up
When an environmental stimulus triggers a nerve impulse st a receptor.(1) The impulse is transmitted along a sensory neurone (2) to the spinal cord, where it crosses a synapse (3) to an inter neurone. (4) The impulse passes across another synapse to a motor neurone (5) which then transmits it to an effector, usually a muscle (6).
When a reflex arc operates, where are impulses also sent?
To the brain. Thus, although the spinal cord starts off the response, it is via n that we are made aware of what has happened.
What is a hormone?
A chemical released into the bloodstream by endocrine glands, in one part of the body, that affects cells in other parts of the organism. Hormones are chemical messengers.
A specific hormone can only affect what kind of cells?
Target cells, that have the specific protein receptor that can bind to the hormone.
What does ‘CRP’ stand for?
Complementary Receptor Protein
Give 2 examples of hormones, along with where they’re produced, the target organ and their effect.
Insulin - Pancreas - Liver & Skeletal Muscle - Triggers the production of enzymes which converts glucose to glycogen.
Glucagon - Pancreas - Kidney - Triggers the production of enzymes which converts glycogen to glucose.
