Coordination and response Flashcards
What tissue do electrical impulses travel along?
Neruones.
What does the CNS consist of?
The brain and spinal cord
What does the PNS consist of?
Nerves, which are outside the brain and spinal cord
What is the role of the nervous system?
Coordinaton and regulation of body functions
The reflex arc.
Receptor –>Sensory neurone –> relay neurone –> motor neurone –> effector
What is a reflex action?
A means of automatically and rapidly integrating and coordinating stimuli with responses of effectors
What is a synapse?
A gap between 2 neurones
How does an electrical impulse travel from one neurone to the other?
An impulse stimulates the release of neurotransmitter molecules from vesicles into the synaptic gap
The neurotransmitter molecules diffuse across the cap
Neurotransmitter molecules bind with receptor proteins in the next neurone
an impulse us then started in the next neurone
What are sense organs?
Groups of receptor cells responding to different stimuli
Describe the function of the following:
Cornea
iris
Lens
Retina
Optic Nerve
Cornea - controls the amount of light entering the eye
Iris - regulate the amount of light that can enter the retina
Lens - to transmit and focus light onto the retina
Retina - Contains receptor cells that respond to light
Optic nerve - relay messages from your eyes to the brain to create visual images
Explain how the eye reacts to a nearby object and a distant objects
Ciliary muscles and suspensory ligaments are antagonistic to each other
When an object is distant, the ciliary muscles relax and the suspensory ligaments are pulled tight, making the lens appear thinner
When an object is near, The ciliary muscle contracts and and the suspensory ligaments slacken, making the lens more rounded
Explain the pupil reflex
Describe the distribution of cones and rods
Rods are found on the outer cornea and Cones are found on the inside of the cornea
Outline the function of the Rods
They allow us to see in dim light but only in black and white
Outline the function of the Cones
They allow us to see a detailed image in colour vision
What is the function of the fovea?
Contains receptor cells
Define the term hormone
A chemical substance, produce by a gland, and carried by the blod which alters the activity of one or more specific target organs
Outline the hormones that the following endocrine glands secrete
Adrenal gland
Pancreas
Testes
Ovaries
Adrenal gland - adrenaline
Pancreas - insulin
Testes - testosterone
Ovaries - Oestrogen
Define adrenaline and its effects on the body
Adrenaline - A hormone secreted in “Fight or flight” situations
Effects - Increases breathing rate
Increases heart rate
Dialates the pupil
Compare nervous and hormonal systems
-Nervous system uses electrical impulses and the endocrine system uses chemicals
-Nervous system transmits messages much faster than the endocrine system
-Endocrine system lasts longer than nervous system
How does adrenaline alter metabolic activity
This causes the liver to release glucose into the blood for energy
Increases the breathing rate of the lungs to supply the body with more oxygen
Define Homeostasis
The maintenance of a constant internal environment
What is the function of insulin?
To maintain the blood-glucose concentration
Explain the concept of homeostatic control by negative feedback
Negative feedback is a mechanism that helps to maintain homeostasis by making changes in the internal environment.
Each condition has a set point and if the conditions are beyond the set point, negative feedback occurs to return the condition back to the set point
Describe the control of blood glucose concentration
After having a meal rich in carbs, the blood glucose concentration increases, to lower it to normal, insulin is secreted by the pancreas, to reduce the blood glucose concentration. If the blood glucose concentration is too low, the pancreas detects this and sends glucagon to the liver so that it covers the stored starch into glucose which is then sent through the blood to parts of the body that may need it.
Treatment of type 1 diabetes
Insulin shots
Controlled diet
Describe what happens when the body temperature rises and falls
The temperature receptors detect the increase in temperature and send electrical impulses to the brain
