B3 Flashcards
(20 cards)
What do sensory neurones do?
Carry electrical impulses from receptor cells to the CNS
What do relay neurones do?
Carry electrical impulses from sensory neurones to motor neurones
What do motor neurones do?
Carry electrical impulses from the CNS to effectors
What are effectors?
Muscles and glands
What is the direction of impulse on a neurone?
From the dendrites to axon
What is a change in environment?
A stimulus
What do receptor cells in the eye detect?
Light
What do receptor cells in the mouth detect?
Taste
What do receptor cells in the skin detect?
Pressure and temperature
What do receptor cells in the nose detect?
Smell and taste
Summary of a nervous reaction
Stimulus —> receptor cells —> sensory neurone —> spinal cord —> brain —> motor neurone —> effector —> response
What does insulin do?
Insulin turns glucose into glycogen
Type 1 diabetes
When the pancreas produces little or no insulin
Type 2 diabetes
When a person becomes resistant to insulin (their body doesn’t respond properly to the hormone)
What does your body do when it’s too hot
Vasodilation
What does your body do when you’re too cold
Vasoconstriction
What happens in vasoconstriction
-Erector muscles contract. Hairs stand in end to trap an insulating layer of air, which help Kees you warm.
-very little sweat is produced
-blood vessels near the surface of the skin constrict(narrow)
-less blood flows near the surface, so less energy is transferred to the surroundings
-when you’re cold you shiver too(your muscles contract automatically) this needs respiration which transfers some energy to warm the body
What happens in vasodilation
-Erector muscles relax, so hairs lie flat.
-lots of sweat is produced. When the sweat is evaporated it transfers energy from your skin to the environment,cooling you down
What does insulin do?
Makes liver turn glucose into glycogen
What does glucagon do?
Makes liver turn glycogen into glucose
