B5 - The Nervous System Flashcards
Homeostasis, Brain + Spine & Eye Nerves
What is the Hypothalamus responsible for?
Regulating body temperature, hunger, etc
What does the Relay Neurone do?
Carries and decides what to do with received impulses
What does the Sensory Neurone do?
Carries information as electrical impulses from the receptor to the Relay Neurones (CNS)
What is Homeostasis?
Regulation of constant body vitals (Temperature, Oxygen Levels, etc)
What is the Central Nervous System?
Where decision making occurs (Brain + Spine)
What is the Peripheral Nervous System?
Consists of all the neurones outside the Brain and Spine (Motor & Sensory)
What is a Stimulus?
A sense (Heat, Sound Touch).
What does a Receptor do?
Detects Stimuli
What does a Motor Neurone do?
Carries impulses from the CNS to effectors
What is an Effector?
A Muscle or a Gland that responds to impulses
What is a Synapse?
The connection (gap) between two Neurones
How does a synapse trigger an impulse?
Neurotransmitters (chemical) diffuse across the Synapse and bind with specific Receptor Cells on the second Neurone
What does the Nerve Cell consist of?
Nerve Ending, Axon, Dendron, Myelin Sheath, Cell Membrane, Nucleus and Cytoplasm
What is an Axon?
A long fibre insulated by Myelin Sheath, which carries electrical impulses across Neurones
What does a Dendron do?
Receives impulses from other Neurones
What are the regions of the Brain?
Medulla, Cerebellum, Cerebral Cortex & Hypothalamus
What does the Medulla control?
Unconscious activities (Breathing, Heartbeat, etc)
What does the Cerebellum control?
Muscle coordination and balance
What does the Cerebral Cortex control?
Consciousness, Memory & Language
Function of the Cornea
Refracts light into the eye.
How does the Iris work?
Controls amount of light that enters the pupil by extending or pulling away from the Pupil.
Function of the Lens
Focuses light onto the Retina.
Function of the Retina
Detects Light (by Rods) & Colours (by Cones), in the Receptor Cells.
Function of the Sclera
Protects & Supports the eye due to its toughness,
Function of the Optic Nerve
Carries impulses from the Retina directly to the Brain.
What happens to the Iris in Dim Light?
The Radial Muscles contract and Circular Muscles relax, Dilating the Pupil (More light enters).
Where are the Radial and Circular Muscles Located?
Circular Muscle (Inner Iris), Radial Muscle (Outer Iris) - Think Radius for Radial.
