Nervous Syste Flashcards
What are the two main branches of the nervous system?
Central nervous system
Peripheral nervous system
What two branches split off the peripheral nervous system?
Motor pathways
Sensory pathways
What two branches split of the motor pathways?
Somatic nervous system
Autonomic nervous system
What two branches split of the autonomic nervous system?
Sympathetic nervous system
Parasympathetic nervous system
What is the general structure and function of the myelin sheath?
Acts as insulation for neurons;
helps nerve impulses travel faster; made up of
Schwann cells
Whats the fuction of a neuron?
Processed and transmits information by electrical and cehmical signaling.
What are the structures of a neuron?
Node of Ranvier, sensory receptor, sonsory neuron, cell body, axon, axon bulb, dndrites, cell body, interneuron, motor neuron, schwann cell, effector.
What are the main functions for the main parts of a neuron?
Dendrites: recievs nerve impulse from other neurons or sensory receptors
Cell body: processes input of dendrites
Nucleus: controls cell
Axon: conducts nerve impulse away from body
Myelin sheath: ‘insulation of neurons’ helps impulse to travel faster (Schwann cell)
Node of ranvier: areas between myelin sheath
All or none response
For a response to occur a stimuli must have a certain intensity (threshold intensity), below this intensity no reaction will occur
Synapses
The small spaces between neurons
When a nerve impulse reaches the end of a
nerve it needs some way to move across the
synapse to the next neuron
What are the main chemical transmitters for synapsis?
Acetocyline, Cholinesterase
Reflex arc
Involuntary movements that dont involve brain, process occurs in less then a secon
Sturcutres and functions of the eye
Sclera: protects and supports eyball
Cornea: bend light rays into eye
Choroid: absorbs scattered light and contains blood vessels
Iris: regualates amount of light that enters eye
Pupil: opening for light to enter inner eye
Ciliary muscles: changes shape of lense to focus
Rods: photoreceptors that are sensitive to dim light
Cones: photoreceptors sensitive to wavelength of light
Fovea centralis: provides acute vision
Lens: focusses light rays onto fovea centrialis
Humours: support eyeball, with pressure of fluids in eyeball
Optic nerve: transmits sensory info to brain
Describe the human ear and the functions
Pinna: skin and cartilage enhance vibration and focuses into ear
Auditory canal: Aplify sound, lined with hairs to protect
Tympanum: vibrates in response to sound waves, converts sound into mechanical energy
Ossicles: Amplify sounds
Oval window: creates pressure waves in fluid of cochlea
Semicircular canals: detect movements hair cells transmit nerve impulse
Vestibule: gravitational equilib.
Adreanal cortex
Cortiso - all tissue
Inhibits healing - rduces swelling, releases glucose and other compunds need for repair of tissues
Aldosterone - kidney tubule, increases reabsorption of HOH and salts thereby increase HOH volumes of the body
Long terms stress response
ACTH (pituitary gland)
The eye
