Nervous system Flashcards
What is a positive feedback system?
Strengthen or increase a change in variable.
Example is contractions during or before childbirth
What is negative feedback system?
Reverse a change detected in a variable. Bringing a variable back to normal levels
Ex. Thermoregulation
Decreasing body temperature: Blood vessels dilate, more blood is brought to the surface this results in heat loss
Increasing body temperature:
Muscles contract while shivering, increases heat producing, blood vessels constrict , heat loss through skin is decreased.
Flow Chart of the Nervous System
1.Nervous system
2. Central Nervous system Peripheal Nervous system
3.Brain and Spinal cord Sensory pathways
Motor Pathways
4. Somatic System
Autonomic system
5. Sympathetic
Parasympathetic
Structure of a Neuron, and functions
Dendrites: Recieve nerve impluses
Cell Body: Site of metabolic reactions and processes information that comes from dendrites
Axon: Carries impluses away from the cell body. Enclosed in a fatty insulation layer called the mylein shealth
Branching ends
Types of Neurons and Where theyre found
Multipolar- Brain and spinal cord
Bipolar- Inner ear, Retina of eye and olfactory of brain
Unipolar- Peripheral nerves
What is an Reflex arc?
Simple connections of neurons that don’t go to the brain but straight to the spinal cord. Sensory neurons then inter neurons and then the motor neuron.
Ex. Pain receptor in skin -> trigger nerve endings in sensory neuron-> message up arm to spinal cord interneuron-> signal to motor neuron in arm to remove contact from object
What is the Sodium Potassium pump?
The most important factor that contributes to resting membrane potiental.
- Uses ATP to transport 3 Na+ ions out and 2 K+ ions in to the cell.
What is a glial cell?
support the nervous system that nourishes neurons.
Removes wastes , defends against infection and provides framework
Ex mylien shealth
What makes the inside of a neuron negative?
- Negatively charged protiens on the inside
- Sodium Potassium Pump
- Diffusion rates and ion channels
What are the steps to action potential?
Step 1 -Nerve becomes excited -Na+ channels open and K+ channels close -Action potential is triggered and the threshold potiental reaches -55 mV Step 2 -Voltage gated Na+ channels open -Na+ move down concentration gradient and rush into Axon. - Now DEPOLARIZED Step 3 - VG Na+ close -VG K+ channels open -K+ move down concentration gradient and exit axon -Membrane now HYPERPOLARIZED to -90mV Step 4 -VG K+ channels close -Sodium potassium pump and diffusion restore the resting membrane to -70 mV
Single Transmission across a synapse?
Using neurotransmitters they cross the synapse cleft and bind to specific receptor protiens to carry information from one neuron to the next neuron
What is cerebral spinal fluid?
Dense , clear liquid found in ventricles of the brain and central canals of the spinal cords. Transports hormones, white blood cells and nutrients to cells of brain and spinal cord.
What are the 3 parts of the brain? Parts within them?
Hindbrain: Cerebellum, Medbulla obongata, Pons
Midbrain: Midbrain
Forebrain: Cerebrum, Thalamus, Hypothalamus
What is the Corpus Callosum?
Nerve fibres that connect the left and right hemispheres of the brain. Where scientist believe all human intellect is.
What are the 4 lobes and parts of each?
Frontal Lobe -Primary motor area -Premotor area -Motor speech(Broca's area) - Prefrontal lobe Temporal Lobe -auditory association lobe -primary auditory lobe -sensory speech(Wemicks area) Parietal Lobe -Primary somatasensory area -Somasensory associastion area -Primary taste area Occipital area -primary visual area -visual association area
