Nervous System Flashcards
Function of nervous system
Detects impulses from senses; control center of the body
Major organs of nervous system
Brain, spinal cord, senses, nerves
Difference between neurons and neuroglia
Neurons- make up 10% of nervous system
Neuroglia- “nerve glue”, make up 90% of nervous system
Dendrite
Receives the nerve impulses from the senses or another neuron
Soma
The body of the neuron that holds the nucleus
Schwann Cells
Allows myelin sheath to grow
Node of Ranvier
Impulses jump from node to node, which increases speed of impulse
Myelin
Insulates the axon. Produced by the Schwann cells
Axon
Passageway for nerve impulses after cell body; end in axon terminal
Axon terminal
Button-like endings of axon through which axons make contact with other nerve cells
CSF (Cerebrospinal Fluid)
- Between the arachnoid layer and the pia mater is the cerebrospinal fluid (CSF)
- The cerebrospinal fluid protects the brain by preventing the it from contacting the skull
Cerebrum
- Largest part of brain
- Divided into 2 hemispheres
- Outer cerebral cortex= Gray matter, made of cell bodies and dendrites
- Inner cerebral medulla= White matter, made of myelinated axons
Thalamus
- 2 bulb-shaped halves in the center of the brain
- Relays sensory impulses to the cerebral cortex for processing and sorting
Hypothalamus
- Controls hormones released by pituitary gland
- Responsible for autonomic processes (body temperature, hunger, sleep, thirst, blood volume, etc)
Brainstem
- Located between the cerebrum and spinal cord.
- Broken into three regions
Brainstem (midbrain)
- Also known as mesencephalon
- Relays info to cerebrum
- Controls body movements and postures
Brainstem (Pons)
- The Bridge!
- Almost completely made of white matter that links cerebral cortex and cerebellum
- Carries info from one side of brain to the other (why its called the bridge)
- Central control of breathing
Brainstem (Medulla Oblongata)
- Located above the spinal cord
- Transmits impulses between spinal cord and the brain
- Controls blood pressure, heart rate, swallowing, and coughing
Cerebellum
- Second largest part of brain
- Near back of skull
- Responsible for coordinating the movements directed by the cerebrum so that they are graceful and efficient
- All involuntary movements
- Aids in “muscle memory”
Spinal Cord
- Extends from the medulla oblongata
- 31 pairs of spinal nerves branch out from the spinal cord, connecting to all parts of the body
- Relays impulses from the PNS to the brain
- A cross section of the spinal cord has a “butterfly” of gray matter surrounded by white matter
Frontal lobe
- Voluntary movements (walking)
- Reasoning & decision-making
- Memory
- Verbal communication
Parietal lobe
- Sensations
- Visual-spatial processing
- Body position
Occipital lobe
-Visual processing: vision and memory of objects
Temporal lobe
- Memory
- Comprehension & pronunciation of words
- Sensations of smell and sound
Merkel’s Disk
Touch receptor
Hair Follicle Receptor
Touch receptor
Ruffini’s Corpuscle
Touch and pressure receptors
Pacinian Corpuscle
Pressure receptor
Free Nerve Ending
Pain and temperature receptors
Malleus
Bone in your ear, known as the hammer
Anvil
Bone in your ear, known as the anvil
Stapes
Bone in your ear, known as the stirrup
Cochlea
- Located in inner ear
- A bony snail-shaped structure containing membranes filled with fluid
Cornea
- Made of thick, transparent tissue
- Allows light into the eye
Iris
- Located behind the cornea
- Colored part of the eye
- Works with pupil to regulate light entering the eye
Pupil
- Opening in the center of the iris
- Muscles regulate the amount of light entering the eye
- Low light: pupil wide open
- High light: pupil nearly closed
Retina
- Located in the back of the eye, contains thousands of photoreceptors
- Two kinds of photoreceptors: Rods and Cones
- Rods: all over retina, responsible for vision in low light, extremely sensitive
- Cones: center of retina, responsible for detection of colors, less sensitive
Lens
Semi-solid disc that directs light waves towards retina
Farsighted vs. Nearsighted
- Farsighted- eyeballs are too short
- Nearsighted- eyeballs are too long
