Nervous System Flashcards
Function of Nervous System
The function of the nervous system is to detect impulses from the senses; control center of the body
Major organs
Brain
Spinal Cord
Senses
Nerves
Difference between Neurons and Neuroglia
Neurons (make up 10% of the nervous system)
Neuroglia (“nerve-glue”, make up 90% of the nervous system)
Dendrite
receive the nerve impulses from the senses or another neuron
Soma
body of the neuron that holds the nucleus
Schwann Cells
type of glial cell that surrounds neurons
Node of Ranvier
impulses jump from node to node, which increase 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
the button-like endings of axons through which axons make contact with other nerve cells.
CSF
The cerebrospinal fluid protects the brain by preventing the it from contacting the skull.
Cerebrum
Divided into 2 hemispheres
Controls conscious activities
The cerebrum is divided into 4 lobes, based on their functions. They are named for the parts of the skull protecting them.
Thalamus
Relays sensory impulses to the cerebral cortex for processing and sorting
Hypothalamus
Controls hormones released by pituitary gland (often called the “master endocrine gland”)
Responsible for autonomic processes (body temperature, hunger, sleep, thirst, blood volume, etc)
Brainstem
Located between the cerebrum and spinal cord.
Cerebellum
Responsible for coordinating the movements directed by the cerebrum so that they are graceful and efficient
Spinal cord
Relays impulses from the PNS to the brain
Frontal Lobe
Reasoning & decision-making
Verbal communication
Parietal Lobe
Sensations
Visual-spatial processing
Body position
Occipital Lobe
Visual processing- vision & memory of objects
Temporal Lobe
Comprehension & pronunciation of words
association of memories
Brainstem (Midbrain)
Controls body movements and postures
Brainstem (Pons)
Carries info from one side of brain to the other (why its called the bridge)
Brainstem (Medulla Oblongata)
Controls blood pressure, heart rate, swallowing, and coughing
Merkel’s disk
touch
Hair follicle receptor
touch
Free nerve ending
pain and temperature
Ruffini’s corpuscle
touch and pressure
Pacinian corpuscle
Pressure
Malleus
the hammer
incus
the anvil
stapes
the stirrup
Cochlea
a bony snail-shaped structure containing membranes filled with fluid.
Cornea
s made of thick, transparent tissue
Function: allows light into the eye
Pupil
is the opening in the center of the iris
Function: muscles regulate the amount of light entering the eye
Iris
The iris is located behind the cornea. It is the colored part of the eye.
Function: works with pupil to regulate light entering the eye
Retina
located in the back of the eye, contains thousands of photoreceptors.
Lens
is a semi-solid disc that directs light waves towards the retina.
Farsighted
eyeball is too short
is the ability to only clearly see objects that are far away
Nearsighted
nearsightedness means the ability to see things nearby with relative clarity,
