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 of Nervous System
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
The main glial cells of the peripheral nervous system which wrap around axons of motor and sensory neurons to form the myelin sheath.
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. It also maintains the blood-brain barrier, which controls homeostasis for the brain and prevents infection.
Cerebrum
Largest part of brain. Divided into 2 hemispheres. Outer cerebral cortex= “gray matter,” made of cell bodies & dendrites. Controls conscious activities. Inner cerebral medulla= “white matter,” made of myelinated axons
Frontal Lobe
Voluntary movements (walking), Reasoning & decision-making, Memory, Ability to predict consequences of actions, Planning, Verbal communication
Parietal Lobe
The parietal lobe controls: Sensations, Visual-spatial processing, Body position
Occipital Lobe
The occipital lobe controls: Visual processing- vision & memory of objects
Temporal Lobe
The temporal lobe controls: Memory, Comprehension & pronunciation of words, Sensations of smell and sound, Emotional association of memories
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 (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.
Midbrain
Also known as mesencephalon. Relays info to cerebrum. Controls body movements and postures
Pons
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
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.
Merkel’s Disk
Touch.
Free Nerve ending
Pain and Temperature. 1st layer under skin.
Hair follicle receptor
Touch. Where the hair.
Ruffni’s Corpsucle
Touch and Pressure
Pacinian Corpuscle
Pressure
malleus
Hammer
incus
Anvil
stapes
Stirrup
Cochlea
The inner ear contains the cochlea, a bony snail-shaped structure containing membranes filled with fluid.
Cornea
Cornea is made of thick, transparent tissue. Function: allows light into the eye
Pupil
Pupil is the opening in the center of the iris.
Function: muscles regulate the amount of light entering the eye. Low light- pupil wide open. High light- pupil nearly closed.
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
The retina, located in the back of the eye, contains thousands of photoreceptors. There are two kinds of photoreceptors: Rods (distributed all over the retina. Responsible for vision in low light, extremely sensitive). Cones (concentrated in center of retina. Responsible for detection of colors, less sensitive)
Lens
The lens is a semi-solid disc that directs light waves towards the retina. It is controlled by ciliary muscles and suspensory ligaments. These muscles and ligaments help bend or flatten the lens based on the distance of the image being viewed. The lens becomes less elastic with age, causing some adults to need corrective lenses to have difficulty focusing at certain distances.
Papillae
The tongue is filled with bumps called papillae. Many of these papillae contain taste buds, which contain chemoreceptors.
Farsighted vs Nearsighted (what is the difference?)
Short sightedness is the exact opposite of long sightedness and means your near-vision (ability to see things up close) is clear, while your long-vision (ability to see things in the distance) is blurry.
