Week 4 Flashcards
What is the central nervous system?
Brain and spinal cord
What is the peripheral nervous system?
Connect the brain and spinal cord to the rest of the body
What is the somatic nervous system?
Axons conveying messages from the sense organs to the central nervous system and from the CNS to the muscles.
What is the autonomic nervous system?
Where are its cell bodies?
Control the heart, intestines, and other organs.
Has some cell bodies within the brain or spinal cord and some in clusters along the sides of the spinal cord.
What is dorsal?
Towards the back
What is ventral?
Toward the stomach
What is anterior?
Toward the front end
What is posterior?
Towards the rear end
What is superior?
Above another part
What is inferior?
Below another part
What is lateral?
Toward the side, away from the midline
What is proximal?
Located close (approximate) to the point of origin or attachment
What is distal?
Located more distant from the point of original or attachment
What is ipsilateral?
On the same side of the body
E.g. Two parts on the left or two on the right
What is contralateral?
On the opposite side of the body
E.g. One on the left, one on the right
What is the coronal / frontal plane?
A plane that shows brain structures as seen from the front
What is the sagittal plane?
A plane that shows brain structures as seen form the side
What ist he horizontal / transverse plane?
A plane that shows brain structures as seen from above
What is a lamina?
Row or layer of cell bodies separated from other cell bodies by a layer of axons and dendrites
What is a column?
Set of cells perpendicular to the surface of the cortex, with similar properties
What is a tract?
Set of axons within the CNS, also known as a project. If axons extend from cell bodies in structure A to synapses onto B, we say that the fibres “project” from A onto B.
What is a nerve?
A set of axons in the periphery, either from the CNS to a muscle or gland or from a sensory organ to the CNS
What is a nucleus?
A cluster of neuron cell bodies within the CNS
What is a ganglion?
A cluster of neuron cell bodies, usually outside the CNS (as in the sympathetic nervous system)
What is a gyrus?
A protuberance on the surface of the brain
What is the sulcus?
A fold or groove that separates one gyrus form another
What is a fissure?
A long, deep sulcus
What term means “towards the midline” and what term means its opposite?
Medial
Lateral
Which sense organs and muscles does the spinal cord communicate with?
All except those of the head
What do the entering dorsal roots (axon bundles) do?
Carry sensory information
What do the exiting ventral roots do?
Carry motor information
What are the cell bodies of sensory neurons, which are in clusters of neurons outside the spinal cord, called?
Dorsal root ganglia
What are the two parts of the autonomic nervous system?
Sympathetic and parasympathetic nervous systems
What is the sympathetic nervous system?
What are some of its functions?
A network of nerves that prepare the organs for a burst of vigorous activity.
Consists of chains of ganglia just to the left and right of the spinal cord’s central regions (the thoracic and lumbar regions).
Prepares the organs for fight or flight, such as by increasing breathing and heart rate, and decreasing digestive activity.
What kinds of things have sympathetic input, but not parasympathetic input?
Sweat glands
Adrenal glands
Muscles that constrict blood vessels
Muscles that erect hairs of the skin.
What is the parasympathetic nervous system?
What are some of its functions?
“Rest and digest” system
Facilitates vegetative, nonemergency responses.
Often performs the inverse of the sympathetic nervous system; decreases heart rate, increases digestive activity.
Promotes sexual arousal, including erection in males.
How are parasympathetic ganglia arranged?
Preganglionic axons extend from the spinal cord to parasympathetic ganglia close to each internal organ.
Shorter postglangionic fibres then extend from the parasympathetic ganglia into the organs themselves.
What neurotransmitter does the PNS’s axons release into the organs?
Acetylcholine
What neurotransmitters do the SNS’s axons release?
Norepinephrine, although some like the sweat glands use acetylcholine
How do drugs affect the PNS and SNS?
Different drugs excite or inhibit one system or the other.
E.g. Cold remedies exert most of their effects by blocking parasympathetic activity or increasing sympathetic activity.
Some cold remedies block sinus flow. What effect on the PNS or SNS is this displaying?
Suppressing the PNS
Motor nerves leave from which side of the spinal cord, dorsal or ventral?
Ventral
What are the three major divisions of the brain?
Hindbrain
Midbrain
Forebrain
Where is the hindbrain?
What are its three components?
Posterior part of the brain
Medulla
Pons
Cerebellum
Which parts of the brain constitute the brainsteam?
Hint: This is quite broad
Medulla and pons
Midbrain
Certain central structure of the forebrain
What is the medulla?
Enlarged extension of the spinal cord.
Just as the lower parts of the body connect to the spinal cord via sensory and motor nerves, the head and the organs connect to the medulla and adjacent areas.
What vital reflexes does the medulla control?
Breathing Heart rate Vomiting Salivation Coughing Sneezing
How do opiates affect the medulla?
Opiate receptors are abundant in the medulla and can produce a dangerous decrease in breathing and heart rate.