Lec. 14 Flashcards
What are the two main divisions of the human nervous system?
the CNS and PNS
What two structures compose the CNS?
The brain and spinal cord
What are the two divisions of the PNS?
Sensory and Motor divisons
What are the two types of fibers of the sensory division?
The somatic and visceral fibers.
In which direction do sensory division fibers run?
From receptors to the CNS.
What are the two types of motor nerve fibers and what are their effectors?
Motor somatic fibers are voluntary and signals are sent from the CNS to muscle fibers. Autonomic motor fibers are involuntary and run from the CNS to cardiac muscle, smooth muscle, and glands.
What is a ganglion?
A collection of neuron cell bodies in the PNS.
Describe the process of integration in the nervous system.
It is the nervous system processing/interpreting sensory input and deciding on a course of action.
What characteristic of the brain is important to intelligence/knowledge/etc?
The complexity of wiring is more important than the size of the brain.
What are the two types of matter in the brain? What differentiates them?
Grey matter consists of short, non-myelinated neurons and cell bodies and white matter consists of mostly myelinated axons.
What are the three large subdivisions of the brain not including the hemispheres?
The diencephalon, brain stem, and cerebellum.
What are the subdivisions of the brain stem in order of most superior to most inferior?
The midbrain, pons, and medulla oblongata.
What is the basic pattern of grey and white matter in the CNS?
It is grey matter surrounded by white matter.
What does a cross section of the brain stem look like in terms of grey and white matter?
There is still grey matter surrounded by white matter, but there is more grey matter scattered within the white matter.
What is the definition of cortex and where are they found?
A cortex is an outer layer of grey matter, and ca be found on the cerebral hemispheres and the cerebellum.
What do rostral and caudal mean?
Rostral is towards the front of the brain, and caudal is towards the back.
What is the brain ventricle?
It is a space that is continuous with other cavities and the spinal cord that is filled with CSF and surrounded by ependymal cells.
How many brain ventricles are there?
4 Brain ventricles
What are the names of the ventricles?
There are two lateral ventricles, a third ventricle, and a fourth ventricle.
What do the two lateral ventricles look like?
Horns.
What separates the two lateral ventricles?
A double membrane called the septum pellucidum.
What links the lateral ventricles with the third ventricle?
The intraventricular foramen.
Around what big structure is the 4th ventricle found?
The pons
What structure links the 3rd and 4th ventricles?
The cerebral aqueduct.
What are the 3 protrusions of the 4th ventricle called? What do they do?
The 2 lateral apertures and the medial aperture connect the ventricles to the subarachnoid space around the brain.
What is a gyrus?
It is a ridge of the brain.
What is the difference between a sulcus and a fissure?
A fissure is a larger furrow dividing the brain into lobes. A sulcus is a groove in the cortex.
What separates the two brain hemispheres?
The longitudinal fissure.
What separates the frontal and parietal lobes, and what is found on either side of it?
The lateral sulcus separates the two lobes, and the precentral and postcentral gyrus are on the front and back of it.
What separates the cerebellum and occipital lobes?
The transverse cerebral fissure.
What separates the parietal lobe and occipital lobe?
The parieto-occipital sulcus.
How much brain mass do the hemispheres make up?
Roughly 83 percent.
What are the five lobes?
The frontal, parietal, temporal, occipital lobes; and the insula.
What sulcus is found on the insula?
The insular central sulcus.
What are some functions of conscious behavior (found in the cerebral cortex)?
Perception, communication, memory, understanding, initiating voluntary movement.
What is the cerebral cortex composed of? How thick is it?
Cell bodies, dendrites, and unmyelinated axons. It is 2-4mm thick.
What are Brodmann Areas?
It is a system of organizing the brain according to thickness/histology developed in the 1900s by Korbinan Brodmann.
What are the three functional areas of the cerebral cortex?
The motor, sensory, and association divisions.