43.2 Structure and Function of the Nervous Systems of
The brains begin as three major divisions.
Some forebrain structures are not shown.
Section 43.2 describes the functions of these structures.
The brains aren't shown to scale.
The surface area of the brain of certain mammals is increased due to the folding of the cerebral cortex.
A small brain is limited in its behavior.
Lion are interacting with fellow members of their species.
The brain mass of nervous systems has been determined by scientists.
Homo neanderthals was larger than ours.
Does this mean that Neanderthals were more intelligent?
The nervous system of humans has over 100 billion neuron and glial cells, and is very complex.
There are enormous numbers of connections late body temperature and those that recognize visual information between neurons in the human brain.
There are many myelinated axons within the nervous system.
There are tracts that convey information between the brain and the spine.
The axons of nerves may be found within the cell bodies of the internal or external environment.
In other words, a nerve may carry information from an outside source to the PNS.
If you lean against a newly painted fence, it's because you accidentally entered the CNS.
There are connections between your skin and the brain or spine that transmit the PNS.
The information goes to your brain and midbrain.
The axons were bundled together in large numbers.
The brain and spine are encased in bone.
The PNS includes cranial nerves, ganglia, and spinal nerves, which carry information to and from the central nervous system.
The cerebral cortex is composed of gray and connects to the central canal that extends the matter that sits on top of a large collection of white matter pathways.
The gray matter is located in the center of the spine and forms a cushion of support for the central nervous system.
The sensory nerves of the PNS send information to the Dorsal roots.
The PNS of animals is divided into two major nerves.
The central canal carries the nervous system and the protective fluid through the spine.
Both divisions have sensory and motor nerves.
The vous system receives stimuli, such as heat, light, odors, chemicals dura mater, and is a thick pro (in food), sounds, and touch, and transmit signals to the central nervous system.
The tective layer is just inside the skull.
The arachnoid mater is the middle efferent motor neurons of the nervous system.
There are many weblike tissue connections in the motor neuron's cell bodies and they are located within spidery mother.
The axons from these cells leave the spine and go to the pia mater, the innermost part of the body.
The pia mater is very thin and lies along the way.
There are many responses of the nervous system that can be con.
We use the nervous system space.
Not all responses are voluntary.
The brain that responds to sudden movements or blows to the head is called the knee-jerk response.
The automatic is shown in Figure 42.4.
It is involved system.
In addition to the subarachnoid space, the fluid in the brain regulates a number of bodily functions.
Skull bone confront or avoid a perceived threat.
Venous blood is involved in body functions.
Fuel is supplied to the blood from the body's tissues.
Some of the oldest structures of the brain are located in the back of the brain and control the basic processes that sustain life.
The inputs from the meninges are exaggerated for illustrative the spinal cord and inner ears that convey information about the position purposes.
The entire central nervous system of the limbs and head is covered by the fluid of the brain.
In a procedure known as a lumbar puncture, physicians use a needle to withdraw a motor activity such as texting, making a jump shot in basketball, or small amount of cerebrospinal fluid from the brain.
Scientists have thought that the cerebellum doesn't function in learning, memory, and conscious thought, but recent evidence shows that it does.
The full extent of the cerebellum's nervous system remains to be discovered, but the auto dence suggests that it is mostly composed of efferent motor cognitive functions.
The autonomic nervous system is not a substitute for voluntary control.
The pons are used as a relay set of motor neurons by the autonomic nervous system.
Between the cerebellum and other areas of the brain is the cell body of the first neuron.
The pons contains nuclei that have a cord and are part of the PNS.
The rate and depth of breathing are regulated by this second neuron.
The axon is sent to an effector cell.
Smooth muscles, cardiac muscle, and glands are controlled by these neurons.
The processes that maintain homeostasis are the same that both divisions of the autonomic system act on.
It is involved in the control of organs.
Imagine if a person came upon a bear while hiking.
The midbrain is near the pons.
It processes several types of sen activity, increased blood flow to skeletal muscles, and increased Secre sory inputs.
Some of the major functions of each division are shown in the figure.
Most parts of the body receive inputs from both divisions of the sympathetic and parasympathetic systems.
The sympathetic division's nerves make connections with a chain of ganglia, but not all of them.
The parasympathetic division's nerves make connections near or in their targets.
The nervous system of the body is called the autonomic nervous system.
The nervous system's two divisions control the different organ systems in the body.
The functions of these structures can be changed.
The heart rate can be accelerated or slowed to match the animal's needs.
The limbic system consists of the olfactory bulbs, amygdala, and hippocampus, all of which are part of the cerebrum.
The brainstem consists of the midbrain, pons, and medulla oblongata.
The midbrain is responsible for sensory information in a way that allows us to pay attention to impor activating neural pathways that change the diameter of the pupils of tant cues while temporarily ignoring less important ones.
A change in the amount of ambient light filters the eye.
If the mechanism begins in the reticular formation, it can be damaged.
The medulla oblongata, the pons, and the midbrain all allow attention to certain stimuli.
A new parent's ability to sleep through a storm but not wake their baby immediately is one of the functions described.
The network of motor activities that it receives from the cerebellum and other nuclei and tracts extends throughout much of the brainstem and structures to the cerebral cortex, which can adjust its outgoing signals to many other brain regions.
Because of the importance of the brain's functions, the surface of the brain can be damaged and result in coma or death.
The thalamus, hypothalamus, and epithalamus make up the diencephalon.
The cerebral cortex is one of the parts of Epithalamus brum.
It gets input from all sensory systems.
This area is important for controlling behavior.
The right cerebral hemisphere has its own vital functions.
The severed pituitary gland regulates hormones from other parts of the body.
The hypothalamus is sensitive to the actions of other hormones.
Left cerebral hemisphere gonads act within the hypothalamus to facilitate feed ing, drinking, sexual, and aggressive behaviors.
melatonin is a hormone that is produced in the pineal gland in the center of the brain.
melatonin is regulated by the length of the light period.
melatonin has been suggested to function in the wake and sleep cycles.
The left and right hemispheres have different functions according to research done in the 1950s.
When a split-brain patient in a laboratory animal had a split-brain surgery in which they held an object in his right hand but couldn't see it or touch it, they couldn't touch it.
He could give a name to the animals that underwent the surgery.
He kept their health and functioning.
He was able to describe the object in his left hand that was held during the surgery.
split-brain surgery was "smooth" in 1961.
With her eyes closed, a split-brain patient was given a rock that was characterized by electrical activity that began rock to hold, and she described it as a rock.
The dominant functions were decreased when the connection between the hemispheres was cut.
The right hemisphere is more dominant in severity of epileptic seizures.
The opportunity for research was provided in 1981 by the split-brain surgery, which resulted in the winner of the Nobel Prize in Physiology or Medicine.
The cerebral tion is due to the fact that both hemispheres can function independently.
The left hemisphere produces a descriptive word for an object in sensory, motor, or other functions when there are identifiable regions within the cortex.
The cerebral cortex is divided into four parts, the frontal, parietal, occipital, and temporal left hemispheres.
They are capable of walking once decision making, controlling impulses, making plans, and showing judg has begun, but they move slowly with muscle tremors, short-term memory, and conscious thought and social awareness.
The somatosensory cortex and parietal lobe ing in the substantia nigra take up the l-dopa and convert it into dopa, which is then released onto cells of the basal nuclei.
The ability to use visual reduces the symptoms of Parkinson's disease because dopamine is increased in the parietal lobe.
The regions of the body are represented in propor diencephalon because of the amount of cortical area devoted to them.
The larger part of the cerebral cortex is devoted to sensory inputs from involved in the formation and expression of emotions, and it plays the lips more than other areas of the face.
The lips are more sensitive to touch than other parts of the body.
The expression of emotions is mapped in this way in humans.
There is a map early in childhood that shows the different sound frequencies in the cortex.
Even very young babies can express fear.
The organization of the cerebral cortex can be used to bond with their parents.
The ability to recognize emotional expression in others is also involved in this structure.
Animals can establish and maintain relationships with the help of a group of nuclei that surround the thalamus and lie beneath the cere.
Like the cerebellum, the Basal nuclei are involved in plan and help an animal defend itself against danger by avoiding ning, learning, and fine-tuning movements.
They function in a conflict.
A key behav complex circuitry is associated with anger.
Parkinson's disease is a neurological disor Adjacent to the amygdala and forms a loop in the middle of the brain.
The hippocampus is involved in trunk learning.
Many animals use their sense of smell as a major way to learn and remember aspects of their environments.
The amount of cortex devoted to body parts is related to the size of the parts.
The damage to the hippocampus results in perception of sensory inputs, attention, integration of sensory, and an inability to form new memories, a devastating condition that pre and motor information.
Experiments with laboratory animals have shown the importance of the hippocampus for memory and learning in other learning.
There is a hidden platform in a pool of water.
The animals swim until they find a platform that is safe to stand on.
As they learn and remember the platform's location, the time it takes to find it is shorter.
Although the cerebral cortex is not unique to humans, its that describes the relationships among the larger and smaller extensive development is one of the defining features of the structures of the human brain.
The question asks you to identify a hierarchy of structure in a region paring human genes with genes known to be involved in brain of the human brain.
The human brain can determine whether a relationship exists between the numerous structures that contain smaller structures within expression of a particular gene and the organization of them.
One disorder involves the development of larger structures.
You may remember that the three major divisions of the cerebral cortex are many small folds.
The forebrain, midbrain, and hindbrain are the parts of the brain that have many folds.
The cerebral cortex is a part of the brain in people with polymicrogyria.
You need to remember which part of the forebrain was affected by multiple and small gyri.
The symptoms are related to visual processing.
The major divisions of the forebrain are in a hierarchy, with the forebrain at the top and eight different variations of a single gene responsible for visual processing.
Refer to Figures 43.9.
The ability of the G-protein-coupled receptor to bind its ligand is altered by all eight of the polymicrogyriamutations.