Anatomic Differences Between Rods And Cones

Sight is one of the special senses and it is accomplished with an organ called the eye. The eye receives light and transforms the photon signal into an electrical signal that the brain interprets. This transformation of information is done via the photoreceptor cells found at the back of the eye on the retina. The photoreceptors, rods and cones, are distributed across the back of the eye to capture all light with a higher concentration found in the fovea for fine vision. The light stimulates rods and cones resulting in a change in their membrane potential. This change results in a cascade of signals via sensory nerve cells along an optic nerve to the visual cortex. The image that is seen is focused on via the use of both intraocular and extraocular

Music affects the brain in different ways because everyone’s brain operates differently. There are four major parts of the brain that turn on when music enters the brain. These parts are the auditory cortex, the cerebrum, the cerebellum, and the limbic system. Each major part has smaller parts that also have a role in processing music.

Blindsight is the phenomenon where individuals who are completely blind in some or all of their visual fields (the total area where objects can be seen as one’s eyes are fixed on a single point in space) are capable of detecting, localizing, or identifying a visual stimulus located in their affected visual fields despite denying that they see the stimulus (Cowey 2004).

- Maintain boundaries, move, respond to environmental changes, take in and digest nutrients, carry out metabolism, dispose of wastes, reproduce themselves, and grow.

There are two points of view of the evolutionary history of the seal, the first view is the eared seals came from a bear like ancestor and the earless seal came from a otter like ancestor due to some similar function of the internal and external organs . The second view is that seals came from the monophyletic group and in a certain point they share a common ancestor. There was an animal called the enaliarctos and it was the last common ancestor of the seals. This animals spent more time on land than in the water than any other pinnipeds. The enaliarctos swim in the water while using both the foreflippers and hind flippers. In modern seals they do not use the foreflippers, they use their tails for steering in the water and the hind flippers

The brainstem is located underneath the limbic system is the brain stem. The midbrain includes the tectum and tegmentum. The brain stem is made up of the midbrain, pons, and medulla. The midbrain is the rostral part of the brain stem. The pons are a part of the metencephalon in the hindbrain. The medulla oblongata is located between the pons and spinal cord. This structure is responsible for basic vital life functions such as breathing, heartbeat, and blood pressure. The midbrain is involved in functions such as vision, hearing, eye movement, and body movement. The pons are involved in motor control and sensory analysis. For example, information from the ear first enters the brain in the pons. It also has parts that are important for the level of consciousness and for sleep.

The primary sensory cortex is responsible for receiving information from the body senses. This area receives information from different regions of the body. The information is then sent to the sensory association cortex. The sensory association cortex is responsible for analyzing the information and storing memories. One difference in these two areas of the brain is that the primary sensory cortex is only involved in perception, while the sensory association cortex in involved in perception, analysis, and memory storage of information received from more than one system. Another difference involves when damage is done to

Ten pairs of cranial nerves originate in the brain stem continuing to different areas of the face and body. Two pairs of cranial nerves originate in the cerebrum. Cranial nerves travel through specialized holes (foramina) in the skull originated for this purpose. The Abducens nerve offers the precise control needed for specialized movements such as the blink of an eye to a smile resulting from a scant upturning of a lip made possible by the Facial nerve. Damage to any of these 12 specialized nerves can result from trauma, tumors, malformations and disease. Cranial nerves possess either afferent or efferent nerve fibers or both. Afferent neurons convey information to the sensory stimulus in the brain while efferent neurons convey information to muscle

The mantis shrimp, is a marvel of natural selection, showing the utmost phenomena of our creature world; in comparison, nothing can match the riches of the mantis shrimp. The mantis testament of the power of the natural selection, this animals exceeds the realms of human engineering, with transcending our understanding of the world with the art of sonoluminescence, incredibly strong arms, and unimaginably advanced eyes.

Parkinson's disease (PD) is a degenerative motor disorder resulting from the progressive loss of dopaminergic neurons in an area of the brain known as the basal ganglia, in particular two clusters of cells called the substantia nigra. The manifestations of PD appear when 80% or more of the dopamine producing neurons have been destroyed. Symptoms of PD include difficulty initiating movement (bradykinesia); a shuffling gait; the classic pill rolling hand tremor; a blank facial expression; muscle rigidity; and in 10-15% of cases, the onset of dementia late in the course of the disease.

There are two major neurpathologic finding in PD. The first is the loss of dopaminergic neurons of the substantia nigra which cause the motor symptoms. The other finding is the presentence of Lewy bodies which is related to the cognitive decline. It is now thought that PD is multifactorial when looking at neural cell death. In PD, there are three major contributing factors: inflammation, dysfunctional mitochondria, and oxidative stress that affect these neuropathic findings. Each of these factors can act alone, but normally is seen as a cascading event, which is triggered by epigenetics and genetic causes mentioned above.

The brain and the spinal cord work together to aid the coordination of the body. The brain can be divided into three main regions: the forebrain, midbrain and hindbrain. The forebrain interprets sensory information, thought processes and memory and it also monitors the composition of the blood and temperature on the body. The midbrain acts as an important link between

It 's a layer located in the back of the eye, have cells activated when exposure to light and that trigger nerves response impulse that are connected to optic nerve in the brain.

Leber’s congenital amaurosis is an autosomal recessive blindness, more than 30 mutations in the gene RPE65 are thought to be causative of the condition. The disease is onset in childhood and causes sufferers to lose daylight vision and lack night vision. The study found that about 6 -16% of sufferers contained a mutated form of the gene RPE65 (retinal pigment epithelium-specific protein 65 kDa), an important enzyme of the retinoid cycle of vision. RPE65 is a gene that codes for the production of a protein in the retina which works to nourish the retina. It is essential for the visual cycle which is the way light that is entering the eye gets converted into electrical signals that can be recognised by the brain. If an individual suffers from Lebers congenital amaurosis, the light-detection cells die and disrupt communication between the brain and retina, causing blindness.

Research Question: To what extent do Hodgkin-Huxley models successfully define action potential generation of an organism mathematically?