Nervous System

Cephalopods are widely regarded as the most intelligent of the invertebrates, and have well developed senses and large brains (larger than those of gastropods). The nervous system of cephalopods is the most complex of the invertebrates and cephalopods is the most complex of the invertebrates and their brain-to-body-mass ratio falls between that of warm- and cold-blooded vertebrates.The brain is protected in a cartilaginous cranium. The giant nerve fibers of the cephalopod mantle have been widely used as experimental material in neurophysiology for many years; their large diameter (due to lack of myelination) makes them relatively easy to study. Cephalopods are social creatures; when isolated from their own kind, they will take to shoaling with fish. Some cephalopods are able to fly through air for distances up to 50 m. While the organisms are not particularly aerodynamic, they achieve these rather impressive ranges by use of jet-propulsion; water continues to be expelled from the funnel while the organism is in flight.

The reversal of polarity during an action potential is due to the changes in ion concentrations across the cell membrane. When the membrane depolarizes, sodium ions rush into the cell and make the inside more positive. Repolarization occurs when potassium ions leave the cell, bringing the membrane potential back to negative.

Diagnosing nervous system disorders can be challenging due to the complexity of the nervous system, the wide range of symptoms and conditions that can arise, and the need for specialized tests like imaging studies, nerve conduction studies, and spinal taps. Symptoms can also vary significantly from person to person, making it harder to identify a specific disorder.

ADH (antidiuretic hormone) is primarily stimulated by humoral factors, such as changes in blood osmolality and blood volume. However, it can also be influenced by the nervous system, specifically through signals from the hypothalamus in response to stress or pain.

The sodium-potassium pump prevents the accumulation of sodium ions inside the cell and helps maintain the proper balance of sodium and potassium ions across the cell membrane. This pump actively transports three sodium ions out of the cell for every two potassium ions it transports into the cell, utilizing ATP energy in the process. Disruption of this pump can lead to cellular and physiological imbalances.

oligodendrocytes for C.N.S. and shcwann cells for P.N.S.

While our nervous system does have its own specialized cells, normal microbiota are generally not found within the nervous system. The blood-brain barrier helps protect the brain and spinal cord from microorganisms that could cause infection. However, recent research has suggested that there may be interactions between the gut microbiota and the nervous system through the gut-brain axis.

Parasympathetic stimulation stimulates the muscarinic receptors (and nicotinic) leading to increased Salivation, Lacrimation, Urination, Defacation, increased Gastric motility, Emesis etc

Baroreceptors detect increased BP (vessel stretch) and increase vagal tone - > increase parasympathetic tone ->increase muscarinic stimualtion - > diuresis

Also consider the effect of Atrial Natruetic Peptide and its effect...

The utricle and saccule are both structures found in the inner ear, specifically within the vestibular system. They are responsible for detecting changes in head position and helping to maintain balance and spatial orientation.

The main function of the central nervous system is to process and coordinate information received from the body's sensory receptors. This system consists of the brain and spinal cord, which work together to send and receive signals that control various bodily functions and behavior. Additionally, the central nervous system plays a crucial role in transmitting messages between different parts of the body to maintain homeostasis.

The nervous control of gastric secretion is mainly regulated by the enteric nervous system, which is a network of nerves within the walls of the gastrointestinal tract. The vagus nerve also plays a vital role in stimulating gastric secretion, especially during the cephalic phase of digestion when the brain anticipates food. Additionally, hormonal factors like gastrin, produced by the stomach and duodenum, can also influence gastric secretion.

The presence of theta waves in an adult brain is typically associated with drowsiness, relaxation, or light sleep. It can also occur during deep meditation or creative thinking. They are not typically seen in a fully awake state.

The motor pathway of the autonomic nervous system typically involves two neurons: a preganglionic neuron that originates in the central nervous system and a postganglionic neuron that extends to the target tissue or organ.

It is possible to experience temporary memory loss or confusion after a head injury, but amnesia as commonly portrayed in media is rare. Severe head trauma, such as a concussion or traumatic brain injury, can result in memory problems and cognitive impairments. It is important to seek medical attention if you have hit your head and are experiencing memory loss or confusion.

Information from the peripheral nervous system is carried to the central nervous system by neural cables called nerves. The work groups that neurons cluster into are known as neural networks.

Another name for the parasympathetic nervous system is the craniosacral, which describes the area of the spinal cord where the nerves are located.

Autoreceptors are located on the presynaptic neuron and are activated by neurotransmitters released by that neuron. When neurotransmitter levels reach a certain threshold, autoreceptors inhibit further release of neurotransmitters, providing negative feedback regulation to control neurotransmission and maintain homeostasis in the nervous system.

Data indicate a marked variability and suggest that motor and sensory cortices overlap and are not divided in a simple manner by the central sulcus. The central sulcus is the word that you are looking for.

This approach is known as biological determinism or biopsychological perspective, which focuses on how genetics, neurobiology, and other physiological factors influence human behavior. It emphasizes the role of biological processes in shaping behavior, such as the impact of hormones, brain structures, and genetic predispositions on individual actions and traits.

An automatic nerve response is an involuntary reaction initiated by the nervous system without conscious control. It is rapid and helps the body to respond to stimuli quickly, such as moving your hand away from a hot object without having to consciously think about it. Examples include the dilation of pupils in response to low light levels or the increase in heart rate during physical exertion.

Tobacco can affect the nervous system by increasing heart rate and blood pressure, leading to narrowed blood vessels and reduced blood flow to the brain. Nicotine can also bind to receptors in the brain, altering neurotransmitter levels and contributing to addiction. Long-term tobacco use can have detrimental effects on cognitive function and increase the risk of developing neurological disorders.

There are 31 pairs of nerves that leave the central nervous system - 12 pairs of cranial nerves that exit from the brain and 31 pairs of spinal nerves that exit from the spinal cord.

Cholinesterase breaks down acetylcholine into choline and acetic acid. This process helps to quickly terminate the signal transmission at cholinergic synapses, preventing overstimulation and allowing the synapse to reset for the next signal.