Neuroscience

No, dead neurons in the cortex are not typically replaced by new neurons. The brain has limited capacity for neurogenesis, especially in the cortex. Dead neurons are usually not replaced, but the brain can adapt and reorganize to compensate for lost function through processes like synaptic plasticity.

The adrenal medulla develops from the sympathetic nervous system. It is responsible for secreting hormones such as adrenaline (epinephrine) and noradrenaline (norepinephrine) in response to stress or danger.

Prophase occurs during the first stage of the cell cycle, which is the mitotic phase. It is characterized by the condensation of chromatin into visible chromosomes, the disintegration of the nuclear envelope, and the formation of the mitotic spindle.

No, nerve impulses travel down the internodal pathways towards the AV node, not from it. The internodal pathways conduct the impulse from the SA node to the AV node, assisting in the synchronization of the heart's electrical activity.

The presynaptic cell that must have action potentials to produce one or more action potentials in the postsynaptic cell is the neuron releasing neurotransmitters at the synapse. When an action potential reaches the presynaptic terminal, it triggers the release of neurotransmitters into the synaptic cleft, which then bind to receptors on the postsynaptic cell membrane, leading to the generation of an action potential in the postsynaptic cell.

Action potentials occur along the axon of a neuron, where the electrical signals are transmitted from the cell body to the axon terminals. The action potential is initiated at the axon hillock and propagates down the axon to trigger the release of neurotransmitters at the synapse.

The tip of a neuron's axon culminates in several endings call terminal buttons. When an action potential is conducted down the axon, this is where it goes.

Sensory neurons are called afferent neurons because they carry information from sensory receptors to the central nervous system. "Afferent" means to carry inward, referring to the direction of information flow towards the central nervous system.

Generally, cardiac excitation begins in the sinoatrial (SA) node. An action potential spontaneously arises in the SA node and then conducts throughout both atria via gap junctions in the intercalated discs of atrial fibers. Following the action potential, the two atria finish contracting at the same time. The action potential also reaches the atrioventricular (AV) node, located in the interatrial septum, just anterior to the opening of the coronary sinus, where the action potential slows whereby providing time for the atria to empty their blood into the ventricles. Then the action potential enters the atrioventricular (AV) bundle because it is the only site where action potentials can conduct from the atria to the ventricles. After conducting along the AV bundle, the action potential then enters both the right and left bundle branches that course through the interventricular septum toward the apex of the heart. Large-diameter Purkinje fibers rapidly conduct the action potential, first to the apex of the ventricles and then upward to the remainder of the ventricular myocardium. Then, a fraction of a second after the atria contract, the ventricles contact.

Postganglionic neurons cell bodies are located in autonomic ganglia, which are small clusters of nerve cells located outside the central nervous system. These ganglia are found along the pathway of the autonomic nerves, allowing for communication between the central nervous system and peripheral organs.

Yes you can. I'm walking with a cane now. My legs on down to my feet is very sensitive. I have pain in my knees down to my feet, lots of pain, if I stay on my feet

long or stand long my feet and legs will give out on me. My balance is off when I stand.

So yes I'm a cripple and my sugar is up and down.

Opiate drugs typically bind to opioid receptors rather than dopamine receptors. Opioids act on the brain and nervous system to produce pain relief and feelings of pleasure, whereas dopamine is a neurotransmitter involved in reward and pleasure pathways in the brain.

Eyes: constricts pupils, stimulates salivation and tears

Lungs: constricts airways

Heart: slows heartbeat

Stomach: slows digestion

Pancreas: stimulates to release insulin and digestive enzymes

Intestines: dilates blood vessels in gut

Bladder: stimulates urinary bladder to contract

Reproductive organ: stimulates arousal

Basically it acts in accordance to the term "rest and digest".

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.

Great Dane seizures are just like those in any other breed. Treatment may depend on the underlying cause. Symptomatic treatment for seizures in dogs can include giving anti-seizure medications such as phenobarbital, potassium bromide, zonisamide or levetiracetam. You will need to visit your vet to find out which treatment is right for your dog or if treatment is even necessary. Many vets only treat frequent seizures (more than one a month) as the side effect of some anti-seizure medications can be serious.

Increased production of acetylcholine in cerebral nuclei would enhance neurotransmission in the central nervous system, leading to improved cognitive function, enhanced memory formation, and potentially increased muscle movement or tone. However, excessive levels of acetylcholine could also lead to overstimulation of neurons, potentially resulting in conditions such as seizures or tremors.

Hyperintense on a medical imaging scan, such as MRI, indicates a stronger signal compared to surrounding tissue. This can suggest the presence of certain abnormalities or conditions, depending on the context of the scan and the specific characteristics of the hyperintensity.

Therapeutic drugs that block dopamine receptors are most likely to reduce symptoms of psychosis, such as delusions and hallucinations. Blocking dopamine receptors can also help manage symptoms of certain movement disorders, like Parkinson's disease. However, these drugs may also have side effects related to movement, cognition, and motivation.

The drug you are referring to is likely a muscle relaxant or a central nervous system depressant. These types of drugs work by decreasing the activity of the muscles or the nervous system, resulting in relaxation and reduced muscle spasms or nerve-related symptoms. It is important to use these medications as directed by a healthcare professional to avoid potential side effects or interactions.

Neurotransmitter receptors are located on the postsynaptic membrane of neurons. When a neurotransmitter binds to its specific receptor, it can either excite or inhibit the postsynaptic neuron, thereby influencing the transmission of signals in the brain.

The motor neuron and the muscle fiber it controls constitute a motor unit. This functional unit is essential to the process of muscle contraction and movement in the body. When the motor neuron sends signals to the muscle fiber, it results in the activation and coordination of muscle fibers to produce movement.

The parts of a multipolar neuron include the dendrites which receive nerve impulses, the cell body which integrates the signals, and the axon which conducts the signals away from the cell body. In terms of receiving nerve impulses, the order is generally dendrites, cell body, and then axon.

Sensory neurons typically have a unique shape with a long projection called an axon that transmits signals from sensory receptors in the body to the central nervous system. They also have shorter projections called dendrites that receive signals from the environment or other neurons.

Voltage-gated potassium channels open immediately after the action potential peak, allowing potassium ions to exit the cell. This repolarizes the cell membrane and helps bring it back to its resting state.