Psychology condense 6 p-35-42 Peripheral Somatosensation and Muscle Stretch Reflex

A collection of axons from upper motor neurons (UMNs) that travel from the cerebral cortex to the spinal cord, where they cross to the opposite side and synapse on lower motor neurons (LMNs).

A collection of axons from upper motor neurons (UMNs) that travel from the cerebral cortex to the brainstem, where they synapse on lower motor neurons (LMNs) that control cranial nerves.

An exaggerated muscle stretch reflex, usually caused by increased sensitivity of muscle spindle receptors due to lack of UMN stimulation

Rhythmic, involuntary contractions of a muscle, usually triggered by a muscle stretch reflex

Increased muscle tone, or stiffness, often observed in patients with upper motor neuron lesions.

An abnormal response to a plantar reflex test, where the toes extend upward instead of curling down.

The pathway in the nervous system that carries sensory information about position, vibration, and fine touch to the brain.

The pathway in the nervous system that carries sensory information about pain, temperature, and gross touch to the brain.

Somatosensation includes five main senses: position sense, vibration, touch, pain, and temperature. Mechanoreceptors detect position, vibration, and touch. Nociceptors detect pain. Thermoreceptors detect temperature.

Receptors responsible for position, vibration, and touch have large diameter axons with thick myelin sheaths, allowing for fast transmission of signals. Receptors for pain and temperature have smaller diameter axons and slower transmission speeds.

Touch involves both fine and less precise information transmission. Fine touch travels through fast neurons, while less precise information travels through slower neurons.

Mechanoreceptors are located in the skin, with some closer to the surface and others deeper. Deep tissues, including muscles, also contain mechanoreceptors that detect stretch.

Pain and temperature receptors end in uncovered terminals, unlike mechanoreceptors which have structured receptors.

Afferent axons carry sensory information from receptors to the central nervous system.

A muscle stretch reflex is a protective response that causes a muscle to contract after it's stretched. This reflex has two parts: an afferent (stimulus) and efferent (response).

The knee-jerk reflex is an example of a muscle stretch reflex. When a hammer hits the tendon below the knee, it stretches the muscle spindles (muscle fibers). These somatosensory neurons send excitatory signals to lower motor neurons in the spinal cord, causing the muscle to contract.

A network of neurons scattered throughout the brainstem, crucial for regulating vital functions like breathing, digestion, and even higher-level cognitive processes.

Bundles of axons that connect the cerebrum and brainstem, carrying signals between these two brain regions.

A crucial pathway within the cerebrum that contains the corticospinal tract, which controls voluntary movements.

A structure that connects the right and left hemispheres of the cerebrum, allowing communication between them.

A group of nuclei involved in motor control, planning, and execution of movements, as well as cognition and emotion.

Changes to gene expression that don't involve alterations to the DNA sequence itself. Examples include adding methyl groups to a gene, making it harder for transcription factors to activate it.

The function of behavior is to maintain a stable internal environment, also known as homeostasis. Behavioral adaptations help organisms cope with their environment and survive.

The study of animal behaviors, focusing on observable actions.

The most common excitatory neurotransmitter in the brain. It plays a crucial role in learning, memory, and neuronal communication.

The most common inhibitory neurotransmitters in the brain and spinal cord, respectively. They play a vital role in regulating and controlling neuronal activity.

A neurotransmitter released from nuclei in the frontal lobe. It is involved in learning, memory, and muscle activity.

A neurotransmitter released from the hypothalamus. It is involved in regulating sleep-wake cycles, appetite, and mood.

A neurotransmitter released from the locus ceruleus in the pons. It is involved in alertness, attention, and stress response.

A neurotransmitter released from the raphe nuclei in the midbrain and medulla. It is involved in mood, sleep, and appetite.

A neurotransmitter released from the VTA and substantia nigra. It is involved in reward, motivation, and movement.

A method used to study brain function by creating temporary or permanent lesions in specific brain areas. This helps to understand the function of the damaged region by observing behavioral changes in the subject.

A technique that measures brain activity through magnetic fields produced by electrical currents in the brain. It is a non-invasive technique that has better spatial resolution than EEG, allowing for more precise localization of brain activity.

A neuroimaging technique that combines functional imaging with structural imaging. It measures blood flow in the brain, which is an indicator of neural activity.

A neuroimaging technique that uses radioactive tracers to measure brain activity. It cannot provide detailed structural information but can be combined with other imaging techniques like CAT scans or MRIs.

A person's characteristic emotional reactivity and sociability. Temperament is thought to be established before birth and persists throughout life.

The passing of traits from parents to offspring through genes. These traits can include physical features, talents, and even predispositions to certain diseases.

A type of twin study that compares identical twins (sharing 100% of their genes) to fraternal twins (sharing 50% of their genes), raised in the same environment. This helps researchers understand the relative influence of genetics and environment on traits and conditions.

Studies that compare adopted individuals to their biological families and adoptive families to understand the influences of genetic and environmental factors on various traits.

A study comparing identical twins raised in the same environment to see if a specific condition is more prevalent in identical twins, suggesting a genetic component. If similar rates of the condition are found in both identical and fraternal twins, it suggests a stronger environmental influence.