Name: spinal cord nerves and reflexes
Uploaded: 2024-08-29T22:13:37.000Z
Duration: 1 min 26 s
Channel: JoVE

K12 Standards

Florida Department of Education

High School

Life Science

SC.912.L.14

SC.912.L.14.28

Spinal Cord

脊髓起始于脑底部，沿背部中央向下延伸，是大脑与身体之间重要的信息传递通路。
脊髓分为多个节段，包括八个颈段、十二个胸段、五个腰段、五个骶段和一个尾段。由脊髓发出的神经通过周围神经系统连接到特定的身体部位。
脊髓中有三种类型的神经细胞：感觉神经元、运动神经元和中间神经元。&#160;
感觉神经元将感觉信息传递至脊髓，而运动神经元则将信息从脊髓传递至腺体和肌肉。中间神经元连接感觉神经元和运动神经元，构成了脊髓的大部分结构。
此外，脊髓可以在没有大脑输入的情况下启动反射动作。
例如，当一个人触碰到一个热锅时，皮肤中的感觉神经元会检测到疼痛，并将信号传递至脊髓。该输入信号会立即由中间神经元处理，进而激活运动神经元，迅速促使肌肉将手收回。

脊髓

脊髓是中枢神经系统的重要组成部分，从脑干底部延伸到脊柱的腰部。它对于维持身体稳定性和促进大脑与身体周围部位之间的交流至关重要。

<ul style="list-style-type: disc; display: flex; flex-direction: column; gap: 10px; padding: 0 0 0 40px;">
 <li>脊髓包裹在脊柱的保护性骨结构内，分为 30 个节段，与椎骨相对应。
 </li>
 <li>这些节段在通过庞大的神经网络连接特定身体区域方面发挥着重要作用，允许双向信息流动，这对于各种身体功能至关重要。
 </li>
 <li>每个脊柱节段通过成对的脊神经连接到身体的特定部位，根据它们在脊柱上的位置，脊神经分为颈椎、胸椎、腰椎、骶椎和尾椎区域。
 </li>
 <li>这些神经通过椎骨之间的间隙离开脊髓，传递感觉和运动信息。
 </li>
</ul>
脊髓由三种主要类型的神经细胞组成:感觉神经元、运动神经元和中间神经元。

<ul style="list-style-type: disc; display: flex; flex-direction: column; gap: 10px; padding: 0 0 0 40px;">
 <li>感觉神经元在将外部刺激信息从感觉受体传递到脊髓方面起着关键作用。这些信息包括触觉、温度和疼痛等感觉。
 </li>
 <li>中间神经元是脊髓结构中数量最多的神经元，它们处理和整合这些感觉信息。它们充当中介，使感觉神经元和运动神经元之间能够进行交流，并促进适当运动反应的协调。
 </li>
 <li>运动神经元将脉冲从脊髓传递到身体的肌肉和腺体，启动和控制所有自主运动和许多非自主行为。这强调了脊髓在运动功能中不可或缺的作用。
 </li>
</ul>
脊髓的一个显著功能是它能够独立于大脑协调反射动作。反射弧是一种神经回路，可直接对感觉输入做出激活反应，从而产生即时反应。例如，当接触到热表面时，感觉神经元会迅速向脊髓发出信号。中间神经元会立即处理此信息并激活运动神经元，导致手迅速缩回。这种反射动作是为了保护身体免受伤害，并凸显了脊髓的复杂功能及其在人体运作层次中的关键作用。

脊髓起始于脑底部，沿背部中央向下延伸，作为大脑与身体其余部分之间的重要通信枢纽……

Education

教育

JoVE Core

Introduction to Psychology

心理学导论

Unit 1

第一单元

Biopsychology

生物心理学

KEY TERMS AND CONCEPTS

关键术语与概念

spinal cord nerves and reflexes

The spinal cord is a major part of the central nervous system. It runs from the base of the brainstem to the lumbar region of the vertebral column. It helps keep the body stable and carries signals between the brain and the rest of the body.

The spinal cord sits inside the bony spine for protection. It is divided into 30 segments that match the vertebrae. Each segment connects to a specific body region through paired spinal nerves.

These spinal nerves are grouped by where they leave the vertebral column. The regions are cervical, thoracic, lumbar, sacral, and coccygeal. They exit through spaces between the vertebrae and carry sensory and motor information.

The spinal cord contains three main types of nerve cells. Sensory neurons bring information from sensory receptors to the spinal cord. This includes touch, temperature, and pain.

Interneurons are the most numerous nerve cells in the spinal cord. They process and combine sensory input. They also link sensory neurons to motor neurons so the body can respond in the right way.

Motor neurons send signals from the spinal cord to muscles and glands. They control voluntary movement and many involuntary actions. The spinal cord also handles reflex arcs, which are fast neural pathways that work without direct brain control.

A reflex arc can protect the body from harm. When a person touches a hot surface, sensory neurons send a signal to the spinal cord. Interneurons process the message and activate motor neurons, which make the hand pull away quickly.

Spinal Cord Nerves and Reflexes

introduction to biological bases of psychology

introduction-to-biological-bases-of-psychology

Biological Factors Shaping Behavior and Mind

Biopsychology connects biology and psychology by showing how the body influences behavior and mental processes. It focuses on the nervous system, neurotransmitters, hormones, genetics, and evolutionary ideas. Together, these areas help explain why people think, feel, and act the way they do. The nervous system is the main foundation of biopsychology. It has two parts: the central nervous system, or CNS, and the peripheral nervous system, or PNS. The CNS includes the brain and spinal cord and...

nervous system

Nervous System: CNS, PNS, and Reflexes

The nervous system helps the body sense, move, and respond. It works through a network of nerve cells that carry signals around the body. This system has two main parts: the central nervous system and the peripheral nervous system. The central nervous system, or CNS, includes the brain and spinal cord. The brain acts as the body’s control center. It processes sensory information and helps coordinate responses. The spinal cord serves as a major pathway for signals between the brain and the rest...

neurons as communicators of the brain

Neuron Parts and Signal Transmission

Neurons are the cells that carry information through the brain and nervous system. They use electrical and chemical signals to help control body functions, from heartbeat regulation to complex thinking. Their structure is built for fast, efficient communication. The cell body, or soma, is the neuron’s control center. It contains the nucleus, which holds the cell’s genetic material and helps maintain the neuron’s health and function. The cytoplasm around it contains organelles that make...

neuronal communication

How Neurons Send Signals

Neurons send signals through electrochemical communication that supports brain and nervous system function. A key part of this process is the action potential, a rapid electrical change that starts when the neuron’s internal charge rises above a threshold. That signal then travels along the axon to the axon terminal, where it is ready to pass to another neuron. The connection point between two neurons is called a synapse. Synapses can be electrical or chemical, and each type moves information...

neurotransmitters

Brain Chemicals That Shape Mood and Movement

Neurotransmitters are chemical messengers that help neurons communicate. They play a major role in nervous system function, as well as in mood, movement, sleep, and social behavior. Serotonin is made in the brain and intestines. It is linked to well-being and happiness, and it helps regulate mood, appetite, and sleep. When serotonin levels are out of balance in the brain or in peripheral sites, depression and sleep problems can occur. Dopamine is produced in several brain areas, including the...

cerebral hemispheres

How the Brain’s Two Halves Work

The brain’s two cerebral hemispheres work together to process information and control the body. The left and right hemispheres are linked by the corpus callosum, a large bundle of nerve fibers. This connection lets the two sides share sensory and motor information, with each hemisphere controlling the opposite side of the body. The hemispheres are also specialized for different tasks. This is called lateralization, which means certain functions are handled more strongly by one side than the...

lobes of the cerebrum

How Brain Lobes Shape Perception

The cerebral cortex is divided into two hemispheres, and each hemisphere has four lobes: frontal, parietal, temporal, and occipital. Together, these lobes support the brain’s main cognitive and sensory jobs. They work as a team to help you think, feel, move, and respond to the world. The frontal lobe sits behind the forehead and acts as a control center for personality, intelligence, and voluntary muscle movement. It also contains the prefrontal cortex, a region that helps with planning,...

spinal cord

The spinal cord is a major part of the central nervous system. It runs from the base of the brainstem to the lumbar region of the vertebral column. It helps keep the body stable and carries signals between the brain and the rest of the body. The spinal cord sits inside the bony spine for protection. It is divided into 30 segments that match the vertebrae. Each segment connects to a specific body region through paired spinal nerves. These spinal nerves are grouped by where they leave the...

lateralization

Brain Hemisphere Specialization

Brain hemisphere specialization divides mental tasks between the left and right sides of the brain. This split can improve neural efficiency and support more complex human abilities. Each hemisphere tends to handle the work it does best, which helps cognitive processing run more smoothly. The left hemisphere is especially strong in logic and language-related tasks. It supports analytical thinking, which means breaking a problem into parts and solving it step by step. This is important for...

human genetics

Genes, Behavior, and Mental Health

Human genetics explains how genes can influence behavior, emotions, and mental health. It also shows how a person’s genetic code can shape physical traits and the risk of disease. Each individual carries a unique set of genes, so the effects can be subtle or more noticeable. Genes help direct how the brain, hormones, and cells work. These body systems are all shaped by genetic instructions, and they help produce differences in thoughts and behavior. Human genetics therefore links biology with...

genetic material

Chromosomes, DNA, and Inherited Traits

Chromosomes, DNA, and inherited traits explain how genetic information is organized in the human body. Each cell contains a nucleus, and the nucleus holds 46 chromosomes arranged in 23 pairs. These chromosomes are tightly coiled structures made of DNA, which carries the instructions passed from parents to offspring. An individual inherits one set of chromosomes from the mother through the egg and one set from the father through the sperm. This combination creates a unique genetic makeup. Of...

genetic variation

How Alleles Shape Inherited Traits

Genetic variation helps explain why individuals in the same species can look and act differently. It comes from differences in DNA sequences. This diversity matters because it helps a species survive and adapt when the environment changes. Variation starts at fertilization, when an egg and sperm cell join. Each of these cells carries 23 chromosomes, so the fertilized egg can have up to 46 chromosomes. Chromosomes are long DNA strands that contain genes, which are the basic units of heredity. <br...

behavioral genetics and its designs

How Behavior Genetics Studies Inheritance

Behavior genetics studies how inherited genes influence human behavior. It looks at how genes passed from parents to offspring help shape behavioral traits and tendencies. The field also examines how inherited factors and environmental influences work together. Researchers use family studies, twin studies, and adoption studies to separate genetic and environmental effects. Family studies track traits within biological families to find possible genetic patterns. They have helped identify...

organization of the brain

Brain Regions and Their Key Functions

The brain is the main control center of the nervous system. It processes sensory input, makes decisions, and directs body actions. Its structure is divided into the hindbrain, midbrain, and forebrain, and each part supports important functions. The hindbrain sits at the base of the brain. It helps regulate automatic life processes. The medulla oblongata controls involuntary functions such as heartbeat, breathing, and blood pressure. Nearby, the pons acts as a bridge between brain regions,...

evolutionary psychology

Evolutionary Psychology and Human Behavior

Evolutionary psychology explains human behavior and mental processes through natural selection. It uses Darwin’s idea that traits can spread when they help survival and reproduction. In this view, some common behaviors may be adaptations that were useful to our ancestors. One clear example is fear of snakes. This fear is nearly universal, which suggests that early humans who avoided snakes were more likely to survive deadly encounters. Over many generations, that caution could be passed on and...

neuroplasticity

How the Brain Rewires Itself

Neuroplasticity is the brain’s ability to change its structure and function in response to learning, experience, or injury. It allows neural circuits to reorganize over time. This flexibility supports lifelong development and adaptation. One part of this change begins when dendrites and axons grow. Dendrites receive signals, and axons send them. As they grow, the brain’s circuitry becomes more complex and can support more connections. Next, synaptogenesis occurs. Synaptogenesis is the...

brain imaging

Brain Scanning Techniques

Brain scanning techniques help scientists and doctors see the structure and activity of the human brain. These methods support the diagnosis, study, and treatment of neurological and psychiatric disorders. The main techniques include computerized axial tomography, or CT, positron-emission tomography, or PET, magnetic resonance imaging, or MRI, functional magnetic resonance imaging, or fMRI, and transcranial magnetic stimulation, or TMS. CT scans use X-ray technology to build detailed...

the endocrine system

Endocrine Glands and Hormone Signals

The endocrine system is a network of glands that send hormone signals through the body. Hormones are chemical messengers that help control many body functions. They enter the bloodstream and travel to cells with the right receptors, or target sites, so the signal can be received. Because of this, hormone effects are widespread, unlike the more localized effects of neurotransmitters. This signaling helps the body keep a stable internal environment, called homeostasis. Several major glands...

somatosensory, motor, and association cortex

somatosensory-motor-and-association-cortex

Brain Cortex Areas for Sensation and Movement

The brain cortex uses separate areas for sensation, movement, and higher thinking. The somatosensory cortex is in the parietal lobes. It helps the brain interpret touch, temperature, and proprioception, which is awareness of body position. The somatosensory cortex has an organized map of the body. Neurons at the top of this region mainly process signals from the lower body. Neurons at the bottom handle input from the upper body. This layout helps the brain locate sensory input with precision.

major hormones and their functions

Hormone Imbalances and Their Effects

Hormones are chemical messengers made by endocrine glands. They help control body functions and keep internal conditions stable. When hormone levels shift too far up or down, normal body processes can be disrupted. Several major hormones have clear roles in the body. Oxytocin is made in the hypothalamus and released by the pituitary gland. It supports social bonding, childbirth, and lactation. Low oxytocin can affect social interaction and stress response, and it may contribute to depression.

inheritance

Genes, Traits, and Mendel's Rules

Genes, traits, and Mendel's rules explain how characteristics pass from parents to offspring. Gregor Mendel's pea plant experiments changed how scientists understand heredity. His work showed that traits are controlled by discrete units inside organisms called genes. Genes usually come in pairs. One gene is inherited from each parent, and together they make a person's genotype. Genotype is the genetic blueprint for potential traits. Examples include blood type, eye color, and inherited...

gene-environment interactions

How Environment Shapes Gene Expression

Environmental factors can change how genes are expressed. Gene expression is a dynamic process, and traits can differ even in people with the same DNA. Radiation, temperature, behavior, nutrition, and stress all help shape the final outcome. The reaction range helps explain this process. It means genes set a possible range for a trait, while the environment helps decide where a person falls within that range. For example, genetics may allow a height range from 5'5" to 6'1", but nutrition,...

heritability

Heritability and the Environment

Heritability describes how genetic differences contribute to trait variation in a population. It is a statistical measure, so it shows how much of the spread in a trait can be linked to genes across a group. It does not tell you how “genetic” a trait is in an individual person. Heritability is usually expressed as a percentage. That percentage can change depending on which population is studied and what environmental conditions are present. This means heritability is context-dependent, not...

natural selection and adaptation

Adaptation in Changing Environments

Natural selection explains how organisms become better suited to their environments over time. It favors individuals with traits that improve survival and reproduction. Adaptation is the result. It includes genetic changes that help an organism function in specific conditions, such as extreme cold or thinner air at high altitudes. Adaptation is not only physical. Psychological adaptation also helps organisms, especially humans, succeed in their surroundings. These responses come from both...

natural selection and mating preferences

How Selection Shapes Mate Choice

Natural selection and mating preferences work together to shape how organisms survive and reproduce. Natural selection favors traits that help an organism fit its environment. Mating preferences are part of sexual selection, which influences who mates with whom and how genes are passed on. Evolutionary psychologists argue that these preferences are tied to instincts that support reproduction. For females, conception, pregnancy, and nursing create a strong need to choose mates who can offer...

criticisms of the evolutionary perspective

criticisms-of-the-evolutionary-perspective

Social Learning vs. Evolutionary Psychology

Social learning theory and evolutionary psychology offer two different ways to explain sexual behavior. A study in which strangers gave students compliments and then asked for casual sex showed a clear gender gap. None of the women said yes, while 70% of the men agreed. Evolutionary psychology explains this result by arguing that natural selection may have shaped women to be more selective about sexual partners. From this view, selectivity can help improve survival and reproductive success. It...

key terms and concepts

Explore how spinal cord segments, spinal nerves, and nerve cells work together to relay signals, control movement, and trigger fast reflexes.

Spinal Cord Nerves and Reflexes | JoVE K12

JoVE Core Introduction to Psychology offers an engaging learning experience on the fundamental principles of psychology through concise video lessons. Students will explore important topics such as cognitive processes, emotional regulation, and neural mechanisms, establishing a strong foundation in the study of the mind and human behavior. This series provides an accessible and captivating approach to grasp the essential concepts of the discipline.

introduction to psychology

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Spinal Cord Nerves and Reflexes

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