Podcast
Questions and Answers
What is the primary function of dendrites in a neurone?
What is the primary function of dendrites in a neurone?
Which type of neuroglial cell is primarily responsible for forming the blood-brain barrier?
Which type of neuroglial cell is primarily responsible for forming the blood-brain barrier?
Which of the following substances can quickly cross the blood-brain barrier?
Which of the following substances can quickly cross the blood-brain barrier?
What role do synaptic vesicles play in neurotransmission?
What role do synaptic vesicles play in neurotransmission?
Signup and view all the answers
What differentiates neuroglial cells from neurones?
What differentiates neuroglial cells from neurones?
Signup and view all the answers
Which neurotransmitter is commonly involved in synaptic transmission?
Which neurotransmitter is commonly involved in synaptic transmission?
Signup and view all the answers
Which statement correctly describes the structure of dendrites?
Which statement correctly describes the structure of dendrites?
Signup and view all the answers
What is the role of microglia in the central nervous system?
What is the role of microglia in the central nervous system?
Signup and view all the answers
What are the two main divisions of the nervous system?
What are the two main divisions of the nervous system?
Signup and view all the answers
Which type of cell provides myelin insulation to axons in the peripheral nervous system?
Which type of cell provides myelin insulation to axons in the peripheral nervous system?
Signup and view all the answers
Which feature of a neurone conducts electrical impulses away from the cell body?
Which feature of a neurone conducts electrical impulses away from the cell body?
Signup and view all the answers
What is the function of the Nodes of Ranvier?
What is the function of the Nodes of Ranvier?
Signup and view all the answers
Which neurons are primarily involved in involuntary functions of the body?
Which neurons are primarily involved in involuntary functions of the body?
Signup and view all the answers
Which component of nervous tissue is responsible for providing support and insulation?
Which component of nervous tissue is responsible for providing support and insulation?
Signup and view all the answers
Which statement accurately describes the difference between the nervous system and the endocrine system?
Which statement accurately describes the difference between the nervous system and the endocrine system?
Signup and view all the answers
What is a key characteristic of the myelin sheath?
What is a key characteristic of the myelin sheath?
Signup and view all the answers
What type of nerve impulse is characterized by traveling towards the brain and central nervous system?
What type of nerve impulse is characterized by traveling towards the brain and central nervous system?
Signup and view all the answers
What is the function of synaptic knobs in neural transmission?
What is the function of synaptic knobs in neural transmission?
Signup and view all the answers
How do local anesthetics impede nerve transmission?
How do local anesthetics impede nerve transmission?
Signup and view all the answers
What happens to excessive nerve impulses in conditions like neuralgia?
What happens to excessive nerve impulses in conditions like neuralgia?
Signup and view all the answers
What is the role of neurotransmitters after their release into the synaptic cleft?
What is the role of neurotransmitters after their release into the synaptic cleft?
Signup and view all the answers
What is the consequence of herpes simplex virus reactivation related to trigeminal neuralgia?
What is the consequence of herpes simplex virus reactivation related to trigeminal neuralgia?
Signup and view all the answers
What occurs during synaptic transmission when an action potential reaches the synaptic knob?
What occurs during synaptic transmission when an action potential reaches the synaptic knob?
Signup and view all the answers
Which statement best describes the structure of a synapse?
Which statement best describes the structure of a synapse?
Signup and view all the answers
What is the primary function of the thalamus in the brain?
What is the primary function of the thalamus in the brain?
Signup and view all the answers
Which area of the brain is responsible for higher mental activities such as reasoning and problem-solving?
Which area of the brain is responsible for higher mental activities such as reasoning and problem-solving?
Signup and view all the answers
What role does the hypothalamus play in the nervous system?
What role does the hypothalamus play in the nervous system?
Signup and view all the answers
Which structure separates the two hemispheres of the cerebrum?
Which structure separates the two hemispheres of the cerebrum?
Signup and view all the answers
What is a notable feature of the cerebral cortex?
What is a notable feature of the cerebral cortex?
Signup and view all the answers
How does cerebrospinal fluid primarily benefit the central nervous system?
How does cerebrospinal fluid primarily benefit the central nervous system?
Signup and view all the answers
What function do nuclei in the midbrain serve?
What function do nuclei in the midbrain serve?
Signup and view all the answers
Which structure is primarily responsible for the basic perception of sensory information?
Which structure is primarily responsible for the basic perception of sensory information?
Signup and view all the answers
What is one of the key roles of the Pons in the nervous system?
What is one of the key roles of the Pons in the nervous system?
Signup and view all the answers
Which of the following accurately describes the function of cerebrospinal fluid (CSF)?
Which of the following accurately describes the function of cerebrospinal fluid (CSF)?
Signup and view all the answers
What does the medulla oblongata control?
What does the medulla oblongata control?
Signup and view all the answers
How does cerebrospinal fluid contribute to waste management in the brain?
How does cerebrospinal fluid contribute to waste management in the brain?
Signup and view all the answers
What is the approximate length of the spinal cord?
What is the approximate length of the spinal cord?
Signup and view all the answers
What function does the cerebrospinal fluid serve as an endocrine medium?
What function does the cerebrospinal fluid serve as an endocrine medium?
Signup and view all the answers
What effect does the buoyancy of cerebrospinal fluid have on the brain?
What effect does the buoyancy of cerebrospinal fluid have on the brain?
Signup and view all the answers
Which of the following best describes the location and protection of the spinal cord?
Which of the following best describes the location and protection of the spinal cord?
Signup and view all the answers
Study Notes
Nervous System
- The nervous system detects and responds to internal and external changes.
- Works with the endocrine system to control body functions and maintain homeostasis.
- Nervous system responses are immediate, while endocrine responses are slower and more prolonged.
Divisions of the Nervous System
- Central Nervous System (CNS): Brain & spinal cord
- Peripheral Nervous System (PNS): All other nerves
Peripheral Nervous System Subdivisions
- Sensory Division: Carries sensory information from the body to the CNS.
-
Motor Division: Carries motor commands from the CNS to the body.
- Somatic Nervous System: Controls voluntary movements.
-
Autonomic Nervous System: Controls involuntary actions.
- Sympathetic Nervous System: "Fight or flight" response.
- Parasympathetic Nervous System: "Rest and digest" response.
Nervous Tissue Cells
- Neurones: Specialized cells responsible for transmitting nerve impulses.
- Schwann Cells: Form myelin sheath around axons in the peripheral nervous system.
- Neuroglial/Glial cells: Support network of non-excitable cells in the CNS.
Neurones
- Cell Body: Contains the nucleus and other organelles.
-
Axon: Long, slender extension that conducts impulses away from the cell body.
- Can be over 1 meter long.
- Large axons and those in the PNS are surrounded by a myelin sheath.
- Schwann Cells: Form layers around axons, providing myelin insulation.
- Nodes of Ranvier: Exposed areas between Schwann cells, facilitating rapid transmission of action potentials.
-
Dendrites: Branching extensions that receive information from other neurones.
- Shorter than axons.
- Have dense chemical ion channels for impulse transmission.
- Form synapses with other dendrites or terminate in sensory receptors.
- Synaptic End Bulb: Specialized structure at the end of the axon, responsible for communication with other neurones.
Properties of Neurons
- Irritability: Ability to initiate nerve impulses in response to stimuli.
- Conductivity: Ability to transmit an impulse.
Neuroglial Cells
- Support and maintain neurones in the CNS.
- Continue to replicate throughout life.
- Three types:
- Microglia: Phagocytic cells that remove cellular debris.
- Astrocytes: Star-shaped cells that provide structural support and regulate the environment around neurones.
- Oligodendrocytes: Form myelin sheaths around axons in the CNS.
Blood-Brain Barrier
- Protective barrier that regulates what substances can enter the brain.
- Allows passage of oxygen, carbon dioxide, glucose, and lipid-soluble substances.
- Restricts passage of large molecules, many drugs, inorganic ions, and amino acids.
Synaptic End Bulbs
- Contain synaptic vesicles, sacs that store neurotransmitters.
- Release neurotransmitters into the synaptic cleft, allowing communication between neurones.
Synapse
- Communication point between two neurones or a neurone and an effector.
- Includes:
- Pre-synaptic neurone: Neurone sending the signal.
- Pre-synaptic knob: End of the pre-synaptic neurone.
- Neurotransmitters: Chemical messengers, e.g., acetylcholine, noradrenaline.
- Calcium: Plays a role in neurotransmitter release.
- Mitochondria: Provide energy for the synapse.
- Neurotransmitter receptors: On the post-synaptic membrane.
- Post-synaptic knob: End of the post-synaptic neurone.
- Post-synaptic neurone: Neurone receiving the signal.
Nerve Impulses
- Nerve impulses are initiated by sensory nerve endings or by the passage of an impulse from another nerve.
- A nerve impulse traveling towards the brain and CNS is afferent (sensory).
- A nerve impulse traveling away from the brain and CNS is efferent (motor).
- Nerve impulses (action potential) travel down the neuron.
- Synapses are the points where nerve impulses jump from one nerve to another.
- There are approximately 1000 trillion synapses in the human brain.
- Synaptic knobs contain synaptic vesicles that store neurotransmitters.
- The journey of a neurotransmitter begins with its synthesis by nerve cell bodies, followed by active transport along the axons, storage in synaptic vesicles, and release by exocytosis in response to the action potential.
- Neurotransmitters diffuse across the synaptic cleft and act on specific receptor sites on the postsynaptic membrane.
- The action of neurotransmitters is short-lived and they are inactivated by enzymes or taken back into the synaptic knob after action.
- Local anesthetics block nerve transmission to pain centers in the central nervous system by binding to and inhibiting the sodium channel in the cell membrane of nerve cells.
- The action of local anesthetics obstructs the movement of nerve impulses near the site of injection but does not affect awareness or sense perception in other areas.
- Excessive nerve impulses can result in neuralgia, with trigeminal neuralgia being the most common type.
- The herpes simplex virus lies dormant in the trigeminal ganglion and when re-activated it travels down the trigeminal nerve, emerging on the lip and causing a cold sore.
Central Nervous System
- The brain weighs approximately 1.4 kg.
- It is located within the cranial cavity.
- The brain is comprised of the cerebrum, thalamus, hypothalamus, midbrain, pons, medulla oblongata, and cerebellum.
Cerebrum
- The cerebrum is the largest part of the brain.
- It has three main functional areas:
- Mental activities: memory, intelligence, problem solving, reflection, judgement, thinking, reasoning, initiative, inhibition, moral sense of responsibility and learning
- Sensory perception: perception of pain, temperature and touch
- Initiation and control of voluntary muscle contraction
- The cerebral cortex has wrinkles, which increase its surface area and neuron density, enhancing brain efficiency.
- A deep furrow divides the cerebrum into two halves known as the left and right hemispheres.
- The corpus callosum connects the two hemispheres via bundles of axons.
Thalamus
- The thalamus is a small structure.
- Sensory receptors in the skin and viscera send information about touch, pain and temperature to the thalamus.
- Input from special sense organs also travels to the thalamus.
- The thalamus is involved in basic perception, arousal and the processing of some emotions and complex reflexes.
Hypothalamus
- The hypothalamus is located within the cerebrum and attached to the pituitary gland.
- It controls hormone release from the pituitary gland.
- The hypothalamus controls effectors of the autonomic nervous system.
- The hypothalamus is responsible for: - Emotional reactions - Hunger and thirst - Body temperature - Biological clocks
Midbrain
- The midbrain comprises nuclei and nerve fibres that connect the cerebrum to the lower parts of the brain and spinal cord.
- The midbrain nuclei act as relay stations for ascending and descending nerve fibres.
- It plays a key role in auditory and visual reflexes.
Pons
- The pons contains nerve fibres bridging the two hemispheres of the cerebrum.
- It processes information from several cranial nerves.
Medulla Oblongata
- The medulla oblongata is continuous with the spinal cord.
- It controls effectors such as: - Cardiovascular centre - Respiratory centre
- It also controls reflex centres responsible for: - Coughing - Vomiting - Sneezing - Swallowing
Spinal Cord
- The spinal cord is an elongated, almost cylindrical part of the CNS.
- Nerves carrying impulses from the brain to various organs and tissues descend through it.
- It starts in the medulla oblongata and descends through the spinal column.
- The spinal cord is suspended in the vertebral canal.
- It is surrounded by meninges and cerebrospinal fluid.
- The spinal cord is approximately the thickness of a little finger and about 45 cm long.
Cerebrospinal Fluid
- Cerebrospinal fluid (CSF) is a clear colorless liquid that:
- Occupies the subarachnoid space in the brain.
- Acts as a "cushion" or buffer for the cortex.
- Is renewed four times a day.
- Contains proteins, glucose and lymphocytes.
Functions of Cerebrospinal Fluid
- Protection: CSF protects the brain by 'buffering' it, reducing the impact of blows to the head.
- Buoyancy: CSF immersion reduces the net weight of the brain from 1400g to about 50g, lowering pressure at the base of the brain.
- Excretion of waste products: CSF flow from the CSF to the blood removes potentially harmful metabolites, drugs, and other substances from the brain.
- Endocrine Medium: CSF acts as a transport medium for hormones to reach remote areas of the brain where they may act.
Peripheral Nervous System
- The peripheral nervous system (PNS) is comprised of nerves that connect the CNS to the rest of the body.
- It carries sensory information from the body to the CNS and motor commands from the CNS to muscles and glands.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the essential functions and divisions of the nervous system in this quiz. Covering aspects such as the central and peripheral nervous systems, as well as the roles of sensory and motor divisions, this quiz will test your understanding of how the nervous system works in harmony with the endocrine system. Get ready to dive into the fascinating world of nervous tissue cells and neural communication.
