Nervous 1 Flashcards
the primary control center for coordinating all body activities.
Nervous system
It receives sensory input, processes information, and initiates responses.
nervous system
Ensures homeostasis and supports complex mental activities.
Nervous system
Functions of the Nervous system
Sensory input
Integration
Motor output
Homeostasis
Mental activity
Collects data from internal and external environments.
Sensory input
Receptors detect stimuli (light, temperature, pain, etc.).
Sensory input
Information is transmitted to the brain and spinal cord via sensory neurons.
Sensory input
Processes sensory information and makes
decisions.
Integration
Processes sensory information and makes
decisions.
Integration
The nervous system interprets and integrates sensory input.
Integration
The nervous system interprets and integrates sensory input.
Integration
Decision-making occurs at various levels, from reflexes to conscious thought.
Integration
Commands muscles and glands in response to processed data.
Motor output
The nervous system sends signals to effectors (muscles/glands) for response.
Motor output
Enables voluntary and involuntary movements.
Motor output
Maintains a stable internal environment.
Homeostasis
Maintains a stable internal environment.
Homeostasis
The nervous system regulates heart rate, blood pressure, breathing, and temperature.
Homeostatis
Works with the endocrine system to achieve balance.
Homeostatis
Enables thought, emotion, learning, and memory.
Mental activity
The brain supports complex functions such as thinking, reasoning, emotions, and memory.
Mental activity
Divisions of the Nervous system
Cental nervous system
Peripheral nervous system,
Composed of the brain and spinal cord,responsible for data processing and command initiation
Central nervous system
Includes all nerves outside the CNS, connecting it
to the body for sensory and motor functions
Peripheral nervous system
Divisions of PNS
Sensory (Afferent)
Motor (Efferent)
Conducts impulses from sensory receptors to
the CNS, monitoring external and internal
conditions
Sensory (Afferent) Division of PNS
Conducts impulses from sensory receptors to
the CNS, monitoring external and internal
conditions
Sensory (Afferent) Division of PNS
Transmits signals from the CNS to muscles and
glands, managing voluntary and involuntary
responses
Motor (Efferent) Division of PNS
Regulates involuntary actions through sympathetic
(“fight or flight”) and parasympathetic (“rest and
digest”) responses
Autonomic Nervous system
Regulates involuntary actions through sympathetic
(“fight or flight”) and parasympathetic (“rest and
digest”) responses
Autonomic Nervous system
Specialized network in the digestive tract that can
function autonomously, though it also integrates
with the CNS
Enteric Nervous System
cell of ther nervous system that conducts electrical impulses for communication, consisting of a cell body, dendrites, and axons
Neurons
consist of cell body (soma), dendrites (input), and axon (output).
Neurons
receive signals from other cells
dendrites
receive signals from other cells
dendrites
transmit impulses to the other cells
Axon
Junction where signals are passed from one neuron to another
Synapse
Junction where signals are passed from one neuron to another
Synapse
Types of neuron
Multipolar
Bipolar
Pseudo-unipolar
Many dendrites, one axon
Multipolar
One dendrite, one axon
Bipolar
Single projection divides into two branches
Pseudo-unipolar
CNS Glial Cells
Astrocytes
Oligodendrocytes
Microglia
PNS Glial cells
Schwann cells
Satellite cells
Form blood-brain barrier, support neurons,
and regulate nutrient exchange.
Astrocytes
Produce myelin sheaths for CNS axons.
Oligodendrocytes
Act as immune cells within the CNS, removing
debris and pathogens
Microglia
Form myelin around PNS axons, aiding in signal
transmission.
Schwann cells
Support neuron cell bodies within ganglia,
regulating their environment
Satellite cells
Produced by Schwann cells (PNS) and oligodendrocytes (CNS).
Myelin sheaths
insulates axons, enhancing transmission speed of impulses.
Myelin
Gaps in myelin where action potentials regenerate
to speed up conduction
Nodes of Ranvier
maintained by sodium-potassium pumps, creating a -
70mV charge inside the cell.
Resting membrane potential
Essential for neuron readiness to transmit signals.
Resting membrane potential
Maintained by selective permeability to K+ and Na+ ions
Resting membrane potential
Essential for rapid and coordinated signal transmission along neurons
Action potential mechanism
Na+ channels open, allowing Na+ influx and membrane
potential becomes positive.
Depolarization
K+ channels open, K+ exits, restoring negative charge.
Repolarization
release neurotransmitters to bridge the gap between
neurons.
Chemical synapse
release neurotransmitters to bridge the gap between
neurons.
Chemical synapse
allow direct ion flow between cells for fast communication.
Electrical synapse
involves neurotransmitter release, receptor
activation, and potential continuation of the
signal.
Synaptic transmission
Extends from the brainstem to the lumbar
region, protected by vertebrae.
Spinal cord
Functions in transmitting information
between body and brain.
Spinal codd
Controls reflex actions through local circuitr
Spinal cord
Cross-Section of the Spinal Cord
- Gray matter (cell bodies) centrally located, white
matter (myelinated axons) peripherally.
• Dorsal (sensory) and ventral (motor) roots emerge from
each spinal segment
How many spinal nerves connect the CNS to the body.
31
contain both sensory and motor fibers.
Spinal nerves
Nerve roots continuing from spinal cord end below L2, innervating lower body.
Cauda equina
Facilitates control over lower limbs and pelvic organs.
Cauda equina
Important in diagnosing conditions like cauda equina syndrome
Cauda equina
central organ in the central nervous system, housed
within the skull.
brain
brain divided into four main regions:
brainstem
cerebellum
diancephalon
cerebrum
Located at the base of the brain, connecting it to
the spinal cord.
Brainstem
Positioned just above the spinal cord
within the brainstem.
Medulla oblongata
Positioned just above the spinal cord
within the brainstem.
Medulla oblongata
Contains ascending and descending tracts that carry sensory and motor signals.
Medulla oblangata
Has various nuclei visible under microscopic examination that are responsible for reflex actions
Medulla oblongata
Positioned between the medulla and midbrain, appearing as a rounded bulge.
Pons
Composed of nerve fiber tracts that bridge the cerebellum with the brainstem.
Pons
Contains nerve tracts running longitudinally and transversely
Pons
Located above the pons, it’s the smallest region of the brainstem.
Midbrain
Contains structures such as the tectum and tegmentum
Midbrain
contribute to visual and auditory processing pathways.
Tectum and tegmentum
Contains important neural tracts linking the cerebrum and spinal cord
Midbrain
Situated posterior to the brainstem, beneath the occipital lobes of the cerebrum.
Cerebellum
Characterized by its highly folded surface, called folia,
Cerebellum
highly folded surface which increases surface area.
Folia
Composed of two hemispheres connected by the vermis, with a cortex of gray matter
Cerebellum
Located centrally, just above the brainstem,
enclosed by the cerebrum.
Diancephalon
Diancephalon consist of
Thalamus
Hypothalamus
Epithalamus
Egg-shaped masses forming lateral walls of the diencephalon.
Thalamus
Small, cone-shaped region below the thalamus.
Hypothalamus
Thin, posterior structure housing the pineal gland
Epithalamus
Large, oval structures with two halves connected by the
interthalamic adhesion.
Thalamus
Situated below the thalamus, forms the floor of the
third ventricle.
Hypothalamus
Both structures contain distinct nuclei observed in histological studies
Thalamus and hypothalamus
The largest brain region, occupying most of the cranial cavity.
Cerebrum
Cerebrum divided into left and right hemispheres connected by the
Corpus callosum
Cerebrum feautures a wrinkled outer layer, which is
rich in neuron cell bodies (gray matter)
Cerebral cortex
Surface feautures of the cerebral cortex
Gyri
Sulci
Fissures
Surface feautures of the cerebral cortex
Gyri
Sulci
Fissures
Elevated ridges, increasing surface area.
Gyri
Shallow grooves separating the gyri.
Sulci
Deeper grooves, such as the longitudinal fissure, which
divides the two hemispheres
Fissures
Central cortex lobes
Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe
Central cortex lobes
Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe
Manages voluntary movement, reasoning, problem-
solving, and personality.
Frontal lobe
Processes sensory information like touch, temperature,
and pain.
Parietal lobe
Processes sensory information like touch, temperature,
and pain.
Parietal lobe
Dedicated to visual processing and interpretation.
Occipital lobe
Involved in auditory processing, language comprehension, and memory
Temporal lobe
Involved in auditory processing, language comprehension, and memory
Temporal lobe
are three protective layers surrounding the brain and
spinal cord.
Meninges
Meninges comprised of 3 layers of
Dura matter
Arachoid matter
Pia matter
layers that are situated between the skull and brain, providing a supportive framework
the outermost layer dense and tough, providing a durable protective covering.
Dura matter
the outermost layer dense and tough, providing a durable protective covering.
Dura matter
Dura matter divided into two layers:
Periosteal layer (attached to the skull)
Meningeal layer (closer to brain)
extends into the brain to form partitions, such as the
falx cerebri between the hemispheres
Meningeal layer
extends into the brain to form partitions, such as the
falx cerebri between the hemispheres
Meningeal layer
extends into the brain to form partitions, such as the
falx cerebri between the hemispheres
the middle meningeal layer, lying below the dura
mater.
Arachoid matter
Thin and web-like, it spans over the brain but doesn’t follow brain contours closely.
Arachoid matter
lies beneath the arachoid matter containing web-like projections and bridging veins
Subarachoid space
lies beneath the arachoid matter containing web-like projections and bridging veins
Subarachoid matter
The innermost meningeal layer, pia mater, is thin and delicate, closely adhering to the brain and spinal cord’s surface.
Pia matter
Follows the brain’s contours, dipping into sulci and fissures.
Pia matter
Follows the brain’s contours, dipping into sulci and fissures.
Pia matter
