Central Nervous System (Drugs that affect the brain (mouse party and drugs…
Central Nervous System
Major functions of the
analyzes sensory information, stores some aspects, and makes decisions regarding appropriate behaviors
may respond to stimuli by initiating muscular contractions or glandular secretions
these muscles or glands are called effectors
detects changes within the outside of the body
divisions of nervous system
consists of brain and spinal cord
memories are formed and stored
thoughts and emotions are generated
most nerve impulses that influence effector organs of body
carry information from body to CNS
carry instructions away from CNS to target or effector organs of body
consists of cranial and spinal nerves
PNS divided into
autonomic nervous system
brings information from receptors in internal organs to CNS/motor neurons to smooth and cardiac muscles/glands
responses are involuntary
sympathetic nervous system
"feed and breed'
normal, everyday situations
most organs receive input from long divisions
somatic nervous system
brings information from skin, special senses, body walls and limbs to CNS/ motor neurons to skeletal muscle
voluntary portion of PNS
parasympathetic nervous system
"fight or flight"
emergency or non-normal situations
Spaces and ventricles
The right and left lateral ventricles are structures within the brain that contain cerebrospinal fluid, a clear, watery fluid that provides cushioning for the brain while also helping to circulate nutrients and remove waste.
The fourth ventricle extends from the cerebral aqueduct to the obex, and is filled with cerebrospinal fluid (CSF). The fourth ventricle has a characteristic diamond shape in cross-sections of the human brain. It is located within the pons or in the upper part of the medulla oblongata.
It is filled with cerebrospinal fluid, which helps to protect the brain from injury and transport nutrients and waste. The third ventricle is a narrow cavity that is located between the two halves of the brain.
Names of all the lobes and their
primary motor cortex
in front of central sulcus in precentral gyrus
controls voluntary actions of specific muscles or groups of muscles on the opposite side of the body
coordinates muscle movements for speech
concerned with more complex integrative functions, such as, memory , emotions, reasoning, will, judgement, intelligence, and language comprehension
primary somatosensory cortex
behind central sulcus in post central gyrus
receives impulses for touch, pain, proprioception, and temperature
Drugs that affect the brain (mouse party and drugs of abuse)
It speeds up the central nervous system, increasing heart rate, body temperature, and blood pressure while increasing energy levels, focus, attention, alertness, and wakefulness. They also suppress appetite.
Individuals who abuse it regularly may suffer from hallucinations, anxiety, and confusion as well. Meth also significantly damages the dopamine system in the brain, which can cause problems with memory and learning, movement, and emotional regulation issues.
Opioids block pain sensations, induce drowsiness, reduce body temperature, and slow heart rate, blood pressure, and respiration functions.
Ecstasy stimulates a sense of emotional closeness and warmth, while enhancing and distorting the senses, heightening energy levels, decreasing anxiety, and increasing feelings of pleasure. Heart rate, body temperature, and blood pressure are also elevated by ecstasy use.
Individuals may then take more of the drug to feel the desired effects. The brain will then stop functioning as it did before introduction of the opioid, causing levels of dopamine to drop when the drug wears off.
When a person consumes alcohol above and beyond moderate levels, it can have damaging effects on the body and on the brain—both short-term and permanently. Some of those effects, like slurred speech and diminished memory, can be quite clear; others, like long-term cellular damage, may not be as obvious.
When someone abuses marijuana, impaired motor skills, mood alterations, distorted time and sensory perception, decreased memory, and trouble thinking clearly and solving problems are all common short-term side effects. Marijuana also interferes with levels of dopamine in the brain, causing the euphoric “high” that users document.
The layers of the meninges
thin membrane that lacks blood vessels
fluid filled area between dura and subarachnoid maters
made up of spider-web like collagen/elastic fiber
innermost, nearly transparent layer; has many nerves and blood vessels
follows contours of brain/spinal cord
area between arachnoid and pia mater
filled with cerebrospinal fluid (CSF)
dense, irregular CT w/ many blood vessels and nerves
attached to periosteum
inflammation of menin
Classification of neurons
motor or efferent
transmit motor nerve impulses from CNS to effectors
multipolar neurons in CNS that form links between other neurons
sensory or afferent
transmit sensory impulses
have specialized receptor ends at tips of dendrites or the dendrites are in contact with specialized receptor cells in skin/sense organs
most are unipolar, some are bipolar
several dendrites and one axon
neurons CNS are mostly this type
just one process, and are always sensory neurons
axon terminals are in CNS and cell bodies in ganglia
usually formed in special sense organs
one main dendrite and one axon
Major parts and functions of the spinal cord
Electrical signals are conducted up and down the cord, allowing communication between different sections of the body and with the brain, since the cord runs through different levels of the trunk section.
These are predictable involuntary responses to stimuli that involve the brain, spinal cord and nerves of the peripheral nervous system (PNS).
During walking, several muscle groups in the legs are coordinated to contract over and over again.The neurons send signals to the muscles in the legs, causing to the extend or contract, producing the alternating movements that are involved in walking.
Grey matter can be divided into two halves, and each half divided into a dorsal horn, ventral horn and lateral horn. The different horns have different functions. The ventral and dorsal horns supply different types of muscle – the ventral horn contains the cell bodies of neurons that supply skeletal muscle, while the lateral horn contains cell bodies that supply cardiac and smooth muscle.
The white consists of bundles of nerve fibers called axons that extend the length of the cord and run up and down it. This allows different levels of the CNS to communicate with one another. Each bundle of axons is known as a tract, and is specific in the type of information it transmits.
strong enough stimulation or nerve impulse causes Na+ gates to open -> Na+ rush into cell causing depolarization (membrane potential goes towards OV or unpolarized, and momentarily becomes positively changed)
K+ rush out of neuron after Na+ rush in, which causes a repolarization of the membrane back to resting potential
nerve impulse is transmitted during action potential
if a strong enough depolarization occurs, threshold potential is reached (+30) and impulse is sent down the axon
Tissues (structure & function of a neuron)
nerve tissue are made of neuron/neuroglia
made up of
contains nucleus and other organelles
receiving portions, short tapered/highly branched
starts as a single fiber, but may give off branches called lateral axons
axon collaterals end in axon terminals which end in synaptic end bulbs
end bulbs contain sympathetic vesicles that contain neurotransmitters
most axons are surrounded by a myelin sheath
myelin acts as an insulator
increases the speed at which the impulse travels
gaps between myelin sheath are called the nodes of Ranvier
Major part of the brain and their functions
It is extremely important for being able to perform everyday voluntary tasks such as walking and writing. It is also essential to being able to stay balanced and upright. If you suffer from a damaged cerebellum, you often struggle with keeping their balance and maintaining proper muscle coordination.
acts as a relay center connecting the cerebrum and cerebellum to the spinal cord. It performs many automatic functions such as breathing, heart rate, body temperature, wake and sleep cycles, digestion, sneezing, coughing, vomiting, and swallowing.
is the largest part of the brain and is composed of right and left hemispheres. It performs higher functions like interpreting touch, vision and hearing, as well as speech, reasoning, emotions, learning, and fine control of movement.
Diseases in the Brain
An inflammation of the lining around the brain or spinal cord, usually due to infection; Neck stiffness, headache, fever, and confusion are common symptoms.
An inflammation of the brain tissue, usually due to a viral infection; meningitis and encephalitis often occur together, which is called meningoencephalitis.
Included in the seizure category of brain diseases is epilepsy, a condition characterized by recurring seizures caused by abnormal and excessive electrical activity in the brain. Head injuries, brain infections, and strokes may cause epilepsy, as well.
A brain injury that causes a temporary disturbance in brain function, sometimes with unconsciousness and confusion; traumatic head injuries cause concussions and may result in headache, along with concentration and memory problems.
Any abnormal tissue growth inside the brain; whether malignant (cancerous) or benign, brain tumors usually cause problems by the pressure they exert on the normal brain.
An abnormally increased amount of cerebrospinal (brain) fluid inside the skull; usually, this is because the fluid is not circulating properly.