Nervous System Kimberly Sandoval (Druga that affect the brain (Nicotine-…
Nervous System Kimberly Sandoval
Tissues (structure and functions of a neuron)
Nervous tissue contains two categories of cells- neurons and neuroglia . Neurons are highly specialized nerve cells that generate and conduct nerve impulses. Neuroglia are supporting cells that provide physical sport, remove debris, and provide electrical insulation.
Nervous tissue is composed of three main parts : nerves, the spinal cord and the brain. The primary function of nervous tissue is to receive stimuli and send the impulse to the spinal cord and brain. The brain sends back a response to the muscles via the nerves.
Compare and contrast the autonomic nervous system
The major differences between the two systems are evident in the responses that each produces. The somatic nervous system causes contraction of skeletal muscles. The autonomic nervous system controls cardiac and smooth muscle, as well as glandular tissue.
Major parts of the brain and their functions
Cerebellum: located under the cerebrum. Function: to coordinate muscle movements , maintain posture, and balance.
Brainstem: acts as a relay center connecting the cerebrum and cerebellum to the spinal cord . It preforms many automatic functions such as breathing , heart rate, body temperature , wake and sleep cycles, digestion , sneezing , coughing , vomiting, and swallowing.
Cerebrum: the largest part of the brain and is composed of right and left hemispheres. It preforms higher functions like interpreting touch , vision, hearing, speech , resining, emotions, learning , and fine control of movement.
Major divisions and subdivisions
Peripheral nervous system- consists of nerves that run throughout the body , made itself of two subdivisions.
Central nervous system- made up of the brain and the spinal cord.
Subdivisions - the sympathetic nervous system, the parasympathetic nervous system and the entire nervous system.
Somatic nervous systems- responsible for movement of voluntary muscles and the process known as a reflex arc.
Diseases associated with the brain
Meninhitis- an inflammation (swelling) of the protective membranes covering the brain and spinal cord . A bacterial or viral infection of the fluid surrounding the brain and spinal cord usually causes the swelling.
Concussion- a mild traumatic brain injury(TBU). It can occur after an impact to your head or after a whiplash type injury causes your head and brain to shake quickly back and forth. A concussion results in an altered mental state that may include becoming unconscious .
Hydrocephalus- the buildup of fluid in the cavities (ventricles) deep within the brain, the excess fluid increases the size of the ventricles and puts pressure on the brain. Cerebrospinal fluid normally flows through the ventricles and bathes the brain and spinal column .
Contusion- is a medical term for a common bruise . While you likely think of bruises as splotchy areas of discoloration on skin, the can also happen to bones and muscles.In most cases , both soft tissue and bone contusions heal on their won within a week or two, bone contusion s might take longer.
Closed-head injury- traumatic brain injury where the skull and dura mater remain intact . They are the leading cause of death in children of 4 years and most common cause of physical disability also cognitive impairment in young people.
Intracranial hemorrhage- a type of bleeding that occurs inside the skull(cranium) , bleeding around or within the brain itself known as the cerebral hemorrhage (intracerebral hemorrhage ). Bleeding caused by blood vessel in the brain that leaked or ruptured (torn) is called a hemorrhagic stroke.
Dementia- a group of symptoms affecting memory , thinking and social abilities severely enough to interfere with daily life. Isn't specific disease , but several different diseases may cause dementia , through dementia generally involves memory loss, memory loss has different causes.
Anencephaly- absence of major portion of the brain, skull, and scalp that occurs during embryonic development. It's a cephalic disorder that results from a neural tube defect that occurs when rostral (head) end of the neural tube fails to close, usually between the 23rd and 26th day following conception.
Stroke- a disease that affects the arteries leading to and within the brain . its number 5 cause of death and a leading cause pf disability in the United States . Occurs when a blood vessel carries oxygen and nutrients to the brain is either blocked by clot or Burts.
Anatomy of the spinal cord
The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata the brain stem to the lumbar region of the vertebral column. It encloses the central canal of the spinal cord, contains cerobrospinal fluid.
The meninges refer to the membranous coverings of the brain and spinal cord. Three layers of the meninges, known as the dura matter , aracnoid matter and pia mater.
Neurotransmitters- glutamate is the main excitatory transmitter in the central nervous system. GABA is the main inhibitory neurotransmitter in the adult vertebrate brain , Glycine is the main inhibitory neurotransmitter in the spinal cord.
Major functions of the nervous system
PNS- peripheral Nervous system
controlling all 3 muscles types and glands; skeletal, cardiac, smooth and motor output.
neurons are specialized cells of the nervous system that transmit signals through the body.
Integrating information: the control center.
motor neurons are not just limited to spending signals to muscles, they can also send signals to glands within our and stimulate or inhibit secretion of various substances that then carry out or regulate many body functions.
Receiving sensory input: external and internal.
Action potential-An action potential is apart of the process that occurs during the firing of a neuron. During the action potential, part of the neural membrane opens to allow positively charged ions out. This electrical impulse is carried down the nerve through a series of action potentials.
Spaces and ventricles
Are the two ventricles deep within the cerebral hemisphere called lateral ventricles. They both connect with the third ventricle through a separate opening called foramen of Monro. The third ventricle connects with the fourth ventricle through a long narrow tube called the aqueducts of Sylvius . From the fourth ventricle , CSF flows into the subarachnoid space where it bathes and cushions the brain. CSF is recycled (or absorbed ) by special structures in the superior sagittal sinus called arachnoid villi.
A balance is maintained between the amount of CSFthat is absorbed and the amount that is produced . A disruption or blockage in the system can cause a build cup of CSF, which can cause enlargement of the ventricles (hydrocephalus ) or cause a collection of fluid in the spinal cord (syrinogomyelia)
Druga that affect the brain
Cocaine- mumming effect, increase energy, confidence , appetite decreases and its highly addictive.
Alcohol - slows brain function, causes death, abuse, addiction and memory loss.
Opioids - pinpoint pupils, stop breathing and itchiness
Methamphetamine- speed up brain, increase alertness, decreases in appetite , heart damage and memory loss.
Inhalants- impairs coordination , speech, judgment, affects brain and sudden death could occur.
Nicotine- increase nerve activity, withdraw symptoms and intense cravings.
Marijuana- relaxed, peaceful feeling, anxiety, paranoid, impair thinking, memory and attention.
MDMA- increases in energy, muscle cramping , chills, sweat, panic attacks ,and seizures.
Psychedelics- entestity sensation, motion, hallucinations and increases body temperature.
GHB and Rohypnol- relaxing , hallucinations, slow breathing, comma, death and mixing with other drugs can kill you as well.
Dissociative Drug- hallucinations , feeling detached from then body and surroundings, lose of sensation with reality, fever and coma.
Sensory neurons are unipolar , bipolar, or multipolar shaped cells that conduct action potentials toward or into the central nervous system.
Motor neurons efferent neurons; lower motor neurons) are multipolar hasped cells that conducts action potentials out of the central nervous system.
Interneurons (internuncial or association neurons) are billions of cells that form much of the central nervous system and link the sensory and motor neurons
Cranial nerves are the nerves that emerge directly form the brain; in contrast to spinal nerves (which emerge from segments of the spinal cord ). 10 of the cranial nerves originate the brainstem. Cranial nerves relay information between the brain and parts of the body . Primarily to and from regions of the head and neck.
Names of all the lobes and their functions
Parietal lobe- interprets language, words, sense of touch , pain, temperature , interprets signals from vision , hearing, motor, sensory and memory spatial and visual perception.
Occipital Lobe- interprets vision (color, light,movement
Frontal lobes- personality , behavior, emotions, judgement , planing, problem solving , speech , body movement , intelligence , concentration, and self-awareness.
Temporal lobe- understanding, language, memory, hearing, sequencing, and organization.
Divisions of the PNS of the body
Sensory neurons are nerve cells within the nervous system responsible for converting external stimuli from organism's environment into internal electrical impulses. Example- some sensory neurons respond to tactile stimuli and can activate motor neurons in order to achieve muscle contraction.
A motor neuron (or motor neuron) is a neuron whose cell body is located in the motor cortex, brainstem or the spinal cord, whose axon (fiber) projects to the spinal cord or outside of the spinal cord to directly or indirectly control effector organs, mainly muscles and glands.
Reflex Arc - is a neural pathway that controls a reflex . In vertebrates , most sensory neurons do not pass directly into the brain, but synapse in the spinal cord . This allows for faster reflex actions to occur by activating spinal motor neurons without the delay of routing signals through the brain.
The layers of the meninges
Arachnoid- or arachnoid mater is the middle layer , of the meninges . In some areas it protects into the sinuses formed by dura mater . These projections are the arachnoid granulation/ arachnoid villi. They transfer cerebrospinal fluid from the ventricles back into the bloodstream.
Cerebrospinal fluid- a clear liquid produced within spaces in the brain called ventricles , likes like saliva its a filtrate of blood. It also found inside the subarachnoid space of the meninges which surrounds both the brain and the spinal cord. A space inside the spinal cord called the central canal also contains cerebrospinal fluid.
Dura mater is the most superior of the meningeal layers. Its name means "hard mother" in Latin and it is tough and inflexible . This tissue forms several structures that separate the cranial cavity into compartments and protect the brain displacement .