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Peripheral nervous system

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Peripheral nervous system

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Peripheral nervous systemThe human nervous system. Sky blue is PNS; yellow is CNS.IdentifiersAcronym(s)PNSMeSHD017933TA98A14.2.00.001TA26129FMA9093Anatomical terms of neuroanatomy

The peripheral nervous system (PNS) is one of two components that make up the nervous system of bilateral animals, with the other part being the central nervous system (CNS). The PNS consists of the nerves and ganglia outside the brain and spinal cord.[1] The main function of the PNS is to connect the CNS to the limbs and organs, essentially serving as a relay between the brain and spinal cord and the rest of the body.[2] Unlike the CNS, the PNS is not protected by the vertebral column and skull, or by the blood–brain barrier, which leaves it exposed to toxins and mechanical injuries.

The peripheral nervous system is divided into the somatic nervous system and the autonomic nervous system. In the somatic nervous system, the cranial nerves are part of the PNS with the exception of the optic nerve (cranial nerve II), along with the retina. The second cranial nerve is not a true peripheral nerve but a tract of the diencephalon.[3]Cranial nerve ganglia originated in the CNS. However, the remaining ten cranial nerve axons extend beyond the brain and are therefore considered part of the PNS.[4] The autonomic nervous system exerts involuntary control over smooth muscle and glands. The connection between CNS and organs allows the system to be in two different functional states: sympathetic and parasympathetic.

Structure

The peripheral nervous system is divided into the somatic nervous system, and the autonomic nervous system. The somatic nervous system is under voluntary control, and transmits signals from the brain to end organs such as muscles. The sensory nervous system is part of the somatic nervous system and transmits signals from senses such as taste and touch (including fine touch and gross touch) to the spinal cord and brain. The autonomic nervous system is a ‘self-regulating’ system which influences the function of organs outside voluntary control, such as the heart rate, or the functions of the digestive system.

Somatic nervous system
See also: List of nerves of the human body

The somatic nervous system includes the sensory nervous system and the somatosensory system and consists of sensory nerves and somatic nerves, and many nerves which hold both functions.

In the head and neck, cranial nerves carry somatosensory data. There are twelve cranial nerves, ten of which originate from the brainstem, and mainly control the functions of the anatomic structures of the head with some exceptions. One unique cranial nerve is the vagus nerve, which receives sensory information from organs in the thorax and abdomen. The accessory nerve is responsible for innervating the sternocleidomastoid and trapezius muscles, neither of which being exclusively in the head.

For the rest of the body, spinal nerves are responsible for somatosensory information. These arise from the spinal cord. Usually these arise as a web (“plexus”) of interconnected nerves roots that arrange to form single nerves. These nerves control the functions of the rest of the body. In humans, there are 31 pairs of spinal nerves: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal. These nerve roots are named according to the spinal vertebrata which they are adjacent to. In the cervical region, the spinal nerve roots come out above the corresponding vertebrae (i.e., nerve root between the skull and 1st cervical vertebrae is called spinal nerve C1). From the thoracic region to the coccygeal region, the spinal nerve roots come out below the corresponding vertebrae. It is important to note that this method creates a problem when naming the spinal nerve root between C7 and T1 (so it is called spinal nerve root C8). In the lumbar and sacral region, the spinal nerve roots travel within the dural sac and they travel below the level of L2 as the cauda equina.

Cervical spinal nerves (C1–C4)
Further information: Cervical plexus

The first 4 cervical spinal nerves, C1 through C4, split and recombine to produce a variety of nerves that serve the neck and back of head.

Spinal nerve C1 is called the suboccipital nerve, which provides motor innervation to muscles at the base of the skull.
C2 and C3 form many of the nerves of the neck, providing both sensory and motor control. These include the greater occipital nerve, which provides sensation to the back of the head, the lesser occipital nerve, which provides sensation to the area behind the ears, the greater auricular nerve and the lesser auricular nerve.

The phrenic nerve is a nerve essential for our survival which arises from nerve roots C3, C4 and C5. It supplies the thoracic diaphragm, enabling breathing. If the spinal cord is transected above C3, then spontaneous breathing is not possible.

Brachial plexus (C5–T1)
Further information: Brachial plexus

The last four cervical spinal nerves, C5 through C8, and the first thoracic spinal nerve, T1, combine to form the brachial plexus, or plexus brachialis, a tangled array of nerves, splitting, combining and recombining, to form the nerves that subserve the upper-limb and upper back. Although the brachial plexus may appear tangled, it is highly organized and predictable, with little variation between people. See brachial plexus injuries.

Lumbosacral plexus (L1–Co1)

The anterior divisions of the lumbar nerves, sacral nerves, and coccygeal nerve form the lumbosacral plexus, the first lumbar nerve being frequently joined by a branch from the twelfth thoracic. For descriptive purposes this plexus is usually divided into three parts:

3D Medical Animation still shot of Lumbosacral Plexus
lumbar plexus
sacral plexus
pudendal plexusAutonomic nervous system

The autonomic nervous system (ANS) controls involuntary responses to regulate physiological functions.[5] The brain and spinal cord of the central nervous system are connected with organs that have smooth muscle, such as the heart, bladder, and other cardiac, exocrine, and endocrine related organs, by ganglionic neurons.[5] The most notable physiological effects from autonomic activity are pupil constriction and dilation, and salivation of saliva.[5] The autonomic nervous system is always activated, but is either in the sympathetic or parasympathetic state.[5] Depending on the situation, one state can overshadow the other, resulting in a release of different kinds of neurotransmitters.[5]

Sympathetic nervous system

The sympathetic system is activated during a “fight or flight” situation in which mental stress or physical danger is encountered.[5] Neurotransmitters such as norepinephrine, and epinephrine are released,[5] which increases heart rate and blood flow in certain areas like muscle, while simultaneously decreasing activities of non-critical functions for survival, like digestion.[6] The systems are independent to each other, which allows activation of certain parts of the body, while others remain rested.[6]

Parasympathetic nervous system

Primarily using the neurotransmitter acetylcholine (ACh) as a mediator, the parasympathetic system allows the body to function in a “rest and digest” state.[6] Consequently, when the parasympathetic system dominates the body, there are increases in salivation and activities in digestion, while heart rate and other sympathetic response decrease.[6] Unlike the sympathetic system, humans have some voluntary controls in the parasympathetic system. The most prominent examples of this control are urination and defecation.[6]

Enteric nervous system

There is a lesser known division of the autonomic nervous system known as the enteric nervous system.[6] Located only around the digestive tract, this system allows for local control without input from the sympathetic or the parasympathetic branches, though it can still receive and respond to signals from the rest of the body.[6] The enteric system is responsible for various functions related to gastrointestinal system.[6]

Disease

Main article: Peripheral neuropathy

Diseases of the peripheral nervous system can be specific to one or more nerves, or affect the system as a whole.

Any peripheral nerve or nerve root can be damaged, called a mononeuropathy. Such injuries can be because of injury or trauma, or compression. Compression of nerves can occur because of a tumour mass or injury. Alternatively, if a nerve is in an area with a fixed size it may be trapped if the other components increase in size, such as carpal tunnel syndrome and tarsal tunnel syndrome. Common symptoms of carpal tunnel syndrome include pain and numbness in the thumb, index and middle finger. In peripheral neuropathy, the function one or more nerves are damaged through a variety of means. Toxic damage may occur because of diabetes (diabetic neuropathy), alcohol, heavy metals or other toxins; some infections; autoimmune and inflammatory conditions such as amyloidosis and sarcoidosis.[5] Peripheral neuropathy is associated with a sensory loss in a “glove and stocking” distribution that begins at the peripheral and slowly progresses upwards, and may also be associated with acute and chronic pain. Peripheral neuropathy is not just limited to the somatosensory nerves, but the autonomic nervous system too (autonomic neuropathy).[5]

See also

Wikimedia Commons has media related to Peripheral nervous system.Classification of peripheral nerves
Connective tissue in the peripheral nervous system
Preferential motor reinnervation

References

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^ “Slide show: How your brain works – Mayo Clinic”. mayoclinic.com. Retrieved 17 June 2016.

^ Board Review Series: Neuroanatomy, 4th Ed., Lippincott Williams & Wilkins, Maryland 2008, p. 177. ISBN 978-0-7817-7245-7.

^ James S. White (21 March 2008). Neuroscience. McGraw-Hill Professional. pp. 1–. ISBN 978-0-07-149623-0. Retrieved 17 November 2010.

^ a b c d e f g h i Laight, David (September 2013). “Overview of peripheral nervous system pharmacology”. Nurse Prescribing. 11 (9): 448–454. doi:10.12968/npre.2013.11.9.448. ISSN 1479-9189.

^ a b c d e f g h Matic, Agnella Izzo (2014). “Introduction to the Nervous System, Part 2: The Autonomic Nervous System and the Central Nervous System”. AMWA Journal: American Medical Writers Association Journal (AMWA J). ISSN 1075-6361.

External links

Peripheral nervous system photomicrographs
Peripheral Neuropathy from the US NIH
Neuropathy: Causes, Symptoms and Treatments from Medical News Today
Peripheral Neuropathy at the Mayo ClinicvteNervous systemCentral nervous system
Meninges
Spinal cord
Brain
Hindbrain
Medulla
Pons
Cerebellum
Midbrain
Forebrain
Diencephalon
Retina
Optic nerve
Cerebrum
Limbic systemPeripheral nervous systemSomatic
Sensory nerve
Motor nerve
Cranial nerve
Spinal nerveAutonomic
Sympathetic
Parasympathetic
Enteric
Authority control
GND: 4173794-5
LCCN: sh85090903
MA: 545314008
TA98: A14.2.00.001

Retrieved from “https://en.wikipedia.org/w/index.php?title=Peripheral_nervous_system&oldid=1008194435”

Nervous System: Facts, Function & Diseases | Live Science

Nervous System: Facts, Function & Diseases | Live Science – The peripheral nervous system consists of sensory neurons, ganglia (clusters of neurons) and nerves that connect to one another and to the central Once they have completed medical training, neurologists complete additional training for their specialty and are certified by the American Board of…PNS (Peripheral nervous system) – Made of peripheral nerves which link the CNS to the body's receptors and effectors. The majority of this activity occurs in the brain, but certain responses can be mediated by the spinal cord (reflex actions).peripheral nervous system lo nerves and nerve fibres and peripheral nerve structure. neuron is nerve cell which consists of axons and dendrites The area of the skin innervated by the branches of a single spinal segment is called a dermatome; this can be used to help locate the injured region of…

Nervous System | BioNinja – The peripheral nervous systems (PNS) is a highly complex structure, containing the longest axons in the human body and formed by many different classes Traditionally, the nervous system is divided into central and peripheral components. The brain (cerebrum, cerebellum, and brain stem) and spinal…The peripheral nervous system governs all structures outside the brain and spinal cord. Peripheral nerves branch from the spinal cord through the foramen transversarium of each vertebrae. I suppose the structure it would not affect is the brain itself since cranial nerves are responsible for brain activity.The peripheral nervous system is a channel for the relay of sensory and motor impulses between the central nervous system on one hand and the body surface, skeletal muscles, and internal organs on the other hand. Each spinal nerve is formed by the joining of a dorsal root and a ventral root, and it…

Nervous System | BioNinja

Lecture notes, lecture Week 6 – Peripheral nervous system – StuDocu – Nerve cells may be described as receivers and transmitters of information that allow an organism to respond appropriately. * For every two potassium that is pumped into the cell by the sodium-potassium pump, three sodium ions are pumped out which maintains the state of the resting potential.Peripheral Nervous System Structure and Functions. As mentioned above, the overall function is to carry information to and from your CNS, so that normal bodily function is carried out. It helps in the regulation of many functions such as fight and flight mechanisms, voluntary and involuntary actions etc.Peripheral nervous system nerves often extend a great length from the central nervous system to reach the periphery of the body. The peripheral nervous system can be divided into somatic, autonomic and enteric nervous systems, determined by the function of the parts of the body they…

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Anatomy of yawning – .

Dr. Mark Scheideler presents CMTA's Strategy to Accelerate Research at Bio International Convention – Hello.
My name is Mark Scheideler. I'm a
founder of an R&D consultancy based in the Washington, DC area called Human
First Therapeutics. I worked closely with the Charcot-Marie-Tooth Association
developing its research strategy in alliances. We'd like to talk today about a
broad capability we put into place to provide preclinical testing in our
alliances in supportive therapy development for Charcot-Marie-Tooth
disorders. The CMTA STAR consortium was launched as a means to facilitate
collaboration and accelerate therapy development in rare hereditary
peripheral neuropathies. These disorders are collectively called
Charcot-Marie-Tooth neuropathies. The diseases can affect myelin producing
Schwann cells in the peripheral nervous system leading to demyelination. These
are called Type 1 disorders, or in a peripheral nerve leading to an axon neuropathy, these are called type 2 disorders. In both cases, there's a
progressive neurodegeneration. The increasing deficits imbalance walking
ability and grip strength. The overall disease prevalence is 1 in 2,500, and
diseases are of known genetic causation, making them attractive candidates for
therapeutics development. There's a high unmet medical need as there are no
disease modifying therapies for patients currently available. The starting point
in developing a therapy program is to recognize that a variety of skill sets.
You need to come together and collaborate in order to advance
promising ideas in lab bench testing and patients. STAR was created as such a
collaborative vehicle for the CMTA, initially starting out as a network of
sponsored scientific and clinical investigators active in CMT research.
The state of knowledge has advanced such that professional drug developers needed
to enter the conversation. The key gaps in preclinical testing filled by service
research organizations specializing in cell and animal model creation and neurological testing. In the case of STAR, the CMTA is acting as a key convener that
the organization's and people needed to put the whole picture together. I'm
providing this slide as an overall snapshot of STAR activity that the CMTA
has recently assembled. I'm not going to go through all the fine detail. I'm
showing it to you to convey a sense of commitment the organization has. What I'd like you to come away with is that the CMTA has a track record now encompassing 32 alliances. Over 50 collaborative sponsored research projects have been
funded in multiple CMT disorders including all those with the highest
disease frequency. And over 15 million dollars has been spent in active and
lean management effort allowing the CMTA to make progress and moving
potential treatments from bench to bedside I want to now focus on different
models we've used engage in alliance activities primarily at the drug
discovery and preclinical phases. Our first partnerships have been
collaborative research alliances where there's shared know-how, work effort and
funding. These are vertically integrated relationships where drug discovery
efforts, if successful, will further migrate preclinical and clinical stage
work. We've also engaged in smaller entrepreneurial alliances where the
CMTA has a principal responsibility to move a project forward. Our preclinical
option alliances the CMTA bears the cost of drug validation and in turn gets
an option to acquire the test asset. The rest of my talk I want to focus on
preclinical testing alliances, an area where we've seen a good deal of
interest and activity. All these alliance activities are what I call "therapy
agnostic." We're involved in advancing genetic small-molecule and biological
therapies. Getting the structure right is key in making this work and I'm going to
pass along some of our learnings of key ingredients in putting a
pre-clinical therapy evaluation program in place. CMTA is assembled preclinical
toolboxes for different disorders. This allows proof of principle testing on the
role of therapeutic target the disease process. There's also an expert ability
to evaluate if the therapy can arrest or even reverse the CMT disease pathology,
and this is an attraction to a company interested in seeing if it can position an
asset it has into a CMT disorder. Alliances are conducted by a broad CMT
expert and pharmaceutical testing network, and the key operational elements to implementing the toolbox approach include expert direction for study
planning and project execution, therapy evaluation by a network of leading
specialty service groups and straightforward agreements for
protecting and sharing data. The preclinical toolbox essentials mostly
center around the animal models. The CMTA has either made or licensed models for
use in therapeutic evaluation. There's freedom to operate for both research use
and therapeutic evaluation. We are continuously breeding cohorts of animals. This allows us to quickly build study groups for partners. There are currently
four different CMT diseases represented in toolboxes, which we consider to
be best-in-class models of each of these diseases. And for each of them there's a
well-established therapeutic evaluation test window as a result of longitudinal
profiling of motor behaviors, electrophysiology and histology
responses. The CMTA is also engaged in a New York Stem Cell Foundation
collaboration aimed at creating a bank of IPSC cell lines. There are currently
six CMT diseases represented. These cell lines are available to researchers and
companies via an MTA. This slide shows some of the key service alliance
partners we've relied upon to execute on preclinical studies. They provide
capabilities and include model generation, breeding, and specialized
testing and sample analysis. A path to initiating a preclinical testing
alliance is pretty straightforward. There's typically an initial CMTA
contact and preliminary discussion to scope out what the interest of the
partner would be in doing CMT testing. This typically leads to a mutual
non-disclosure agreement, and this allows sharing of information by both sides
that can inform now the strategy for going forward. It also incorporates CMTA
expert access through our advisory boards. We have a number of people that
can provide information about outcome measures and see different CMT disorders. The actual testing is under a master service agreement and all study planning
is jointly performed between the alliance partner, the service partner and
the CMTA. We have agreements with the service providers and are responsible
for directing the study together with them. The data from the study transfers to the alliance partner under the MSA. There are
no additional agreements or negotiations. Studies are added to the MSA as they're
planned and a direct interaction with study directors facilitates the
design and modification of study plans downstream. In other words the CMTA, the alliance partner and the service partner all participate in designing and
approving a plan that we would put into practice. In return for hosting this
alliance network and directing the effort with the service and alliance
partners, the CMTA simply asks for cost
reimbursement of the study cost that are encumbered in doing the work.
The typical preclinical workflow which applies to genetic therapies, biologicals
and small molecules starts off really with finding out what kind of existing
exposure and formulation exists if information is available from a partner.
Now the CMTA it has a capability in this network to be able to provide
additional information on these disease models. Whether it's tissue penetration
or plasma exposure, we can provide samples for analysis to the partner labs.
We like to start off by performing a max tolerated dose assessment. The goal here
is really to find the limit of tolerability of drug dosage–tolerability
defined as the absence of effect on broad motor skills. In some CMTs we're
able to do target engagement studies and I'll show you a stock example of that
on the next slide. All these studies really aim at that chronic efficacy study and
they typically are run for twelve weeks and involve specific motor behavior
outcomes such as grip, balance and gait and terminal electrophysiology and
histology outcome measures. This is an example of a study we performed with a
alliance partner that was published in the Journal of Clinical Investigation. It
involves a rat model of CMT1A. CMT1A is the most prominent CMT disorder and
results from a gene duplication in a Schwann cell chain or the protein
peripheral myelin protein 22. So in Figure A you can see an example of a
target engagement readout where we can measure message expression and different
nerve samples from the rats following drug dosing. What you see here is that the ASO in green is able to substantially
reduce the expression of message from the disease over expression that
normally is present. We also of course do a variety of other outcome measures as I
mentioned. In panel D on the middle right you can see that we can look at the
effect. We did look at the effect of an ASO on myelination of a nerve and
normalizing it from the lower T state in the control animals, and figure E and F shows functional outcome measures of micro physiology where the ASO is able to
normalize nerve conduction velocity and Cmap amplitudes–towards the–in the
direction of the wild-type unaffected animals following dosing. It's good
to show you a little snapshot of the kind of activity we've been engaged in
and in this slide shows you a summary for 2019 of our therapy Development
Alliance work. There were nine active platform alliance partners in 2019. At
the end of the year we had five companies actively testing therapeutics
and four companies and one University group in relationship
discussions. Five groups sought access to CMTA toolbox of either the stem cell
lines or the animal models, and the breakdown of alliance partner interest
shows testing across the different CMT disorders I showed you for the toolboxes.
In all, we executed study plans for 22 preclinical animal studies across five
partners and three CMTs, and positive results were obtained and models for two
different CMTs through these studies. I want to leave you with a bigger picture
of the kind of support the CMTA is putting into to therapy development. It's this assembled advisory group at CMTA CMT experts. It sponsors investigators
working to develop new CMT models and validate options for treatment. I've
described to you already the preclinical turnkey support system we've put in
place. The CMTA sponsors efforts also in clinical markers, natural history studies,
and clinical trials planning, and "Patients as Partners" is an advocacy
effort that provides access to companies to its seventy US patient chapters where
I can get the direct feedback in interaction with patients–CMT patients. I
just want to leave you with contact information. You can contact me to learn
more about how the CMTA can work with you to aid your therapy development
program, and thank you very much. .

Smoking Causes Cancer, Heart Disease, Emphysema – في كل مرة تدخن فيها سيجارة
، تنتقل غازات سامة إلى الرئتين،
ثم إلى مجرى الدم، حيث تنتشر لكل عضو في الجسم.
تصنع السيجارة
باستخدام أوراق التبغ، الذي يحتوي على النيكوتين
ومجموعة متنوعة من المركبات الأخرى. مثل التبغ و
من ثمَّ تحترق هذه المركبات ، مطلقةً الآلاف من
المواد الكيميائية الخطرة، بما في ذلك أكثر من أربعين مادة معروفة
بتسببها السرطان. دخان السجائر يحتوي على غازات سامة
أول أكسيد الكربون وأكسيد النيتروجين، وكذلك كميات ضئيلة من
الجسيمات المشعة المسببة للسرطان. جميع أشكال التبغ خطيرة، بما في ذلك السيجار، والأنابيب، والتبغ الذي لا يدخن، مثل المضغة أو النفة والسعوط. النيكوتين هو مادة كيميائية تسبب الادمان في التبغ.
بعد استنشاق دخان التبغ، يتدفق النيكوتين من خلال مجرى الدم للدماغ، حيث يؤدي الى شعور ممتع. عند تعرض دماغك مراراً للنيكوتين، يصبح غير حساس، ويجعلك نتلهف
المزيد والمزيد من النيكوتين فقط لتشعر أنك طبيعي. التدخين يسبب الموت. الاشخاص الذين يدخنون يموتون عادة
في سن مبكرة أكثر من غير المدخنين. في الواقع، 1 من كل 5 وفيات في الولايات المتحدة
يرتبط بتدخين السجائر. إذا كنت تدخن، أنت في خطر لمشاكل صحية كبيرة تزيد بشكل كبير، بما في ذلك:
أمراض القلب والنوبات القلبية والسكتة الدماغية، سرطان الرئة، والموت من
مرض الانسداد الرئوي المزمن. التدخين يسبب أمراض القلب والأوعية الدموية.
عندما يتدفق النيكوتين من خلال الغدد الكظرية، انها تحفز اطلاق ادرينالين،
وهو الهرمون الذي يرفع ضغط الدم. وبالإضافة إلى ذلك، النيكوتين وأول أكسيد الكربون
يمكن أن تتلف بطانة الجدران الداخلية في الشرايين. الترسبات الدهنية، تسمى الصفائح العصيدية، يمكن أن تتراكم في هذه المواقع الإصابة وتصبح كبيرة بما فيه الكفاية
لتضييق الشرايين وخفض تدفق الدم بشدة، مما يؤدى إلى حالة
تدعى تصلب الشرايين. في مرض الشريان التاجي تصلب الشرايين
يضيق الشرايين التي تغذي القلب، مما يقلل من إمدادات الأوكسجين إلى
عضلة القلب، ويزيد من خطورة تعرضك لنوبة قلبية. كما يرفع التدخين من خطورة تكون جلطات الدم لأنه يسبب تجمع الصفيحات الدموية في الدم
معا. التدخين يزيد من خطر ال أمراض الأوعية الدموية المحيطية، حيث تسد اللويحات العصيدية
الشرايين الكبيرة في الذراعين والساقين. التدخين يمكن أن يسبب أيضا على
أم دم (توسع) الشريان اأبهري البطني، وهو تورم أو ضعف الشريان الأبهر الخاص بك
حيث يتم تشغيله من خلال البطن. الفتدخين يدمر جزأين رئيسيين من رئتيك:
الطرق الهوائية، كما تدعى الشعب الهوائية، والحويصلات الهوائية الصغيرة تسمى الأسناخ الرئوية. مع كل نفس، ينتقل الهواء إلى أسفل
أنبوب الهواءالخاص بك، وتدعى القصبة الهوائية ، ويدخل الرئتين من خلال أنابيب الشعب الهوائية الخاصة بك. ثم ينتقل الهواء إلى
الآلاف من الحويصلات الهوائية الصغيرة، حيث ينتقل الأكسجين من الهواء
إلى مجرى الدم وثاني أكسيد الكربون الناتج من النفايات
يتحرك للخروج من مجرى الدم. بروزات صغيرة تشبه الشعر تدعى الأهداب، تبطن أنابيب الشعب الهوائية الخاصة بك وتطرد المواد الضارة خارج رئتيك. دخان السجائر تهيج بطانة الخاصة بالشعب الهوائية، مسبباً توذمها وتكون المخاط فيها . يبطئ دخان السجائر أيضا
من حركة الأهداب الخاصة بك، مما يتسبب ببقاء بعض الدخان والمخاط في رئتيك. عند النوم،
بعض من أهداب تشفى تبدأ في دفع المزيد من الملوثات
والمخاط من الرئتين. عندما تستيقظ، يحاول الجسمطرد
هذه المواد عن طريق السعال مراراً وتكراراً، وهي حالة تعرف باسم
سعال المدخن. يتطور التهاب الشعب الهوائية المزمن مع مرور الوقت،
بينها تتوقف أهدابك عن العمل، تنسد الطرق الهوائية الخاصة بك مع ندوب والمخاط،
ويصبح التنفس صعبا. رئتيك هي الآن أكثر عرضة لأمراض أخرى. يضر دخان السجائر أيضا
بالحويصلات الهوائية الخاصة بك، مما يصعب تبادل الأكسجين و
ثاني أكسيد الكربون مع الدم. مع مرور الوقت لا يصل إلا القليل من الأكسجين إلى الدم مما قد يسبب النفاخ الرئوي هي حالة حيث يتوجب عليك أ تتعب لتلتقط كل نفس وتردتدي أنبوب أوكسجين تحت أنفك
من أجل التنفس. التهاب الشعب الهوائية المزمن وانتفاخ الرئة
تسمى مجتمعة مرض الانسداد الرئوي المزمن،
أو COPD. مرض الانسداد الرئوي المزمن هو الفقدان التدريجي للقدرة على التنفس
والذي لا يوجد له علاج. يحتوي دخان السجائر ما لا يقل عن 40 مادة مسببة للسرطان
تدعى مواد مسرطنة، بما في ذلك السيانيد، والفورمالديهايد،
البنزين، والأمونيا. في الجسم، تنمو الخلايا السليمة،
تصنع خلايا جديدة، ثم تموت. المادة الوراثية داخل كل خلية،
تدعى الحمض النووي، ويوجه هذه العملية. إذا كنت تدخن، والمواد الكيميائية السامة
يمكن أن تتلف الحمض النووي في الخلايا السليمة الخاصة بك. ونتيجة لذلك، الخلايا التالفة تصنع خلايا جديدة غير سليمةة، التي تنمو خارج نطاق السيطرة
وقد تنتشر إلى أجزاء أخرى من الجسم. أكثر أنواع السرطان شيوعا
في العالم هو سرطان الرئة، مع أكثر من مليون حالة جديدة
تشخص كل عام. المواد الكيميائية الضارة في السجائر يمكن أن تتسبب
السرطان في أجزاء أخرى من الجسم، مثل: في الدم ونخاع العظام،
الفم والحنجرة والحلق، المريء، المعدة،
البنكرياس، الكلى، المثانة والرحم وعنق الرحم. التدخين يمكن أن يسبب العقم
في كل من الرجال والنساء. إذا كانت المرأة الحامل و
تدخن خلال فترة الحمل، أنها تعرض طفلها إلى المواد الكيميائية سامة في السيجارة
، مما تسبب في زيادة خطر: انخفاض الوزن عند الولادة والإجهاض،
الولادة المبكرة، ولادة جنين ميت، وفاة الرضع، و
متلازمة موت الرضع المفاجئ. التدخين هو أيضا خطير
إذا كانت الأمالمدخنة تتبع الرضاعة الطبيعية. يمر النيكوتين للطفل
عن طريق حليب الثدي، ويمكن أن يسبب الأرق، سرعة ضربات القلب،
والتقيؤ، وتوقف النوم، أو الإسهال. الآثار الصحية الأخرى من التدخين
تشمل انخفاض كثافة العظام وتزايد خطر الإصابة بكسرالورك
بين النساء أمراض اللثة، وغالبا ما تؤدي
إلى فقدان الأسنان والجراحة، ضعف جهاز المناعة
وتأخر التئام الجروح. والعجز الجنسي عند الرجال. .