SPINAL CORD AND PERIPHERAL NS

Summary

The video provides an informative overview of the spinal cord and the nervous system. It explains the spinal cord's function in connecting the brain to the rest of the body and highlights its protective structure, the vertebrae. The video also covers the two divisions of the peripheral nervous system: the somatic nervous system, responsible for voluntary movements, and the autonomic nervous system, which controls involuntary functions like heart rate and digestion. It emphasizes the contrasting roles of the sympathetic and parasympathetic systems in managing the body's response to stress and rest.

Takeaways

• 🧠 The spinal cord is a long, cylindrical structure connecting the brain and lower back, containing tissues, fluids, and nerve cells.
• 🦴 The spinal cord connects to the brainstem and runs down the back, protected by a series of bones called the spinal column or vertebra.
• 📏 It is about 40-50 cm long and roughly the width of a small finger, holding most of the nerves that connect the brain to the body.
• 🔄 The spinal cord sends signals between the brain and body, enabling movement, sensation, and reactions to the environment.
• ⬆️ Sensory signals travel from peripheral senses to the brain through ascending tracts, while motor commands move from the brain to muscles via descending tracts.
• 🦾 The peripheral nervous system (PNS) includes nerves and cells outside the brain and spinal cord, lacking bony protection and prone to damage from trauma.
• 🧑‍🔬 The PNS is divided into the somatic nervous system, which controls voluntary movements, and the autonomic nervous system, which manages involuntary functions.
• 👟 Somatic nerves control skeletal muscles and are categorized as cranial (head) or spinal (spine) nerves.
• 💓 The autonomic nervous system is further split into the sympathetic nervous system, which prepares the body for stress, and the parasympathetic system, which supports rest and digestion.
• 🧘‍♂️ The sympathetic and parasympathetic systems have opposite functions, but both influence key processes such as heart rate, digestion, and sexual arousal.

Q & A

What is the primary function of the spinal cord?

The spinal cord connects the brain to the lower back and helps transmit messages between the brain and the rest of the body, facilitating movement and sensory functions.

How long is the spinal cord and how is it protected?

The spinal cord is about 40 to 50 cm long and is protected by a series of bones called the spinal column or vertebra.

What is the width of the spinal cord compared to a body part?

The width of the spinal cord is roughly the size of a person's small finger.

How does the spinal cord transmit signals from the peripheral senses to the brain?

The spinal cord receives signals from peripheral senses like touch through ascending tracts, which send the signals upward to the brain for processing.

What role do descending tracts in the spinal cord play?

Descending tracts in the spinal cord carry signals from the brain down to the muscles, allowing the body to move and react.

What are the two main divisions of the peripheral nervous system?

The two main divisions of the peripheral nervous system are the somatic nervous system and the autonomic nervous system.

What is the function of the somatic nervous system?

The somatic nervous system controls voluntary movements, such as walking and typing, by directing the actions of skeletal muscles.

What is the difference between cranial and spinal nerves in the somatic nervous system?

Cranial nerves, which consist of 12 pairs, send information between the brainstem and the body, aiding in senses and head movements. Spinal nerves, consisting of 31 pairs, connect the body to the spinal cord and manage sensory and motor functions.

How does the autonomic nervous system differ from the somatic nervous system?

The autonomic nervous system controls involuntary functions like heart rate, breathing, and digestion, whereas the somatic nervous system controls voluntary movements.

What are the two branches of the autonomic nervous system, and what do they do?

The two branches are the sympathetic nervous system, which prepares the body for 'fight or flight' by increasing heart rate and redirecting blood flow to muscles, and the parasympathetic nervous system, which promotes 'rest and digest' activities by slowing the heart rate and conserving energy.

Outlines

00:00

🧠 Introduction to the Spinal Cord and Its Structure

The spinal cord is a long, cylindrical structure connecting the brain to the lower back. It is composed of tissues, fluids, and nerve cells, and is protected by a series of bones called the spinal column or vertebrae. Although small, roughly the size of a pinky finger, it plays a crucial role in transmitting messages between the brain and the rest of the body, enabling movement, sensation, and reaction. Signals travel upward through ascending tracts for processing by the brain and downward through descending tracts to facilitate muscle movements.

05:00

🦴 Overview of the Peripheral Nervous System

Following the central nervous system discussion, the focus shifts to the peripheral nervous system (PNS), which lacks the bony protection of the central nervous system. Peripheral nerves are more vulnerable to damage from cuts, pressure, or stretching. The PNS is divided into two parts: the somatic nervous system (which controls voluntary muscle movements) and the autonomic nervous system (which regulates involuntary body functions). The somatic system controls movements like walking or typing, while the autonomic system manages functions like heart rate, breathing, and digestion.

10:03

🦾 Functions of the Somatic and Autonomic Nervous Systems

The somatic nervous system controls voluntary muscle actions, such as walking or lifting objects, through cranial and spinal nerves. There are 12 pairs of cranial nerves and 31 pairs of spinal nerves responsible for sending sensory information to the brain and delivering motor commands to muscles. The autonomic nervous system, on the other hand, is responsible for involuntary bodily functions like heart rate, digestion, and respiration. It is further divided into the sympathetic system (responsible for the fight-or-flight response) and the parasympathetic system (which promotes rest and digestion).

🔄 Sympathetic and Parasympathetic Nervous Systems

The sympathetic nervous system prepares the body for emergencies by increasing heart rate, dilating airways, and directing blood flow to muscles. In contrast, the parasympathetic system manages restful activities, such as slowing heart rate and aiding digestion. Notably, sexual arousal is influenced by both systems, with the parasympathetic initiating arousal and the sympathetic managing later stages. These systems work in opposition, ensuring balance in bodily functions. The video ends by summarizing the key components of the nervous system, with a promise to explore the next system in future discussions.

Keywords

💡Spinal cord

The spinal cord is a long, cylindrical structure that connects the brain to the lower back, playing a crucial role in transmitting signals between the brain and the body. It is about 40-50 cm long and protected by bones called vertebrae. The spinal cord contains tissues, fluids, and nerve cells and is responsible for facilitating communication through nerve signals, as mentioned in the video.

💡Vertebrae

Vertebrae refer to the series of bones that protect the spinal cord. These bones make up the spinal column, which provides structural support and protection to the nerves running through the spinal cord. In the video, the vertebrae are explained as part of the protective mechanism for the central nervous system.

💡Central nervous system

The central nervous system (CNS) is made up of the brain and spinal cord. It processes information and controls most bodily functions. The video highlights the CNS's role in protecting the brain and spinal cord with bones like the skull and vertebrae.

💡Peripheral nervous system

The peripheral nervous system (PNS) consists of nerves outside the central nervous system. It connects the CNS to limbs and organs and is divided into the somatic and autonomic nervous systems. The video emphasizes its vulnerability to physical trauma since it lacks bony protection, unlike the CNS.

💡Somatic nervous system

The somatic nervous system, also called the voluntary nervous system, controls voluntary movements of skeletal muscles, such as walking or typing. It transmits sensory and motor information. The video explains how this system helps us consciously control actions.

💡Autonomic nervous system

The autonomic nervous system (ANS) is responsible for involuntary bodily functions like heart rate, digestion, and breathing. It operates without conscious effort and is divided into the sympathetic and parasympathetic systems. The video describes its role in controlling internal organ activities and smooth muscles.

💡Sympathetic nervous system

The sympathetic nervous system is a branch of the autonomic nervous system that prepares the body for the 'fight or flight' response during stress or emergencies. The video explains how it increases heart rate, dilates airways, and redirects blood flow to muscles during stressful situations.

💡Parasympathetic nervous system

The parasympathetic nervous system is the counterpart to the sympathetic system, promoting 'rest and digest' activities like slowing the heart rate and aiding digestion. The video discusses its role in conserving energy and maintaining bodily functions during restful states.

💡Cranial nerves

Cranial nerves are part of the somatic nervous system, consisting of 12 pairs of nerves that connect the brain stem to the periphery. These nerves are crucial for sensory functions like the five senses and for controlling movements in the head, neck, and tongue. The video mentions them in the context of sensory and motor function.

💡Descending and ascending tracts

Descending tracts carry motor signals from the brain to the body, while ascending tracts send sensory signals from the body to the brain. These pathways are vital for movement and sensory processing. In the video, they are discussed in relation to how the spinal cord transmits signals to and from the brain.

Highlights

Introduction to the spinal cord and its connection between the brain and lower back.

The spinal cord is a cylindrical structure containing tissues, fluids, and nerve cells.

The spinal cord connects to the brain stem and is about 40-50 cm long.

The spinal cord is protected by a series of bones called the spinal column or vertebra.

Despite its small size (the width of a small finger), the spinal cord is crucial for communication between the brain and the body.

The spinal cord sends signals from the brain to the body and receives signals from the body's peripheral senses.

Ascending tracts in the spinal cord send sensory information to the brain for processing.

Descending tracts carry motor signals from the brain to the body, allowing movement.

Introduction to the peripheral nervous system, which is more exposed and prone to injury compared to the central nervous system.

The peripheral nervous system has two divisions: the somatic and autonomic nervous systems.

The somatic nervous system controls voluntary movements like walking, typing, and lifting objects.

There are 12 pairs of cranial nerves and 31 pairs of spinal nerves in the somatic nervous system.

The autonomic nervous system controls involuntary functions such as heart rate, breathing, and digestion.

The autonomic nervous system is divided into the sympathetic and parasympathetic systems, which control fight-or-flight and rest-and-digest responses, respectively.

The sympathetic nervous system uses neurotransmitters like noradrenaline to increase heart rate and redirect blood flow in stressful situations.

Sexual arousal involves both the sympathetic and parasympathetic nervous systems, making it an exception to the usual division of responsibilities.

Transcripts

All right so Hello

um continuing from our lesson last

Wednesday so we have now the spinal cord

so your spinal cord is the long

cylindrical structure that connects your

brain and your lower back So it it

contains tissues Fluids and nerve cells

to be more specific um the spinal cord

connects to the brain stem and runs down

your back So um it's it's about 40 to to

50 CM long and it is protected by a

series of Bones at ang tawag sa series

of Bones na ito is the spinal column or

vertebra so to provide you with a visual

presentation here is what I was talking

about

on what this slide Is Telling us naman

is that the spinal cord is a small but

important part of the body so it is

about the size of your Uh small finger

sa in terms of its width tapos pero it

it holds most of the the nerves that

connect your brain to the rest of your

body Okay so this nerves help Uh para

i-send yung mga messages back and forth

Okay um kaya you can you can move you

can feel things at saka you can react

then to your surroundings Okay so

despite being

compact this um spinal cord plays a big

role in controlling many body

functions speaking further about its

functions the spinal cord receives ah

Itong mga signal na nanggagaling sa

ating peripheral senses katulad ng touch

ah sa sa pamamagitan ng pathways or

through Through the pathways called the

Ascending tract Okay so Itong mga

signals na ito ay na idadala upward to

the brain para sa processing at the same

time the spinal cords neurons carry

signals from the brain downward naman

through the descending tracks Okay so

Itong mga signal na ito cause the

muscles para mag-crack at saka Uh para

tulungan yung ating katawan to Uh to

move okay and so we move on now to the

peripheral nervous system So um

Kakatapos lang natin sa central nervous

system which are the brains and your um

spinal cord so we have now the

peripheral nervous system Okay so Ah

yung brain at spinal cord natin na

na-mention ko lang kanina na part ng

central nervous system ay protektado ng

mga bones katulad ng skull at saka yun

ngang vertebra pero iyung mga nerves and

cells ng peripheral nervous system naman

wala sila ng ganitong bony protection

kasi hindi sila

sa sa mga bones okay ang mga peripheral

nerves ay mas Exposed at saka mas madali

silang ma-in or ma-damage ng physical

trauma katulad ng ah mga cuts Okay Iyung

ah prone sila na mahiwa or ma-pressure

at saka ma- stretch din ang peripheral

nervous system ay may dalawang division

so itong os somatic at saka autonomic

nervous systems iisa-isahin natin sila

first off is the is the somatic nervous

system Okay so This is also known as the

voluntary nervous system kasi ah

responsible siya sa pag-control ng ating

voluntary movements sa ating katawan

okay so ah it primarily directs the

actions of skeletal muscles which are

the muscles that we can consciously

control ah katulad ng um iyung mga

muscles that are used for Walking typing

or carrying or lifting objects mga ganon

the nerves in the somatic nervous system

are classified based on their location

either in the head regions iyan Iyung

cranial or in the spine region Ito naman

Iyung spinal nerves Okay so there are 12

pairs of cranial nerves which um s

information to the brain stem Or from

the brain stem to the periphery Okay so

this nerves are required para sa ating

five senses and sa UM movement din ng

ating head neck at saka ng ating tong

Okay the spinal nerves naman consist of

31 pairs of nerves that play a role in

connecting the body to the spinal cord

Okay so these nerves are responsible for

two main functions um first off is its

function in sending um sensory

information from the periphery So this

are say for example the skin muscles at

saka um the the joints Okay Uh So from

from this to the spinal cord Okay um

this helps the brain process sensations

like touch pain and temperature Okay The

second one here is its function in

carrying motor commands from the spinal

cord to the skeletal muscles naman and

this allows the body to

move moving on to the second division we

have the autonomic nervous system So you

remember your Uh um What's that your

somatic nervous system is Otherwise

called the voluntary nervous system

right So this one naman the autonomic

nervous system is also called the

vegetative nervous system Okay

this division is responsible for

controlling involuntary Functions in the

body example of this ones would be the

heart rate breathing and digestion Okay

you see it it influences the the

activity of Internal organs as well as

the glands um and and the smooth muscles

without conscious effort kaya it says

They're not under voluntary control the

autonomic nervous system is divided into

two main branches namely the sympathetic

and then the parasympathetic nervous

system Okay so unahin natin yung

sympathetic nervous system this one

prepares the body for fight or flight

response

Okay so it say for example increases

heart rate It also it dilates airway for

better oxygen intake and it redirects

blood flow for um Uh two muscles during

stressful situations or emergencies Okay

on the other hand the parasympathetic

nervous system promotes Rest and Digest

activities naman sa pamamagitan ng safer

for example slowing the heart rate

facilitating digestion and conserving

energy when the body is at

rest So if you notice ito iyung mga

nasabi ko kanina about the sympathetic

nervous system now ah para i-activate

Itong mga responses na ito iyung mga

sympathetic

fibers ginagamit niya ngayon yung

neurotransmitter na noradrenaline

para i-activate ung blood flow sa

skeletal muscles and lungs ah para

[Musika]

i-dilaw

in responses katulad ng heart rate

atsaka digestion Okay pero ah there is

an Only Exception here and that is

sexual arousal so hindi kasali sa sa

pinapares ng parasympathetic division

ang sexual arousal kasi sexual arousal

is influenced by a combination of both

the parasympathetic and sympathetic

nervous system Okay so the nervous

system um facilitates the initial stages

of

arousal such as um Iyung Increasing

Iyung blood flow to the genital area but

Iyung overall process also involves

sympathetic responses All right so at to

put it simply the sympathetic and

parasympathetic nervous systems have

opposite actions have you noticed Ayan

this again is the summary of the parts

of the nervous system mukhang we did not

miss naman to discuss any of the parts

noo Okay So um for for this

for this um video I will stop here para

then to

um para ihiwalay

yung nervous system next na system ataka

para din hindi masyado mahaba yung video

I'll see you on the next one Bye for now