This is a comprehensive and detailed summary of the Nervous System chapter of the Gr11 IEB Mind Action Series Life Sciences textbook.
Diagrams are not included, so please page through this section in the textbook when revising diagrams.
Coordinating systems = structures that allow communication between
receptors and effectors so that the correct reaction to any change in the
environment can be brought about
The following systems work together to respond to changes in environ +
control conditions inside body:
❏ NERVOUS CO-ORDINATING SYSTEM
❏ Fastest response
❏ Brought about by impulses traveling along nerves
❏ ENDOCRINE CO-ORDINATING SYSTEM
❏ Slower
❏ Brought abt by chemicals [hormones] carried by blood
FUNCTION OF THE NERVOUS SYSTEM:
1. SENSORY FUNCTION
a. Sensory receptors detect changes in external environ + body
2. INTEGRATIVE FUNCTION
a. Central nervous system [CNS] receives info, then decides
which effectors should react to the stimulus
b. Integrates the sensory input
3. MOTOR FUNCTION
a. Effectors [muscles + glands] bring about movement
STIMULI:
Stimuli = physical/chemical changes in internal/external environ that can
cause a response in an organism
External: light, temp, touch, sound, atmospheric pressure
Internal: blood pressure, blood pH, muscle tension
THE HUMAN NERVOUS SYSTEM
Divided into the Central nervous system [CNS] / Peripheral nervous
system [PNS]
, THE CENTRAL NERVOUS SYSTEM
❏ Made up of a concentrated mass of interconnected neurons (nerve
cells) grouped together to form:
❏ Brain
❏ Spinal cord
❏ Both = responsible for processing all info from senses + keeping
organs & reflexes functioning + directing movements, thoughts &
feelings
PROTECTION OF THE CENTRAL NERVOUS SYSTEM
❏ Protected by meninges [3 connective tissue membranes]
❏ Cerebro-spinal fluid fills space between 2nd & 3rd layer of meninges
❏ Shock absorber + prevents damage, acts as a pillow
❏ CSF = fluid formed from blood plasma in special areas in the
walls of the ventricles
CNS + meninges = enclosed in bony case of 2 structures:
❏ Cranium
❏ Strong, dome-shaped
❏ Protects brain from mechanical injuries
❏ Made up of 8 curved skull bones joined by fibrous joints called
sutures
❏ vertebral column
❏ Made up: 33 irregular vertebrae
❏ Surrounds + protects spinal cord from mechanical injury
❏ S-shaped curve of vertebral column + cartilaginous discs :
❏ Prevent jarring of the CNS
❏ Give body spring + resilience
1. THE BRAIN
- Enlarged upper part of spinal cord
- Enclosed by cranium
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through EFT, credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller anandasaravanja. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R50,00. You're not tied to anything after your purchase.
