Complete set of IGCSE/GCSE Biology notes. Typed out, highly-detailed, contains plenty of diagrams, tables and illustrations for easy learning.
Topics (01-21):
01 Characteristics and Classification of Living Organisms
02 Organization of The Organism
03 Movement in and out of Cells
04 Biolog...
Co-ordination and Response:
Nervous Control in Humans:
Nerve Impulse: an electrical signal that passes along nerve cells called Neurons.
brain
spinal cord
spinal nerve
The Human Nervous System is:
- The central nervous system consisting of the brain and the spinal cord.
- The peripheral nervous system consisting of the nerves that connect the body to
the central nervous system.
- The co-ordination and regulation of body functions.
,1. Voluntary and Involuntary Actions:
Voluntary: an action that happens in coordination with the brain and while being fully
aware of it happening, given the choice to either do it or not as a result of an external
event taking place.
Involuntary: an automatic action that happens without being aware of it happening and
often as a protective procedure.
2. Nerve Cells (neurons):
A nerve cell (neurons) is a cell specialized for the rapid transfer of electrical impulses.
They are divided into three types:
Motor Neurons: carry impulses from the central nervous system to muscles and glands.
Sensory Neurons: carry impulses from the sense organs to the central nervous system.
Relay Neurons are: make connections to other neurones inside the central nervous
system.
dendrites
cell body
nucleus
sheath
long distance
nerve fibre
(c) relay
neurone
(in brain or
spinal cord)
direction
of impulse
sensory
motor nerve receptor
endings in in skin
muscle
(a) motor neurone (b) sensory neurone
, 3. The Reflex Arc:
A reflex action is an automatic response to a stimulus.
A reflex arc is the arrangement of neurons along which an impulse pass during a reflex
action.
leg extensor nerve spinal
muscle fibre cord stimulus (tapping the
tendon below the kneecap)
receptor (stretch receptor)
sensory neurone
tap tendon
here co-ordinator (spinal cord)
femur pelvis
motor neurone
tibia
effector (leg extensor muscle)
lower leg
jerks forward
response (leg extensor muscle contracts,
making the leg kick forwards)
cell white grey
body matter matter
dorsal root
spinal nerve synapse
sensory
neurone motor
neurone
spinal cord in transverse section
stretch
receptor
in muscle ef
effector
(muscle
fibres)
striated muscle fibre nerve
fibres
stretch receptor
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 credit card 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 these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller BIOSCIENCER. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £20.49. You're not tied to anything after your purchase.
