ervous system:
N
Consists of the central nervous system and the peripheral nervous system and
communicates
using electrical signals
Two main functions of the nervous system:
- To collect, process and respond to information in the environment
- To co-ordinate the working of different organs and cells in the body
- Consists of the brain and spinal cord and is the origin of all complex commands and
decisions
- Sends information to the CNS from the outside world, transmits messages from the
CNS to muscles and glands in the body
- he nervous system is made up of the central nervous system (CNS - brain and
T
spinal cord), whilst the peripheral nervous system (PNS) relays messages from the
environment to the CNS,via sensory neurons and from the CNS to effectors, via
motor neurons.
- The PNS Is subdivided into the
- Automatic nervous system - controls involuntary, vital functions of the body,
suchas maintaining heart rates and breathing rates
- Somatic nervous system - receives information from sensory receptors
belonging to each of the 5 senses, and results in effectors being stimulated. It
also governs muscle movement
- The autonomic nervous system is also subdivided into the sympathetic and
parasympathetic branches
- These branches work as antagonistic pair (they are opposites)
- Either being in the 'rest and digest' response (parasympathetic)- decreases
- Or the fight or flight response (sympathetic) - increases
- e.g. sympathetic nervous system increases heart rate, breathing
rates, causes vasoconstriction and pupil dilation
- Whereas, the parasympathetic nervous system decreases heart
rates, causes vasodilation and pupil constriction
Gland- An organ in the body that synthesises substances such as hormones
heSomatic Nervous System(SNS) controls muscle movement and receives information
T
from
the sensory receptors (what you are feeling, hearing, smelling, tasting and seeing at all
times)
heAutonomic Nervous System(ANS) is responsible for organs and ensuring vital
T
functioning happens such as breathing, digestion and heart rate.
, ndocrine system- One of the body's major information systems that instructs glands to
E
release hormones directly into the bloodstream. These hormones are carried towards target
organs in the body. Communicates via chemicals.
ormones- Chemical substances that circulate in the bloodstream and only affect target
H
organs. They are produced in large quantities but disappear quickly. Their effects are very
powerful
ight or flight- The way an animal responds when stressed, the body becomes
F
physiologically aroused in readiness to fight an aggressor or flee
drenaline- A hormone produced by the adrenal glands which is part of the human body's
A
immediate stress response system. Adrenaline has a strong effect on the cells of the
cardiovascular system - stimulating heart rate, contracting blood vessels and dilating air
passages.
- ituitary gland- Controls the release of hormones from all the other endocrine
P
glands in the body
- Thyroid gland- Releases the hormone thyroxine , which increases heart rate, in
turn, increases metabolic rates and therefore increases the rate of growth. The target
organ is the kidneys and the liver.
- Adrenal gland- Releases adrenaline which create the physiological arousal
preceding the fight or flight response , through increasing the activity within the
sympathetic branch of the nervous system
Fight or flight response
- he endocrine system and the autonomic nervous system (ANS) work in parallel with
T
one another
- The fight or flight response is an acute response and is automatic
1) The body senses and becomes aware of a stressor in the environment
2) Through sensory receptors and sensory neurons in the PNS , this information is sent
to the hypothalamus in the brain which coordinates a response and triggers
increased levels in the sympathetic branch of the ANS
3) The ANS changes from its normal resting state (parasympathetic) to the
physiologically aroused sympathetic state
)
4 The SNS sends a signal to the adrenal medulla
5) Adrenaline is released from the adrenal medulla in the adrenal glands
6) This causes physiologically changese.g. heart beats faster, pushing blood into
muscles, dilation of pupils, decreased production of saliva and triggers the
release of glucose
7) Glucose is released to sustain the fight or flight response ,the purpose of this is to
enable us to escape the stressor and increase the likelihood of survival
8) Once the stressor is no longer a threat ,as part of an antagonistic pairing ,the
hypothalamus triggers less activity in the sympathetic branch and more activity in the
parasympathetic branch of the ANS.
N
Consists of the central nervous system and the peripheral nervous system and
communicates
using electrical signals
Two main functions of the nervous system:
- To collect, process and respond to information in the environment
- To co-ordinate the working of different organs and cells in the body
- Consists of the brain and spinal cord and is the origin of all complex commands and
decisions
- Sends information to the CNS from the outside world, transmits messages from the
CNS to muscles and glands in the body
- he nervous system is made up of the central nervous system (CNS - brain and
T
spinal cord), whilst the peripheral nervous system (PNS) relays messages from the
environment to the CNS,via sensory neurons and from the CNS to effectors, via
motor neurons.
- The PNS Is subdivided into the
- Automatic nervous system - controls involuntary, vital functions of the body,
suchas maintaining heart rates and breathing rates
- Somatic nervous system - receives information from sensory receptors
belonging to each of the 5 senses, and results in effectors being stimulated. It
also governs muscle movement
- The autonomic nervous system is also subdivided into the sympathetic and
parasympathetic branches
- These branches work as antagonistic pair (they are opposites)
- Either being in the 'rest and digest' response (parasympathetic)- decreases
- Or the fight or flight response (sympathetic) - increases
- e.g. sympathetic nervous system increases heart rate, breathing
rates, causes vasoconstriction and pupil dilation
- Whereas, the parasympathetic nervous system decreases heart
rates, causes vasodilation and pupil constriction
Gland- An organ in the body that synthesises substances such as hormones
heSomatic Nervous System(SNS) controls muscle movement and receives information
T
from
the sensory receptors (what you are feeling, hearing, smelling, tasting and seeing at all
times)
heAutonomic Nervous System(ANS) is responsible for organs and ensuring vital
T
functioning happens such as breathing, digestion and heart rate.
, ndocrine system- One of the body's major information systems that instructs glands to
E
release hormones directly into the bloodstream. These hormones are carried towards target
organs in the body. Communicates via chemicals.
ormones- Chemical substances that circulate in the bloodstream and only affect target
H
organs. They are produced in large quantities but disappear quickly. Their effects are very
powerful
ight or flight- The way an animal responds when stressed, the body becomes
F
physiologically aroused in readiness to fight an aggressor or flee
drenaline- A hormone produced by the adrenal glands which is part of the human body's
A
immediate stress response system. Adrenaline has a strong effect on the cells of the
cardiovascular system - stimulating heart rate, contracting blood vessels and dilating air
passages.
- ituitary gland- Controls the release of hormones from all the other endocrine
P
glands in the body
- Thyroid gland- Releases the hormone thyroxine , which increases heart rate, in
turn, increases metabolic rates and therefore increases the rate of growth. The target
organ is the kidneys and the liver.
- Adrenal gland- Releases adrenaline which create the physiological arousal
preceding the fight or flight response , through increasing the activity within the
sympathetic branch of the nervous system
Fight or flight response
- he endocrine system and the autonomic nervous system (ANS) work in parallel with
T
one another
- The fight or flight response is an acute response and is automatic
1) The body senses and becomes aware of a stressor in the environment
2) Through sensory receptors and sensory neurons in the PNS , this information is sent
to the hypothalamus in the brain which coordinates a response and triggers
increased levels in the sympathetic branch of the ANS
3) The ANS changes from its normal resting state (parasympathetic) to the
physiologically aroused sympathetic state
)
4 The SNS sends a signal to the adrenal medulla
5) Adrenaline is released from the adrenal medulla in the adrenal glands
6) This causes physiologically changese.g. heart beats faster, pushing blood into
muscles, dilation of pupils, decreased production of saliva and triggers the
release of glucose
7) Glucose is released to sustain the fight or flight response ,the purpose of this is to
enable us to escape the stressor and increase the likelihood of survival
8) Once the stressor is no longer a threat ,as part of an antagonistic pairing ,the
hypothalamus triggers less activity in the sympathetic branch and more activity in the
parasympathetic branch of the ANS.
