Transcript Endocrine and Nervous System

• Main Function:
It releases hormones (chemical
messengers) into the blood to signal
other cells (target cells) to behave in
certain ways. It is a slow but
widespread form of communication.
Consists of:
Endocrine glands
Release hormones into
the bloodstream.
Hormones are chemicals
released in one part of the
body that travel through
the bloodstream and
affect the activities of cells
in other parts of the body.
Interaction of Glands
The hypothalamus is
located in the brain
and controls the
release of hormones
from the pituitary
gland. It is an
important link
between the
endocrine and
nervous systems.
Interaction of Glands
The brain and glands
work together to
maintain homeostasis
through a process
called negative and
positive feedback
mechanisms.
Endocrine System
Pituitary Gland
Pituitary Gland
Function: It secretes nine
hormones that control all other
endocrine glands.
-produces human growth
hormone
- Disorders: Too much growth
hormone can result in a
condition called gigantism.
Robert
Wadlow
Endocrine System
Pituitary Gland
Thyroid Gland
Thyroid Gland
• Hormone: Thyroxin
• Function: plays a major role in the regulation the
body’s metabolism.
• Disorders:
Hyperthyroidism-too much thyroxin; fast metabolism
Hypothyroidism- too little thyroxin; slow metabolism
Goiter-lack of iron in diet, no thyroxin secretion,
enlargement of thyroid gland
Endocrine System
Pituitary Gland
Adrenal Glands
Thyroid Gland
Adrenal Gland
• Functions:
-The adrenal
glands release
Adrenaline in the
body that helps
prepare for and
deal with stress.
-Also regulates
kidney function.
Endocrine System
Pituitary Gland
Thyroid Gland
Ovaries
Adrenal Glands
Ovaries
• Functions:
– Pair of reproductive organs found in
women that produce eggs.
– Also secrete estrogen and
progesterone, which control ovulation
and menstruation.
Endocrine System
Pineal Gland
Pituitary Gland
Parathyroid Gland
Thyroid Gland
Pancreas
Ovaries
Thymus
Adrenal Glands
Testes
Testes
• Functions:
– Pair of reproductive glands that
produces sperm.
– Also secrete Testosterone to give
the body its masculine
characteristics.
Endocrine System
Pineal Gland
Pituitary Gland
Parathyroid Gland
Thyroid Gland
Pancreas
Ovaries
Thymus
Adrenal Glands
Testes
Pancreas
[Islets of Langerhans]
Insulin:
Reduces levels of glucose in the blood
• conversion of glucose to glycogen
•promoting glucose absorption and use
by body cells
Glucagon:
Increases levels of glucose in the blood
• causes liver to convert glycogen to glucose
Negative Feedback
• Is a type of self-regulation associated with
endocrine regulation
Functions like a thermostat. Only activated
when there is a need. Shuts off once that
need has been met.
Negative Feedback
A
B
Glycogen
If there is too
much glucose
in the blood,
insulin converts
some of it to
glycogen
Glucose in the blood
Glycogen
If there is not
enough glucose
in the blood,
glucagon
converts some
glycogen into
glucose.
Glucose in the blood
Glucose
Concentration
Glucose levels rise
after a meal.
Insulin is produced
and glucose levels
fall to normal
again.
Normal
Meal eaten
Time
Failure of Homeostasis:
Diabetes:
[Islets of Langerhans]
Islets of Langerhans don’t make enough insulin
• Glucose in blood can’t be stored as glycogen
•Blood levels of glucose INCREASE
Glycogen
The
glucose
in
But there
is no
Glucose
the
blood
insulin
to convert
concentration
increases.
it into glycogen.
rises to
dangerous levels.
Glucose in the blood
Glucose
Concentration
Glucose levels rise
after a meal.
Diabetic
Insulin is not
produced so
glucose levels stay
high
Meal eaten
Time
Positive Feedback
• Enhances an existing response
– Child birth
Interaction of Glands
The feedback the
brain gets is from the
information it collects
as the hypothalamus
monitors the
bloodstream.
Using this information,
the brain knows what
hormones to start and
stop releasing.
Main Function:
This communication
system controls and
coordinates functions
throughout the body and
responds to internal and
external stimuli.
Our nervous system
allows us to feel pain.
Consists of: brain, spinal cord, nerves and
sense organs
Sense Organs: Eyes, Skin, Ears, Nose & Tongue
A nerve is an organ
containing a bundle
of nerve cells called
neurons.
Neurons carry
electrical messages
called impulses
throughout the
body.
Picture shows hundreds of
severed neuron axons
dendrite
Axon
cell body
cell
body
TYPICAL MOTOR
NEURON
synapse
muscle
tissue
Because neurons never touch, chemical
signalers called neurotransmitters must
travel through the space called synapse
between two neurons.
Neurotransmitters (pink
spheres)
Synapse (gap)
The message
is transferred
when
RECEPTORS
receive
neurotransmitters.
Parts of a Neuron
1. Cell body: contains nucleus & most of the
cytoplasm
2. Dendrites: projections that bring impulses into
the neuron to the cell body.
3. Axon: long projection that carries impulses away
from cell body
travels dendrite towards axon
1
2
3
Parts of a Neuron
1. Cell body: contains nucleus & most of the
cytoplasm
2. Dendrites: projections that bring impulses into
the neuron to the cell body.
3. Axon: long projection that carries impulses away
from cell body
1
2
3
Sensory
Neuron
Interneuron
Synapse
Synapse
Motor
Neuron
Interneuron
Synapse
Motor
Neuron
Sensory
Neuron
Muscle
Contracts
Sensory
Neuron
carry impulses from
sense organs to
spinal cord & brain
Fun Fact:
Where can the
largest cells in the
world be found?
The giraffe’s sensory and
motor neurons! Some
must bring impulses from
the bottom of their legs
to their spinal cord
several meters away!!
Interneuron
-processes impulses
in brain and spinal
cord
- connect sensory and
motor neurons
Motor Neurons
carry impulses from the
brain & spinal cord to
muscles & glands
Axon End
Axons branching out
to muscle fibers
• Nerves work together with muscles for
movement. An impulse begins when one
neuron is stimulated by another neuron or
by the sense organs.
• The impulse travels down the axons of
Sensory neurons to the brain cells called
Interneurons.
• The brain will then send an impulse
through motor neurons to the necessary
muscle or organs, telling it to contract.
A reflex is an
involuntary
response that is
processed in the
spinal cord not
the brain.
Reflexes protect
the body before
the brain knows
what is going on.
Reflex Arc
Reflex Arc
Path reflex impulse travels
Sense Receptor
Muscle/Gland
Sensory
Neuron
Motor
Neuron
S
P
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N
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L
C
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D
Human Nervous System
Central Nervous System
[CNS]
Brain & Spinal Cord
Peripheral Nervous System
[PNS]
Nerves branching from the
brain and spinal cord
Consists of: Brain and Spinal Cord
Cerebrum
brain
Cerebellum
Medulla Oblongata
Spinal Cord
Cerebrum
Voluntary or conscious activities of
the body-learning, judgment
Cerebellum
Coordinates and balances the
actions of the muscles
Medulla Oblongata
(Brain Stem)
Spinal Cord
Controls involuntary actions like
blood pressure, heart rate,
breathing, and swallowing
The main communications link
between the brain and the rest of
the body
Consists of:
Sensory division
and Motor
division
-includes all
sensory neurons,
motor neurons,
and sense organs
Subdivisions of PNS
Somatic Nervous System:
• voluntary control
• responsible for conscious body movement
Autonomic Nervous System:
• no voluntary control
• serve internal organs
• involved with: heart rate
blood flow
breathing movements
digestive system
gland secretions
Autonomic Nervous System:
Sympathetic: “fight or flight”
speed up body functions
Parasympathetic:
slow down body functions
Concept Map
The Nervous
System
is divided into
Central nervous
system
Peripheral
nervous system
Motor
nerves
which consists of
that make up
Somatic nervous
system
Autonomic
nervous system
which is divided into
Sympathetic
nervous system
Parasympathetic
nervous system
Sensory
nerves
Nervous vs. Endocrine System
Similarities:
• both involved with maintaining homeostasis
• both secrete chemicals
 Endocrine System: hormones
 Nervous System: neurotransmitter
Differences:
• NS response is much faster than ES response
• ES response lasts longer than NS response
• Nerve impulse transmitted by neuron, hormones
transported by the blood