Download 29.1 How Organ Systems Communicate - Morales Biology

29.1 How Organ Systems Communicate
QQ 4/14/08
Draw and label a nerve cell include: cell body,
dendrite, axon, schwann cell, terminal, synapse.
29.1 How Organ Systems Communicate
KEY CONCEPT
How do the organ systems communicate?
By the Nervous System and Endocrine System
29.1 How Organ Systems Communicate
Communication systems = maintain homeostasis.
• A stimulus causes a response.
– Responses can be chemical, cellular, or behavioral.
– The nervous and endocrine systems respond to stimuli.
29.1 How Organ Systems Communicate
• The nervous system controls
thoughts, movement, and
motion.
• This happens quickly
• The endocrine system controls
growth, development, and
digestion.
• This happens more slowly
29.1 How Organ Systems Communicate
The nervous and endocrine systems have different
methods and rates of communication.
• The nervous system works quickly, using chemical and
electrical signals.
– interconnected network of
cells
– signals move through cells
– divided into central nervous
system (CNS) and peripheral
nervous system (PNS)
spinal
chord
nerves
29.1 How Organ Systems Communicate
• The endocrine system works more slowly.
– only chemical signals
– signals move through bloodstream
– physically unconnected organs
target cell
hormone
bloodstream
receptor
not a target cell
29.1 How Organ Systems Communicate
KEY CONCEPT
Nervous System - made of highly specialized cells.
29.1 How Organ Systems Communicate
Neurons are highly specialized cells.
• A neuron has three parts.
– cell body has nucleus and organelles
1
Cell body
29.1 How Organ Systems Communicate
Neurons are highly specialized cells.
• A neuron has three parts.
– cell body has nucleus and organelles
– dendrites receive impulses
2
dendrites
29.1 How Organ Systems Communicate
Neurons are highly specialized cells.
• A neuron has three parts.
– cell body has nucleus and organelles
– dendrites receive impulses
– axon carries impulses
3
axon
29.1 How Organ Systems Communicate
• Neurons have other structures to transmit signals.
– Schwann cell
29.1 How Organ Systems Communicate
• Neurons have other structures to transmit signals.
– Schwann cell
– synapse
synapse
29.1 How Organ Systems Communicate
• Neurons have other structures to transmit signals.
– Schwann cell
– synapse
– terminal
axon
terminal
29.1 How Organ Systems Communicate
Neurons receive and transmit signals.
• Resting potential means no signal is being transmitted.
– more Na+ outside of cell
– more K+ inside of cell
29.1 How Organ Systems Communicate
• An action potential is a moving electrical impulse.
– It is generated by a stimulus.
– Na+ enters, and cell becomes
positively charged.
– K+ leaves, and area of positive
charge moves.
area of detail
29.1 How Organ Systems Communicate
• A chemical signal passes between neurons.
– Impulse reaches terminal.
impulse
29.1 How Organ Systems Communicate
• A chemical signal passes between neurons.
– Impulse reaches terminal.
impulse
29.1 How Organ Systems Communicate
• A chemical signal passes between neurons.
– Impulse reaches terminal.
– Neurotransmitters released into synapse.
synapse
impulse
neurotransmitter
vesicles
receptor
29.1 How Organ Systems Communicate
• A chemical signal passes between neurons.
– Impulse reaches terminal.
– Neurotransmitters released into synapse.
– Neurotransmitters stimulate next cell.
synapse
impulse
neurotransmitter
vesicles
receptor
29.1 How Organ Systems Communicate
KEY CONCEPT
The senses detect the internal and external
environments.
29.1 How Organ Systems Communicate
The senses help to maintain homeostasis.
• Senses gather stimuli, and send
it to the nervous system.
• Nervous system responds to
stimuli.
– Pupils shrink when too much
light enters the eyes.
– Goose bumps when cold air
touches skin.
29.1 How Organ Systems Communicate
The senses detect physical and chemical stimuli.
• The eye is for vision.
– Special cells collect light
information (rod and cone
cells)
– Send information to brain in
the optic nerve (a bunch of
neurons)
29.1 How Organ Systems Communicate
• The ear is for to hearing.
– Special hair cells in inner ear.
– Bend with sound, each hair cell is attached to a neuron
that sends the information to the brain
29.1 How Organ Systems Communicate
• Taste and smell use chemoreceptors.
– Special cells in nose and mouth that are sensitive to
chemicals
– Attached to neurons that send the information to the
brain
29.1 How Organ Systems Communicate
• The skin senses touch.
– Special cells to detect three things
– Pressure / touch
– Pain
– Temperature
pain receptor
light pressure receptor
hair follicle
heavy pressure receptor
29.1 How Organ Systems Communicate
• The spinal cord controls reflexes.
– sensory neuron sends information to spinal cord
– spinal cord directs information to motor neuron
– does not involve the brain
interneuron
motor neurons
sensory neuron
29.1 How Organ Systems Communicate
The PNS links the CNS to muscles and other organs.
• The somatic nervous system regulates voluntary
movements.
• The autonomic nervous system controls involuntary,
functions
– sympathetic nervous
system: “fight vs. flight”
– parasympathetic nervous
system: calms the body,
conserves energy
29.1 How Organ Systems Communicate
KEY CONCEPT
The endocrine system produces hormones that affect
growth, development, and homeostasis.
29.1 How Organ Systems Communicate
Hormones influence a cell’s activities by entering the cell
or binding to its membrane.
• Glands are organs of the
endocrine system.
29.1 How Organ Systems Communicate
• Hormones are chemical signals that influence cell’s
activities.
– produced by glands
– travel through the circulatory system
– affects cells with matching receptors
target cell
hormone
bloodstream
receptor
not a target cell
29.1 How Organ Systems Communicate
Endocrine glands secrete hormones that act throughout
the body.
• There are many glands located throughout the body.
HYPOTHALAMUS
PITUITARY
THYROID
THYMUS
ADRENAL GLANDS
PANCREAS
FEMALE GONADS
:OVARIES
MALE GONADS : TESTES
– Hormones travel through the bloodstream to cells with
matching receptors.
29.1 How Organ Systems Communicate
The hypothalamus interacts with the nervous and
endocrine systems.
• The hypothalamus is a gland found in the brain.
– a structure of both the nervous and
endocrine systems
– produces releasing hormones,
sent to pituitary gland
• The pituitary gland is found below
the hypothalamus in the brain.
– controls growth and water
levels in blood
– produces releasing hormones
sent throughout the body
29.1 How Organ Systems Communicate
• Releasing hormones stimulate other glands to produce
hormones.
– allow glands to
communicate with one
another
– are used in temperature
regulation