Transcript Intro to the Human Body and Regulation

THE HUMAN BODY
Life Processes

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Regulation
Nutrition
Transport
Respiration
Locomotion
Excretion
Organ Systems
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Because humans are complex multicellular
organisms, organ systems are needed to carry out
the major life processes.
Levels of organization:
cellstissuesorganssystems
Regulation

The nervous and endocrine systems control and
coordinate life activities to maintain homeostasis.
 This
is known as regulation.
Nervous System
Nervous System

Neurons – specialized cells that transmit
electrochemical messages called impulses.
 This
is how the body communicates rapidly producing
responses of short duration.
A Neuron
Section 35-2
Neuron
Nucleus
Axon terminals
Cell body
Myelin sheath
Nodes
Axon
Dendrites
Neuron
•
Active transport maintains nerve cells in a charged state
ready to transmit a message.
•
Nerve cells use lots of glucose and have lots of mitochondria.
Active Transport
Synapse

Neurons communicate with each other by secreting
chemicals across a tiny gap called the synapse.
Figure 35-8 The Synapse
Synapse
Section 35-2
Direction of Impulse
Dendrite of
adjacent neuron
Axon
Vesicle
Receptor
Axon
terminal
Synaptic cleft
Neurotransmitter
Commonly Abused Drugs
Section 35-5
Drugs Affect the Synapse
Drug Type
Medical Use
Examples
Effects on the body
Stimulants
Used to increase alertness,
relieve fatigue
Amphetamines
Increase heart and respiratory rates;
elevate blood pressure; dilate pupils;
decrease appetite
Depressants
Used to relieve anxiety,
irritability, tension
Barbiturates
Tranquilizers
Slow down the actions of the central
nervous system; small amounts cause
calmness and relaxation; larger
amounts cause slurred speech and
impaired judgement
Opiates
Used to relieve pain
Morphine
Codeine
Act as a depressant; cause
drowsiness, restlessness, nausea
Nervous System

Central Nervous System
 Brain

& spinal cord
Peripheral Nervous System
 Nerve
branches off the brain and spinal cord
 Sense organs
Figure 35-9 The Brain
Brain
Section 35-3
Cerebrum
Thalamus
Pineal
gland
Hypothalamus
Cerebellum
Pituitary gland
Pons
Medulla oblongata
Spinal cord
Cross Section of the Spinal Cord
Spinal Cord
Section 35-3
Gray matter
Spinal nerve
Central canal
White matter
Meninges
Sense Organs
The Senses of Smell and Taste
Section 35-4
Olfactory
(smell) bulb
Taste
sensory
area
Olfactory
nerve
Thalamus
Cerebral cortex
Smell
receptor
Nasal cavity
Smell
sensory area
Taste bud
Taste
pore
Taste
receptor
Sensory
nerve fibers
Figure 35-14 The Eye
Eye
Section 35-4
Vitreous humor
Muscle
Lens
Fovea
Aqueous humor
Cornea
Pupil
Optic nerve
Iris
Blood vessels
Ligaments
Retina
Choroid
Sclera
Ear
Figure 35-15 The Ear
Section 35-4
Anvil Stirrup
Hammer
Oval
window
Semicircular canals
Cochlear nerve
Cochlea
Bone
Auditory canal
Tympanum
Round window
Eustachian tube