Title: Recommended Websites:
1Life Science Mr. Galloway
Chapters 20-21 Human Biology Health Nervous,
Endocrine, Reproductive Systems
Recommended Websites www.soulcare.org www.icr.org
www.AnswersInGenesis.org
2Three Functions of Nervous System
- Receive Information
- Sensing stimuli
- Respond to Information
- Reacting to a stimuli
- Maintaining Homeostasis
- Directing the body to keep in balance
3Major Structures of the Nervous System
4A Neuron
5Key Terms Nervous System
- Nerve (Neuron) a bundle of nerve fibers, that
carries information (impulse) through the nervous
system. - Axon carries impulses away from the cell body.
- Dendrite carries impulses toward the cell body
- Synapse tiny space between each axon tip and
the next structure. - Neurochemicals carry the impulse across the
synapse.
6(No Transcript)
7More Terms Nervous System
- Stimulus any change or signal in the
environment that can make an organism react. - Response what you body does in reaction to a
stimulus. - Three Types of Neurons
- Sensory picks up stimuli inside or outside body
- Interneurons carries impulses nerve to nerve
- Motorneurons sends impulses to a muscle
8Types of Neurons
9(No Transcript)
10(No Transcript)
11Central Nervous SystemControl Center of the Body
- Brain Controls most of the bodys functions
- Concussion bruiselike injury of the brain.
- Using a helmet on skateboards and bikes is
important. - Spinal Cord thick column of nerve tissue
linking the brain to the peripheral nerve system.
12(No Transcript)
13The Human Brain
14The Brain
- 100 billion neurons (all interneurons)
- Each receives from up to 10,000 other neurons
- Each sends to about 1,000 more neurons
- Cerebrum interprets input from senses and
controls skeletal muscles, thinking, etc. - Cerebellum coordinates muscles and balance
- Brainstem controls involuntary actions
- Automatic actions like breathing, heart beat, etc.
15Spinal Cord
16(No Transcript)
17Peripheral Nervous System
- A network of nerves branching out from the
central nervous system and connecting it to the
rest of the body. - It is subdivided into two branches
- Somatic controls the voluntary actions using
your skeletal muscles (like tying your shoes). - Autonomic controls the involuntary actions
using your smooth muscles (stomach, blood
vessels).
18A Voluntary Somatic Response
19Reflex Automatic response that occurs very
rapidly and without conscious control.
20Your Six Senses
- Vision cells convert light stimulus to a nerve
signal - Hearing cells converts sound waves to nerve
signal - Smell cells in nose convert chemical stimuli
- Taste cells on tongue convert chemical stimuli
- Touch cells on skin convert mechanical pressure
to nerve signals (impulses). - Balance Inner ears semicircular canals
indirectly convert the effect of gravity to nerve
signals for balance
21Structures of the Human Eye
22Vision
- Eyes convert light into nerve impulses
- Eye Structure
- Cornea clear tissue covering the front of the
eye - Pupil the opening through which the light
enters - Iris colored area around the pupil which opens
or closes - Lens flexible structure that focuses the light
(bends rays) - Retina layer of receptor cells at back of the
eye (130 million) (Rod cells see black/white)
(Cones see color)
23Vision Problems
- Nearsightedness
- Able to see near objects clearly, not distant
objects - Eyeball is too long, so focal point is before
retina. - Corrected by a concave lens
- Farsightedness
- Able to see far off objects clearly, not near
objects. - Eyeball is too short, so focal point is beyond
retina. - Corrected by a convex lens
24(No Transcript)
25Hearing
- Ears convert sound waves into nerve impulses
- Sound waves are vibrating waves in any substance
- Hearing Structures and Processes
- Eardrum receives waves and vibrates the ear
bones - Cochlea receives vibrations from the stirrup
bone - It is filled with fluid lined with receptors
that respond to sound. - Sensory neurons send the receptor signals to the
interneurons of the brain. - Biotechnologists have now invented an artificial
cochlea that can be surgically implanted for
those with certain hearing problems.
26Your Brain on Alcohol Drugs Eph 515-18 Be
filled (controlled) by Gods Spirit
- Medicines used properly are helpful, but even
they can have serious side-effects. - Drowsiness, confusion, tremors, memory loss, etc
- Can become addictive, making you a slave of the
chemical - Alcohol and many drugs are chemicals that
interfere with your ability to control your
brain. - Disrupts coordination, making many activities
dangerous - Can damage heart and brain cells.
- Can become addictive, making you a slave of the
chemical
27Endocrine System
28The Endocrine System
- Chemically controls many body functions as well
as long-term changes like development. - Endocrine Glands make the chemicals (hormones)
- Hormones change the functions of other organs
(Turn them on off, speed them up or slow down) - Endocrine chemicals work differently from nerves
which cause quick responses, the effect of
endocrine hormones take longer. - The Brains Hypothalamus area controls the
release of hormones from various endocrine glands.
29How Hormones Work
- Hypothalamus is a tiny middle part of the brain,
which links the nervous endocrine systems. - It produces nerve impulses controlling sleep,
hunger, etc. - It produces hormones controlling other endocrine
glands - Both play a major role in maintaining
homeostasis. - Target Cells are specific cells in certain organs
that respond ONLY to particular hormones. - Hormones are chemicals, so they fit like a keys
into locks, and each lock is a specific target
cell.
30Pituitary Gland
- It lays just below the hypothalamus
- Communicates with the hypothalamus to control
many body activities. - It responds to both nerve signals and hormones
from the hypothalamus. - It then releases its hormones, which then act on
other endocrine glands.
31 Homeostasis Uses negative feedback in a way
very similar to a house thermostat.
32Negative Feedback
- Like a thermostat controlling the room temp.
- Negative feedback means the system is turned OFF
by the condition it produces. - When the air conditioner in the room makes the
temperature go above the set level, it turns off. - When the amount of a released hormone reaches a
certain level, a feedback signal causes the body
to turn off the release of that hormone.
33The Reproductive System
- Sex Cells Contain HALF the chromosomes of a
normal cell (46 normal, sex cell has 23). - Eggs female sex cell
- Sperm male sex cell
- Zygote (Fertilized Egg by Sperm) is a new baby
formed when the sperm and egg unite into a single
cell.
34Sperm Cell
35One Egg cell many sperm, but it only takes one
sperm
A Baby Trillions of Cells
36Male Reproductive System
37Male Reproductive System (Mostly external
structures)
- Testes Two oval structures made up of hundreds
of tiny coiled tubes. - Produce sperm cells
- Produce male hormones (testosterone)
- Testosterone controls development of male
characteristics like facial hair, deeper voice,
ability to produce sperm.
38Female Reproductive System(Mostly internal
structures)
- Ovaries two oval shaped organs
- Produces eggs
- Produces female hormones (estrogen)
39Egg Releasing
40Female Menstrual Cycle
- Menstrual Cycle monthly cycle of changes
- Stages ovulation, fertilization or menstruation
- Endocrine Control cycle is regulated by
hormones.
41Human Life Beginning to Birth
- Zygote fertilized egg/sperm union
- Cells divide and multiply until is hollow ball
- Embryo name for growing baby (1-8 weeks)
- Amniotic Sac filled with fluid is where embryo
lives - Placenta a mass of blood vessels from Mom
baby - Their blood never mixes, but O2, nutrients,
waste exchange. - Umbilical Cord forms between embryo placenta
- Fetus name for baby (9 weeks to birth)
- Birth occurs about nine months after fertilization
42(No Transcript)
43Psalm 13913-14 13 For You formed my inward
parts You covered me in my mother's womb. 14 I
will praise You, for I am fearfully and
wonderfully made Marvelous are Your works, And
that my soul knows very well. Psalm 13923-24 23
Search me, O God, and know my heart Try me, and
know my anxieties 24 And see if there is any
wicked way in me, And lead me in the way
everlasting.