Unit 4 - Human Populations: Reproduction and Ecology

Major Topic I: Reproduction

Chapter 16 – Reproductive System
16.1 Human Life Cycle
16.2 Male Reproductive System
16.3 Female Reproductive System
16.4 Female Hormone Levels
16.5 Control of Reproduction
16.6 Sexually Transmitted Diseases

Chapter 17 – Development and Aging
17.1 Fertilization
17.2 Pre-Embryonic and Embryonic Development
17.3 Fetal Development
17.4 Pregnancy and Birth
17.5 Development After Birth

Major Topic II: Human Landscapes

Chapter 22 – Human Evolution
22.1 Origin of Life
22.2 Biological Evolution
22.3 Classification of Humans
22.4 Evolution of Hominids
22.5 Evolution of Humans

Chapter 23 – Global Ecology and Human Interferences
23.1 The Nature of Ecosystems
23.2 Energy Flow
23.3 Global Biogeochemical Cycles

Chapter 24 – Human Population, Planetary Resources, and Conservation
24.1 Human Population Growth
24.2 Human Use of Resources and Pollution
24.3 Biodiversity
24.4 Working Toward a Sustainable Society

Embryonic and Fetal Development Online Lab Write-Up
Human Demographics Online Lab Write-Up
Lab Project Write-Up – Interaction with other species
Ethical Issue Essay
Reflection on course work – self evaluation


Major Topic I: Reproduction

Chapter 16 – Reproductive System

16.1 Human Life Cycle
The life cycle of higher organisms requires two types of cell division: mitosis and meiosis.
• Mitosis: growth and repair of tissues.
• Meiosis: gamete production.



16.2 Male Reproductive System
The external genital of males are:
• The penis which is used for sexual intercourse
• The scrotum which contains the testes – Spermatogenesis, occurring in seminiferous tubules of the testes, produces sperm.
• Mature sperm are stored in the epididymides
• Sperm pass from the vasa deferentia to the urethra
• The seminal vesicles, prostate gland, and bulbourethral glands add gluids by secretion to sperm
• Sperm and secretions are called semen or seminal fluid.
Orgasm in males results in ejaculation of semen from the penis.



Hormonal Regulation in Males:
• Hormonal regulation, involving secretions from the hypothalamus, the anterior pituitary, and the testes, maintains a fairly constant level of testosterone.
• FSH from the anterior pituitary promotes spermatogenesis.
• LH from the anterior pituitary promotes testosterone production by interstitial cells.



16.3 Female Reproductive System
Oogenesis occurring within the ovaries typically produces one mature follicle each month.
• This follicle balloons out of the ovary and bursts, releasing an egg that enters an oviduct.
• The oviducts lead to the uterus, where implantation and development occur.
• The female external genital area includes the vaginal opening, the clitoris, the labia minora, and the labia majora.
• The vagina is the organ of sexual intercourse and the birth canal.
• Orgasm in females culminates in uterine and oviduct contractions.



16.4 Female Hormone Levels
Ovarian Cycle: Nonpregnant
• The ovarian cycle is under the hormonal control of the hypothalamus and the anterior pituitary.
• During the cycle’s first half, FSH from the anterior pituitary causes maturation of a follicle that secretes estrogen and some progesterone.
• After ovulation and during the cycle’s second half, LH from the anterior pituitary converts the follicle into the corpus luteum.
• The corpus luteum secretes progesterone and some estrogen.
Uterine Cycle: Nonpregnant
• Estrogen and progesterone regulate the unterine cycle.
• Estrogen causes the endometrium to rebuild.
• Ovulation usually occurs on day 14 of a 28 day cycle.
• Progesterone produced by the corpus luteum causes the endometrium to thicken and become secretory.
• A low level of hormones causes the endometrium to break down as menstruation occurs.





Fertilization and Pregnancy
• If fertilization takes place, the embryo implants itself in the thickened endometrium.
• The corpus luteum is maintained because of HCG production by the placenta, and therefore, progesterone production does not cease.
• Menstruation usually does not occur during pregnancy.

16.5 Control of Reproduction
Numerous birth control methods and devices are available.
• A few of these are the birth control pill, diaphragm, and condom.
• Effectiveness varies.
• Assisted reproductive technologies may help infertile couples to have children. Some of these technologies are:
o Artificial insemination by donor (AID)
o In vitro fertilization (IVF)
o Gamete intrafallopian transfer (GIFT)
o Intracytoplasmic sperm injection (ICSI)



16.6 Sexually Transmitted Diseases
STDs are caused by viruses, bacteria, protists, fungi, and animals.
STDs Caused by Viruses:
• AIDS is caused by HIV (human immunodeficiency virus).
• Genital warts are caused by human papillomaviruses; these viruses cause warts or lesions on genitals and are associated with certain cancers.
• Genital herpes is caused by herpes simplex virus type 2: causes blisters on genitals.
• Hepatitis is cause by hepatitis viruses A, B, C, D, E, and G. A and E are usually acquired from contaminated water; hepatitis B and C from blood borne transmission; and B, D, and G are sexually transmitted.
STDs Caused by Bacteria
• Chlamydia is caused by Chlamydia trachomatis: PID can result.
• Gonorrhea is caused by Neisseria gonorrhoeae; PID can result.
• Syphilis is cause by Treponema pallidum. It has three stages, with the third stage resulting in death.
Two Other Infections
• Bacterial vaginosis is caused by Gardnerella vaginalis.
• Trichomoniasis is an overgrowth of Candida albicans.

Chapter 17 – Development and Aging

17.1 Fertilization
The acrosome of a sperm releases enzymes that digest a pathway for the sperm through the zona pellucida. The sperm nucleus enters the egg and fuses with the egg nucleus.

17.2 Pre-Embryonic and Embryonic Development
• Cleavage, growth, and morphogenesis, and differentiation are the processes of development.
• The extraembryonic membranes (chorion, allantois, yolk sac, and amnion) function in internal development.



17.3 Fetal Development
• At the end of the embryonic period, all organ systems are established, and there is a mature and functioning placenta. The umbilical arteries and umbilical vein take blood to and from the placenta, where exchanges take place.
• Exchanges supply the fetus with oxygen and nutrients and rid the fetus of carbon dioxide and wastes.
• The venous duct joins the umbilical vein to the inferior vena cava.
• The oval duct and arterial duct allow the blood to pass through the heart without going to the lungs. Fetal development extends from the third through the ninth months.
• During the third and fourth months, the skeleton is becoming ossified.
• The sex of the fetus becomes distinguishable. If an SRY gene is present, testes and male genitals develop. Otherwise, ovaries and female genitals develop.
• During the fifth months, the fetus continues to grow and to gain weight.

17.4 Pregnancy and Birth
Major changes take place in the mother’s body during pregnancy.
• Weight gain occurs as the uterus occupies most of the abdominal cavity.
• Many complaints, such as constipation, heartburn, darkening of certain skin areas, and pregnancy-induced diabetes, are due to the presence of placental hormones.
Birth
• A positive feedback mechanism that involves uterine contractions and oxytocin explain the onset and continuation of labor.
• During stage 1 of birth, the cervix dilates.
• During stage 2, the child is born.
• During stage 3, the afterbirth is expelled.



17.5 Development After Birth
Development after birth consists of infancy, childhood, adolescence, and adulthood.
• Aging encompasses progressive changes from about age 20 on that contribute to an increased risk of infirmity, disease, and death.
Hypothesis on Aging
• Aging by have a genetic basis.
• Aging may be due to changes that affect the whole body
• Aging may be due to extrinsic factors like diet and exercise.
Effect of Age on Body Systems
• Deterioration of organ systems can possibly be prevented or reduced in part by utilizing good health habits.

Major Topic II: Human Landscapes

Chapter 22 – Human Evolution

22.1 Origin of Life
A chemical evolution could have produced the protocell.
• Using an outside energy source, small organic molecules were produced by reactions between early Earth’s atmospheric gases.
• Macromolecules evolved and interacted.
• The RNA-first hypothesis – only macromolecule RNA was needed for the first cell(s).
• The protein-first hypothesis – amino acids join to form polypeptides when exposed to dry heat.
• The protocell, a heterotrophic fermenter, lived on preformed organic molecules in the ocean.
The protocell eventually became a true cell once it had genes composed of DNA and could reproduce.



22.2 Biological Evolution
Biological evolution explains both the unity and diversity of life.
• Descent from a common ancestor explains the unity of living things.
• Adaptation to different environments explains the great diversity of living things.
• Fossil evidence supports evolution. The fossil record gives us the history of life in general and allows us to trace the descent of a particular group.
Darwin discovered much evidence for common descent.
• Biological evidence – The distribution of organisms on Earth is explainable by assuming that organisms evolved in one locale.



• Anatomical evidence – The common anatomies and development of a group of organisms are explainable by descent from a common ancestor.
• Biochemical evidence – All organisms have similar biochemical molecules.
Darwin developed a mechanism for adaptation known as natural selection.
The result of natural selection is a population adapted to its local environment.



22.3 Classification of Humans
The classification of humans can be used to trace their ancestry.
• Humans are primates
• A primate evolutionary tree shows that humans share a common ancestor with African apes.



22.4 Evolution of Hominids
• The first hominid most likely lived about 6-7 MYA.
• Certain features identify fossil hominids.
• Ardipithecines were most likely hominids
Evolution of Australopithecines
The evolutionary tree of hominids resembles a bush (not a straight line of fossils leading to modern humans).
• Australopithecines lived about 3 MYA.
• They could walk erect, but they had a small brain.
• This testifies to a mosaic evolution for humans (not all advanced features evolved at the same time).

22.5 Evolution of Humans
Fossils are classified as Homo with regard to their brain size (over 600cm3), jaws and teeth, and evidence of tool use.
• H.habilis made and used tools.
• H.erectus was the first Homo to have a brain size of more than 1000 cm3.
• H.erectus migrated from Africa into Europe and Asia.
• H. erectus used fire and may have been big-game hunters.
Evolution of Modern Humans
Two hypotheses of modern human evolution are being tested.
• The multiregional continuity hypothesis suggests that modern humans evolved separately in Europe, Africa, and Asia.
• The out-of-Africa hypothesis says that H.sapiens evolved in Africa but then migrated to Asia and Europe.
Neanderthals and Cro-Magnons
• The Neanderthals were already living in Europe and Asia before modern humans arrived.
• They had a culture, but did not have the physical traits of modern humans.
• Cro-Magnons are the oldest fossil to be designated H.sapiens. Their tools were sophisticated, and they had a culture.



Chapter 23 – Global Ecology and Human Interferences.

23.1 The Nature of Ecosystems
Ecology is the study of the interactions of organisms with each other and with the physical environment.
• Organisms interact with the physical and chemical environment, and the result is an ecosystem.
• Terrestrial ecosystems are forests, grasslands, and deserts, which includes the tundra.
• Aquatic ecosystems are either salt water or freshwater.
Biotic Components of an Ecosystem
• In a community, each population has a habitat and a niche.
• Autotrophs produce organic nutrients for themselves and others from inorganic nutrients and an outside energy source.
• Heterotrophs consume organic nutrients.
• Consumers are herbivores, carnivores, and omnivores.
• Decomposers feed on detritus, releasing inorganic substances back into the ecosystem.
Energy Flow and Chemical Cycling
• Ecosystems are characterized by energy flow and chemical cycling.
• Energy flows through the populations of an ecosystem.
• Chemical cycle within and among ecosystems.

23.2 Energy Flow
Various interconnecting paths of energy flow are called food web.
• A food web is a diagram showing how carious organisms are connected by eating relationships.
• Grazing food webs begin with vegetation eaten by a herbivore that becomes food for a carnivore.
• Detrital food webs begin with detritus, food for decomposers and for detritivores.
• Members of detrital food webs can be eaten by above ground carnivores, joining the two food webs.
Trophic Levels
• A trophic level is all the organisms that feed at a particular link in a food chain.
• Ecological pyramids illustrate that biomass and energy content decrease from one trophic level to the next because of energy loss.



23.3 Global Biogeochemical Cycles
Chemicals circulate through ecosystems via biogeochemical cycles, pathways involving both biotic and geological components. Biogeochemical cycles:
• Can be gaseous or sedimentary.
• Have reservoirs that contain inorganic nutrients available to living things on a limited basis.
• Exchange pools are sources of inorganic nutrients.
• Nutrients cycle among the biotic communities of an ecosystem.
The Water Cycle
• The reservoir of the water cycle is freshwater that evaporates from the ocean.
• Water that falls on land enters the ground, surface waters, or aquifer and evaporates again.
• All water returns to the ocean.



The Carbon Cycle
• The reservoirs of the carbon cycle are organic matter, limestone, and the ocean.
• The exchange pool is the atmosphere.
• Photosynthesis removes carbon dioxide from the atmosphere.
• Respiration and combustion add carbon dioxide to the atmosphere.



The Nitrogen Cycle
• The reservoir of the nitrogen cycle is the atmosphere.
• Nitrogen gas must be converted to a form usable by plants.
• Nitrogen-fixing bacteria convert nitrogen gas to ammonium, a form producers can use.
• Nitrifying bacteria convert ammonium to nitrate.
• Denitrifying bacteria convert nitrate back to nitrogen gas.
The Phosphorus Cycle
• The reservoir of the phosphorus cycle is ocean sediments.
• Phosphate in ocean sediments becomes available through geological upheaval, which exposes sedimentary rocks to weathering.
• Weathering slowly makes phosphate available to the biotic community.
• Phosphate is a limiting nutrient in ecosystems.

Chapter 24 – Human Population, Planetary Resources, and Conservation

24.1 Human Population Growth
• Populations have a biotic potential for increase in size.
• Biotic potential is normally held in check by environmental resistance.
• Population size usually levels off at carrying capacity.
The MDCs Versus the LDCs
• The MDCs have a 0.1% growth rate since 1950
• The LDC growth rate is presently 1.6% after peaking at 2.5% in the 1960s. Age-structure diagrams can be used to predict population growth.
• MDCs are approaching a stable population size.
• LDC populations will continue to increase in size.

24.2 Human Use of Resources and Pollution
Five resources are maximally used by humans:
• Land
• Water
• Food
• Energy
• Minerals
Resources are either renewable or nonrenewable.
• Nonrenewable resources are not replenished and are limited in quantity.
• Renewable resources are replenished but still are limited in quantity.
Land
• Human activities, such as habitation, farming, and mining, contribute to erosion, pollution, desertification, deforestation, and loss of biodiversity.
Water
Industry and agriculture use most of the freshwater supply. Water supplies are increased by damming rivers and drawing from aquifers. As aquifers are depleted, subsidence, sinkhole formation, and saltwater intrusion can occur. If used by industries, water conservation methods could cut world water consumption by half.
Food
Food comes from growing crops, raising animals, and fishing.
• Modern farming methods increase the food supply, but some methods harm the land, pollute water, and consume fossil fuels excessively.
• Genetically engineered plants increase the food supply and reduce the need for chemicals.
• Raising livestock contributes to water pollution and uses fossil fuel energy.
• The increased number and high efficiency of fishing boats have caused the world fish catch to decline.
Energy
Fossil fuels are nonrenewable sources. Burning fossil fuels and burning to clear land for farming cause pollutants and gases to enter the air.
• Greenhouse gases include CO2 and other gases. Greenhouse gases cause global warming because solar radiation can pass through, but infrared heat cannot escape back into space.
• Renewable resources include hydropower, geothermal, wind and solar power.
Minerals
Minerals are nonrenewable resources that can be mined. These raw materials include sand, gravel, phosphate, and metals. Mining causes destruction of the land by erosion, loss of vegetation, and toxic runoff into bodies of water. Some metals are dangerous to health. Land ruined by mining can take years to recover.
Hazardous wastes – Billions of tons of solid waste are discarded on land and in water.
• Heavy metals
• Synthetic organic chemicals include chlorofluorocarbons, which are involved in the production of plastic, pesticides, herbicides, and other products.
• Ozone shield destruction is associated with CFCs
• Other synthetic organic chemicals enter the aquatic food chain, where the toxins become more concentrated.

24.3 Biodiversity
Biodiversity is the variety of life on Earth. The five major causes of biodiversity loss and extinction are
• Habitat loss
• Introduction of alien species
• Pollution
• Overexploitation of plant and animals, and
• Disease
Direct Value of Biodiversity
Direct values of biodiversity are:
• Medicinal value
• Agricultural value
• Consumptive use values
Indirect Value of Biodiversity
Biodiversity in ecosystems contributes to:
• Waste disposal
• Freshwater provision through the water biogeochemical cycle.
• Prevention of soil erosion, which occurs naturally in intact ecosystems
• Function of biogeochemical cycles
• Climate regulation
• ecotourism

24.4 Working Toward a Sustainable Society
A sustainable society would use only renewable energy sources, would reuse heat and waste materials, and would recycle almost everything. It would also provide the same goods and services presently provided and would preserve biodiversity.

Embryonic and Fetal Development Online Lab Write-Up
















Human Demographics Online Lab Write-Up





1. My high fertility rate country is Sudan, with a fertility rate of 6.30 children.

2. My low fertility rate country is Norway, with a fertility rate of 1.80 children.

3. High fertility rates mean that there are more young people in a country than there are old people. This is because each couple is having an average ( in Sudan) of 6.3 children. When you do the math, that is a lot more children than adults. This also indicates that the population will experience greater growth. In fact, when compared to the world, Sudan's population will approximatly quadruple by the year 2050.

4. If a country has a low fertility rate, it means that as people die, there are less young people to grow the population. In fact, with Norway being used as the example, the population will hardly increase by the year 2050.

5. Some things that come to mind when I think of less young people:
- slow, old, no one to teach, no one to learn, lack of progress, no inspiration, decay, decline, less laughter, safe, more money, but nothing to spend it on.

Some things that come to mind when I think of too many young people:
- fast, inexperience, not enough teachers, progressive but unwise, dreams, fun, more crime, risk, no balance.

Lab Project Write-Up – Interaction with other species

Ethical Issue Essay

Reflection on course work – self evaluation

I am disappointed with the way I am ending the semester. I feel very rushed to complete all of my classes, and I wish I would have organized deadlines for myself better. That is what I have struggled with the most in this class. The other classes had more deadlines established by the teacher, so they seemed to always come first, which leaves me scrambling to complete my work for this class. This has been a good lessons for self-discipline (hopefully I can figure out this skill before next semester!) I do have to say though, that I have learned a lot, and I really enjoyed most of the work.

Unit 3 - Nervous Function & Movement

Table of Contents
Chapter 13 – The Nervous System
13.1 – Overview of the Nervous System
13.2 – The Central Nervous System
13.3 – The Limbic System and Higher Mental Functions
13.4 – The Peripheral Nervous System
13.5 – Drug Abuse

Chapter 14 – Senses
14.1 – Sensory Receptors and Sensations
14.2 – Proprioceptors and Cutaneous Receptors
14.3 – Senses of Taste and Smell
14.4 – Sense of Vision
14.5 – Sense of Hearing
14.6 – Sense of Equilibrium

Chapter 11 – The Skeletal System
11.1 – Overview of the Skeletal System
11.2 – Bone Growth, Remodeling and Repair
11.3 – Bones of the Axial Skeleton
11.4 – Bones of the Appendicular Skeleton
11.5 - Articulations

Chapter 12 – The Muscular System
12.1 – Overview of the Muscular System
12.2 – Skeletal Muscle Fiber Contraction
12.3 – Whole Muscle Contraction
12.4 – Muscular Disorders
12.5 - Homeostasis

Leech Neurons Lab Write-Up
Ethical Issue Essay – Exercise in our Nation
Model of a Limb



Major Topic I – Nervous Function

Chapter 13 – The Nervous System
13.1 – Overview of the Nervous System
The nervous system is divided into the central nervous system (CNS) and the peripheral nervous system (PNS). The Nervous system has three functions: 1) reception of input; 2) integration of data; 3) generation of motor input.

Nervous tissue contains two types of cells: neurons and neuroglia. Neurons transmit nerve impulses. Neuroglia nourish and support neurons.



A neuron is composed of dendrites, a cell body, and an axon. There are three types of neurons:
Sensory neurons take nerve impulses from sensory receptors to the CNS. Interneurons occur within the CNS. Motor neurons take nerve impulses from the CNS to effectors (muscle or glands).



Long axons are covered by a myelin sheath.


The Nerve Impulse
Resting Potential – More Na+ outside the axon and more K+ inside the axon. The axon does not conduct an impulse.
Action Potential – A change in polarity across the axonal membrane as a nerve impulse occurs. When Na+ gates open, Na+ moves to the inside of the axon, and a depolarization occurs. When K+ gates open and K+ moves to outside the axon, a repolarization occurs.

The Synapse
When a neurotransmitter is released into a synaptic cleft, transmission of a nerve impulse occurs. Binding of the neurotransmitter to receptors in the receiving membrane causes excitation or inhibition. Integration is the summing of excitatory and inhibitory signals.



13.2 – The Central Nervous System
The CNS receives and integrates sensory input and formulates motor output. The CNS consists of the spinal cord and brain.

The Spinal Cord
Gray matter of the spinal cord contains neuron cell bodies. White matter consists of myelinated axons that occur in tracts. Conduction to and from brain; carries out reflex actions.

The Brain
The cerebrum has two cerebral hemispheres connected by the corpus callosum. Sensation, reasoning, learning and memory, and language and speech take place in the cerebrum. The cerebral cortex of each cerebral hemisphere has four lobes: frontal, parietal, occipital, and temporal. The primary motor area in the frontal lobe sends out motor commands to lower brain centers, which pass them on to motor neurons. The primary somatosensory area in the parietal lobe receives sensory information from lower brain centers in communication with sensory neurons. Association areas are located in all the lobes.


http://science.nationalgeographic.com/science/photos/brain.html

The Diacephalon – The hypothalamus controls homeostasis. The thalamus sends sensory imput on to the cerebrum.

The Cerebellum – the cerebellum coordinates skeletal muscle contractions.

The Brain Stem – The medulla oblongata and the pons have centers for breathing and the heartbeat.


http://science.nationalgeographic.com/science/photos/brain/brain-spinal-cord.html

13.3 – The Limbic System and Higher Mental Functions
The limbic system lying deep in the brain in involved in determining emotions. The amygdale determines when a situation deserves the emotion we call fear. The hippocampus is particularly involved in storing and retrieving memories.

13.4 – The Peripheral Nervous System
The PNS contains only nerves and ganglia. Cranial nerves take impulses to and from the brain. Spinal nerves take impulses to and from the spinal cord. The PNS is divided into the somatic system and the autonomic system.

Somatic System
The somatic system serves the skin, skeletal muscles, and tendons.
• Some actions are due to reflexes, which are automatic and involuntary.
• Other actions are voluntary; originate in cerebral cortex.
Autonomic System
Two divisions in this system are the sympathetic division and the parasympathetic division.
• Sympathetic Division – Responses that occur during times of stress.
• Parasympathetic Division – Responses that occur during times of relaxation.
Actions in these divisions are involuntary and automatic. These divisions innervate internal organs. Two neurons and one ganglion are utilized for each impulse.

13.5 – Drug Abuse
Neurological drugs either promote or prevent the action of a particular neurotransmitter. Dependency occurs when the body compensates for the presence or neurological drugs.

Chapter 14 – Senses
14.1 – Sensory Receptors and Sensations
There are four types of sensory receptors: chemoreceptors, photoreceptors, mechanoreceptors and thermoreceptors.
• Sensory receptors initiate nerve impulses that are transmitted to the spinal cord and/or brain.
• Sensation occurs when nerve impulses reach the cerebral cortex.
• Perception is and interpretation of sensations.

14.2 – Proprioceptors and Cutaneous Receptors
Proprioceptors are mechanoreceptors involved in reflex actions. They help maintain equilibrium and posture.



Cutaneous receptors are found in the skin. They are for touch, pressure, temperature, and pain.

14.3 – Senses of Taste and Smell
Taste and smell are due to chemoreceptors that are stimulated by molecules in the environment.

Sense of taste – Microvilli of taste cells have receptor proteins for molecules that cause the brain to distinguish sweet, sour, salty, and bitter tastes.



Sense of smell – The cilia of olfactory cells have receptor proteins for molecules that cause the brain to distinguish odors.



14.4 – Sense of Vision
Vision depends on the eye, the optic nerves, and the visual areas of the cerebral cortex.



Anatomy and Physiology of the Eye
The eye has three layers:
• The sclera protects and supports the eyeball.
• The choroid absorbs stray light rays
• The retina contains the rod cells and cone cells.
Function of the Lens – The lens (assisted by the cornea and the humors) brings the light rays to focus on the retina. To see a close object, visual accommodation occurs as the lens rounds up.



Visual Pathway to the Brain – The visual pathway begins when light strikes photoreceptors in the retina. The optic nerves carry nerve impulses from the eyes to the optic chiasma, then pass through the thalamus before reaching the primary vision area in the occipital lobe of the brain.
Abnormalities of the eye are blindness, misshapen eyeballs which causes vision abnormalities like nearsightedness, farsightedness, etc.

14.5 – Sense of Hearing
Hearing depends on the ear, the cochlear nerve, and the auditory areas of the cerebral cortex.

Anatomy and Physiology of the Ear
The ear has three parts:
• In the outer ear, the pinna and the auditory canal direct sound waves to the middle ear.
• In the middle ear, the tympanic membrane and the ossicles amplify sound waves.
• In the inner ear, the semicircular canals detect rotational equilibrium; the utricle and saccule detect gravitational equilibrium; and the cochlea houses the spiral organ, which contains mechanoreceptors for hearing.



The auditory pathway begins when the outer ear receives and the middle ear amplifies sound waves that then strike the oval window membrane.
The mechanoreceptors for hearing are hair cells on the basilar membrane of the spiral organ.
Nerve impulses begin in the cochlear nerve and are carried to the primary auditory area in the temporal lobe of the cerebral cortex.

14.6 – Sense of Equilibrium
The ear also contains mechanoreceptors for equilibrium.
Rotational equilibrium pathway - Mechanoreceptors in the semicircular canals detect rotational and/or angular movement of the head.
Gravitational equilibrium pathway – Mechanoreceptors in the utricle and saccule detect head movement in the vertical or horizontal planes.




Major Topic II – Movement

Chapter 11 – The Skeletal System
11.1 – Overview of the Skeletal System


http://www.bio.psu.edu/people/faculty/strauss/anatomy/skel/skeletal.htm

Functions of the skeletal system:
• Supports the body
• Produces blood cells
• Stores mineral salts, particularly calcium phosphate. It also stores fat.
• Along with the muscles, permits flexible body movement.
The bones of the skeleton are composed of bone tissues and cartilage. Ligaments composed of fibrous connective tissue connect bones at joints.
In a long bone:
• Hyaline cartilage covers the ends of a long bone.
• Periosteum covers the rest of the bone
• Spongy bone containing red bone marrow is in the epephyses
• Yellow bone marrow is in the medullary cavity of the diaphysis.
• Compact bone makes up the wall of the diaphysis.

11.2 – Bone Growth, Remodeling and Repair
Cells involved in growth, remodeling, and repair of bone are:
• Osteoblasts, which are bone-forming cells
• Osteocytes, which are mature bone cells derived form osteoblasts, and
• Osteoclasts, which break down and absorb bone.

Bone Development and Growth
• Intramembranous ossification: bones develop between sheets of fibrous connective tissue. Examples are flat bones such as bones of the skull.
• Endochondral ossification: cartilaginous models of the bones are replaced by calcified bone matrix.
• Bone growth is affected by vitamin D, growth hormone, and sex hormones.
Bone Remodeling and Its Role in Homeostasis
• Bone remodeling is the renewal of bone. Osteoclasts break down bone and osteoblasts re-form bone. Some bone is recycled each year.
• Bone recycling allows the body to regulate blood calcium.
Bone Repair
Repair of a fracture requires four steps:
• Hematoma formation,
• Fibrocartilaginous callus
• Bony callus, and
• remodeling

11.3 – Bones of the Axial Skeleton
The axial skeleton consists of the skull, the hybrid bone, the vertebral column and the rib cage.
• The skull is formed by the cranium, which protects the brain and the facial bones.
• The hyoid bone anchors the tongue and is the site of attachment of muscles involved with swallowing.
• The vertebral column is composed of vertebrae separated by shock-absorbing disks, which make the column flexible. It supports the head and trunk, protects the spinal cord, and is a site for muscle attachment.
• The rib cage is composed of the thoracic vertebrae, ribs, costal cartilages, and sternum. It protects the heart and lungs.

11.4 – Bones of the Appendicular Skeleton
The appendicular skeleton consists of the bones of the pectoral girdles, upper limbs, pelvic girdle, and lower limbs.
• The pectoral girdles and upper limbs are adapted for flexibility.
• The pelvic girdle and the lower limbs are adapted for supporting weight; the femur is the longest and strongest bone in the body.



11.5 – Articulations
Bones are joined at joints, of which there are three types:
• Fibrous joints are immovable
• Cartilaginous joints are slightly movable
• Synovial joints are freely moveable




Chapter 12 – The Muscular System
12.1 – Overview of the Muscular System
Human have three types of muscle tissue:
• Smooth muscle is involuntary and occurs in walls of internal organs
• Cardiac muscle is involuntary and occurs in walls of the heart.
• Skeletal muscle is voluntary, contains bundles of muscle fibers called fascicles, and is usually attached by tendons to the skeleton.
Skeletal muscle functions:
• Helps maintain posture
• Provide movement and heat
• Protect underlying organs
Skeletal muscles of the body – when achieving movement, some muscles are prime movers, some are synergists, and others are antagonists.

Names and actions of skeletal muscles – Muscles are named for their size, shape, location, direction of fibers, number of attachments, and action.

12.2 – Skeletal Muscle Fiber Contraction
Muscle fibers contain myofibrils, and myofibrils contain actin and myosin filaments. Muscle contraction occurs when sarcomeres shorten and actin filaments slide past myosin filaments.



• Nerve impulses travel down motor neurons and stimulate muscle fibers at neuromuscular junctions.
• The sarcolemma of a muscle fiber forms T tubules that almost touch the sarcoplasmic reticulum, which stores calcium ions.
• When calcium ions are released into muscle fibers, actin filaments slide past myosin filaments.
• At a neuromuscular junction, synaptic vesicles release acetylcholine, which diffuses across the synaptic cleft.
• When acetylcholine is received by the sarcolemma, impulses begin and lead to the release of calcium.
• Calcium ions bind to troponin, exposing myosin binding sites.
• Myosin filaments break down ATP and attach to actin filaments, forming cross-bridges.
• When ADP and P are released, cross-bridges change their positions.
• This pulls actin filaments to the center of a sarcomere.



12.3 – Whole Muscle Contraction
Muscles Have Motor Units
• A muscle contains motor units: several fibers under the control of a single motor axon.
• Motor unit contraction is described in terms of a muscle twitch, summation, and tetanus.
• The strength of muscle contraction varies according to recruitment of motor units.
• In the body, a continuous slight tension is maintained by muscle motor units that take turns contracting.
Energy for Muscle Contraction
A muscle fiber has three ways to acquire ATP for muscle contraction.
• Creatine phosphate transfers a phosphate to ADP, and ATP results. This CP pathway is the most rapid.
• Fermentation also produces ATP quickly. Fermentation is associated with an oxygen debt because oxygen is needed to metabolize the lactate that accumulates.
• Cellular respiration provides most of the muscle’s ATP, but takes longer because much of the glucose and oxygen must be transported in blood to mitochondria. Cellular respiration occurs during aerobic exercise and burns fatty acids in addition to glucose.



Fast-Twitch and Slow-Twitch Muscle Fibers
• Fast-twitch fibers, for sports like weight lifting, rely on an anaerobic means of axquiring ATP; have few mitochondria and myoglobin, but motor units contain more muscle fibers; and are known for explosive power, but fatigue quickly.
• Slow-twitch fibers, for sports like running and swimming, rely on aerobic respiration to acquire ATP; and have a plentiful supply of mitochondria and myoglobin, which give them a dark color.

12.4 – Muscular Disorders
Muscular disorders include spasms and injuries, as well as diseases such as muscular dystrophy and myasthenia gravis.

12.5 – Homeostasis
• The muscles and bones produce movement and protect body parts.
• The bones produce red blood cells and are involved in the regulation of blood calcium levels.
• The muscles produce the heat that gives us a constant body temperature.


Leech Neurons Lab Write-Up





1. What is the electrode measuring?
The electrode is measuring the action potential of a neuron cell as it is being stimulated by a feather, a probe and forceps.

2. Why use leeches in neurophysiology experiments?
Leeches have very large neuron ganglia that are easy to work with.

3. What is the difference between a sensory and a motor neuron?
A sensory neuron brings information from the skin or extremity to the brain. It allows the brain to interpret feeling and pain. A motor neuron brings information from the brain to an extremity telling it to function.

4. Do you think a leech experiences pain? What is pain?
Leeches must feel pain. In the beginning of the lab, we anesthetized the leech. There would be no reason to do this if it did not feel pain. Pain is the brain’s interpretation of information being brought to it by sensory neurons. It protects us by allowing us to know when something is wrong.

5. What were the two most interesting things about doing this lab?
I like the dissection. I wish I could have done the lab in real life. I also like injecting dye into the cell to see what it looked like under UV light.

6. Anything you found confusing or didn't like about the lab?
I didn’t like the fact that I couldn’t actually control the tools. I was only able to click and let the computer do the work.


Ethical Issue Essay – Exercise in our Nation
Exercise is a real problem in this country. Our bodies were designed to work hard, but due to the way our race has evolved, there are less and less opportunities to use our bodies for physical labor. After researching websites for other countries, it seems that the problem is world-wide. Transportation, elevators, computers, even air conditioning has contributed to our decline of health. The question is though, should we rid ourselves of these achievements to gain in health? I believe the answer is no. The answer should be more education.
I liked Hong Kong’s website (silly as it was) on nutrition and exercise. They even had a page that provided education on breast-feeding. Our society has become so liberal about alternative choices, that we neglect what nature has provided us.
Instead of reverting back to a low-tech society, we should be teaching our children a smarter way to live. Exercise as a family and set limits on television time. Don’t allow your children to sit in a stupor in front of video games for hours on end. Try not to purchase many food products that are filled with chemicals and words that are not easily pronounced. These foods are normally junk foods and frozen meals.
In elementary school, Health class should be more comprehensive and it should follow into high school. If good habits can be built in our children, those habits are more likely to follow as adults.

Model of a Limb