1. What were the three aspects of the assignments I've submitted that I am most proud of?

Probably the reproduction section, the fetal section and just finishing the class. :-)

2. What two aspects of my submitted assignments do I believe could have used some improvement?

Again the essay my weakness and the final lab.

3. What do I believe my overall grade should be for this unit?

I believe I should recieve a B. While I know I could have put more effort in I did try very hard to do well.

4. How could I perform better in the next unit?

There is no next unit. :-)





At what moment during this unit did you feel most engaged with the course?

I enjoyed the fetal development. Probably because I am a mom and have experienced it.


At what moment unit did you feel most distanced from the course?

Towards the end. Knowing this was the last project I was anxious to get done and rushed some of the work.


What action that anyone (teacher or student) took during this unit that find most affirming and helpful?

Looking over the other blogs to give me ideas when I felt stuck.


What action that anyone (teacher or student) took during this unit did you find most puzzling or confusing?

None


What about this unit surprised you the most? (This could be something about your own reactions to the course, something that someone did, or anything else that occurs to you.)

I really enjoyed certain topics in this class more than I thought I would.

essay

I feel like countries like Ethiopia need to do something about their fertility rate. I am not trying to be mean but, it is not fair to bring children into a life of poverty and starvation. While we do see some families like that in the United States for the most part most people take into consideration the expense of having a child.

While I don't believe in forced abortions and killing children of a certain sex. I feel like some form of birth control or sterilization should be mandatory in the poorer countries.

lab

List of species we come in contact with:

1. Canis lupus familiaris - domestic dog





2. Felis silvestris catus - domestic feline/cat





3. Budrerigar - domestic bird/parakeet





4. Cricetinae - hamster can be domestic





5. Streptococcus - harmful bacteria found in the mouth, cavity causing





6. Squamata - snake can be domestic


7. Feces - fecal matter/poop

8. Dermatophagoides pteronyssinus - dust mite




9. Formicidae - ant





10. Rodents - rats, mice etc.. can be domestic





11. Canis latrans - coyote


12. Geococcyx californianus - road runner




13. Bos primigenius taurus - cow, domesticated





14. Swine - pig

lab

1. What was your high fertility rate country and what was its fertility rate?

Burundi 6.80

2. What was your low fertility rate country and what was its fertility rate?

Albania 2.80

3. The initial demographic "shape" of your high fertility rate country should have been a pyramid, with high population in young age groups. Explain why high fertility rate results in a high percentage of young people in the population. How does this affect future population growth?

High fertility rates result in a high percentage of young people because people are having kids younger and faster so the younger population is multiplying faster.

4. Your low fertility rate country might have had a more oval-shaped curve with high population in middle age groups. This is especially exaggerated if the fertility rate is below 2.00. Explain why low fertility rate leads to lots of middle-aged people.

The older you get the lower your fertility is. Since their fertility rate is low they have more middle aged people than younger because the population is not multiplying as fast.

5. Write ten adjectives or descriptive phrases for what you might expect life, people's attitudes, conditions on the streets, etc. will be like in each of those situations. Imagine a situation with lots of middle-aged and older people in the population and write ten quick "brain-storm" descriptors for you think it would be like (Prescott, Arizona?). Then do the same for a situation with lots of children in the population.


high fertility

chaos
teen parents
poverty
child abuse
troubled youth

low fertility

cranky
wealthier
cleaner
snobby
successful

Lab

Ten events that occur during fetal development:

1. Fertilization - begins when the sperm penetrates the egg. This usually takes place 14 days after day one of a woman's menstrual cycle. This is a major event because without this there would be no baby to develope.



2. Around day 18 the heart begins to beat. This is a major time because if this doesn't happen the mother will miscarry.

3. Legs and arm buds begin to develope around 6 weeks. Any problems occuring during this time can cause the baby to be physically handicapped/disfigured at birth.


4. Week 12 vocal cords are complete and infant can silent cry in the womb.

5. Week 15 taste buds are formed and infant may be able to taste some of the mothers meals. I just found this interesting. I couldn't imagine living without these and never tasting food.

6. The sucking reflex develops around 4 1/2 months. Without this reflex the infant would not be able to nurse.


7. Hearing develops around week 17. Without proper development of this the infant could be born deaf.

8. 20 weeks sex organs are fully evident. Very exciting time for new parents to learn sex of baby.


9. Week 26 infants retinas are finishing developing and infant will start to open eyes and blink. Without proper development infant could have a visual impairment.


10.Fetus is fully formed during the last few weeks of pregnancy. This time is for the babies lungs to finish maturing and weight to be put on to help it survive in the world.

Work Cited

www.healthscout.com/ency/1/002334.html

www.allwords.com/word-epididymides.html

www.thefreedictionary.com/vasa+deferentia

www.medterms.com/script/main/art.asp?articlekey=5448

www.kidshealth.org/parent/general/body_basics/male_reproductive.html

Human Biology; Sylvia Mader 10e

www.wprc.org/parenting/fetal-development/first-trimester/

www.pregnancy.org/pregnancy/fetaldevelopment2.php

www.tqnyc.com/NYC040719/life_cycle.htm

en.wikipedia.org/wiki/Natural_selection

Human Ecology

"Human ecology is an academic discipline that deals with the relationship between humans and their natural, social and created environments. Human ecology investigates how humans and human societies interact with nature and with their environment."

Domestication is the "process of taming a population of animals (although it can also be used to refer to plants) or even a species as a whole. Humans have brought these populations under their care for a wide range of reasons: to produce food or valuable commodities (such as wool, cotton, or silk), for help with various types of work, transportation and to enjoy as pets or ornamental plants. Plants domesticated primarily for aesthetic enjoyment in and around the home are usually called house plants or ornamentals, while those domesticated for large-scale food production are generally called crops. Likewise, animals domesticated for home companionship are usually called pets while those domesticated for food or work are called livestock or farm animals."

Natural Selection

"Natural selection is one of the cornerstones of modern biology. The term was introduced by Charles Darwin in his groundbreaking 1859 book The Origin of Species[1] in which natural selection was described by analogy to artificial selection, a process by which animals with traits considered desirable by human breeders are systematically favored for reproduction. The concept of natural selection was originally developed in the absence of a valid theory of inheritance; at the time of Darwin's writing, nothing was known of modern genetics."

The critical elements of the natural selection process are variatin - physical variations can be passed from generation to generation. Competition for limited sources and adaptation.

Meiosis



Meiosis is a type of nuclear division that occurs as part of sexual reproduction in which the daughter cells receive the haploid number of chromosomes in varied combinations.

There are two division phases of meiosis:

First division stage -

Prophase 1: Duplicated chromatin condenses. Each chromosome consists of two, closely associated sister chromatids. Crossing-over can occur during the latter part of this stage.
Metaphase 1: Homologous chromosomes align at the equatorial plate.
Anaphase 1: Homologous pairs separate with sister chromatids remaining together.
Telophase 1: Two daughter cells are formed with each daughter containing only one chromosome of the homologous pair.

Second division stage -

Prophase 2: DNA does not replicate.
Metaphase 2: Chromosomes align at the equatorial plate.
Anaphase 2: Centromeres divide and sister chromatids migrate separately to each pole.
Telophase 2: Cell division is complete. Four haploid daughter cells are obtained.

Human Life Cycle

There are four stages of the human life cycle.

Stage 1 Infancy - Birth to two years. During this time you learn coordination- walking and talking. Teeth grow rapidly. The head is out of proportion to the body during this time.

Stage 2 Childhood - Two years to adolescence (puberty). Bones and teeth grow rapidly and baby teeth are replaced with permanent teeth. Intellectual skills are developed.

Stage 3 Adolescence - Puberty happens. Some changes you may notice are acne, pubic hair, boys voices will deepen and girls will start their menstrual cycle. This is sometimes an emotionally distressing time for teens.

Stage 4 Adulthood - Body starts to slow down. Hair may start to fall out, physical activity decreases. You will start to notice physical differences in your skin as it loses it elasticity.

Unit Four Human Populations: Reproduction and Ecology

In this unit we learned about the reproductive system and ecology. Some of the topics I will be discussing are:
*the reproductive system
*fetal development and birth
*the human life cycle
*meiosis
*human history long term
*human ecology - physical and biological landscape
*natural selection

The Reproductive System









The male reproductive system consists of the:

Testes - The testes are two egg shaped organs located in the scrotum. They produce sperm and testosterone.

Epididymides _ A long narrow coiled tube located in the testes that stores and transports sperm to the vas deferens.

Vasa Deferentia - The main duct that semen is carried in from the epididymis to the ejaculatory duct.

Seminal Vesicles - About 2 inches long located behind the bladder and about the prostate, contributes fluid to semen.

Prostate Gland - Produces part of the semen, surrounds the ejaculatory ducts at the base of the urethra.

Urethra _ Carries semen and urind outside of the penis.
Bulbourethral Glands - Also known as cowpers gland, pea shaped located beneath the prostate gland. Adds fluid to semen during ejaculation.

Penis - Male sexual and reproductive organ consisting of the glans (head) and shaft (body). Contains many nerve endings that make it sensitive to touch, pressure and temperature.









The female reproductive system consists of:

Fallopian Tubes or Oviducts - Extend from the uterus to the ovaries, although they are not attached to the ovaries. Cilia in the oviduct draws the egg in. The trip down the fallopian tube takes about a week.

Ovary - Also called eggs is the female gonad that produces eggs and female sex hormones.

Uterus - Or womb is an very small organ located in the female pelvis. This is where the fetus develops.

Endometrium - Mucous membrane lining the inside of the uterus. Has a rich cappilary supply to bring food to an embryo that might implant there.

Cervix - Narrow end of the vagina that projects into the vagina. Secretes mucous that varies during different types of the menstrual cycle.

Bladder - Hollow, muscular organ that sits on the pelvic floor. Collects urine excreted by the kidneys.

Urethra - Tube that connects the bladder to the outside of the body. The urethral sphincter is a smooth muscle that allows voluntary control over urination.

Clitoris - Located at the anterior end of the labia, under the pubic bone. Contains erectile tissue and many nerve endings.

Labia majoria - The larger outside pair of labia (lips).

Labia minora - The smaller inner pair of labia (lips).

Vagina - Organ that leads from the uterus to the vestibule and serves as the birth canal and organ of sexual intercourse.

Fetal Development and Birth

8 week old embryo

First Trimester -

Conception occurs at the moment the sperm penetrates the egg. The fertilized egg is called the zygote until it reaches the uterus in approximately 3- 4 days. The embryo attaches to the uterus wall and the placenta starts to form. The most crucial time during the pregnancy. The embryo goes through many rapid changes during the first trimester. Everything from limbs to vital organs are formed during this time.

Second Trimester -



The brain is fully developed now. The fetus can suck, swallow, and make irregulat breathing sounds. Fetal skin is transparent, muscle tissue is lengthening and bones are becoming harder. Liver and organs are producing appropriate fluids. Fetus making active movements. The baby is covered in lanugo (fine hair).

Third Trimester -

Fetus covered in vernix a waxy substance secreted by the sebaceous glands to protect the fetus's skin from dehydration in the womb.

Rapid brain development occurs during this month. The nervous system is able to control some bodily functions. Rapid increase in the fetus's body fat. Footprints and fingerprints form during this time. Fetus sleeps 90-95% of the time. The closer you get to 40th week of pregnancy the higher the fetus's survival rate is.

Birth



Signs of labor may include: a bloody show (mucous plug), contractions, leaking amniotic fluid due to water breaking.

Contractions push the fetus downward and the cervix dilates and stretches.

There are 3 stages of labor.

During the first stage of labor the contraction cause the cervical canal to slowly disappear as the lower part of the uterus is pulled up toward the baby's head. This is called effacement. As the babies head pushes against the cervix it causes it to dilated. The first stage is complete once the cervix is dilated to 10 cm.

During the second stage contractions are closer together, usually occuring 1-2 minutes apart. The mother will feel the urge to push as the baby's head works its way into the vagina. The the baby's head reaches the exterior it turns to that that back of the head is facing up. An episiotomy may be performed at this time to enlarge the opening. Once the baby is fully delivered and breathing normally the umbilical cord is cut.

Stage three of the labor is when the placenta or afterbirth is delivered.

America land of the free, the brave and the obese

In todays society of fast food and video games people are becoming over weight younger and younger. When I was little we were always outside climbing trees, playing tag or riding bikes. Sure we had the Atari and the Nintendo but, it wasn't an all day thing. Mom would come home and tell us to go outside and play until dinner time.

We as americans are so busy now that it is much easier to run through McDonalds or Taco Bell to get dinner, lunch and yes even breakfast at times. I myself am guilty of that. Fortunately for me obesisity isn't an issue in my family.

We as parents have an ethical duty to make sure that the lifestyle that we are raising our kids in is not doing them harm. Nothing bugs me more than to see kindergartners that are already struggling with their weight and their parents giving them more fattening snacks. Give them some fruits and vegetables for snack. Take away the potato chips and the cookies. Tell them to turn off their tv or video games and go outside to get some fresh air and excercise. Easier said than done I know....but, over time the kids will get the routine down and will remember just how fun it is to be outside and that maybe those fruits and veggies aren't so bad.

lab

In this lab we were supposed to show the bone, joint, muscles, and the neuron. I decided to do the femur, fibula, tibia and the patella.

The supplies I used were construction paper, pipe cleaners, and playdough.


In this picture you see the femur bone with the patella connecting it to the fibula and the tibia.


This picture shows the muscles that are attached the bones. The Quadriceps femoris straightens leg at the knee; raises thigh. The Tibialis anterior turns the foot upward, as when walking on heels. The Extensor digitorum longus raises toes and raises the foot.


The hinge joint is a freely moving joint in which the bones are so articulated as to allow extensive movement in one plane.

These pictures show the neuron with the myelin sheath.

This image is of the sarcomeres contracted it shows how when the mycrofibris of a muscle fiber contracts is shortens them.

The Sarcomeres are in a relaxed state here and not contracted.

lab

During this lab we were supposed to see how many times we could squeeze a ball in twenty seconds with our hand a normal temperature and freezing after soaking our hand in ice water. We were also supposed to see what happened as fatigue set in.










Trial # of Squeezes in 20 seconds 9 More X's
1 66 63
2 50 46
3 63 58
4 61 56
5 54 49
6 53 49
7 51 45
8 49 44
9 49 42
10 45 38
ANALYSIS OF DATA:
1. What are the three changes you observed in a muscle while it is working (contracted)? You could see the muscles moving with each squeeze, after a while the muscles started to burn and it was hard to squeeze the ball.
2. What effect did the cold temperature have on the action of your hand muscles? Explain. When the body gets cold everything starts to slow down. Therefore making it harder and painful at times to continue squeezing the ball.
3. In Figure 3, make a line graph of your results of the fatigue experiment. Be sure to fill in the values on the vertical axis.
Figure 3: Graph of Effect of Fatigue on Muscle Action



4. What effect did fatigue have on the action of your hand muscles? Explain.
Fatigue made it hard for me to continue to squeeze the ball. It also made the numbers of times I could decline.

In this section we learned about:

*calcium and muscle
*calcium and bone
*movement across the joints




The skeletal system is made up of 206 bones, cartilage and fibrous connective tissue. The skeletal system has many different purposes. Some of these are to support the body, protect our organs, allow flexiblity and movement with the help of muscle, it produces red blood cells, and stores fats and minerals.




Cartilage is a connective tissue that is not as strong as bone. It contains collagenous and elastic fibers. Cartilage has no nerves or blood vessels. Therefore making it difficult to heal if injured. There are three different types of cartilage:

Hyaline cartilage - firm and somewhat flexible, it's found at the end of long bones, in the nose, at the end of ribs and in the larynx and trachea

Fibrocartilage - stronger than hyaline cartilage, able to withstand tension and pressure, found in the knee and the vertebrae discs

Elastic cartilage - more flexible than hyaline, found in the ears and epiglottis



Connective Tissues is one of the four types of tissues in the body. Connective tissue is involved in support and structure. There are four types of connective tissue.

Areolar (loose) connective tissue - holds organs and the the top layer of skin together

Adipose tissue - is used for cushioning and energy

Fibrous tissue - forms ligaments and tendons

Reticular tissue - form a soft skeleton to support the lymphoid organs



Muscle



The human body has over 600 muscles in their body. There are three different types of muscle tissue:



Smooth muscle - spindle shaped cells with single nucleus, usually aranged in parallel lines, forming sheets, contraction of smooth muscle is involuntary, does not fatigue easily. They are found in the wall of the bladder, digestive tract, uterus, blood vessels and other internal organs.



Skeletal muscle - tubular fibers that are mulitnucleated, and striated. They run the length of the bone. Movement is voluntary such as the legs and arms.



Cardiac muscle - forms the heart wall and has feature of both the smooth muscle and the skeletal muscle. Fibers are generally uninucleated, striated, tubular, and branched allowing it to interlock at intercalated disks. Muscule contraction is involuntary and rhythmical.


Calcium and Muscle

When muscle fibers are stimulated by axons in the motor neurons to contract the vesicles are filled with the neurotransmitter acetylcholine (ACH). When the nerve impulse arrives at the axon terminal, ach is released. When ach is released it quickly binds to receptors in the sarcolemma. Which then generated impulses that spread over the sacrolemma and down T tubules to the sarcoplasmic reticulum. The release of calcium causes the sarcomere to contract. When calcium ions are released from the sarcoplasmic reticulum, it combines with tropomin causing the tropomyosin threads to shift their position, exposing the binding sites and allowing the myosin to bind to actin.

Calcium and Bone

Calcium plays and important role in the development and maintenance of our bone tissue. Bone tissue is constanlty regenerating itself. Without enough calcium in our body our bones start to show weaknesses. A major condition caused by this is osteoporosis. During osteoporosis men may lose up to 25% of their bone mass and women may lose up to 35% of theirs. Thus leaving them vulnerable to broken bones. While osteoporosis can't be prevented by making sure you are taking in an adequate amount of calcium you can help delay the process.

Joint Movement

Thanks to out joints we are able to bend, twist, turn, wave, rotate, etc the different areas of our body.

The most commonly known joint are the hinge joint and the ball and socket joint.



The hinge joint allows movement to take place in a certain spot. Such as our elbows, knees, wrists, etc. It permits only one type of movement and that is an forward and backward motion.

The ball and socket joint allows us to move our limbs in a circular motion. Such as in our shoulders and hips.


Works Sited:

http://www.polychondritis.com/connectivetissue/Cartilage/WhatisCartilage.html

http://en.wikipedia.org/wiki/Connective_tissue

http://www.google.com/search?sourceid=navclient&ie=UTF-8&rls=DMUS,DMUS:2006-49,DMUS:en&q=pictures+muscles

http://www.uoguelph.ca/zoology/devobio/210labs/muscle1.html

Mader Human Biology 10e

Sensory Receptors

Sensory receptors are dendrites that detect stimulation. The exteroceptors detect stimuli from outside the body while the introceptores detect stimulation on the inside of the body. These interoceptors are directly involved with homeostasis.

"The sensory receptors involved in taste and smell contain receptors that bind to specific chemicals. Odor receptors in olfactory receptor neurons, for example, are activated by interacting with molecular structures on the odor molecule. Similarly, taste receptors (gustatory receptors) in taste buds interact with chemicals in food to produce an action potential.

Other receptors such as mechanoreceptors and photoreceptors respond to physical stimuli. For example, photoreceptor cells contain specialized proteins such as rhodopsin to transduce the physical energy in light into electrical signals. Some types of mechanoreceptors fire action potentials when their membranes are physically stretched.

The sensory receptor functions as the first component in a sensory system.

Sensory receptors respond to specific stimulus modalities. The stimulus modality to which a sensory receptor responds is determined by the sensory receptor's adequate stimulus.

The sensory receptor responds to its stimulus modality by initiating sensory transduction. This may be accomplished by a net shift in the initial states of a receptor(see a picture of these putative states [1] with the biophysical description - link [2])."

There are different types of sensory receptors. There is the Chemorceptors that respond to a chemical substance. The pain receptors that respond to damaged tissue. They alert us to possible danger. The photoreceptors respond to light energy. That is why our eyes dilate. The mechnoreceptors are stimulated by mechanical forces which is usually a result of pressure. Thermoreceptors are stimulated by temperature change.

Once the nerve is stimulated it sends a singal to the brain.

Do drugs affect the nervous system?

Yes, Yes and Yes....I can't say it enough. Drugs definetly affect the nervous system. Depending on the type of drug a person is using they will see different results. Not only will it affect the person under the influence but, if they are pregnant it could cause problems to the infant when they are born.

Alot of the "feel good drugs" like coke, crystal, ecstasy deplete the body of dopamine which is a natural chemical we have in our brain. Users of those drugs will feel emotional, depressed and possibly suicidal once the drug leaves their system.

Although most people don't consider alcohol a drug technically it is. Alcohol when abused can be very detrimental to the body and brain over time internal organs will start to show damage. While under the influence of alchol the central nervous system becomes depressed.

Nicotine acts as a stimulant to the central nervous system. The nicotine causes dopamine to be released. Nicotine mimics acetylcholine and increases skeletal muscle activity, heart rate and blood pressure. Long term use of nicotine can cause various types of cancer.

Cocaine/methamphetamine's are also a stimulant to the central nervous system.

Marijuana causes the central nervous system to have a feeling of euphoria, along with altering vision and judgement. Long term use can cause hallucinations, depression, anxiety and paranoia.

The Autonomic System

Blue= parasympathetic
Red= sympathetic

The autonomic system is also in the perepherial nervous system. " The ANS has far reaching effects, including: heart rate, digestion, respiration rate, salivation, perspiration, diameter of the pupils, micturition - (the discharge of urine), and erection. Whereas most of its actions are involuntary, some ANS functions work in tandem with the conscious mind, such as breathing. The ANS is divided into two limbs, the parasympathetic nervous system which is primarily involved in relaxation, and the sympathetic nervous system which causes the body to become more active as in the "fight or flight" response.

The ANS is a classical term, widely used throughout the scientific and medical community. Its most useful definition could be: the sensory and motor neurons that innervate the viscera. These neurons form reflex arcs that pass through the lower brainstem or medulla oblongata. This explains that when the central nervous system (CNS) is damaged experimentally or by accident above that level, a vegetative life is still possible, whereby cardiovascular, digestive and respiratory functions are adequately regulated."

It is divided into the sympathetic and parympatheic divisions. While their functions are different they do share some similar features. They function automatically and it's usually involuntary. They innervate all internal organs. They utilize two nuerons and one ganglian for each impulse.

The sympathetic division is most usefull during emergency situations. It accelerates the heartrate and dialates the bronchial tube. It inhibits digestion during an emergency situation because that is not considered a priority at the time.

The parasympathetic division includes a few cranial nerves as well as fibers that come from the bottom part of the spinal cord. This division is also known as the "housekeeping division" because it promotes all internal responsed when we are relaxed; ie, contracted pupils, slow heartbeat, etc.

The Peripheral Nervous System

The Peripheral Nervous System lies outside the Central Nervous System and contains the nerves. It is not protected by bones therefore it's vulnerable to toxins and mechanical injuries. It is divided into two systems the somatic system and the autonomic system.

The somatic system nerves serve the skin, skeletal muscles and tendons. It is associated with voluntary control of body movements through the actions of the skeletal muscles and external stimuli.
"The somatic nervous system processes sensory information and controls all voluntary muscular systems within the body, with the exception of reflex arcs.

The basic route of nerve signals within the efferent somatic nervous system involves a sequence that begins in the upper cell bodies of motor neurons (upper motor neurons) within the precentral gyrus (which approximates the primary motor cortex). Stimuli from the precentral gyrus are transmitted from upper motor neurons and down the corticospinal tract, via axons to control skeletal (voluntary) muscles. These stimuli are conveyed from upper motor neurons through the ventral horn of the spinal cord, and across synapses to be received by the sensory receptors of alpha motor neuron (large lower motor neurons) of the brainstem and spinal cord.

Upper motor neurons release a neurotransmitter, acetylcholine, from their axon terminal knobs, which are received by nicotinic receptors of the alpha motor neurons. In turn, alpha motor neurons relay the stimuli received down their axons via the ventral root of the spinal cord. These signals then proceed to the neuromuscular junctions of skeletal muscles.

From there, acetylcholine is released from the axon terminal knobs of alpha motor neurons, and received by postsynaptic receptors (Nicotinic acetylcholine receptors) of muscles, thereby relaying the stimulus to contract muscle fibers." (wikipedia)

Central Nervous System

The central nervous system is made up of the brain and the spinal cord. The central nervous system is where sensory information is received and motor control is initiated.

The spinal cord extends from the base of the brain to what we call our tail bone. The role of the spinal cord is to provide a means of communication between the brain and our peripheral nerves. When the brain initiates involuntarily control over our limbs, motor impulses pass down the descending tracts in the spinal cord and out to our muscles by way of motor fibers. That is why when someone severs their spinal cord it results in paralysis.

The brain contains more than 100 billion neurons. The brain contains four lobes: frontal lobe, parietal lobe, temporal lobe and the occipital lobe.

The frontal lobe is where the primary motor function takes place, also plays a part in impulse control, judgement, parts of speech and emotions just to name a few. People with injury to their frontal lobe may suffer from paralysis, the inability to complete a sequence of complex movements, have trouble focusing, mood swings, difficulty problem solving and the inability to verbally express themselves.

The parietal lobe associated with movement, orientation, recognition, perception of stimuli. An injurt to this section could cause a person to have trouble drawing, naming an object, trouble with math, lack of awareness with certain body parts, inability to focus and trouble with hand/eye coordination.

The temporal lobes functions are hearing, speech, memory and emotional responsiveness. Injury to this lobe could result in difficulty in recognizing faces, trouble understanding spoken words, agressive behavior, and short term memory loss just to name a few.

Lastly, we have the occipital lobe. The occipital lobe is the visual processing center. Injury to this lobe could result in vision difficulty, hallucinations, trouble distinquishing colors, and difficulty with reading and writing.

What is a neuron?

A neuron is a nerve cell that characteristically has three parts: dendrites, cell body, and axon. (Human Biology, Sylvia Mader 10e) Neurons send messages electrochemically, meaning that chemicals cause an electrical impulse.

The dendrites are the part of the neuron that receive and carry the impulse to the cell body.

The cell body contains the nucleus and the dendrite and axon extend from this.

The axon carries impulse away from the cell body to the dendrite.

All neurons have the same basic structure. There are three total neurons they are sensory neurons, interneurons, and motor neurons.

Sensory neurons takes nerve impulses from a sensory receptor to the central nervous sysem. They are what detect changes in the environment.

Interneurons are located in the central nervous system. They receive input from the sensory neuron and also from other interneurons in the central nervous system.

Motor neurons are what takes nerve impulses away for the central nervous sytem to a muscle or gland.

Nerve impulse is what conveys the information within the nervous system. The conduction of an nerve impulse is all or nothing. The intensity of a message is determined by how many nerve impulses are generated in a specific time span.

Unit 3 section 1

In this section we learned about the nervous system. And what role it plays in our body. Some of the key things that we learned about and I will be briefly reviewing are:
* the structure of a neuron
* the central nervous system
* the peripheral nervous system
* the autonomic system
* how drugs affect the nervous system
* sensory receptors

Leech Lab

1. What is the electrode measuring?
The electrode measure voltage. While not shown in this lab you have to have an electrode in the solution to get a starting point. You then use the microelectrode to measure the potential difference across the neurons membrane.

2. Why use leeches in neurophysiology experiments?
Leeches are a favorite of scientists to use because they have a small number of neurons that are relatively large.

3. What is the difference between a sensory and a motor neuron?
A sensory neuron is responsible for transmitting information from external stimuli to the central nervous system. While a motor neuron is located in the central nervous system and controls muscles.

4. Do you think a leech experiences pain? What is pain?
I do believe that the leech experiences pain. As we saw with this lab certain nerves were responding to certain stimulations.
Pain is different for different people but, I would describe pain as a feeling of discomfort.

5. What were the two most interesting things about doing this lab?
I found it interesting that different cells felt different stimulations. I would have thought a nerve is a nerve and would feel it all. I also found using the dye to follow the path of the nerve interesting.

6. Anything you found confusing or didn't like about the lab?
I liked this whole lab...it took me a few times to find the T cell, but I was finally able to locate all the different cells.

self evaluation

At what moment during this unit did you feel most engaged with the course?


At what moment unit did you feel most distanced from the course? Probably during the lab when we were figuring out all our body rates.


What action that anyone (teacher or student) took during this unit that find most affirming and helpful? Sending out the emails encouraging us to keep up the good work.


What action that anyone (teacher or student) took during this unit did you find most puzzling or confusing? I didn't find anything puzzling or confusing that anyone did.


What about this unit surprised you the most? (This could be something about your own reactions to the course, something that someone did, or anything else that occurs to you.) I was surprised that I liked learning about the nutrition the most as that is one of my weaknesses.

self evaluation

1. What were the three aspects of the assignments I've submitted that I am most proud of?

For me the tests were probably where I did better on and the compendium reviews.

2. What two aspects of my submitted assignments do I believe could have used some improvement? I think that my lab could have been better as well as my essay.

3. What do I believe my overall grade should be for this unit? I believe my grade should be about a C and no lower because I did try my best.

4. How could I perform better in the next unit?

Making sure that I understand all the projects and maybe looking at other students to get an idea of how they did something.