Unit 3 Topic One Review

Table of Contents

Nervous System

• Overview of the Nervous System
• The Central Nervous System
• The Limbic System and Higher Mental Functions
• The Peripheral Nervous System
• Drug Abuse

Senses

• Sensory Receptors and Sensations
• Proprioceptors and Cutaneous Receptors
• Senses of Taste and Smell
• Sense of Vision
• Sense of Hearing
• Sensce of Equilibrium

Nervous System

Overview of the Nervous System

There are two major divisions, the central nervous system (brain and spinal chord) and the peripheral nervous system (nerves). Both systems work together. There are three functions of the nervous system.

1. Receive Sensory Input- sensory receptors respond to interal and external stimuli. Nerve impulses travel by the peripheral system to the central system.
2. CNS Performs Integration- the central nervous system takes in all the information
3. CNS Generates Motor Output- nerve impulse from the central system travel by the peripheral system to muscles and glands.

Nervous tissue is made up of neurons (transmit nerve impulses) and neuroglia (supports and nourishes the neurons). There are three types of neurons:

1. Sensory Neuron-takes the impulses from a receptor (structure that detects changes)to the central system
2. Interneuron- lies completely in the central system. These receive input from each other and sensory neurons. They then take into account all of the impulses received and communicate with motor neurons
3. Motor Neuron- takes the impulses from the central system to an effector ( this is a muscle fiber or gland that carries out a response to the environmental changes)

A neuron physically consists of a cell body, dendrites and an axon. The cell body has a nucleus and organelles. Dendrites are extensions used to receive signals from receptors and other neurons. An axon conducts nerve impulses. An axon in nerves is called a nerve fiber.

Most axons are covered in a myelin(lipid substance) sheath. This can be formed by neurolgia known as Schwann cells. These cells contain mylein in the plasma membranes. Schwann cells are in the peripheral system. In the central system oligodendrocytes perform the same function. The myelin sheath is developed when the oligodendrocytes wrap around an axon many times. Nodes of Ranvier are spaces where there is no myelin sheath. This occurs because each neuoglia cel can only cover a portion of an axon. Grey matter in the central system is due to a lack of myelinated axons, and white matter is due to myelinated axons.

Nerve impulses relate information in the nervous system. These impulses can be recorded and studied by using a voltmeter. The resting potential is when the axon is not conducting any impulses. (inside of neuron is more negative then outside: Na+ greater on outside and K+ greater on inside due to sodium- potassium pump). Action potential is when polarity rapidly changes across the membrane. This occurs when there is an impulse. Na+ moves in and this is depolarization. Then K+ moves out and this is repolarization. Each action potential will create another one down the length of the axon.

Each axon branches into "fine endings tipped by a small swelling called an axon terminal" These terminals lie close to the dendrite or cell body of another neuron. This is called a synapse. A synaptic cleft is the space between the sending and receiving neurons. Transmission is carried out by neurotransmitters that are stored in synaptic vesicles in axon terminals.

1. Nerve impulses that are traveling along the axon reach the terminal.
2. Calcium ions enter the terminal and stimulate synaptic vesicles and these merge with the sending membrane.
3. Neurotransmitters are released into synaptic cleft where they diffuse across into the receiving membrane and then they bind with specific receptor proteins.

Some known neurotransmitters include acetylcholine, norepinephrine, dopamine, serotonin, glutamate, and gamma aminobutyric acid.

Central Nervous System

Sensory information is received and motor control initiated in the central nervous system. The spinal chord is surrounded by vertebrae while the brain is protected by the skull. Along with bone these structures are also protected in membranes called meninges. Spaces in between are filled with cerebrospinal fluid to cushion the central system. The central system has two types of nervous tissue: white (myelinated axons) and grey (cell bodies and non myelinated fibers).

The spinal cord runs from the base of the brain all the way down the vertebral canal. Spinal nerves project from the cord between the vertebrae, and intervertebral disks separate the vertebrae. Communication between the brain and peripheral nerves occurs through the spinal cord. The left side of the brain controls your right side of the body and vice versa. When the brain starts voluntary control of the limbs, motor impulses starting in the brain pass down the descending tracts to the spinal cord and then to our muscles through muscles fibers.

Reflex actions occur when a stimulus makes the sensory receptors generate a nerve impulse. This impulse travels to sensory axons to the spinal cord. Motor axons then cause skelatal muscles to contract. The spinal cord works the same way for internal organs.

Four ventricles make up the brain: two lateral ventricles, the third ventricle and the fourth ventricle.

The cerebrum is the largest portion of the brain. This is the last stop for sensory input and can communicate with other parts of the brain. The cerebrum is divided into two hemispheres and sulci divide these into lobes (frontal, parietal, occipital, temporal). Cerebral cortex is an outer layer of grey matter covering the hemispheres (is responsible of sensation, voluntary movement, and thought processes)

The cerebellum is located under the occipital lobe and is separated by the fourth ventricle. It is broken into two sections joined by a median portion. Sensory input from the eyes, ears, joints,and muscles come here. It then performs integration and sends motor impulses throught the brain stem to skelatal muscles. (maintains posture and balance)

Brain stem contains mid brain, pns, and medulla oblongata. The midbrain is a relay station between cerbrum and spinal cord and cerbellum. Pons holds axon bundles and regulates breathing rate, and head movements. Medulla oblongata has reflex centers and regulates heartbeat, breathing, blood pressure. It is located superior to the spinal cord.

The Reticular Formation is a complex network of nuclei and receives sensory signals and sends them onward to higher centers. This is responsible for people being alert.

The Limbic System and Higher Mental Functions

The limbic system is a group of linked structures within the cerebrum and is involved in emotions and higher mental functions. It blends our primitive emotions with higher mental functions. Two important structures are the amygdala (causes experiences to have emotional overtones) and the hippocampus (involved in learning and memory)

Memory is the ability to hold a thought or recall events from the past. Learning is when we retain and use the past memories. There is short term memory (in the prefrontal area) and long term memory (mixture of sematic memory, and episodic memory) Long term memory is stored in pieces throughout the sensory association areas of the cerebral cortex. Language is dependent on semantic memory, so if there are disruptions of either memory or language pathways, it could contribute to an inability to comprehend the environment and effectively use speech.

The Peripheral Nervous System

This system is outside of the central nervous system and contains nerves. Cranial nerves arise from the brain and spinal nerves arise from the spinal cord. Nerves are composed of axons. There are 12 pairs of cranial nerves some are sensory and some are motor. The vagus nerve works with the medulla oblongata to control internal organs. Spinal nerves are in 31 pairs. The spinal nerve roots physically separate axons of sensory neurons from motor neurons. Spinal nerves are mixed nerves.

The somatic system is one division of the peripheral system. These nerves relate to the skin, skelatal muscles and tendons. Nerves take info from external sensory receptors the the central system and motor commands from the central system to the skelatal muscles. Reflexes also occur in the somatic system.

The autonomic system regulates smooth muscle and gland activity along with cardiac activity. The autonomic system is broken down into the sympathetic and parasympathetic systems. They both

1. Automatically function in an involuntary manner
2. Innervate internal organs
3. Utilize two neurons and one ganglion for each impulse

These reflex actions (blood pressure and breathing rate) are essential to homeostasis. Sympathetic is used in fight or flight responses. It inhibits the digestive tract and releases norepinephrine. Parasympathetic promotes internal responses in a relaxed state. (digestion, pupil dialation). Known as the rest and digest system.

Drug Abuse

Drugs affect the nervouse system, therefore altering mood and or emotions. They affect the limbic system and either increase or decrease actions of particular neurotransmitters. Drug abuse is classified by someone taking a dose level and under circumstances that can increase potential of a harmful effect. Some of the more common drugs seen today include, alcohol, nicotine, cocaine, methamphetamine, heroin and marijuana.

Senses

Sensory Receptors and Sensations

Sensory receptors are specialized dendrites that detect specific stimuli. Exteroceptors detect from the outside of the body(environmental conditions) and interoceptors detect from the inside of the body. (these effect homeostasis and are controlled by the negative feedback mechanism.)

There are four categories of sensory receptors

1. Chemoreceptors- respond to chemical substances
2. Pain receptors- these are a type of chemoreceptors and respond to the chemicals that damaged tissue releases
3. Photoreceptors- respond to light energy
4. Mechanoreceptors- these are stimulated by mechanical forces and can result in pressure.(sense of touch, hearing)
5. Thermoreceptors- these are in the skin and hypothalamus and respond to changes in temperature.

Our sensory receptors respond to our external environment and send nerve impulses to the cerebral cortex where sensation (consious perception) occurs. All sensory receptors initiate nerve impulses that have been integrated (summing of the signals) When these reach the brain this is when sensation occurs. With out our sensory receptors, we would not receive info about our external and internal environments and homeostasis would not be possible.

Proprioceptors and Cutaneous Receptors

Muscle, joint, tendons and internal organ sensory receptors send their impulses to the spinal cord. After the spinal cord they go to the somatosensory areas. There are three types of general sensory receptors.

1. Proprioceptors- are a type of mechanoreceptor that maintain muscle tone and the body's equillibrium and posture. They know degree of muscle relaxation, contraction, tension and movement.
2. Cutaneous Receptors- located in the dermis of the skin, and effectivly making the skin sensitive to pressure, pain, and temperature. Fine touch gives information about the location, shape, size and texture of the touch (Meissner corpuscles, Merkel discs, and root hair plexus). Pacinian corpuscles and Ruffini endings are sensitive to pressure
3. Pain Receptors- these are sensitive to chemicals released by damaged tissue. Referred pain is when the stimulation of internal pain receptors is felt as pain from the skin or the internal organs

Senses of Taste and Smell

Taste and smell are chemical senses because their receptors are sensitive to molecules in food and air. Chemoreceptors (plasma membrane receptors that bind to certain molecules) communicate by sensory nerve fibers with the respiratory center in the medulla oblongata.

Humans have around 3,00o taste buds on the tongue. The four primary types of taste are sweet sour, salty, and bitter. Molecules bind to receptor proteins on microvilli where nerve impulses are generated in the sensory nerve fibers and sent to the brain.

80-90% of what we think of as taste is actually due to smell. Smell is dependent on up to 20million olfactory cells in the roof of the nasal cavity. An odors signature in the olfactory bulb is determined by which neurons it stimulates. Olfactory cells decline and become less sensitive as we grow older.

Sense of Vision

The eyeball is made up of three layers:

1. Sclera- white and fibrous. The cornea consists of transparent collagen fibers and is the window of the eye.
2. Choroid- vascular and absorbs stray light rays. In the front it becomes the iris which regulates the size of the pupil (where light enters). Behind the iris is the ciliary body which controls the shape of the lens for near and far vision. The lens divides the eye into two compartments, the anterior compartment(filled with aqueous humor) and the posterior compartment.
3. Retina- located in posterior compartment (filled with vitreous humor). Contains rod cells and cone cells. Rods are sensitve to light but do not register color, and cones require bright light to recognize the different wavelengths (color). Fovea centralis is area of densely packed cells, and light is focused here when looking at an object. Sensory fibers from the retina form the optic nerve which in turn takes the impulses to the visual cortex.

The cornea is where focusing starts, and it continues through the lens and humors. Visual accomodation happens for close vision by the lens becoming more round to bring the object into focus.

Sense of Hearing

The two functions of the ear are hearing and balance. All of the sensory receptors of the ear contain hair cells with sereocilia sensitive to mechanical stimulation. These are mechanoreceptors. The ear is divided into three parts

1. Outer- contains the pinna and auditory canal
2. Middle- starts at the tympanic membrane and ends at the oval and round windows. The ossicles between the tympanic membrane and oval windows are: malleus, incus, stapes. The auditory tube allows the equalization of air pressure
3. Inner- filled with fluid and broken down into semicircular canals, vestibule, and cochlea.

Hearing starts when sound waves enter the auditory canal and travel by vibrations to the tympanic membrane. The malleus takes this pressure and passes it using the incus to the stapes which hits the oval window membrane and passes the pressure to the fluid of the cochlea. In the cochlea the spiral organ has little hair cells and a tectorial membrane. Nerve impulses begin in the cochlear nerve and go to the brain. It is thought that the brain interprets tone based on the distribution of the stimulated hair cells

Sense of Equilibrium

The vestibular nerve works to achieve equilibrium and takes the nerve impulses to the cerebellum and brain stem. There are two types of mechanoreceptors involved in equilibrium

1. Rotational- mechanoreceptors in semicircular canals detect angular and rotational movement. The three canals are arranged to each cover one dimension of space. The ampulla of each canal is enlarged and covered in little hair cells. As fluid in the canals moves over the ampulla, the hairs bend and the pattern of impulses being carried to the brain is changed.
2. Gravitational- mechanoreceptors in the utricle and saccule detect verticle and horizontal movement. These are two membraneous sacs containing little hair cells in an otolithic membrane. When the head moves one way or another the otoliths are displaced and hair cells bent sending info to the brain. The brain uses the information it receives to maintain equilibrium by sending signals to the correct skelatal muscles to correct position

Works Cited

Mader, Sylvia. Human Biology 10th ed

Frolich powerpoint

Links to Pictures

1. http://www.virtualsciencefair.org/2004/visa4a0/public_html/brain6.gif
2. http://www.discoveryfund.org/images/Eye_Anatomy-Anat.jpg
3. http://www.biologyreference.com/images/biol_03_img0336.jpg

Unit Break

This is just a break between unit two and unit three

Self and Unit Evaluation

SELF EVALUATION

REGARDING YOUR OWN PERFORMANCE
1. What were the three aspects of the assignments I've submitted that I am most proud of?
This unit I am most proud of the compendium reviews, and the two online labs (I had a fun time doing these)
2. What two aspects of my submitted assignments do I believe could have used some improvement?
Well I was satisfied with my essay, but I'm not sure if it was exactly what Mr. Frolich was looking for. Also, My main lab, because the pictures were not how I wanted, but I needed to turn in what I had.
3. What do I believe my overall grade should be for this unit?
I felt very good about this lab, and feel I had a complete understanding of the topics covered. This unit went well because we were studying the same topics in my Medical Terminology class, so that was extra reinforcement. I feel the majority of this unit was "A" quality work
4. How could I perform better in the next unit?
Again, somehow, I need to make more time to spend on the entire unit, so I am not stressed about trying to complete everything without enough time

REGARDING THE UNIT (adapted from Stephen Brookfield, University of St. Thomas "Critical Incident Questionnaire")
At what moment during this unit did you feel most engaged with the course?
This time, I would have to say during the Lab. Actually taking vitals and seeing how they were affected by different activities really tied the whole unit together
At what moment unit did you feel most distanced from the course?
I felt most distanced during the blood pressure online lab, it was alot of data, but to me there was still significant factors missing to really relate it to real life situations.
What action that anyone (teacher or student) took during this unit that find most affirming and helpful?
Once again, the most helpful action was taken by Mr. Frolich in working with my work schedule to get the unit completed and turned in. Thanks again
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 was actually surprised at how easy this unit came together, as far as me understanding the topics and tying the unit together. I think part of this was due to the fact I was studying the same topics in another class, and also this is information I can apply to everyday life and at work.

Unit Two Ethical Issue Essay

What We Eat

In this day and age I don’t think the majority of people (at least in the US) tend to give much thought as to where their food comes from, or how it has been processed. Obesity is becoming and epidemic affecting 33% of the adult population, not to mention the growing number of children who are obese or at least overweight. Today’s society is focused on weight loss by eating healthy and exercising, but the majority of advertising is for diet pills and diet programs that are cutting out essential nutrients (your body needs a certain amount of "healthy fats", carbohydrates, and proteins to perform everyday functions). Also surgical procedures have become increasingly popular as an easy fix to this problem.
One of the online links for this section show how most of our food travels thousands of miles before reaching the shelves. The majority of the US’s fresh fruit and vegetables come from California, Washington, and Florida. It can take up to 14 days for these products just to arrive on the supermarket shelves. In my opinion, fruits and vegetables are not so fresh after 2 to 3 weeks of being handled and shipped around. On the other hand, locally grown products arrive much sooner, usually in a time frame of 24 hrs after being harvested. If products can go straight from the farm to the shelf, then this means farmer’s can worry more about taste and freshness of the item, rather than how it is going to have to hold up for long distance shipping. Did you know that factories actually produce chickens?! From when they are eggs to when they are ready to go to market, thousands and thousands of chickens are literally produced in factories. Makes you start to think about the differences there might be from these chickens to farm raised ones. This site also has a link for you to find farmer’s markets in your area. There are quite a few in the southern part of the state, but it also says the Yavapai College actually holds one May through October.
As I was studying this section and looking through the links I realized that I have really never thought twice about the food I am buying in grocery stores, and I pretty much live on fast food of one kind or another when working on the ambulance 2-3 days a week. Now, when I am working and we are busy we are lucky to eat period, but fast food is the easiest, quickest option. After reading more on food, I want to try the farmer’s markets and start eating "real food".
For some reason all of this research made me start thinking about when we go to visit family in Vermont. Woodstock is a small town in the country. My grandmother and aunt both have gardens (varies vegetables, herbs, fruit, ect), and if they don’t grow it themselves most of the family stores carry truly fresh foods. There aren’t any large supermarket chains in Woodstock, only a few mom and pop stores. When we visit, depending on the season, we go with my grandmother to pick strawberries, raspberries, and blueberries from farms. She makes fresh jam from the berries. Food that is homegrown and home cooked just tastes so much better. I also think it is probably healthier as it has not been processed or engineered, just grown the good old fashioned way. There is some level of satisfaction when you can grow your own food and you appreciate what has gone into it. Also, when we are back east everyone helps cook the meals and then everyone sits down together and enjoys them. It is a nice change from always eating in a hurry or while on the run. Also, in Woodstock, people are much more active outdoors which, in my opinion, adds to a healthy lifestyle. People growing up in a city might not have this opportunity.
In conclusion, I feel that everybody can do something to make at least a small change towards eating and living healthier. I understand that where you live or work can have an effect on your choices or opportunities that are available to you, however you still decide what to eat and have an option of some physical activity during the week. (Cutting down on sodas and sweets, taking a walk, even if it is short, or finding healthier avenues in which to purchase food). Schools are trying to join in this healthy change by making sure their menu’s offer a variety of healthier foods and some are even getting rid of soda machines. Farm to School organizations are major players in this new change and education on healthier eating.
This was a beneficial topic for me, as it opened my eyes to what I have been eating and where it has come from and how the food has been treated in the process. Also there were many good resources to find fresher, healthier food, and what a true "balanced diet" might look like and why this is so important for our bodies.

Works Cited
1. Mader, Sylvia. Human Biology 10th ed
2.Farm to School www.farmtoschool.org
3.Food Routes- Where Does Your Food Come From www.foodroutes.org/

Unit Two Lab- Vitals

Unit Two Lab, Metabolic Rates

In this Lab I am going to see in real life how the cardiovascular and respiratory systems respond to three different activities. I will be measuring pulse (beats per minute), respiration (breaths per minute) and blood pressure (systolic/diastolic). I will have a baseline set of vitals to compare with the vitals after three different activities.
Pulse can be felt in a few different places: coratid arteries, brachial arteries, radial arteries, femoral arteries, and pedal dorsalis arteries. The most common place to take a pulse is the radial artery. Pulse is equal to heart rate. When you feel the pulse this is the left ventricle contracting and forcing its oxygenated blood out into the arteries, to travel through the arterioles, down to the capillaries where the exchange occurs, then to the venules, veins and back to the heart.
The systolic blood pressure is when the blood is ejected from the heart and the diastolic is during relaxation of the ventricles. By the time the blood has reached the capillaries, the pressure is decreased due to the increase in number of vessels it is flowing through. After the exchange, when blood is in the venules in veins, the respiratory pump helps to assist moving the blood back towards the heart. This works because when we inhale, the chest expands and pressure in the thoracic cavity is reduced. This allows the blood to flow from a higher pressure(abdominal cavity), to the lower pressure (thoracic). Valves prevent backward flow when we exhale, keeping the blood moving in the right direction. Blood pressure an essential element that allows the exchange to occur at the capillary level. The exchange must occur and blood continue to circulate in order for all of cells to be able to receive O2 and nutrients and get rid of CO2, and wastes. Blood pressure is measured in mmHg.
Respiration is the number of breaths you take in a minute. As discussed above, respiration serves to oxygenate and expel CO2 from the lungs and also contributes to the circulation of blood.

Hypothesis:






Materials and Methods:
To measure Pulse, I took it at the radial artery on myself and counted for 30 seconds then multiplied by two to get pulse rate. Respirations were counted for 30 seconds and then multiplied by two to get the rate. Blood pressure was taken with an electric blood pressure cuff that my parents had for keeping track of their blood pressures at home. I chose to measure respirations and pulse for 30 seconds instead of 15, because I think this is more accurate. Vitals were taken immediately after each exercise. Blood pressure first, and I was able to do respirations at the same time, and then pulse right after.

Data:





Analysis: My hypothesis for activity one was correct, except for diastolic BP which actually decreased. My hypothesis for activity two was correct, except for diastolic BP which actually decreased. My hypothesis for activity three was only correct in the aspect of pulse. However, I hypothesized respiration and BP diastolic would stay the same and they were increased by one breath, and decreased by one point respectively, so I was very close. In conclusion, it seems my hypothesis' were mostly accurate, with the exception being diastolic blood pressure.

Problems: Something that could have had an influence on the readings is the blood pressure cuff I used. I do not know how long ago it was calibrated, or it's accuracy compared to other blood pressure cuffs. Also, when you count your own respirations, the data can be skewed because you are thinking about it.

Conclusion: In conclusion, I would have to say that any activities where you are up and moving around in any way increase the metabolic rates we focused on, with the exception of diastolic BP, which tends to decrease in small increments. Pulse, Respiration,and Systolic BP all increase with activity because your muscles and tissues are having to work harder, so they need more oxygen, and need to have the blood circulated faster to make the exchanges needed for the cells to continue their work. If circulation pace picks, up then the left ventricle is going to have to pick up the pace and effort when pumping the blood out of the heart. Diastolic pressure could decrease because there is less time for the ventricles to relax.


Works Cited
Mader, Sylvia. Human Biology 10th ed.

Note-- My digital camera was not cooperating to upload pictures of me doing the actual activities. When I can figure out the problem, I will post these pictures.

Digestive System and Nutrition Compendium Review

Table of Contents

Digestive System and Nutrition

• Overview of the Digestion
• First Part of the Digestive Tract
• The Stomach and Small Intestine
• Three Accessory Organs and Regulation of Secretions
• The Large Intestine and Defecation
• Nutrition and Weight Control

Digestive System and Nutrition

Overview of Digestion

The gastrointestinal tract holds all of the digestive system organs. Digestion takes the macromolecules and breaks them down to the unit molecules which can then cross the plasma membranes. There are four layers in a GI tract wall. The central space where the food is digested is known as the lumen. The firt layer after this is the mucosa (produces mucus to protect the wall from digestive enzymes). Submucosa is the second layer (loose connective tissue containing blood and lymphatic vessels, and nerves). Third layer is muscularis ( two layers of smooth muscle. Inner encircles the tract and outer lies same direction of tract. Contracti0n of these muscles moves digested food). Serosa is the last layer (secretes serous fluid and is part of the peritoneum)

• Ingestion- this is when food enters the mouth
• Digestion- Either mechanical (food broken into pieces that digestive enzymes can work on) or chemical (digestive enzymes.)
• Movement- Food passes from one organ to another through the digestive tract.
• Absorbtion- Unit molecules resulting from digestion are now able to move across the GI tract into the cells that line the GI tract, where they enter the blood for transportation.
• Elimination- Indigestible wastes are defecated through the anus

First Part of the Digestive Tract

Your mouth, pharynx, and esophagus make up the first section of the GI tract. The food enters through the mouth, and this is the beginning of mechanical and chemical digestion. The mouth is made up of your hard palate, soft palate, tonsils (lymphatic tissue), and salivary glands(send saliva containing salivary amylase to the mouth). Teeth (20 baby teeth, replaced by 32 adult teeth) function as a mechanical aspect. Your tongue helps in mechanical digestion along with taste buds that send nerve impulses to the brain.

Pharynx is the next stop after food enters the mouth. This is where the food and air passages intersect (trachea is front of the esophagus). Swallowing is voluntary until food reaches the pharynx, here it becomes automatic. The soft palate blocks off nasal passages, and the epiglottis covers the glottis, blocking food from going into the trachea. The only place left to go is down the esophagus. Peristalsis moves the food down the esophagus and sphinters allow the food to enter the stomach, but prevent stomach acids from entering the esophagus.

The Stomach and Small Intestine

The stomach sits on the left side of the body under the diaphragm. The esophagus conects to the top of the stomach and the duodenum of the small intestine connects on the bottom. In the stomach, food is stored, protein digested and chyme is moved into the small intestine. There are also four layers of the stomach wall: Three layers of smooth muscle(circular, longitudal and obliquely) and a mucosa layer on the inside in which rugae produce gastric juice that contains pepsin, HCl and mucus.

The small intestine completes the digestion process. Here there are many enzymes capable of digesting all types of food including carbohydrates, proteins, and fats. This wide array of enzymes is secreted in the pancreas and enters the duodenum along with bile to emulsify fat. Nutrients are absorbed here. The small intestine's large surface area is designed perfectly for this absorption. Mucosa contains villi which have extensions called microvilli. Each villus has a small lymphatic capillary (lacteal). The vessels in here allow the unit molecules to be carried to all the other cells in your body through the bleed stream.

Three Accessory Organs and Regulation of Secretions

Digestive secretions are regulated by the nervous system and digestive hormones.

1. Pancreas- located behind the stomach. Pancreatic cells produce pancreatic juice containing digestive enzymes for all the types of food.(amylase digests starch, trypsin is for protein, and lipase is for fat). This organ is also very important because it is responsible for producing insulin. When the bodies blood glucose level rises, this triggers an excess amount of insuling to be produced which in turn, brings the glucose level back to normal range. Diabetes type 2 occurs when a body's cells become resistant to the insulin. Type one diabetes occurs when the pancreas does not secrete insulin like it should, and thus blood sugar must be checked frequently and insulin injected when needed.

2. Liver- is the largest metabolic gland. Located in the upper right quadrant of abdominal cavity. Blood travels through the hepatic portal vein into the capillaries of the liver lobules where poisonous substances are removed. The liver also stores iron and vitamins. Glucose is stored as glycogen which is broken down when there is insulin, effectively keeping your blood glucose level constant. The liver also produces plasma proteins and regulates cholesterol and breads down hemoglobin, forming bile

Liver diseases can be life threatening. Two big diseases are hepatitis(inflammation) and cirrhosis(liver tissue replaced by scar tissue)

3. Gallbladder- located below the liver. Bile is stored here.

The Large Intestine and Defecation

The cecum, colon, and rectum all are part of the large intestine. The cecum is located behind the junction of the small intestine with the large intestine and has a projection known as the vermiform appendix. The colon is the ascending, transverse, descending and sigmoid. This leads into the rectum and opens at the anus.

The large intestine functions to absorb water and proteins produced by intestinal flora. The bacteria here break down the indigestible material to form feces. Diseases of the large intestine include: diarrhea, constipation, hemorrhoids, diverticulitis, irritable bowel syndrome, inflammatory bowel disease, polyps and cancer. Most of these can be prevented by exercising a good diet, and good bowel habits.

Nutrition and Weight Control

Obesity affects 33% of adults today. This is determined by your body mass index (BMI). A healthy BMI 19.1-26.4, overweight 26.5-31.1, obese 32.3-39.9 and morbidly obese 40+.

Nutrients are an important part of diet. They are classified into

1. Carbohydrates- either simple or complex. Glucose is preferred by the body for energy. As fatty acids cannot be converted to glucose, it is important to include carbohydrates in your diet. Unrefined products are best

2. Proteins- these are broken down into amino acids when digested and used to synthesize cellular proteins. 8 out of 20 amino acids are essential for children's growth. Absence of just one essential amino acid, and the other 19 will not function properly. Since amino acids are not stored, a daily intake is needed.

3. Lipids- these are the fats, oils and cholesterol. Unsaturated fats do not encourage cardiovascular disease. Polyunsaturated fats are actually needed since they contain linoleic and linolenic acids which the body does not produce on its own.

Minerals are either major( structural components of cells) or trace (part of a larger molecule). Exampels are: calcium, vitamin D, and sodium. Vitamins are organic compounds that the body cannot produce enough of, but is needed for metabolic reasons. There are 13 vitamins and they are either fat soluble or water soluble. Vitamins C, E, and A are antioxidants and can be found in fruits and vegetables.

A healthy diet consists of eating a variety of foods and being physically active. More fruits, vegatables and whole grains should be consumed, and less sugars, saturated fat, salt and cholesterol.

Anorexia, bulima, binge eating and muscle dysmorphia are all eating disorders that effect people everyday.

Works Cited

Mader, Sylvia. Human Biology 10th ed

Frolich Powerpoint

Website links for pictures

1.http://www.mc.vanderbilt.edu/histology/labmanual2002/labsection3/EsophagusandStomach03_files/image004.jpg 2. http://cache.eb.com/eb/image?id=1354&rendTypeId=4
3. http://www.acm.uiuc.edu/sigbio/project/digestive/middle/stomach2.jpg
4.http://a-s.clayton.edu/biology/biol1152l/digestive_system_anatomy/stomach_rugae.jpg
5. http://www.rivm.nl/interspeciesinfo/Images/small-intestine_tcm75-26441.gif
6. http://www.foxriverwatch.com/color_liver2a.jpg

Blood Pressure Online Lab

1.State a problem about the relationship of age and gender to blood pressure.
One problem is as people get older often times they will start smoking or drinking which can increase blood pressure. Also older people might not exercise as much which results in higher blood pressure

2.Use your knowledge about the heart and the circulatory system to make a hypothesis about how the average blood pressure for a group of people would be affected by manipulating the age and gender of the group members.
I hypothesize that as the age groups increase in age there will be more cases of individual hypertension, thus also bringing up the average blood pressures. By manipulating the gender, I hypothesize that males will have higher blood pressures due to obesity factors.

3.How will you use the investigation screen to test your hypothesis? What steps will you follow? What data will you record?
After all the blood pressures have been taken I will look to see if any individual shows hypertension. If so, the factors of their past medical history will be noted. Then I will go through everyone's history and note the factors, even if they are not hypertensive at this time.

4.Analyze the result of your experiment. Explain any patterns you observed.
Females were broken into 5 groups of 10. Group one is age 11-17, group two 18-24, group three 25-34, group four 35-44 and group five 45-54.
Group One- average BP 116/75. No cases of hypertension. Two of the subjects had a family history of hypertension, and one of these two also lacked exercise
Group Two- average BP 117/75. One case of hypertension. This person had family history, lacked exercise and was 30% overweight. Her BP was 140/91
Group Three-average BP 117/76. No cases of hypertension. Two subjects lacked exercise but did not exhibit hypertension due to this fact
Group Four- average BP 126/81. Three cases of hypertension. Of these three, one had family history and a BP of 140/91, one consumed alcohol and had a BP of 141/92 and the third had no history of any kind but a BP of 142/92
Group Five- average 131/80. Two cases of hypertension. Both of these subjects had high salt diets, lacked exercise, and were 30% overweight. BP's were 144/91 and 145/95. Two other subjects had family history of hypertension, but were not hypertensive themselves.
In the females, regardless of age, 6 out of 50 subjects showed hypertension. 1 of these 6 was 30%overweight with a family history, 1 had a family history only, 1 had no history of anything, 1 consumed alcohol only, and 2 had high salt diets and were obese.

Males Group One- average 117/76. No cases of hypertension. 2 subjects were obese
Group Two- average 127/79. One case of hypertension. This subject had a family history and was obese. BP was 141/91
Group Three- average 130/80. No cases of hypertension. Two subjects had a high salt diet
Group Four- average 130/81. One case of hypertension. This subject had a high salt diet, consumed alcohol and was obese. BP was 142/91.
Group Five- average 135/85. Four cases of hypertension. Of these four all had family history, three were obese, and one consumed alcohol on top of the other factors. BP's were 140/90, 144/91, 142/90, and 146/94
In the males 6 out of 50 subjects were hypertensive. 4 of them fell into the age group 45-54. 5 out of these six were obese and had a family history of hypertension.

5.Did the result of your experiment support your hypothesis? Why or why not? Based on your experiment what conclusion can you draw about the relationship of age and gender to group blood pressure averages?
For the most part these tests supported my hypothesis. To get a more accurate result, I feel that a larger number of subjects would need to be tested. From this experiment it shows there were 6 cases in both genders of hypertension, not just males. It also shows more cases of obesity in males in group 5 with hypertension verses females, whose hypertension was spread throughout the age groups, and not strictly related to obesity.

6.During the course of your experiment, did you obtain any blood pressure reading that were outside of the normal range for the group being tested? What did you notice on the medical charts for these individuals that might explain their high reading?
In both male and females there were 6 cases each of hypertesion. Of these 12 subjects only one (female) had no medical history. The other 11 had any combination of family history, high salt diet, lack of exercise, obesity, or alcohol consumption. More males then females were obese.

7.List risk factors associated with the hypertension. Based on your observation, which risk factor do you think is most closely associated with hypertension?
Risk factors of hypertension include smoking, drug abuse, weight gain, and also family history. In this particular study, weight gain was seen most frequently with hyptertension, along with family history. However, smoking and drug abuse were not listed in subjects history

8.What effect might obesity have on blood pressure? Does obesity alone cause a person to be at risk for high blood pressure? What other factors, in combination with obesity, might increase a
person's risk for high blood pressure?
When someone is obese they have more tissues for the blood to circulate through and take care of. To accompish this, the heart must increase the pressure when it pumps. Obesity alone can cause risk of high blood pressure, but other things such as diet, family history, drinking, can all play a part.
Graphs and charts for this lab