Unit III Lab Build a Limb

Unit III Lab

Build a Limb

In this lab I will be building a limb. This will include the muscles, skeletal bones with a joint, and an exploded view of the inner workings of a muscle cell to show how the nerve impulse (action potential) travels along the motor neuron to the muscle cell.

Here are the materials I used to make my model.

Here is the right arm with bones, muscles and an exploded view of a single muscle fiber.

Here is the muscle fiber that contains many myofibrils which are divided into sarcomeres.

This is the part of the muscle that either contracts (shortens) or relaxes (elongates).

Here is the neuromuscular junction where the motor neuron meets the muscle fiber. This is where the neurotransmitter acetylcholine (Ach) is released from the neuron and binds to the muscle receptors, then sending impulses down the T system of the muscle fiber. The T system is connected to the sarcoplasmic reticulum and Ca+ is released. The release of Ca+ causes the sarcomere to contract, resulting in the sliding actin and myosin filaments making the whole muscle contract and thus moving the arm.

In conclusion the model of the arm starts at the motion of the arm and traces back to the action potential on the motor neuron. I learned that something we take for granted everyday (the ability to be mobile) is a truly remarkable process and yet happens so quickly.

Evaluation

I believe the model and the lab work met the following criteria. Which I hope to receive a B for.

• Introduction presents model clearly
• List of limb parts explains how they are represented in the model. There is an understandable and consistent relationship between the model parts and what they are in the limb
• Model includes representation of all the basic parts of a limb listed above. It is easy to understand why each model piece was chosen to represent a certain part of the limb.
• Bone, joint, muscle, and neuron are represented. Pieces are used that make it easy to see how these elements function in the limb.
• Description of action potential and muscle contraction are presented. They are shown in their entirety and it is easy to follow how each process happens.

Presentation of model is orderly, understandable and cohesive. An effective project requires a lot of work. There is evidence that the student has thought through what pieces they want to use for each part of their limb…and WHY. It is easy to see how each piece represents that part of the limb, and to imagine how it works. The Neuron action potential and Muscle Contraction component makes sense and it is possible to follow each aspect of an action potential as it triggers the muscle to contract via the sliding actin and myosin filaments.

I believe I had fun building an arm and it definitely was fun. But where I sometimes have difficulty is just deciding what materials to actually use. Once that is decided the rest is the fun part.

Unit III Muscle Lab

How Do Your Muscles Work?

INTRODUCTION:

Much of the work of the body depends on the contraction of skeletal

muscles. In this experiment you will first observe the characteristics of

muscle contraction and then will investigate the effects of two factors -

temperature and fatigue - on the action of your muscles.

MATERIALS:

dishpan of water

narrow strip of paper which will fit around upper arm

ice or snow

rubber ball or clothespin

timer (clock, watch, or stop watch)

PROCEDURE:

The following exercises will help you understand what happens to your

muscles when they contract.

Muscle Action

1. Place your fingers along the angle of your jaw just in front of your

ear. Grit your teeth and observe what happens to the hardness of the

muscles in your cheek.

The muscle goes from flaccid to hard as you grit your teeth.

2. With the thumb and little finger of one hand, span the opposite arm's

biceps (front muscle of the upper arm) from the elbow to as close to the

shoulder as possible. Bend the arm and observe the change in the length of

the muscle.

From extension to flexion the bicep shortens.

3. Wrap a strip of paper around your upper arm and mark the circumference

of your arm on the paper. Clench your fist tightly and mark the new

circumference on the paper. Observe what happens to the circumference of

the muscle.

The circumference increases as the bicep and tricep both try to contract.

Effect of Temperature on Muscle Action

1. Count the number of times you can make a fist in 20 seconds. Start with

your hand completely outstretched and make a tight fist each time. Do it

as rapidly as you can. Record the count in Figure 1.

2. Now submerge your hand in a dishpan of water to which has been added

snow or ice so that the temperature is near the freezing point. Leave your

hand in the water for one full minute.

3. Remove your hand and immediately count how many forceful fists you can

make in 20 seconds. Record in Figure 1.

Figure 1: Effect of Temperature on Muscle Action

Temperature	Number of Fists
Normal	30
Ice Water	15

Effect of Fatigue on Muscle Action

1. Count how many times you can tightly squeeze a rubber ball in your hand

in 20 seconds. Record in Figure 2.

2. Repeat the squeezing nine more times and record results. Do not rest

between trials.

(An alternative procedure which works well is to open and close a

clothespin with the thumb and index finger while the other fingers are held

out straight.)

Figure 2: Effect of Fatigue on Muscle Action

Trial	# of Squeezes in 20 seconds	9 More X's
1	33	8 sec
2	28	8 sec
3	25	9 sec
4	22	10 sec
5	20	11 sec
6	19	12 sec
7	18	12 sec
8	18	12 sec
9	16	13 sec
10	15	13 sec

ANALYSIS OF DATA:

1. What are the three changes you observed in a muscle while it is working (contracted)?

I observed the longer into the experiment I went the harder it was to physically close my hand, my hand got warmer, more muscle burn at the end (lactic acid build up), had to concentrate more to close my hand tightly, and the interval was longer between fists.

2. What effect did the cold temperature have on the action of your hand muscles? Explain.

The cold made my hand slow to react as well as unable to make as tight of a fist. I have always been told as an athlete to “warm up my muscles by stretching and light exercise before competing”. Warm muscle work better than cold muscles due to increases blood flow (O2 and glucose).

Attempts Number

4. What effect did fatigue have on the action of your hand muscles? Explain.

At a certain point the number of repetitions exceeded the aerobic threshold causing an anaerobic process to start, and lactic acid started building up.

Unit III Chapter11

Chapter 11

Skeletal System

Overview of the Skeletal System

- Supports the body

- Protects soft body parts

- Produces blood cells

- Stores minerals and fats

- The skeleton with muscles provides flexibility and movement

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

Anatomy of a Long Bone

- Medullary cavity (yellow bone marrow)

- Articular cartilage

- Periosteum

Bone

- Compact bone (osteocytes)

- Spongy bone (red bone marrow)

Cartilage

- Hyaline cartilage

- Fibrocartilage

- Elastic cartilage

Fibrous Connective Tissue

- Ligaments

- Tendons

Bone Growth, Remodeling, and Repair

- Osteoblasts

- Osteocytes

- Osteoclasts

Bone Development and Growth

- Intramembranous Ossification

- Endochondral Ossification

- The cartilage model

- The bone collar

- The primary ossification center

- The medullary cavity and secondary ossification sites

- The epiphyseal plate

Hormones Affect Bone Growth

- Growth Hormone (GH)

- Vitamin D

Bone Remodeling and Its Role in Homeostasis

- 18% of bone recycled annually

Bone Repair

- Hematoma

- Fibrocartilaginous callus

- Bony callus

- Remodeling

Bones of the Axial Skeleton

- Skull

- Hyoid Bone

- Vertebral Column

- Rib Cage

Skull (cranium)

- Frontal bone

- Parietal bone

- Occipital bone

- Foramen Magnum

- Temporal bone

- Sphenoid bone

- Ethmoid bone

Facial Bones

- Mandible

- Maxillae

- Zygomatic bones

- Nasal bones

Hyoid Bone

Vertebral Column

- 33 Vertebrae

- 7 Cervical

- 12 Thoracic

- 5 Lumbar

- 5 Sacral (fused)

- 4 Coccyx (fused)

Intervertebral Disks

- Fibrocartilage

The Rib Cage

- 12 Ribs and associated cartilage

- 12 Thoracic Vertebrae

- Sternum

The Bones of the Appendicular Skeleton

The Pectoral Girdle and the Upper Limb

- The Pectoral Girdle

- Scapula

- Clavicle

- The Upper Limb

-Humerus

- Radius

- Ulna

- Carpals

- Metacarpals

- Phalanges

The Pelvic Girdle and the Lower Limb

- The Pelvic Girdle

- Coxal Bone

- The Lower Limb

- Femur

- Tibia

- Fibula

- Patella

- Tarsals

- Metatarsals

- Phalanges

http://academic.kellogg.cc.mi.us/herbrandsonc/bio201_McKinley/f8-1a_appendicular_skel_c.jpg

Articulations

- Fibrous Joint

- Cartilaginous Joint

- Synovial Joint

Sources:

Human Biology 10^th Edition by Sylvia S. Mader

Larry M. Frolich Power Point Unit III

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

http://academic.kellogg.cc.mi.us/herbrandsonc/bio201_McKinley/f8-1a_appendicular_skel_c.jpg

Unit III Ethical Paper

The Battle of the Bulge – Mind over Matter

Exercise is beneficial to health and well-being. It is widely accepted and preached that obesity is dangerous to one’s overall health and can promote a wide variety of health issues up to and including premature death. While everyone seems to agree on these concepts, many of us still find it difficult to incorporate a physical fitness regimen into our daily lives. At least the awareness is there and more communities, businesses, schools, health plans and individuals are making an effort to modify our inactive lifestyles. All of that notwithstanding, I think there is something missing in the article discussing modifying the environment to reverse obesity, namely, our society’s body image issues, unrealistic weight ideals, and diet/binge culture.

It is all well and good to discuss the health benefits of eating well, being physically active and weighing less. However, popular culture portrays a beauty ideal that is almost impossible for a vast majority of normal people to achieve. Short of having personal trainers, personal cooks, and the leisure to exercise many hours a day (or a heroin habit like some of the super models), most people could never maintain the skinny bodies continuously paraded before us in popular media. Eating disorders are rampant, more so among women, but also among men. Until we start to move the beauty ideal to a more realistic image in society, it’s going to be hard for us to have the self-esteem and confidence to feel like we can effectively manage our weight. If we’re constantly battling unrealistic images and feeling unable to achieve them, we’ll continue to be discouraged by our seemingly futile efforts. Psychologically we need to begin addressing this issue.

The next issue that I feel needs to be re-evaluated is what ideal weight really means. I just went out and looked at three different weight charts from three different sources. I looked at the suggested weight for my wife and me, and compared it to a time when we were both cycling and working out a large amount and were at what we both considered comfortable, healthy weights. In both cases the charts showed us as ‘overweight’. Fortunately, we didn’t pay attention to those charts at the time and aren’t overly influenced by societal pressures to be thin. However, many people don’t have such strong defenses and would have felt dissatisfied with what were very healthy, strong bodies. These charts are used by medical doctors, insurance companies and others and add to the psychological barriers I spoke to in the previous paragraph. We need to make sure health is being measured in more realistic terms in our public discourse. There are many body types and sizes, and health is often as much a factor of heredity, what we eat, and how we feel about ourselves and our lives, as some number on a scale that we stand on. I have friends that are thinner and exercise more than I, that are definitely much less healthy, both physically and psychologically.

Finally, I think our dieting/binging culture needs to be changed. The diet industry is huge and advertises extensively – and now more and more with celebrities who have done the program and lost weight. Based on what I’ve seen in my own circle of friends and co-workers who have gone on a fad diet and lost a lot of weight, it’s rarely a long-term weight loss and once the goal weight has been achieved, they’ve gained the weight back over some period of time. Most of these dieting programs are unrealistic for normal eating or exercise routines, or don’t emphasize overall healthier eating habits and lifestyle change. I think diets cause an unhealthy obsession about food and a greater tendency to binge and diet again and again. Not to mention the physiological issues it can cause – like slowing down your metabolism because your body thinks it’s being starved. It’s a vicious cycle and one that I don’t see discussed much in public discourse. It goes back to the overall psychology of physical and emotional well-being that needs to be encouraged to get people on the right track towards healthier lifestyles.

There is no doubt that we are getting fatter and subsequently suffering more ill effects because of it. However, I think we need to make sure that we’re incorporating more complex psychological and emotional factors into the overall effort to cause a change in our society that will turn the tide. Until we can acknowledge and accept more realistic weight and health goals for ourselves, we’ll continue to struggle with our ever-growing waistlines.

Unit III LEECH NEUROPHYSIOLOGY LAB

LEECH NEUROPHYSIOLOGY LAB: 1. What is the electrode measuring?

Impulse activity of the neurons. 2. Why use leeches in neurophysiology experiments?

Because the nerve structures are very large in comparison to other animals. 3. What is the difference between a sensory and a motor neuron?

A sensory neuron sends impulses based on some external input where a motor

neuron is to move a muscle.

4. Do you think a leech experiences pain? What is pain?

In this experiment, no due to it is a cyber leech. But in the real world I would say,

yes otherwise why use anesthesia on the leech. Unless it is to keep it from

moving as it is being dissected. 5. What were the two most interesting things about doing this lab?

Finding the different neurons and seeing different impulses each one had. 6. Anything you found confusing or didn't like about the lab?

No, I found it to be very straight forward.

Unit III Chapter 14

Chapter 14

Senses

Sensory Receptors and Sensations

Sensory receptors initiate the nerve impulses that travel to the CNS. Sensation only occurs once the impulse reaches the cerebral cortex. There are four types of receptors:

- chemoreceptors are receptors that respond to chemicals and are found in the

taste buds and olfactory epithelium.

- pain receptors are specialized receptors that respond to chemicals released by

cells surrounding the receptor.

- photoreceptors are receptors that respond to light energy and are found in the

rods and cones in the retina.

- mechanoreceptors are receptors that respond to pressure and are found in the

hair cells of the inner ear and respond to sound pressure for hearing, motion for rotational equilibrium, and gravity for gravitational equilibrium.

- thermoreceptors are receptors that respond to temperature changes. There are

two types, warmth and cold receptors. They are located in the skin and the

hypothalamus.

Proprioceptors and Cutaneous Receptors

- proprioceptors are special mechanoreceptors that involve the reflex action that

maintain muscle tone and as a result help coordinate posture and

equilibrium.

- cutaneous receptors are the receptors in the dermis layer of the skin

responsible for touch, pressure, pain, and temperature.

Senses of Taste and Smell

We can taste and smell due to chemoreceptors that respond to protein molecules

and are found in the taste buds and olfactory epithelium. The taste buds allow the brain to distinguish five tastes; sweet, sour, salty, bitter, and umami. Our sense of smell is much more acute with the ability to distinguish tens of thousands of smells if not more.

Sense of Vision

Has basically three parts; the eye, the optic nerve, and the cerebral cortex.

Anatomy and Physiology of the Eye

The eye itself is comprised of three layers:

-the sclera, which is the outer layer, supporting and protecting the eye, it

also contains the cornea.

-the choroid, which is the middle layer, absorbs stray light, and also

contains the iris and ciliary body.

-the retina, which is the inner layer, which contains the sensory receptors

(rods, cons, and fovea centralis).

http://www.hollows.org/upload/7727.pdf

Function of the Lens

Light travels through the cornea, lens, and the vitreous humor onto the retina. The ciliary muscle and the suspensory muscle work together to flatten the lens for distant objects and rounded for near objects.

Visual Pathway to the Brain

The pathway to the brain begins as light strikes the retina, stimulating the

photoreceptors (rods distinguish black/white, shapes and motion; and

cones distinguish color), continuing to the optic nerve to the optic

chiasma then on to the occipital lobe of the brain.

Abnormalities of the Eye

- Distance vision is attributed to short eyeballs, where the image is in

focus past the retina.

- Near vision is attributed to long eyeballs, where the image is in

focus before the retina.

- Astigmatism is where the lens or cornea is uneven and cannot evenly

focus an image on the retina.

Sense of Hearing

A sense of hearing depends on the ear, the cochlear nerve and the auditory centers of the cerebral cortex. Sensory inputs for equilibrium (balance) also happen in the ear. This done through mechanoreceptors called stereocilia attached to hair cells in the inner ear.

Anatomy and Physiology of the Ear

The ear has three specific parts:

- the outer ear, containing the pinna, the auditory canal and the tympanic

membrane used in directing pressure wave to the middle ear.

- the middle ear, containing the tympanic membrane, the malleus, the

incus, the stapes, used in amplifying the pressure waves and the oval and

round windows, which are covered by a membrane, separating the

middle ear from the inner ear .

- the inner ear, which has two functions; one containing the semicircular

canals, the vestibule, and the vestibule nerve which are used in

equilibrium (balance); and two containing the cochlea and the cochlear

nerve used in converting sound into impulses to send to the auditory

centers of the brain.

http://images.google.com/imgres?imgurl=http://www.nlm.nih.gov/medlineplus/ency/images/ency/fullsize/1092.jpg&imgrefurl=http://www.nlm.nih.gov/medlineplus/ency/imagepages/1092.htm&h=320&w=400&sz=21&tbnid=US7FA1FPyrYM1M:&tbnh=99&tbnw=124&prev=/images%3Fq%3Danatomy%2Bof%2Bthe%2Bear%26um%3D1&start=1&sa=X&oi=images&ct=image&cd=1

Auditory Pathway to the Brain

The auditory pathway begins as a pressure wave travels down the

auditory canal to the tympanic membrane to the middle ear. Then is

amplified by the middle ear through the membrane at the oval window

and into the inner ear. Nerve impulses are generated by

mechanoreceptors called stereocilia attached to hair cells in the inner

ear. These impulses travel down the cochlear nerve to the auditory center

of the brain.

Sense of Equilibrium

There are three semicircular canals. Sensory inputs for equilibrium (balance) also happen in the ear. This done through mechanoreceptors called stereocilia attached to hair cells in the inner ear (ampulla, utricle and saccule). But the brain also integrates vision and positional information from receptors in the muscles and tendons for a total balance equation.

Rotational Equilibrium Pathway

Rotational and/or angular movements of the head are determined when the

mechanoreceptors called stereocilia attached to hair cells in the ampulla

send impulses into the vestibular nerve and to the brain

GravitationalEquilibrium Pathway

Vertical or horizontal movements of the head are determined when the

mechanoreceptors called stereocilia attached to hair cells in the saccule

and the utricle send impulses into the vestibular nerve and to the brain.

Sources:

Human Biology 10^th Edition by Sylvia S. Mader

Larry M. Frolich Power Point Unit III

http://www.hollows.org/upload/7727.pdf

http://images.google.com/imgres?imgurl=http://www.nlm.nih.gov/medlineplus/ency/images/ency/fullsize/1092.jpg&imgrefurl=http://www.nlm.nih.gov/medlineplus/ency/imagepages/1092.htm&h=320&w=400&sz=21&tbnid=US7FA1FPyrYM1M:&tbnh=99&tbnw=124&prev=/images%3Fq%3Danatomy%2Bof%2Bthe%2Bear%26um%3D1&start=1&sa=X&oi=images&ct=image&cd=1

Unit III Chapter 13

Chapter 13

Overview of The Nervous System

Consists of two parts the Central Nervous System (CNS) and the Peripheral Nervous System (PNS). The CNS has two parts the brain and the spinal cord. The PNS are the rest of the nerves; cranial and spinal nerves, sensory and motor fibers, somatic and autonomic nervous, sympathetic and parasympathetic divisions. The CNS and PNS have three functions: reception of inputs, integration of the inputs (data) and generation of motor outputs.

Nervous Tissue

There are two types of nervous tissue; neurons (which transmit nerve impulses) and neuroglia (which nourish and support the neurons).

Neuron Structure

There are three parts to a neuron: dendrites, the cell body (which contains the nucleus) and the axon.

http://www.emc.maricopa.edu/faculty/farabee/biobk/BioBookNERV.html

The three types of neurons comprise the three functions of the nervous system. Sensory neurons take impulses from the sensory receptors to the CNS. The interneurons integrate the data within the CNS. And the motor neurons take impulses from the CNS to motor effectors.

Myelin Sheath

Is the protective fatty covering on long axons. It also helps with regeneration of these axons if they become severed. And also with conduction of impulses through salutatory conduction.

The Nerve Impulse

The nerve impulse happens when the cell momentarily changes polarity from a negative potential (resting state) to a positive potential (action state).

http://eleceng.ukc.ac.uk/~sd5/pics/research/big/actpot.gif.

The Synapse

The synapse is the junction between neurons. A nerve impulse is transmitted when a neurotransmitter is released into a synaptic cleft. Excitation or inhibition happens when a neurotransmitter binds to a receptor. Data integration happens when the input (excitation and/or inhibition) signals are received and processed.

http://www.emc.maricopa.edu/faculty/farabee/biobk/BioBookNERV.html

The CNS

The CNS has two parts the brain and the spinal cord. This is where integration and initiation of motor responses occurs.

The Brain

The parts of the brain are: the cerebrum, the diencephalon, the cerebellum, and the

brain stem.

The Cerebrum is the last center to receive sensory input, then integrates those

inputs and commands the appropriate motor response. It also coordinates and communicates with the other parts of the brain.

∙cerebral hemispheres - left and right halves connected by the corpus callosum.

∙each hemisphere is divided into four lobes

∙ Frontal lobe - which contains the primary motor area, premotor area

motor speech area, prefrontal area, and primary olfactory area.

∙ Temporal lobe - which contains the auditory association area, primary

auditory area, and sensory speech area.

∙ Parietal lobe - which contains the primary somatosensory area,

somatosensory association area, primary taste area, and the general

interpretation area.

∙ Occipital lobe - which contains the primary visual area and the visual

association area.

The Diencephalon contains the thalamus and the hypo-thalamus.

∙ The thalamus controls all sensory inputs to the cerebrum except for

smell.

∙ The hypo-thalamus helps maintain homeostasis by regulating hunger,

thirst, sleep, body temperature, and water balance. Also by controlling

the pituitary gland it can communicate with the endocrine and nervous

systems.

The Cerebellum coordinates skeletal muscles to produce smooth and graceful

motions.

The Brain stem helps regulate certain autonomic functions such as breathing,

heart rate, and blood pressure. It also contains the centers for coughing,

sneezing, vomiting, swallowing and hiccupping.

http://www.prs.k12.nj.us/schools/PHS/Science_Dept/APBio/pic/brain.gif.

The Spinal Cord

The spinal cord is the link between the PNS and the brain. It carries cerebrospinal

fluid and has gray and white matter. The spinal cord is also the center for

thousands of reflex arcs.

The Limbic System and Higher Mental Functions

Limbic System

The Limbic system involves two distinct structures that are tied to emotions, learning and memory. The two structures are the amygdala and the hippocampus. The amygdala is directly associated with the emotion of fear, the ‘fight or flight’ reaction and the hippocampus is involved in the process of where and whether or not a memory is needed and then stored to be used at a later time.

http://images.google.com/imgres?imgurl=http://www.stanford.edu/group/hopes/basics/braintut/f_ab17limbiccr.gif&imgrefurl=http://www.stanford.edu/group/hopes/basics/braintut/ab5.html&h=350&w=305&sz=23&tbnid=VPH3sMSvj9DrPM:&tbnh=120&tbnw=105&prev=/images%3Fq%3Dlimbic%2Bsystem%26um%3D1&start=2&sa=X&oi=images&ct=image&cd=2

The PNS

The PNS is made up of two parts, the nerves and ganglia. And is divided into two systems the somatic and the autonomic. But the autonomic has two divisions; the sympathetic and the parasympathetic. Also the nerves involved with the head (cranial nerves) only communicate with the brain and the spinal nerves only with the spinal cord.

The Somatic System

This system includes the sensory nerves of the skin and the effector nerves of the muscles and tendons. These actions can be voluntary or involuntary as in reacting to a pin prick.

The Autonomic System

This system has two divisions; the sympathetic and the parasympathetic. All of the actions or reactions in this system are automatic and involuntary. Basically the sympathetic system reacts to situations, whereas the parasympathetic system has the opposite reaction or calming affect. The sympathetic system is more associated with the fight or flight actions where the parasympathetic is the rest and digest system.

Drug Abuse

Have basically two effects; they affect the limbic system and therefore altering the mood or emotions of the individual or they affect specific neurotransmitters interactions with specific receptors.

Sources:

Human Biology 10^th Edition by Sylvia S. Mader

Larry M. Frolich Power Point Unit III

http://www.emc.maricopa.edu/faculty/farabee/biobk/BioBookNERV.html

http://eleceng.ukc.ac.uk/~sd5/pics/research/big/actpot.gif.

http://www.emc.maricopa.edu/faculty/farabee/biobk/BioBookNERV.html

http://www.prs.k12.nj.us/schools/PHS/Science_Dept/APBio/pic/brain.gif.

http://images.google.com/imgres?imgurl=http://www.stanford.edu/group/hopes/basics/braintut/f_ab17limbiccr.gif&imgrefurl=http://www.stanford.edu/group/hopes/basics/braintut/ab5.html&h=350&w=305&sz=23&tbnid=VPH3sMSvj9DrPM:&tbnh=120&tbnw=105&prev=/images%3Fq%3Dlimbic%2Bsystem%26um%3D1&start=2&sa=X&oi=images&ct=image&cd=2