Major Lab, Unit 3

This unit lab is a model of a moving human limb with muscles, tendons, bones, and joints built from "play-doh". Each picture of my model has a description of what units that are involved in order to create movement. I also have models of a Neuron that shows: Axon with Schwann cells, Action Potential, and the propagation of action potential along the axon. Once again, each model is labeled accordingly. Lastly, there is a model of a muscle cell that includes: Sacolemma, T-tuble, Sarcomere, Sarcoplasmic reticulum, and myosin.

Below is an extra model representing action potential.

These models represent how our muscles receive information from the cns and in return, take that information and turn it into a reaction, or stimulation. This lab showed me just how complex are muscle system is. Through afferent and efferent transmission of stimulation, we are able to receive stimulation (or sensation) transmit the information, process, and then create a reaction. This lab was a positive re-enforcement of unit 3.

Unit 3, Lab 2

www.etsu.edu

This lab is to test the effects of muscle fatigue and how the cold effects the function of muscles. First, i recorded how many times i can make a fist in 20 seconds. Then i submersed my hand in a ice/water mix for 60 seconds. I then recorded how many "fists" i could make in 20 seconds.

NORMAL Temp. # of fists: 45

Ice Water # of fists: 40

Next, I wanted to know the effect of fatigue on muscle action while squeezing a rubber ball. I did this for 20 seconds, with 10 trials. I did not rest between each trial.

1. 50

2. 47

3. 40

4. 35

5. 28

6. 21

7. 19

8. 15

9. 8

10. 3

1. What are the three changes you observed in a muscle while it is working (contracted)? I noticed that the muscle would enlarge, it would also tighten up, and i could not continue with the same rate due to muscle fatigue

2. What effect did the cold temperature have on the action of your hand muscles? Explain. The cold caused my muscles to constrict due to the vasoconstriction secondary to the cold water. This in turn, made my muscle feel stiff. I had a hard time making my fist due to the initial vasoconstriction, and the end result made it hard for me to "catch up" with the demand.

3. What effect did fatigue have on the action of your hand muscles? Explain In the beginning, my body was able to keep up with aerobic demand of my muscles. However, this was a task specific challenge placed on group of muscles. As i continued with the exercise, my muscles had received adequate O2, but because i did not rest between trials,i think it is possible that the O2 demand for that specific group of muscles was greater than available. The end result was anaerobic cellular respiration with possible hypertrophy of those muscles.

Unit 3, Compendium 2

Muscular & Bone Systems

1.Muscle

a) 3 types of muscle tissue

b) Skeletal muscles

2.Anatomy of skeletal muscles

a) gross anatomy

b) micro-anatomy

c) myofilaments

3.Contractions

a) neuromuscular junction

b) synaptic knob

4.Action Potential Sequence

a) release of ACh

b) binding of ACh

c) conduction of action potentials

5.Bones

a) osseous tissue

b) calcium phosphate

c) osteocytes

d) osteclasts

e) osteoblasts

6.Remodeling & Homeostatic mechanisms

a) remodeling

b) calcium

c) fracture repair

1.Muscles

a) 3 types of muscle tissue: Skeletal, cardiac, and smooth muscle.

picture of the make up of muscle. http://fig.cox.miami.edu/ >>>>>>>>>>>>>>>>

b) Skeletal muscles attach to bones directly or indirectly, and are used to produce skeletal movement, maintain posture and body position,support tissues, guard entrances and exits, and maintain body temp.

2.Anatomy of skeletal muscles

a) Gross anatomy: Muscle fiber is surrounded by endomysium, sheathed by a perimysium, and covered by an epimysium. At the end of the muscle is a tendon.

b) Micro anatomy: Muscle cells have a sarcolemma, sarcoplasm, and a sarcoplasmic reticulum.

c) Myofilaments consit of a thin filament(actin) and a thick filament(myosin).

3.Contractions

a) Neuromuscular Junction: The link between electrical activity in the sarcolemma and the initiation of a contraction.

b) Synaptic knob, synaptic cleft, and motor end plate are part of the junction. picture of neuromuscular junction http://abdellab.sunderland.ac.uk/ >

4. Action Potential Sequence

a) The release of acetylcholine (ACh): Impulse at synaptic knob release ACh into synaptic cleft.

b) The binding of ACh at motor end plate: This event changes the permeability of the membrane to sodium ions.

c) This conduction of action potentials by the sacrolemma: This triggers a sudden release of calcium ions. The ens result is a contraction. This is how our body achieves movement.

5.Bones

a) Osseous tissue: Supports connective tissue, contains specialized cells, extracellular fibers, and ground substances. end product is a distinct solid with a stony character from the disposition of calcium salt. picture of bone tissue http://medicalimages.allrefer.com/ >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

b) Calcium Phosphate(Ca3(PO4)2: Accounts for 2/3 of the weight of bones. The remaining 1/3 is dominated by collagen fibers.

c) Osteocytes: Mature bone cells that recycle calcium and assists with bone repairs.

d) Osteoclasts: Giant cells with 50 or more nuclei, helps regulate calcium and phosphate concentrations in the bodies fluid.

e) Osteblasts: Cells responsible for the production of new bone.

6.Remodeling & Homeostatic mechanisms

a) Remodeling: Organic and mineral components of bone are continuously recycled and renewed.

b) Calcium: Most abundant mineral in the body. 99% is located in the skeleton, which acts as a calcium reserve for the body.

c) Fracture repair involves the formation of a fracture hematoma.

d) effects of aging on the skeleton can include osteopenia and osteoporosis.

picture of remodeled bone http://www.osteopeak.com/ >>

references: Aris, Mader book, Brady book.

Unit 3, Compendium 1

1. Nervous System

a) Two divisions of nervous system

b) 3 specific functions of nervous system

2. Neuron structure

a) Neurons

b) Axon

c) Dendrites

3. Types of neurons

a) Sensory

b) Motor

4. Nerve Impulse

a) Action Potential picture of nervous system http://www.humananatomyposters.com/^^^^^^^^^^^^^^

b) Resting Potential

c) Synapse

5. CNS components

a) Spinal cord

b) Brain

6. PNS

a) Somatic system

b) Autonomic system

7. Sensation

a) Visual cortex

b) Sensory cortex

c) Cutaneous receptors

d) Senses

1.Nervous system

a) 2 divisions- Central Nervous system (brain, spinal cord) and Peripheral Nervous System (nerves), are connected together and work with the CNS to send and receive information.

b) 3 specific functions are sensory input, integration of input from the body, and motor response.

2. Neuron structure

a) Neurons- Cells that transmit nerve impulses between parts of the nervous system. Neuralgia provide support and nourishment to the neurons.

b) Axon- Part of neuron that conducts nerve impulses. Also, known as a nerve fiber. picture of neuron http://www.nomoreadd.com/ >>>>>>>>>>>>>

c) Dendrites- Extensions that receive signals from sensory receptors or other neurons. These signals can result in nerve impulses conducted by the axon.

3. Types of Neurons

a) Sensory- takes nerve impulses from sensory receptor to the CNS.

b) Motor- Takes nerve impulses away from CNS to an effector, which in turn creates a mechanical response.

4. Nerve impulse

a) Action Potential- Rapid change in polarity across an axonal membrane as the nerve impulse occurs, in an "all or none" manner.

b) Resting Potential- The Axon is not conducting an impulse. This means that the inside of the neuron is more negative (polarity) than the outside of the neuron.

action potential and resting potential illustration http://static.howstuffworks.com/ >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

c) Synapse- Terminal are close to the Dendrite or cell body of a neuron. This is the point of communication between the two neurons that happens by the aid of neurotransmitters that are stored in the synaptic vesicles.

5. CNS components

a) Spinal cord- Center of reflex arcs that serve as a "highway" for all communications.

b) Brain- Computes impulses and determines the response.

6. PNS

a) Somatic system- Serves skin, skeletal, and tendons that receive information from an external sensory receptor. Then this information is transmitted to the CNS, then a motor command is sent from the CNS to skeletal muscles.

picture of parasympathetic nervous system. http://webanatomy.net/ >>>>>>>>>>>>>>>>>>

b) Autonomic system- Regulates activity of cardiac, smooth muscles, and glands. 2 components are sympathetic " fight or flight" and parasympathetic " feed and breed".

7. Sensation

a) Visual cortex

b) Sensory cortex

c) Cutaneous receptors

d) Senses in the head allow for taste, smell, vision, hearing, and equilibrium.

references: ARIS, Mader book, Brady book, Leech lab

Unit 3, Lab 1

Leech Lab

This is a picture of the manipulator and the oscillope that show electrical stimulation of the neuron.

This is an ultra violet image of the neuron with dye showing the shape of the sensory neuron.

1. What is the electrode measuring? Transmembrane potential, also called membrane potential.

2. Why use leeches in neurophysiology experiments? Relatively small number and the large size of the neurons have have made the leech popular with neurobiologists.

3. What is the difference between a sensory and a motor neuron? Sensory neurons send information from PNS to CNS. Motor neurons recive information from the CNS that produces a response.

4. Do you think a leech experiences pain? What is pain? Yes, because the leech has has neurons. Pain is a response to stimulation.

5. What were the two most interesting things about doing this lab? Producing an electrical response to the neuron and the dissection process.

6. Anything you found confusing or didn't like about the lab? I didn't find this lab confusing at all, it was fun!