Treppe Contraction

The treppe contraction is the staircase effect. Graded contractions acummulate because calcium hasn't been absorbed , this causes a graded response . A single stimulus that produces a twitch and the stimulus gets greater ; muscles are warmer and enzymes are more efficient ;  calcium remains in the sarcoplasm and is not all taken up into the sacoplasmic recticulum.

Events That Occur During Each Phase of a Muscle Twitch

Lag Phase : 1] An action potential is progated to the presynatic terminal of the motor neuron.. 2] The action potention causes the permeability of the presynaptic terminal to increase. 3] Calcium ions diffuse into the presynaptic teminal , causing acetylcholine contained within several synaptic vesicles to be released by exocytosis intso the synaptic cleft. 4]Acetylcholine released from the presynaptic terminal diffuses across the synaptic sleft and binds to acetylcholine receptor molecules in the postsynaptic membrame  of the sarcolemma . 5] The binding of acetylcholine to its receptor site causes ligand-gated Na+ channels to open ,and the postsynaptic membrane becomes more permeable to Na+. 6 ] Sodium ions difuse into muscle fiber ,causing a local depolarization that exceeds threshold and produces an action potential .7] Acetycholine is rapidly degraded in the synaptic cleft to acetic acid and choline by acetylcholinesterase , thus limiting the length of  time acetylcholine is bound to its reptor site .The result is that one presynpatic action potential produces one postsynaptic action potential in each muscle fiber . 8] The action potentia produced in a muscle fiber is progated from the postsynaptic membrane near the middle of both ends and into the T tububles .9] The depolarization that occurs in the the T tubule in response to the actio potential causes Ca+ channels of the membrane of the membrane of the sarcoplasmic recticulum to open ,and the membrane of the sarcoplasmic recticulum becomes very permeable to Ca2+. 10] Calcium ions diffuse from the sacroplasplasmic recticulum into the sacrcoplasm. 11] Calcium ions bind troponin ; The troponin -tropomyosin complex changes its postionand exposes the active site on the on the acttin myofilaments.
Contraction Phase
12 ]Cross- bridges  between actin molecules and myosin molecules form, move , release ,and reform many  times , causing the sarcomeres to shorten . Energy stored in the head of the myosin molecule allows cross-bridge formation and movements. After cross-bridge movement has occurred  ,ATP must bind to myosin head . The ATP is broke down to ADP , and some of the energy is used to released the cross-bridge  and cause the head of the myosin molecule to move back to it's resting postion , where its ready to form another cross-bridge . Some of the energy from the ATP is stored in the myosin head and is used for the next cross-bridge formationand monement.
Relaxation Phase
13] Calcium ions are actively transported into the sacoplasmic reticulum .
14] The trponin-tropomyosin complexes inhibit cross-bridge formation.
15] The muscle fibers lengthen passively .

The Skeletal System

I learned in the skeletal system that the bone cells osteocytes  maintain matrix within the lucunae.Osteoblasts deposit matrix , and when they get caught  become osteocytes. Osteoblasts come from osteochondral progenitor cells  , which comes from mesenchymal cells  all cells resposible for making connective tissue. Osteoclasts break down nbone , secrete water , make hydrochloric acid , breaks down collagen fibers . Precursor cells are monocytes ,which phagocyte , andand become become" big eaters" nacrophages. Cells that produce cartilage are chondoblasts ,and are trapped inside and become chondrocytes .The job of the chondrocytes is to maintain cartilage . In the bone matrix the inorganic material consists primarily of hydroxyapatite . The organic molecules has two things C02 ,and H2 .Collagen is a lipid , a big molecule, subunit protein anino acid is 20.Collagen -amino acids are all organic.The function of the skeletal system is to support , to hold the body up ,prtection of all major organs , movement , and storage . I learned there are two types of cartilage ; hyaline  , and fibrocartilage . Fibrocartililage is found in the intervebral discs ,sympyhsis ,balland socket / glenoid cavity . The hyaline cartilage can be found in in the synovial joints , slick surfaces , epephyses paltes , long bones ,synchondroses ,bends ,ribs to sternum . We grow cartilage byinterstitial and appositional growth .Interstitial , catilage replicates, , appositional  , chondroblasts add new cartilage to the outside of the cartilage .I learned the two tyoes of bone growth , intramembranous ossification , and endochondral ossification . Intramembranous growth takes palce within the connnective tissue membrane , while the endochondral ossification takes palcein the cartialage .Both methods produce woven bone , which is then remodeled .

Tisssues and Muscles

I've learned in lab regarding the tissues that the simple squamous epithelium is located in the kidney glomeruli , it's job is to line , cover , filter , and produce serous fluid. It .lines the mesothelium cavity that encloses the organs such as the heart , abdomen and lung . The  simple cuboidal epithelium is located in the kidney tubules , it's function is secretion and absorption. The simple columnar epithelium lines the intestines , job is secretion and absorption . The pseudostratified columnar epithelium moves stuff out of trachea , secretes particularly mucous .The transitional epithelium  tissue is ballooned shaped ,streches to accomadate storage of urine . It lines the ureters , urinary bladder,and part of the urethra .The loose areolar connective tissue consists of looose collection of cells with lots of space .This tissue anchors dermis , epidermis papillary layer .The hyaline cartilage covers the end of long bones ,chronoblasts produce the matrix and when mature chrondrocytes lie in the lucunae .Elastic cartilage supprts the external ear , maintaining the structure while allowing flexibility .The fibrocartilage is located between the interverbral discs , cushions between bones .The compact bone supports , and protects , the osteocytes lie in the lucunae. The pacinian corpuscles lie in the hypodemis ,it's function is deep cutaneous pressure , and vibration. Arranged like leaves of an onion .The integumentary is the skin which has several layers , including the luciden . The scalp  which consists of the hair follicles , with the arrector pili muscle, sebacous glands and sweat glands . The multipolar cell , the nervous tissue consists of motor neurons ,glia cells and other large cells .The retina consisted of the fibrous coat ,sclera ,cornea ,the cell body , rods ,and cones , and ganglion cells .The skeletal muscle  is elongated contiuous fibers , with nucleated striations . The cardiac muscle has a hugh number of thin cells , spindled shaped with overlapping ends . It contracts , and propels blood into circulation .

The Classes of Joints

I learned in class on yesterday from Chap. 8 ,the concept of the classes of joints . An ex. of an fibrous joint is sutures of the skull . Cartilaginous joints have cartilage , and are in the ribs .The synovial joints contains synovial fluid covered with hyaline cartilage called articular cartilage which provides smooth surface where the bone surface . The function of the synarthroses =no movement. Amphiathroses =little movement ,and diathroses =means free movement .

Action of an Odorant Binding to Menbrame of Olfactory Hair /Chap 15

I learned the concept of that airborne molecules enter the nasal cavity and are dissolved in the fluid covering the olfactory epithelium .These molecules are are odorants . The plasma membrane of the olfactory hair , unstimulated , the gate stys closed . An odorant binds to a receptor ,activating the "G" protein . The a ,B,and y come aloose , the" a"  subunit binds to and activates adeny;late cyclase.Adenylate cyclase catalyzes the conversion of ATP to AMP[cAMP] .cAMP opens the ion channels , such as sodium and calcium . Ions cause depolarization of the nueron . This is what causes us to be able smell so many different things.

The Location of the ANS receptors

When you had the class to break off into groups and help each other to learn the location of the ANS receptors , was very helpful .The drawing on the board demostrated that 1] the somatic nerve which the skeletal is the target has one synaspe releases ACH ,which binds to a nicotinic receptor. 2] The autonomic nerve releases ACH to the adrenal gland  , then releases epinephrine and norepinephrine into the bloodstream. 3] The sympathetic division releases ACH causes NE , which relaeases norepinephrine into the adrenal glands . 4] Then there's the parasympathetic division that releases ACH muscarinic is released into the heart . I've learned that  the sympathetic and parasympathetic  neve endings one of the two transmitters. If it secretes ACH it 's a cholinergic , if it secretes norepinephrine it's an adrenergic neuron . I see how they play the neurotransmittor role .

The Formation of the neural tube

Dr. Platt this is my understanding of the formation the neural tube . The central canal and ventricles produce the neural plate [ which forms from the ectoderm ] .The neural fold forms as ridges along the embryo , actually making an fold, and causing the middle of the fold to become a groove [neural groove]. The neural crest then makes the sensory autonomic neruons in the PNS , melanocytes , facial bones and dentin of teeth . This happens because the neural crest breaks away from the folds , meeting at the midline to form the neural tube .The nueral tube then becomes the  brain and the spinal cord . Thank goodness , this concept was relatively simple , and the illustration on page 440 is very good .

Divisions of the brain and thier functions

The brain divisions include the brainstem , which connnects the spinal cord to the cerebrum ; consists of the medulla oblongata ,pons and midbrain ,with the reticular formations scattered throughout the three regions , is in the location of cranial nerve nuclei . The medulla oblongata is the pathway for ascending and descending nerve tracts ; center for several important reflexes [e.g. ,heart rate ,breathing , swallowing , vomiting].The pons contain ascending and descending nerve tracts ; relays information between the cerebrum and cerebellum ; site of reflex centers .The midbrain contains ascending and descending nerve tracts ; serves as a visual nerve center ;part of auditory pathway . The reticular formation is scattered throughout the brainstem ; controls cyclic activities , such as the sleep -wake cycle . Another division of the brain is the cerebellum , which controls muscle movement and tone ; governs balance , posture ; regulates extent of intentional movement iinvolved in leaaarning moter skills. The diencephalon another part of the brain consists of the thalmus ; which is like a call center determining where signals go for information .Then there is the subthalmus . which contains nerve tracts and nuclei , the epithalmus contains nuclei responding to sleep, visual awareness , amd body cycle .Then there the hypothalmus which is the moter control center for maintaining homeostasis , and regulating endocrine function . The cerebrum conscious perception ,thought , and conscious motor activitiy ; can override most other systems. The cerebrum consists of the basal nuclei , which controls muscle activityand posture ; largely inhibits unintentional movement when at rest . The other part of the cerebrum , the limbic system is an autonomic response to smell , emotion , mood ,memory , and other such funtions .

Ion movement through the plasma membrane

During my attempt to get to some understanding of Chapter 11 ,  I see that ion movement through the plasma membrane is the movement of sodium out of the cells requires energy [ATP] , and when calcium binds to proteins in ion channels , the diffussion of sodium into the cell is inhibited . Specific ion channels regulate the diffusion of sodium through the plasma membrane .

The Resting Membrane Potential

I think I finally have some understanding of the concept of resting membrane potential . I understand that the electrical charge across a membrane is called a porential difference.  In the resting cell the potential difference is called the resting membrane potential .The resting membrane potential of neurons is approxiamately -70mV .The potential difference is a negative number because the inside of the plasma membrane is negative  compared with the outside .The greater the charge difference across the plasma membrane the greater the potential difference . It results from the pearmebility characteristcs of the resting membrane and the difference in the concentration of ions betweenthe intracellular and extracullar fluids .The resting membrane potential is established when the movement of pottassium out of the cell is equal to the movement in the cell . I Googled "resting membrane potential ", and it had different tutorials that helped me gain an better understanding of this concept  .Example a resting membrane  potential of -85mV has an greatercharge than a resting membrane of -70 mV.

Learning the Skeletal System

Today in lab while studying the bones ,having learned the  directional terms in class previously is really helped to learn the anantomy of the bones . For example while learning about the pelvic girdle today in lab,I realized how the ilium connects to the the sacrum , and the iliac creast is in the superior margin . While learning about the cranium knowing about the different planes helped me to understand the frontal bone , the anterior frontal bone the sagittal suture , coronal suture ,etc. When studying the cervical veterbrae knowing the difference in anterior, superior ,and tranverse as it related to anterior and posterior tubercle , and tranverse foramina it really helped . I see how every vsubject matter interrelates to the next subject matter .

BIO-207 Ethics Paper Review

This article regarding the ethical dilemmas of nursing points out that nurses are increasingly realizing that they offer relevant information in decision making, involving ethical issues. Inter-professional communication [which usually includes the doctors and nurses], are frequently inadequate, and do not a permit exchange of opinions .This causes frustrations for nurses whose care is affected by other’s policies. As stated earlier nurses realized that they can offer relevant information and participate in decision making involving ethical issues .Working in the medical field for a number of years, I know firsthand, the desire of registered nurses and licensed nurses alike to become more responsible and contributory to the welfare of the patients they take care of .Due to the subordinate roles nurses have held  the conscience of the entire multidisciplinary team needs to be awaked to see the value of the nurse’s role in the patient’s care .One of the number one goals should be to promote interdisplinary harmony and support . This will show up in your overall patient care and isn’t this what this is all about patient care? As the article stated “Recent developments in nursing practice reflect increased knowledge of effective care, changing needs of patients and an attempt by the profession to become complementary to the doctor not poor substitutes or ancillaries. “While doctors may try to exploit their influences, their science and expertise concern the prevention and prevention of disease.  Nurses on the other hand are attempting to care for people by understanding their personal strengths. One of the most important resources a nurse has to give patients is relevant information about their condition, their treatment and ways of coping with both .Nurse are put in difficult situations when their beliefs or those of the patient himself are at variance with those of the others in the medical and nursing team. This is where nurses need to get more comfortable in expressing their views. The primary goal should be is to honest to the patient and represent his view above others, the advocacy role needs to studied carefully, but to effective it has to accepted by the doctor .As I’ve personally witnessed in my own career, doctors may support one or two nurses whom they know and respect performing the advocacy role, but the idea of nursing in general acting as a go between or a confidant discussing medical treatments may seem unacceptable. Perhaps professional respect between doctors and nurses must grow in order to permit frank discussions and questions when either disagrees with their treatment plans, or when the nurse feels she should relay the patient’s doubts or dissatisfactions to the doctor. Controversies today over whether a  nurse should question or disagree with doctors is just as prevalent as in the past structure of medicine and nursing. As the article states “Unilateral decision decisions on medical treatment [or lack of it] were justified in the past through a belief in benign paternalism: doctors knew more about medicine than others, they took legal responsibility for their actions and most members of society were very grateful that this was so. In general this can now be seen only to seen to be justified when responsible others can be informed or participate in such decisions. Throughout this article it continues to emphasize that nurses are adopting more responsibilities for identifying or planning to resolve or reducing illness and related problems. This require freedom

The Nervous System

Studying the nervous system . I understand the functions of the nervous system . I understand that the sensory imput sends information to the CNS then it's integrated , then the imformation leaves and goes to the motor output , and commands a response .I've learned that the CNS consists of the  brain and spinal cord ,and the PNS is  outside the central  nervous system . There are two sets of nerves in the PNS ; the sensory division which is afferent ,meaning going towards the center , and the motor which is eferrent which means moving away out the muscles . I 've also learned that the PNS has two parts ; the somatic which is found in the skeletal is voluntary , and the autonomic  found in cardic muscle , smooth muscle , and the glands is in voluntary . What I'm having problems undestanding is the concept of measuring resting membrane potential . I realize that potential energy is stored energy , and that electrons are charged particles, that flows throughs  our cells to induce movement , but then it's kinda fuzzy the whole concept of the resting membrane potential . I plan to read my text ,and Google some  of the concepts in Chapter 11, to get a bettter understanding .

The number of functions of protective functions of the skin

I've aquired alot knowledge after reading , and reviewing Chapter 5 . I had no idea of all the different proctective functions of the skin .I've learned that the dermis of the skin provides structual strength , and prevents tearing of the skin . I've learned that the stratified epithelium of epidermis  protects against abrasions , as the outer cells of the stratum corneum sloughs off, and are replaced by stratum basale . I't's been reinforced that skin prevents microorganisms from entering the body , as well as keeping microorgananisms , and other foriegn objects out . I really didn't realize the function of  the eyebrows and eye lashes [ to keep sweat out your eyes , and to protect eyes from other foreign objects ] . Like I said it's interesting to learn how all these funtions relate to the funtions of the hair , glands , and nails . the melanin of the skin absorbs ultravilent light protecting underlying structures from it's damaging effects . The nails even have a job , to protect the ends of fingers /toes from damage . Intact skin is important in reducing water loss because lipids acts as barriers to the diffusin of water .

Tissue Repair

Dr.Platt ,  Excited to to share with you the four steps of tissue repair : 1] The fresh wound cuts through the epidermis and dermis , and forms a clot .2] One week after the injury , a scab is present , new epidermis is growing on the wound . 3] Two weeks after the injury , the epithelium has grown completely into the wound , and fibroblasts has formed granulation tissue .4] One month after the injury the wound has completely closed , the scab has sloughed .granulation tissue is repalced by new connective tissue . Back to studying.

What I'm learning about the tissues

Dr. Platt , just alittle note to inform you of how much I've learned about the epithelial tissue by reading chap 4, and discussing it among my group members on yesterday[and of course with the help of your expertise on the subject ]. I got it down packed the , the characteristics of the epithelial tissue , the five major functions . Presently I'm working on learning the functional characteristics of these tissues. Well let my lunch break is almost over . Talk to you later .                                       
                                                                         Cynthia Witcher

Greetings Group 4 !

Hey Grp 4 , This is Cynthia I'll be working on the assignments this weekends ,and cotacting you with questions . Have a good one . Will be talking to you soon .
                                                                                                        
                                                                                                          Cynthia

Welcome

Welcome to my blog Dr.Platt.