Heartbeat Control in Leeches. I. Constriction Pattern and Neural Modulation of Blood Pressure in Intact Animals

2004 ◽  
Vol 91 (1) ◽  
pp. 382-396 ◽  
Author(s):  
Angela Wenning ◽  
Gennady S. Cymbalyuk ◽  
Ronald L. Calabrese
Keyword(s):  
Coordination Mode ◽  
Motor Pattern ◽  
Systolic Pressure ◽  
Circulatory System ◽  
The Body ◽  
The Other ◽  
Coordination Modes ◽  
Neural Modulation ◽  
Pressure Profiles ◽  
Intravascular Pressure

Two tubular hearts propel blood through the closed circulatory system of the medicinal leech. The hearts are myogenic but are driven by a centrally generated motor pattern that controls heart rate and intersegmental coordination. In two consecutive papers, we address the question of how the motor pattern is translated into the pattern of diastole and systole of leech hearts. We imaged the constriction patterns of the hearts in quiescent intact animals. In one heart, systole progresses rear-to-front (peristaltic coordination mode), whereas systole occurs nearly simultaneously in the other heart (synchronous coordination mode) with regular switches between these two coordination modes. Intersegmental phase relations between heart segments do not vary with changes in the heartbeat period. The peristaltic heart drives blood forward through itself and then rearward through the other longitudinal vessels. The synchronous heart does not seem to contribute to rearward flow along the body axis and may support segmental circulation instead. Simultaneous monitoring of heart motor neuron discharge and the constriction of the corresponding heart segment in innervated, reduced preparations enabled us later to meld the constriction pattern with the fictive motor pattern described in the following paper. Current injections into one heart modulatory neuron while monitoring intravascular pressure from the corresponding heart showed that these neurons can acutely change diastolic and systolic pressure. However, they do not determine the different systolic pressure profiles associated with the two coordination modes, which appear to result from the constriction pattern.

Embryonic development—the first few weeks

2013 ◽  
Author(s):  
Martin E. Atkinson
Keyword(s):  
Embryonic Development ◽  
Human Body ◽  
Circulatory System ◽  
Building Blocks ◽  
The Body ◽  
The Other ◽  
Developmental Anatomy ◽  
Fetal Period ◽  
Embryonic Period ◽  
Degree Of Overlap

Embryology is a fascinating subject and is the foundation of the development, growth, and maturation of all the cells, organs, and tissues of the body. Strictly, embryology is the study of the early processes of development beginning at fertilization and following the processes that turn a single cell into a multicellular organism. It is all about generation of the building blocks required to make a human body. Developmental anatomy is the study of how these building blocks are turned into specific cells, tissues, and organs as well as the general growth of the body. As you will soon appreciate in the following paragraphs, all organs and systems do not develop at the same rate so there is a degree of overlap between embryology and developmental anatomy. For example, the heart and circulatory system must develop and be functioning very early in development to ensure adequate supplies of nutrients to the developing fetal tissues. Teeth, on the other hand, are not going to be used until about six months after birth at the earliest; while the heart is already beating away, each developing tooth is merely a tiny group of cells bearing little resemblance to a fully formed tooth. Human gestation is considered to take nine months; more accurately, it usually lasts for 38 to 39 weeks from fertilization to birth. Clinically, it is divided into three trimesters of three months each. In this chapter, we will focus on events in the first few weeks. During the first two and a half weeks after fertilization, the very basic building blocks are formed from the single fertilized cell; this is the pre-embryonic period. The embryonic period covers the next five and half weeks during which these basic building blocks develop into the cells, tissues, and organs. As already indicated, some of these may be in a very rudimentary state at the end of the embryonic period. The remaining 30 or so weeks is the fetal period when the tissues and organs of the body grow and develop and the fetus grows considerably. We are not fully mature organisms at birth and have another 20 years a-growing.

Circulation in the Leech, Hirudo Medicinalis L

1988 ◽  
Vol 134 (1) ◽  
pp. 235-246 ◽  
Author(s):  
JAN-PETER HILDEBRANDT
Keyword(s):  
Blood Flow ◽  
Circulatory System ◽  
The Body ◽  
Diastolic Filling ◽  
Dorsal Vessel ◽  
Capillary Networks ◽  
Different Shapes ◽  
Blood Flow Velocities ◽  
Improved Model ◽  
Intravascular Pressure

In the leech, the physiological significance of high-pressure phases (HIP) and lowpressure phases (LOP) of the lateral vessels was studied by intravascular pressure recordings and observation of blood flow in different parts of the circulatory system, and by measurements of the blood flow velocities in the dorsal vessel. Different shapes of the pressure pulses were found in the anterior lateral vessel segments during HIP and LOP phases, according to the different modes of diastolic filling in both phases. Pressure recordings in the lateral abdominal vessels showed the different action of the lateral abdominal sphincters in the HIP and LOP phases of the ipsilateral lateral vessel. The LOP contractions were responsible for the blood supply to the capillary networks of the organs and the body wall, with the possible exception of the intestine. The HIP contractions caused a forward bloodflow within the lateral vessel. In the dorsal vessel, the blood pressure was about 0.9-1.9kPa in different animals. The blood flow was discontinuous with velocities of 0.5-10 mms−1. Average blood flow in the dorsal vessel was 22.9μl min−1. An improved model of the circulation in the leech is presented.

Heartbeat Control in Leeches. II. Fictive Motor Pattern

2004 ◽  
Vol 91 (1) ◽  
pp. 397-409 ◽  
Author(s):  
Angela Wenning ◽  
Andrew A. V. Hill ◽  
Ronald L. Calabrese
Keyword(s):  
Motor Neurons ◽  
Sensory Feedback ◽  
Coordination Mode ◽  
Motor Pattern ◽  
Preceding Paper ◽  
Rhythmic Activity ◽  
Pattern Generator ◽  
Inhibitory Input ◽  
Combine Data ◽  
Coordination Modes

The rhythmic beating of the tube-like hearts in the medicinal leech is driven and coordinated by rhythmic activity in segmental heart motor neurons. The motor neurons are controlled by rhythmic inhibitory input from a network of heart interneurons that compose the heartbeat central pattern generator. In the preceding paper, we described the constriction pattern of the hearts in quiescent intact animals and showed that one heart constricts in a rear-to-front wave (peristaltic coordination mode), while the other heart constricts in near unison over its length (synchronous coordination mode) and that they regularly switch coordination modes. Here we analyze intersegmental and side-to-side-coordination of the fictive motor pattern for heartbeat in denervated nerve cords. We show that the intersegmental phase relations among heart motor neurons in both coordination modes are independent of heartbeat period. This finding enables us to combine data from different experiments to form a detailed analysis of the relative phases, duty cycle, and intraburst spike frequency of the bursts of the segmental heart motor neurons. The fictive motor pattern and the constriction pattern seen in intact leeches closely match in their intersegmental and side-to-side coordination, indicating that sensory feedback is not necessary for properly phased intersegmental coordination. Moreover, the regular switches in coordination mode of the fictive motor pattern mimic those seen in intact animals indicating that these switches likely arise by a central mechanism.

Blood Pressure in the Leech Hirudo Medicinalis

1983 ◽  
Vol 107 (1) ◽  
pp. 163-168 ◽  
Author(s):  
BODO KRAHL ◽  
IRENE ZERBST-BOROFFKA
Keyword(s):  
Blood Pressure ◽  
High Pressure ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Low Pressure ◽  
Hirudo Medicinalis ◽  
The Other ◽  
Pressure Pulses ◽  
Intravascular Pressure ◽  
Peristaltic Action

1. Intravascular pressure recordings in the lateral vessels of the leech, Hirudo medicinalis, show two distinct pressure patterns: high pressure phases (diastolic pressure: 5 ± 3 mmHg, systolic pressure: 48 ± 14mmHg) alternate with low pressure phases (diastolic pressure: 4 ± 2.5 mmHg, systolic pressure: 26 ± 11 mmHg). 2. The lateral vessel of one side produces high pressure pulses during peristaltic action while the other vessel generates low pressure pulses during non-peristaltic action. After 20–60 pulses a transition occurs, which sometimes appears more gradually.

High Heels sebagai Agensi bagi Tubuh Wanita

2020 ◽  
Vol 5 (2) ◽  
pp. 196
Author(s):  
Sunandar Macpal ◽  
Fathianabilla Azhar
Keyword(s):  
Body Image ◽  
Literature Review ◽  
The Body ◽  
The Other ◽  
Body Image Disturbance ◽  
Other Hand ◽  
High Heels ◽  
Experience Pain ◽  
Woman's Body

The aims of this paper is to explain the use of high heels as an agency for a woman's body. Agency context refers to pain in the body but pain is perceived as something positive. In this paper, the method used is a literature review by reviewing writings related to the use of high heels. The findings in this paper that women experience body image disturbance or anxiety because they feel themselves are not beautiful or not attractive. The use of high heels, makes women more attractive and more confident, on the other hand the use of high heels actually makes women feel pain and discomfort. However, for the achievement of beauty standards, women voluntarily allow their bodies to experience pain. However, the agency's willingness to beauty standards here is meaningless without filtering and directly accepted. Instead women keep negotiating with themselves so as to make a decision why use high heels.

EXPRESSION OF SOME IMMUNOLOGIC MARKERS FOR THE DIAGNOSIS OF SUSPECTED LYMPHOID LESIONS OF LYMPHOMA

2018 ◽  
Vol 8 (4) ◽  
pp. 28-33
Author(s):  
Mao Nguyen Van ◽  
Thao Le Thi Thu
Keyword(s):  
Correct Diagnosis ◽  
Tumour Cells ◽  
The Body ◽  
The Other ◽  
Cervical Region ◽  
Cross Sectional ◽  
Immunologic Markers ◽  
Microscopic Features ◽  
Poor Differentiation ◽  
Benign Tumours

Background: In practice it was difficult or impossible to have a correct diagnosis for the lymphoid proliferation lesions based on only H.E standard histopathology. In addition to histopathology, the application of immunohistochemistry was indispensable for the definitive diagnosis of the malignant or benign tumours and the origin of the tumour cells as well. Objectives: 1. To describe the gross and microscopic features of the suspected lesions of lymphoma; 2. To asses the expression of some immunologic markers for the diagnosis and classification of the suspected lesions of lymphoma. Materials and Method: Cross-sectional research on 81 patients diagnosed by histopathology as lymphomas or suspected lesions of lymphoma, following with immunohistopathology staining of 6 main markers including LCA, CD3, CD20, Bcl2, CD30 and AE1/3. Results: The most site was lymph node 58.1% which appeared at cervical region 72.3%, then the stomach 14.9% and small intestine 12.4%. The other sites in the body were met with lower frequency. Histopathologically, the most type of the lesions was atypical hyperplasia of the lymphoid tissue suspecting the lymphomas 49.4%, lymphomas 34.5%, the other diagnoses were lower including inflammation, poor differentiation carcinoam not excluding the lymphomas, lymphomas differentiating with poor differentiation carcinomas. Immunohistochemistry showed that, LCA, CD3, CD20, Bcl2, CD30 and AE1/3 were all positive depending on such type of tumours. The real lymphomas were 48/81 cases (59.3%), benign ones 35.8% and poor differentiated carcinomas 4.9%. Conclusion: Immunohistochemistry with 6 markers could help to diagnose correctly as benign or malignant lesions, classify and determine the origin of the tumour cells as lymphocytes or epithelial cells diagnosed by histopathology as lymphomas or suspected lesions of lymphomas. Key words: histopathology, immunohistochemistry, lymphomas, poor differentiated carcinomas, hyperplasia, atypicality

Basic Concepts and Definitions of Allergology

2019 ◽  
Author(s):  
Zoran Vrucinic
Keyword(s):  
Immune Reaction ◽  
The Body ◽  
The Other ◽  
Specific Response ◽  
Other Hand ◽  
Medical Vocabulary ◽  
The Future ◽  
Basic Concepts ◽  
Basic Insight ◽  
Insight Into

The future of medicine belongs to immunology and alergology. I tried to not be too wide in description, but on the other hand to mention the most important concepts of alergology to make access to these diseases more understandable, logical and more useful for our patients, that without complex pathophysiology and mechanism of immune reaction,we gain some basic insight into immunological principles. The name allergy to medicine was introduced by Pirquet in 1906, and is of Greek origin (allos-other + ergon-act; different reaction), essentially representing the reaction of an organism to a substance that has already been in contact with it, and manifested as a specific response thatmanifests as either a heightened reaction, a hypersensitivity, or as a reduced reaction immunity. Synonyms for hypersensitivity are: altered reactivity, reaction, hypersensitivity. The word sensitization comes from the Latin (sensibilitas, atis, f.), which means sensibility,sensitivity, and has retained that meaning in medical vocabulary, while in immunology and allergology this term implies the creation of hypersensitivity to an antigen. Antigen comes from the Greek words, anti-anti + genos-genus, the opposite, anti-substance substance that causes the body to produce antibodies.

Body and Soul

2017 ◽  
Author(s):  
Isabella Image
Keyword(s):  
Human Person ◽  
Fourth Century ◽  
The Body ◽  
The Other ◽  
Spiritual Nature ◽  
Body And Soul ◽  
Century Thought

This chapter discusses Hilary’s dichotomous body–soul anthropology. Although past scholars have tried to categorize Hilary as ‘Platonic’ or ‘Stoic’, these categories do not fully summarize fourth-century thought, not least because two-way as well as three-way expressions of the human person are also found in Scripture. The influence of Origen is demonstrated with particular reference to the commentary on Ps. 118.73, informed by parallels in Ambrose and the Palestinian Catena. As a result, it is possible to ascribe differences between Hilary’s commentaries to the fact that one is more reliant on Origen than the other. Nevertheless, Hilary’s position always seems to be that the body and soul should be at harmony until the body takes on the spiritual nature of the soul.

scholarly journals The Respiration of some Planktonic copepods II. The Effect Of Temperature

1953 ◽  
Vol 31 (3) ◽  
pp. 447-460 ◽  
Author(s):  
D. T. Gauld ◽  
J. E. G. Raymont
Keyword(s):  
Respiratory Rate ◽  
The Body ◽  
The Other ◽  
Effect Of Temperature ◽  
Acartia Clausi ◽  
Temora Longicornis ◽  
Different Temperatures ◽  
Planktonic Copepods ◽  
The Difference ◽  
The Relationship

The respiratory rates of three species of planktonic copepods, Acartia clausi, Centropages hamatus and Temora longicornis, were measured at four different temperatures.The relationship between respiratory rate and temperature was found to be similar to that previously found for Calanus, although the slope of the curves differed in the different species.The observations on Centropages at 13 and 170 C. can be divided into two groups and it is suggested that the differences are due to the use of copepods from two different generations.The relationship between the respiratory rates and lengths of Acartia and Centropages agreed very well with that previously found for other species. That for Temora was rather different: the difference is probably due to the distinct difference in the shape of the body of Temora from those of the other species.The application of these measurements to estimates of the food requirements of the copepods is discussed.

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