Physiology and Anatomy PDF

Physiology part: 1. Organism and function: Levels of organization; The basic characteristics of all living organisms Every organism has a characteristic pattern of organization that differs from that of inanimate objects. Levels of organizations: 1. The molecular level: The smallest stable units o...

Physiology part: 1. Organism and function: Levels of organization; The basic characteristics of all living organisms Every organism has a characteristic pattern of organization that differs from that of inanimate objects. Levels of organizations: 1. The molecular level: The smallest stable units of matter, can combine to form molecules with complex shapes 2. the cellular level: Molecules can interact to form organelles, such as the protein filaments found in muscle cells. Each type of organelle has specific functions. Cells are the smallest living units in the body: organelles are their structural and functional components. 3. the tissue level: A tissue is a group of cells working together to perform one or more specific functions 4. the organ level: Organs consist of two or more tissues working in combination to perform several functions. Layers of cardiac muscle tissue in combination with connective tissue from the mass of the wall of the heart, a hollow, three- dimensional organ. 5. the organ system level: Organs interact in the organ system. Each time it contracts, the heart pushes blood into a network of blood vessels. Together the heart, blood and blood vessels form the cardiovascular system, one of organ systems in the body. 6. the organism level: All organ systems of the body work together to maintain life and health. (the highest level) 2. Nervous and muscular tissues properties: Irritability / excitability; The periods of excitability Irritability- Organisms respond to change in their immediate environment Excitability- The property to respond to stimuli from the external or internal environment. - It only occurs from the tissue level- it is higher form (or degree) of responsiveness - An action of stimulus initiates changes of excitability in the tissue - Excitability reaches the initial size (resting stage) after the recovery cycle. 3. Homeostasis and regulation Homeostatic mechanisms include the regulation of body temperature, respiratory rate, blood pH, heart rate, blood pressure, levels of blood glucose and body water, and electrolyte concentrations. A change in a property of the extracellular fluid causes the homeostatic mechanisms that will return it to within its optimal range. This may involve the communication systems of the body (the nervous and endocrine systems) as well as those systems that are in contact with the external environment (the respiratory, digestive and urinary systems). Two general mechanisms involved in homeostatic regulation: Autoregulation- Occurs when activities of cell, tissue, organ or organ system automatically compensate for environmental variation. When cells need more oxygen they release chemicals which dilate blood vessels in the immediate area. Extrinsic regulation- Occurs when the nervous or endocrine system controls or adjusts many systems simultaneously. Steps of maintenance of the homeostasis: Sensors→ Controllers→Effectors Sensors- There are structures that detect information from the inner and the outer environment of the body. The sensors may be nervous receptor cells, cytoplasmic or membrane proteins and other specialized molecules. Controllers- There are structures responsible for processing and interpreting information received from the sensors. Controllers in general are specialized regions of the CNS but on the molecular level there are also some of them, like DNA, a molecule that can get information from proteins to inhibit or stimulate the expression of some genes Effectors- There are elements commanded by the controllers. That has the function of performing actions. That in fact regulates and maintains the equilibrium of the organism, like muscles, glands, cellular organelles, etc. Anatomy part: 1. Directional terms and planes of the animal body. The median plane- Is an imaginary plane passing through the body craniocaudal, which divides the body into equal right and left halves. A sagittal plane- is any plane parallel to the median plane. A transverse plane- is at right angles to the median plane and divides the body into cranial and caudal segments. A horizontal plane- Is at right angles to both the median plane and transverse plane divides the body into dorsal and ventral segment Carnial- is a directional term meaning towards the head Caudal- means towards the tail Dorsal- is a directional term meaning towards or beyond the backbone or vertebral column Ventral- means away from the vertebral column or toward the mid-abdominal wall. Medial- is an adjective meaning close to or towards the median plane Lateral- Is the anatomy of medial: means away from the median