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Organization Of The Human Body. Maintaining Homeostasis. Definition of Anatomy & Physiology. Anatomy: study of Structures Relationship of structures. Definition of Anatomy & Physiology. Physiology: study of the Function of structures. First “Real” Anatomist. William Harvey
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Organization Of The Human Body Maintaining Homeostasis
Definition of Anatomy & Physiology • Anatomy: study of • Structures • Relationship of structures
Definition of Anatomy & Physiology • Physiology: study of the • Function of structures
First “Real” Anatomist • William Harvey • 1578 - 1657 • First to observe heart and circulation. • First to notice differences between warm and cold blooded animals. William Harvey
Levels of Structural Organization • Chemical • Cellular • Tissue • Organ • Organ system • Organism
Integration of Body Systems • 8organ systems • Integrated- they work together to keep the organism alive • Strength of systems: they are specialized • therefore efficient • Weakness of systems: interdependence • When one system fails, the others also begin to fail
Unifying Processes of Life • Metabolism • Catabolism = reactions that break down complex molecules into smaller ones (releases energy) • Anabolism=reactions that build complex molecules from smaller ones (requires energy) • Responsiveness: detecting and reacting to stimuli • Movement: from organelles cells organism • Growth:increase in body size • # of cells, cell size, space around cells. • Differentiation: process where unspecialized cells become specialized cells • Reproduction • New cells for growth or repair • Organism: production of a new individual
Tortora Page: 7-9 Maintaining An Internal Balance • Homeostasis (sameness/standing still) • Ensures that the internal environment remains constant, even if external conditions change • Homeostasis is dynamic
Tortora Page: 9 Homeostasis and Blood Pressure • Pressure-sensitive nerves in arteries sense higher BP. • Nerves send signal to brain. • Brain sends signals to slow heart rate.
Negative Feedback System: Blood Pressure
Homeostasis and Blood Pressure • Blood pressure is the force behind blood as it flows through the arteries. • Systolic pressure: force exerted as ventricles contract: High BP reading • Diastolic pressure: force exerted as ventricles relax: Low BP • Increased heart rate and stroke volume increase BP.
Tortora Page: 9 Feedback Systems • Feedback systems are either negative or positive. • Negative feedback systems reverse a change in a controlled condition • Positive feedback systems strengthen a change in a controlled condition. It is shut off by an event outside the system. • Most feedback systems in the human body are negative. • Childbirth is a positive feedback system
The glucose roller coaster: • Low levels after sleep • High levels after breakfast, especially if lots of sugar is eaten • Low levels by lunch. • High levels after lunch high carb/ high sugar foods • Low levels by 2:00 Regulation of Glucose Levels Note the higher glucose levels after eating meals high in starches and sugars
If excess glucose is present in the blood: • Insulin is secreted by islets of Langerhans (beta cells) in pancreas. • Insulin in the blood causes cells to take in glucose. • Glucose is also absorbed by liver cells which convert glucose to glycogen. (polysaccharide) • Net result: less glucose in the blood Regulation of Glucose Levels
Regulation of Glucose Levels • When blood glucose levels are low: • Glucagon (hormone) is secreted by alpha cells in pancreas. • In the liver, glycogen is broken down into glucose and released into blood. • Net result: Glucose levels surrounding the cells stays fairly even throughout the day. See Figure 13.12, pg 360
Tortora Page: 11-15 Basic Anatomical Position • Individual is standing upright. • Arms placed at sides of the body. • Palms facing forward. • Feet flat on floor, toes forward.
Tortora 13 Directional Terms • Used to locate various body structures in relationship to each other. • Superior/ Inferior (Cranial/ Caudal) • Anterior Vs Posterior (Ventral /Dorsal) • Medial/ Lateral • Intermediate • Proximal/ Distal • Superficial/ Deep
Tortora Page 15 Planes & Sections • Imaginary flat surfaces through the body. • Sagittalplane • Midsagittal • Parasagital • Frontal (Coronal) plane • Transverse
Tortora Page16-17 Body Cavities • Spaces within the body that contain organs. • Ventral body cavity • Thoracic (heart& lungs) • Pericaridal cavity • Pleural cavity • Abdominal (digestive, liver, reproductive) • Lining of cavity is called the peritoneum
Tortora Page 16 Body Cavities • The Dorsal cavity contains 1. Cranial cavity • Cranial bones • the brain 2.Vertebral canal • Vertebral column (bones) • Spinal cord • Beginnings of spinal nerves