maintaining homeostasis organization of the human body
TRANSCRIPT
MAINTAINING HOMEOSTASIS
Organization Of The Human Body
Definition of Anatomy & Physiology
Anatomy: study of StructuresRelationship of
structures
Definition of Anatomy & Physiology
Physiology: study of theFunction of
structures
First “Real”
AnatomistWilliam 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
ChemicalCellularTissueOrganOrgan systemOrganism
Integration of Body Systems
8 organ systemsIntegrated- they work together to keep
the organism aliveStrength of systems: they are
specialized therefore efficient
Weakness of systems: interdependence When one system fails, the others also begin
to fail
Unifying Processes of LifeMetabolism
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 stimuliMovement: from organelles cells organismGrowth: increase in body size
# of cells, cell size, space around cells.Differentiation: process where unspecialized cells
become specialized cellsReproduction
New cells for growth or repair Organism: production of a new individual
Maintaining An Internal
BalanceHomeostasis
(sameness/standing still)
Ensures that the internal environment remains constant, even if external conditions change
Homeostasis is dynamic
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Homeostasis and Blood Pressure
Pressure-sensitive nerves in arteries sense higher BP.
Nerves send signal to brain.
Brain sends signals to slow heart rate.
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NegativeFeedbackSystem: BloodPressure
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.
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
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Regulation of Glucose Levels
• 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 2:00Note the higher glucose levels after eating meals high in starches and sugars
Regulation of Glucose Levels
• 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
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
Basic Anatomical
Position1. Individual is standing
upright.2. Arms placed at sides of
the body.3. Palms facing forward.4. Feet flat on floor, toes
forward.
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Directional TermsUsed 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
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Planes & SectionsImaginary flat surfaces through the body.
Sagittal plane Midsagittal Parasagital
Frontal (Coronal) plane Transverse
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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
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Body CavitiesThe Dorsal cavity contains
1. Cranial cavity Cranial bones the brain
2. Vertebral canal Vertebral column (bones) Spinal cord Beginnings of spinal nerves
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