The Study of Body Function | Human physiology | PPT Download

December 18, 2012 | By | Reply More

The Study of Body Function | Human physiology | PPT Download

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The Study of Body Function

www.neuronarc.com

 

Human Physiology

Study of how the human body functions.

Pathophysiology:

How physiological processes are altered in disease or injury.

 

Scientific Method

Confidence in rational ability, honesty and humility.

Formulate hypothesis.

Testing the hypothesis.

Analyze results.

Draw conclusion.

 

Homeostasis

Maintaining constancy of internal environment.

Dynamic consistency.

Maintained by negative feedback loops.

 

Feedback Loops

Sensor:

Detects deviation from set point.

Integrating center:

Determines the response.

Effector:

Produces the response.

 

Negative Feedback

Defending the set point.

Reverse the deviation.

Produces change in opposite direction.

 

Positive Feedback

Action of effectors amplifies the change.

Is in same direction as change.

Examples:

Oxytocin (parturition)

Voltage gated Na+ channels (depolarization)

 

Primary Tissues

4 Different Primary Tissues:

Muscle

Nervous

Epithelial

Connective

 

Muscle Tissue

Specialized for contraction.

3 Types of Muscle Tissue:

Skeletal

Cardiac

Smooth

 

Skeletal Muscle

Voluntary muscle.

Striated.

Attach to bones at both ends (tendons).

Arranged in parallel.

Grade contraction.

 

Cardiac Muscle

Striated.

Found only in the heart.

Interconnected.

Intercalated discs.

Syncytium.

 

Smooth Muscle

Not striated.

Gap junctions.

Calmodulin.

Peristalsis.

Syncytium.

 

Nervous Tissue

Neurons (nerve cells):

Specialized for conduction of action potentials.

Supporting cells:

Provide anatomical and functional support.

 

Neuron

Dendrites:

Receive input.

Cell body:

Nucleus.

Metabolic center.

Axon:

Conducts nerve impulses.

 

Epithelial Tissue

Types of Epithelial Tissue:

Cells that form membranes:

Squamous

Columnar

Cuboidal

Exocrine glands

Endocrine glands

 

Squamous Cells

Flattened in shape.

Adapted for diffusion and filtration.

Line all blood vessels.

 

Cuboidal Cells

Cube-shaped cells.

Excretion, secretion and absorption.

Line kidney tubules, salivary ducts, and pancreatic ducts.

 

Columnar Cells

Taller column shaped cells.

Excretion, secretion and absorption.

May contain cilia.

Line digestive tract and respiratory passageways.

 

Exocrine Glands

Derived from cells of epithelial membranes.

Secretions are released through ducts.

Simple tubes or modified as acini.

Examples:

Tear glands

Sweat glands

Prostate glands

 

Endocrine Glands

Lack ducts.

Secrete hormones into capillaries within the body.

May be discrete organs:

Primary functions are the production and secretion of hormones.

 

Connective Tissue

Large amounts of extracellular (ECF) material in the spaces between connective tissue cells.

4 Types of Connective Tissue:

Connective tissue proper

Cartilage

Bone

Blood

 

Connective Tissue Proper

Loose connective tissue:

Scattered collagen and tissue fluid.

Dermis of skin

Dense fibrous connective tissue:

Regular arranged.

Collagen oriented in same direction.

Tendons

Irregularly arranged.

Resists forces applied in many directions.

Capsules and sheaths

 

Cartilage

Chondrocytes.

Supportive and protective tissue.

Elastic properties to tissues.

Precursor to many bones.

Articular surfaces on joints.

 

Bone

Hydroxyapatite crystals

Osteoblasts:

Bone-forming cells

Osteocytes:

Trapped osteoblasts: less active

Osteoclasts:

Bone resorbing cells

 

Blood

Classified as connective tissue.

Half its volume is plasma.

 

Organs

Organs:

Composed of at least two primary tissues.

Serve different functions of the organ.

 

Systems

Organs that are located in different regions of the body and perform related functions.

Examples:

Skeletal system

Cardiovascular system

GI system

 

Body-Fluid Compartments

65-75% of total body weight H20.

Intracellular compartment:

Fluid inside the cell.

2/3 of H20

Extracellular compartment:

1/3 H20

2 Subdivisions:

Blood plasma

Interstitial fluid

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