HD in Nursing Studies-Human Biology

Levels of Structural Organization

• Chemical – atoms combined to form molecules

Structural and Functional Organization of the Human Body

• Cellular – cells are made of molecules • Tissue – consists of similar types of cells • Organ – made up of different types of tissues • Organ system – consists of different organs that work closely together • Organismal – made up of the organ systems

Levels of Structural Organization

Organ Systems of the Body

• Integumentary system • Forms the external body covering • Composed of the skin, sweat glands, oil glands, hair, and nails • Protects deep tissues from injury and synthesizes vitamin D

Skin Structure

Organ Systems of the Body

• Skeletal system • Composed of bone, cartilage, and ligaments • Protects and supports body organs • Provides the framework for muscles • Site of blood cell formation • Stores minerals

Bones and Cartilages of the Human Body

Organ Systems of the Body

• Muscular system • Composed of muscles and tendons • Allows manipulation of the environment, locomotion, and facial expression • Maintains posture • Produces heat

Skeletal Muscle

Organ Systems of the Body

• Nervous system • Composed of the brain, spinal column, and nerves • Is the fast-acting control system of the body • Responds to stimuli by activating muscles and glands

Major Skeletal Muscles

Simplified Design of the Nervous System

Organ Systems of the Body

Gross Anatomy of Heart: Frontal Section

• Cardiovascular system • Composed of the heart and blood vessels • The heart pumps blood • The blood vessels transport blood throughout the body

Veins of Systemic Circulation

Aorta and Major Arteries

Organ Systems of the Body

Lymphatic System: Overview

• Lymphatic system • Composed of red bone marrow, thymus, spleen, lymph nodes, and lymphatic vessels • Picks up fluid leaked from blood vessels and returns it to blood • Disposes of debris in the lymphatic stream • Houses white blood cells involved with immunity

Organ Systems of the Body

• Respiratory system • Composed of the nasal cavity, pharynx, trachea, bronchi, and lungs • Keeps blood supplied with oxygen and removes carbon dioxide

The Components of the Respiratory System

Organ Systems of the Body

The Components of the Digestive System

• Digestive system • Composed of the oral cavity, esophagus, stomach, small intestine, large intestine, rectum, anus, and liver • Breaks down food into absorbable units that enter the blood • Eliminates indigestible foodstuffs as feces

Organ Systems of the Body

• Urinary system • Composed of kidneys, ureters, urinary bladder, and urethra • Eliminates nitrogenous wastes from the body • Regulates water, electrolyte, and pH balance of the blood

The Urinary System Organs

Organ Systems of the Body

Male Reproductive System

• Male reproductive system • Composed of prostate gland, penis, testes, scrotum, and ductus deferens • Main function is the production of offspring • Testes produce sperm and male sex hormones • Ducts and glands deliver sperm to the female reproductive tract

Organ Systems of the Body • Female reproductive system • Composed of mammary glands, ovaries, uterine tubes, uterus, and vagina • Main function is the production of offspring • Ovaries produce eggs and female sex hormones • Remaining structures serve as sites for fertilization and development of the fetus • Mammary glands produce milk to nourish the newborn

Female Reproductive Anatomy

Organ System Interrelationships

Organ System Interrelationships

• The integumentary system protects the body from the external environment

• Nutrients and oxygen are distributed by the blood

• Digestive and respiratory systems, in contact with the external environment, take in nutrients and oxygen

• Metabolic wastes are eliminated by the urinary and respiratory systems

HD in Nursing Studies-Human Biology

Cell Theory

• The cell is the basic structural and functional unit of life

Cellular Physiology

• Organismal activity depends on individual and collective activity of cells • Biochemical activities of cells are dictated by subcellular structure • Continuity of life has a cellular basis

Structure of a Generalized Cell

Plasma Membrane • Separates intracellular fluids from extracellular fluids • Are selectively permeable • Plays a dynamic role in cellular activity • Glycocalyx is a glycoprotein area abutting the cell that provides highly specific biological markers by which cells recognize one another

Fluid Mosaic Model

Phospholipid Molecules

• Clothespin shape • The head (phosphate portion) – relatively soluble in water (polar, hydrophilic). • The tails (the lipids) – relatively insoluble (non-polar, hydrophobic) & meet in the interior of the membrane.

Fluid Mosaic Model

Fluid Mosaic Model

• Double bilayer of lipids with imbedded, dispersed proteins • Bilayer consists of phospholipids, cholesterol, and glycolipids • Glycolipids are lipids with bound carbohydrate

• Integral proteins --embedded in the membrane

• Phospholipids have hydrophobic and hydrophilic bipoles

• Peripheral proteins --loosely bound to the inner or outer surface • Anchored proteins

Functions of Membrane Proteins

Functions of Membrane Proteins

• Transport

• Intercellular adhesion

• Enzymatic activity

• Cell-cell recognition

• Receptors for signal transduction

• Attachment to cytoskeleton and extracellular matrix

Phospholipid Membrane

Passive Membrane Transport: Diffusion

• Simple diffusion – nonpolar and lipidsoluble substances • Diffuse directly through the lipid bilayer • Diffuse through channel proteins • Selective permeability • regulates the type & rate of molecules traffic into and out of the cell

Passive Membrane Transport: Diffusion

Passive Membrane Transport: Osmosis

• Facilitated diffusion – large, polar molecules such as simple sugars

• Occurs when the concentration of a solvent is different on opposite sides of a membrane

• Combine with protein carriers

• Diffusion of water across a semipermeable membrane • Osmolarity – total concentration of solute particles in a solution

Effect of Membrane Permeability on Diffusion and Osmosis

Effect of Membrane Permeability on Diffusion and Osmosis

Passive Membrane Transport: Filtration

Sodium-Potassium Pump

• The passage of water and solutes through a membrane by hydrostatic pressure • Pressure gradient pushes solute-containing fluid from a higher-pressure area to a lower-pressure area

Active Transport

Membrane Transport System • Symport system – two substances are moved across a membrane in the same direction • Antiport system – two substances are moved across a membrane in opposite directions

• Uses ATP to move solutes across a membrane • Requires carrier proteins

Membrane Transport System

Membrane Transport System

• Primary active transport – hydrolysis of ATP phosphorylates the transport protein causing conformational change

[ Na+ ]high

[ K+ ]low Na+, K+ -pump Carrier proteins

[ K+ ]high

[ Na+ ]low

• Carrier proteins involved in transporting molecules ‘uphill’ against an electrochemical gradient from a region of low concentration to a region of high concentration.

• Secondary active transport – use of an exchange pump (such as the Na+-K+ pump) indirectly to drive the transport of other solutes

Vesicular Transport

Vesicular Transport

• Transport of large particles and macromolecules across plasma membranes • Exocytosis – moves substance from the cell interior to the extracellular space • Endocytosis – enables large particles and macromolecules to enter the cell • Receptor-mediated transport – uses clathrin-coated pits as the major mechanism for specific uptake of macromolecules

HD in Nursing Studies-Human Biology

Homeostasis • Homeostasis is the maintenance of relatively constant conditions within the body's internal environment.

Homeostasis

Homeostasis

Homeostasis

Bring a deviation in a physiological event back into line.

Homeostasis

Homeostasis

A response which further enhances the change that set it in motion.

Negative Feedback

Positive Feedback

• In negative feedback systems, the output shuts off the original stimulus

• In positive feedback systems, the output enhances or exaggerates the original stimulus

• Example: Regulation of blood glucose levels

• Example: Regulation of blood clotting