A&P - EXAM 1

Describe and give example of each level of organization from the simplest to most complex

1. Chemical - atoms, molecules

2. Cellular - single cells

3. Tissues - groups of cells

4. Organs - two or more tissue types

5. Organ System - organs that work together

6. Organismal - all organ systems combine to make the whole organism

Compare and contrast the fields and subfields of A&P and give an example of each

Anatomy - studies structure of body parts; asks where is it/ what is it (example: structure of the heart)

Physiology - studies the function of body parts; asks how does it work (example: how the heart pumps blood)

Integumentary System (structures and function)

• Hair, skin, nails

• Encloses internal body structures; site of many sensory receptors

Skeletal System

• Cartilage, bone, joints

• Supports the body

• Enables movement (with muscular system)

Muscular System

• Skeletal muscles, tendons

• Enables movement (with skeletal system)

• Helps maintain body temperature

Nervous System

• Brain, spinal cord, peripheral nerves

• Detects and processes sensory information

• Activates bodily responses

Endocrine System

• Pituitary gland, adrenal gland, thyroid gland, pancreas, testes

• Secretes hormones

• Regulates bodily processes

Cardiovascular System

• Heart, blood vessels

• Delivers O2 and nutrients to the tissues

• Equalizes temperature in the body

Lymphatic System

• Thymus, lymph nodes, spleen, lymphatic vessels

• Returns fluid to the blood

• Defends against pathogens

Respiratory System

• Nasal passage, trachea, lungs

• Removes CO2 from the body

• Delivers O2 to the blood

Digestive System

• Stomach, liver, gallbladder, large intestine, small intestine

• Processes food for use by the body

• Removes waste from undigested food

Urinary System

• Kidneys, urinary bladder

• Controls water balance in the body

• Removes wastes from blood and excretes them

Male Reproductive System

• Epididymis, testes

• Produces sex hormones and gametes

• Delivers gametes to the female

Female Reproductive System

• Mammary glands, ovaries, uterus

• Produces sex hormones and gametes

• Supports embryo/fetus until birth

• Produces milk for infant

Define and explain terms relating to homeostasis and give physiological examples for each

• The maintenance of relatively stable internal conditions despite continuous changes in the environment

  • Maintained by contributions of all organ systems

• The body is constantly monitored and regulated to maintain

• Variables are factors that change: blood sugar, body temperature, blood volume, etc.

  • Three components involved: Sensor/Receptor, Control Center, and Effector

Negative Feedback System (with example)

• Reverses/opposes the original change and moves the variable back towards its normal range

• Change → body fights the change → back toward normal

  • Stimulus: Body temperature gets too high

  • Sensor: Nerve cells in skin and brain

  • Control Center: temperature regulatory center in brain

  • Effector: sweat glands throughout the body

  • Response: increased heat loss (temperature goes down)

• Most used feedback mechanism in the body

• Response reduces or shuts off original stimulus

Positive Feedback System

• Reinforces/amplifies the original change, pushing the process farther in the same direction until a specific endpoint stops it

• Change → body increases the change → increases more → endpoint

  • Stimulus: Childbirth; baby’s head stretches the cervix

  • Sensor: stretch receptors in the cervix detect the stretching

  • Control center: hypothalamus receives the signal and causes the posterior pituitary to release oxytocin

  • Effector: oxytocin travels through the blood to uterine smooth muscle

  • Response: uterine muscles contract more strongly, pushing the baby farther against the cervix; more stretching

Describe the structure of the plasma membrane and its components

Phospholipid bilayer (hydrophilic head, hydrophobic tail), containing many different molecular components, including proteins and cholesterol, and even attached carbohydrate groups

Describe the function of the plasma membrane and its components

1. Mechanical barrier - separates two of the body’s fluid compartments

2. Selective permeability - determines the manner in which substances enter or exit the cell

3. Electrochemical gradient - generates and helps to maintain the electrochemical gradient required for muscle and neuron function

4. Communication - allows cell-to-cell recognition and interaction

5. Cell signaling - plasma membrane proteins interact with specific chemical messengers and relay messages to the cell interior

Compare and contrast the types of transport across plasma membranes

• Passive Transport - no energy required; high → low concentration

  • Down the concentration/electrochemical gradient

  • Simple diffusion (non-polar substances like O2 and CO2 pass through the cell membrane), facilitated diffusion, osmosis (movement of solvent, like water)

• Active Transport - energy (ATP) required; low → high concentration

  • Can move against the gradient

  • Pumps, co-transport, vesicular transport

Explain how osmosis and tonicity result in the movement of water across the plasma membrane

• Osmosis - the passive movement of water across a selectively permeable membrane

  • Water moves toward the side with less water and a higher solute concentration (water follows solute)

• Tonicity - describes how a solution affects cell volume because of water movement

  • Hypotonic - water into cell → cell swells

  • Isotonic - no net movement → cell stays the same size (water moves in both directions)

  • Hypertonic - water out of the cell → cell shrinks

• Example: hypotonic = higher solute inside → water goes in → cell swells

  • Hypertonic = higher solute solute inside → water goes out → cell shrinks

Describe acids

• Acids - substance that increases the concentration of H+ in a solution

  • Acid → more H+ → less pH = acidic

  • Ex: HCl → H+ + Cl-

Describe bases

• Bases - decreases the concentration of H+, often by accepting H+ or by releasing OH- that can combine with H+

  • Base → less H+ → more pH

  • Ex: H+ + OH- → H2O

Describe buffers

• Buffers - resists sudden changes in pH

  • Ex: If H+ is too high → buffer can release H+ → prevents pH from rising dramatically

Describe how the pH scale is used

• pH indicates how acidic or basic a solution is based on its hydrogen ion concentration

• 0-6.9 = acidic → H+ higher

• 7 = neutral

• 7.1-14 = basic/alkaline → H+ lower

What is the anatomical position?

• Body standing upright

• Facing forward

• Arms at sides

• Palms facing forward

• Feet pointing forward

• Person’s POV of right and left

Superior

• Toward the head/above

• Ex: chest is superior to the abdomen

Inferior

• Toward the feet/below

• The knee is inferior to the hip

Cranial

• Toward the head

• The chest is cranial to the pelvis

Caudal

• Toward the lower end of the body

• The abdomen is caudal to the chest

Anterior / ventral

• Toward the front

• The sternum is anterior to the heart

Posterior / dorsal

• Toward the back

• The spine is posterior to the heart

Medial

• Toward the body’s midline

• The nose is medial to the eyes

Lateral

• Away from the body’s midline

• The arms are lateral to the chest

Proximal

• Closer to the trunk/point of attachment

• The elbow is proximal to the wrist

Distal

• Farther from the trunk/point of attachment

• The fingers are distal to the elbow

Saggital plane

Divides the body into right and left portions

Frontal (coronal) plane

Divides the body into anterior (front) and posterior (back) portions

Transverse plane

Divides the body into superior (upper) and inferior (lower) portions

Oblique plane

Cuts through the body at an angle (diagonal cut)

What is a body cavity?

The space within the body that contains and protects internal organs

Dorsal body cavity

• Located along the posterior (back) side of the body

• Contains:

  • Cranial cavity → inside the skull = brain

  • Vertebral cavity → within the vertebral column = spinal cord

Ventral body cavity

• Larger cavity along the anterior portion of the body

• Divided into:

  • Thoracic cavity → the chest cavity located superior to the diaphragm

    • Subdivisions:

      • Right and left pleural cavities → contain the lungs

      • Mediastinum → central region between the lungs

      • Pericardial cavity → located within the mediastinum and associated with the heart

    • Abdominopelvic cavity → located inferior to the diaphragm

      • Divided into:

        • Abdominal cavity → superior portion

        • Pelvic cavity → inferior portion

Structures and functions of epithelial tissue

• Sheets of cells that cover surfaces or cavities

• Forms boundaries, protects, secretes absorbs, and filters

• Skin surface; lining of the GI tracts and hollow organs

Structures and functions of connective tissue

• Tissue that supports and connects other tissues

• Supports, protects, and binds

• Bones, tendons, fat/soft padding

Structures and functions of muscle tissue

• Cells specialized to contract

• Contracts to cause movement

• Skeletal muscle, cardiac muscle, smooth muscle

Structures and functions of nervous tissue

• Specialized cells involved in communication

• Internal communication

• Brain, spinal cord, nerves

Describe the structures and locations of specific types of epithelial tissues and classify them using microscopic images

• A sheet of cells that covers body surfaces or cavities

• Two main forms:

  • Covering and lining epithelia → found on external and internal surfaces (ex: skin)

  • Glandular epithelia → secretory tissues in glands (ex: salivary glands)

• COVER, LINE, SECRETE

5 characteristics of epithelial tissues

Five characteristics:

1. Polarity

   • Apical surface - exposed to the surface or cavity

     • Some apical surfaces have microvilli

   • Basal surface - lower/attached surface

     • Attaches to the basal lamina

     • Located next to the underlying connective tissue

2. Specialized contacts

   • Epithelial tissues fit closely together to form continuous sheets

   • Tight junctions (seal) and gap junctions (communicate)

3. Supported by connective tissues

   • All epithelial sheets are supported by connective tissue

   • Consists of collagen fibers

   • Reinforces the epithelial sheet

   • Resists stretching and tearing

   • Defines the epithelial boundary

4. Avascular, but innervated

   • No blood vessels in epithelial tissues

   • Epithelia supplied by nerve fibers

5. Regeneration

   • High regenerative capacities

   • Stimulated by loss of polarity and broken lateral contacts

   • Due to friction, hostile substances, or damage

   • Requires adequate nutrients and cell division

What are the 6 major functions of epithelial tissue?

1. Protection

2. Absoprtion

3. Filtration

4. Excretion

5. Secretion

6. Sensory Reception

Describe cell junctions and the different types of junctions

• Most cells are bound together to form tissues and organs

• Types of Cell Junctions

  • Tight Junctions

  • Gap Junctions

  • Anchoring Junctions

Describe the structure and function of tight junctions

• Integral proteins on adjacent cells fuse to form an impermeable junction that encircles the whole cell

• Prevents fluids and most molecules from moving in between cells

Describe the structure and function of gap junctions

• Transmembrane proteins (connexons) form tunnels that allow small molecules to pass from cell to cell

• Main function: communication

• Used to spread ions, simple sugars, or other molecules between cells

• Allows electrical signals to be passed quickly from one cell to the next cell

  • Used in cardiac and smooth muscle cells

What are the specific types of epithelial tissue?

• Simple Squamous

• Simple Cuboidal

• Simple Columnar

• Stratified squamous

• Pseudostratified columnar

Describe the structures, functions, and locations of simple squamous epithelium

• Single layer of flattened cells with disc-shaped central nuclei and sparse cytoplasm; the simplest of the epithelia

• Function: allows materials to pass by diffusion and filtration in sites where protection is not important

  • Secretes lubricating substances in serosae (linings of ventral body cavity)

• Location: kidney glomeruli; air sacs of lungs; lining of heart, blood vessels, and lymphatic vessels; serosae

Describe the structures, functions, and locations of simple cuboidal epithelium

• Single layer of cube-like cells with large, spherical central nuclei

• Function: secretion and absorption

• Location: kidney tubules, ducts and secretory portions of small glands; ovary surface

Describe the structures, functions, and locations of simple columnar epithelium

• Single layer of tall cells with round to oval nuclei; many cells bear microvilli, while others bear cilia; layer may contain mucus-secreting unicellular glands (goblet cells)

• Function: absorption; secretion of mucus, enzymes and other substances

  • Ciliated type propels mucus by ciliary action

• Location: nonciliated type lines most of the GI tract (stomach to rectum), gallbladder, and excretory ducts of some glands; ciliated variety lines small bronchi, uterine tubes, some regions of the uterus

Describe the structures, functions, and locations of pseudostratified columnar epithelium

• Single layer of cells of differing heights, not reaching the free surface

  • Nuclei are seen at different levels; may contain mucus-secreting cells and bear cilia

• Function: secrete substances, particularly mucus; propulsion of mucus by ciliary action

• Location: ciliated variety lines the trachea and most of the upper respiratory tract; nonciliated types in males’ sperm-carrying ducts and ducts of large glands

Describe the structures, functions, and locations of stratified squamous

• Thick epithelium composed of several cell layers; basal cells are cuboidal or columnar and metabolically active; surface cells are flattened (squamous)

• Function: protects underlying tissues in areas subjected to abrasion

• Location: non-keratinized type forms the moist linings of the esophagus, mouth, and vagina; keratinized variety forms the epidermis of the skin, a dry epithelium

Describe the structures, functions, and locations of transitional

• Resembles both stratified squamous and stratified cuboidal; basal cells are cuboidal or columnar, and surface cells are dome-shaped or squamous-like, depending on the degree of organ stretch

• Function: stretches readily, permits stored urine to distend the urinary organ

• Location: lines the ureters, bladder, and part of the urethra

Describe glands (glandular epithelia) and the different classifications

• Gland - one or more cells that make and secrete an aqueous fluid called a secretion

• Classified by:

  • Site of product release

  • Endocrine - internally secreting (ex: hormones)

  • Exocrine - externally secreting (ex: sweat)

• Relative number of cells forming the gland

  • Unicellular (ex: goblet cells) or multicellular (ex: salivary)

Describe the structure and functions of endocrine glands

• Ductless glands

  • Secretions are released into the surrounding interstitial fluid, which is picked up by circulatory system

  • Secrete hormones: messenger chemicals that travel through lymph or blood to their specific target organs

Describe the structure and functions of exocrine glands

• Secretions are released onto body surfaces, such as the skin, or into body cavities

• Secrete products into ducts

• Ex: mucus, sweat, oil, salivary glands

• Can be unicellular or multicellular

Describe the structure of unicellular exocrine glands

• The only important unicellular glands are mucous cells and goblet cells

• Found in epithelial linings of intestinal and respiratory tracts

• All produce mucin, a sugar-protein that can dissolve in water to form mucus, a slimy protective, lubricating coating

Describe the structure of multicellular exocrine glands

• Composed of a duct and a secretory unit

• Classified by:

  • Structure

  • Mode of secretion

Describe the modes of glandular secretion in multicellular exocrine glands

1. In merocrine secretion, the cell remains intact (most sweat glands)

2. In apocrine secretion, the apical portion of the cell is released (sweat glands in armpits and genitalia)

3. In holocrine secretion, the cell is destroyed as it releases its product and the cell itself becomes part of the secretion (sebaceous glands of the skin)