A&P I Exam #1

electrolytes 

cations and anions that dissociate in water

nonelectrolytes

molecules do not dissociate in water and do not conduct electricity

important roles of inorganic molecules

1. O2 we breathe

2. CO2 we exhale

3. Water is essential for life

4. Calcium phosphate makes up our bones

5. Metals required for protein function

cohesion

the attraction of water to other water molecules

adhesion

water molecules attracted to other molecules

colloid

a mixture in which a dispersed substance or particle is unevenly distributed throughout the mixture

suspension

a mixture containing materials that separate from each other unless they are continually, physically blended together

buffer

chemical that resists changes in pH when acids or bases are added to a solution

3 major roles of carbohydrates in the body

1. part of organic molecules

2. broken down to provide energy

3. provide bulk in feces when undigested

4 major roles of lipids in the body

1. provide protection and insulation

2. help regulate many physiological processes

3. form plasma membranes

4. act as major energy-storage molecules

triglycerides

constitute 95% of fats in the human body and made up of 1 glycerol and 3 fatty acids

fatty acid

a straight chain of carbon atoms with a carboxyl group attached at one end

saturated fat

contains only single covalent bonds between the carbon atoms and consequently it is saturated with the maximum number of H atoms

prostaglandins

class of physiologically active substances present in many tissue; among its effects are vasodilation, stimulation and contraction of uterine smooth muscle, and the promotion of inflammation and pain

eicosanoids

group of important chemicals derived from fatty acids

5 major roles of proteins in the body

1. regulating body processes

2. acting as transportation molecules

3. providing protection

4. helping muscles contract

5. providing structure and energy

cofactors

non-proteins component of enzyme; normally form part of the enzyme’s active site and are required to make the enzyme functional

important consequences of fluid-mosaic model

1. provides means of distributing molecules within the plasma membrane 

2. slight damage can be repaired 

3. enables membranes to fuse with one another 

integral membrane proteins

penetrate deeply into lipid bilayer; has hydrophilic and hydrophobic regions

peripheral membrane proteins

attached to the inner or outer surfaces of the lipid bilayer

interns

proteins that attach cells to extracellular molecules

cadherins

proteins that attach cells to other cells

G protein complex

acts as an intermediary between a receptor and other cellular proteins

crenation

denoting the outline of a shrunken cell

lysis

process by which a cell swells and ruptures

roles of microtubules

• provide support and structure to cytoplasm

  • internal scaffolding 

• involved in cell division and transport of intracellular materials 

• forms essential organelle components 

cytoplasmic inclusions

aggregates of chemical either produced or taken in by the cell

nucleosomes

structural units of chromosomes, consisting of DNA wrapped around proteins called histones

nucleolus

a dense region within the nucleus that lacks a surrounding membrane

cisternae

interior space of the endoplasmic reticulum; isolated from the rest of the cytoplasm

centrosome

a specialized zone of the cytoplasm close to the nucleus; the center of microtubule formation in the cell

basal body

a modified centriole; located in the cytoplasm at the base of the cilium

dynein arms

proteins connecting adjacent pairs of microtubules and push the microtubules past one another 

transcription

synthesis of mRNA, tRNA, and rRNA molecules based on the nucleotide sequence of a gene in a DNA molecule

rough endoplasmic reticulum

synthesizes proteins which are then transported to the Golgi apparatus

• membranous tubules and flattened sacs with attached ribosomes

smooth endoplasmic reticulum 

manufactures lipids and carbohydrates, detoxifies harmful chemicals and stores calcium 

• membranous tubules and flattened sacs with NO attached ribosomes

peroxisome

serves as one site of lipid and amino acid degradation; breaks down hydrogen peroxide

• membrane-bound vesicle 

centrosome

specialized area of the cytoplasm where microtubule formation occurs 

glycocalyx

the collection of glycolipids, glycoproteins, and carbohydrates on the outer surface of the plasma membrane

splicesome

complex structure composed of RNA and proteins; removes introns from the pre-mRNA and remaining exons are spliced together 

centrioles

serve as centers of microtubule formation; determine cell polarity during cell division

alternative splicing

various combinations of exons are incorporated into mRNA

translation

synthesis of a protein at the ribosome based on the sequence of the codons of mRNA

kinetochore

a protein structure that binds the centromere and provides a point of attachment for microtubules that will separate and move the chromatids during mitosis

posttranslational processing

modification of proteins before they are functional in the cell 

caudal

closer to the tail than another structure

cephalic

closer to the head than another structure

coxal

hip

dorsal

back

talus

ankle

crural

leg

leg

between knee and ankle

arm 

between elbow and wrist

dorsum

top of foot

occipital

base of skull

olecranon

point of elbow

sural

calf

plantar

sole of foot

acromial

point of shoulder

sacral

between hips

retroperitoneal organs

abdominal organs that are tightly adhered to the posterior body wall and are covered by peritoneum only on their peritoneal cavity side 

examples: kidneys, ureters, adrenal glands, a large portion of the pancreas, parts of the large intestine, and the urinary bladder

antebrachial

forearm

mesentery

a double-folded sheet of visceral peritoneum that attaches the digestive organs at certain points to the posterior abdominopelvic cavity wall

also, provides a pathways for nerves and blood vessels to reach the digestive organs 

parietal serous membrane

the layer that lines the walls of cavities

visceral serous membrane

the layer covering the internal organs

medial mediastinum

houses the heart and its major blood vessels, and the thymus, the trachea, and the esophagus 

serous membrane

thin sheet composed of epithelial and connective tissues; it lines cavities that do not open to the outside of the body or contain glands but do secrete serous fluid

dorsal body cavity

encloses the brain, organs of the nervous system, and spinal cord

• subdivision: cranial cavity and vertebral canal 

median plane

a sagittal plane that passes through th midline of the body, dividing it into equal right and left halves

epidermis

the superficial layer of skin; consists of stratified squamous epithelial tissue; reduces water loss and protects against abrasion; contains no blood vessels

dermis

a layer of connective tissue; responsible for the strength of skin; cells include fibroblasts, a few adipocytes, and macrophages; contains blood vessels and nerve endings, hair follicles, smooth muscle, glands and lymphatic vessels

subcutaneous tissue

a layer of loose connective tissue that isn’t part of skin or integumentary system, but does connect the skin to the underlying muscle or bone

stratum corneum

most superficial stratum of the epidermis; 25 or more layers of dead squamous cells; provides strength, prevents water loss, and resists abrasion 

stratum lucidium

3-5 layers of dead cells; appears transparent; only usually present in thick skin; disperses keratohyalin around keratin fibers

stratum basale

deepest layer of the epidermis; single layer of cuboidal or columnar cells; basement membrane of the epidermis attaches to the dermis here

produces cells of the most superficial strata; melanocytes production and contributes melanin, which protects against UV

stratum spinosum 

a total of 8-10 layers of many-sided cells; produces keratin fibers

stratum granulosum

2-5 layers of flattened, diamond-shaped cells

produces keratohyalin granules, lamellar bodies release lipids from cells, and cells die 

papillary layer of dermis

papillae project toward epidermis; loose connective tissue

brings blood vessels close to the epidermis; dermal papillae form fingerprints and footprints

reticular layer of dermis

mat of collagen and elastic fibers; dense irregular connective tissue

main fibrous layer of dermis; strong in many directions and forms cleavage lines

Merkel cells

specialized epidermal cells associated with the nerve endings responsible for detecting light touch and superficial pressure 

thick skin

has all 5 epithelial Strat and stratum corner has many layers of cells

found in all areas subject to pressure or friction 

erythema

a condition in which the skin turns a reddish hue when the amount of blood flowing through the skin increases

hair shaft

protrudes above the surface of the skin

epithelial root sheath

divided into external and internal parts; has all the strata at the opening of the follicle and decreases until only the stratum basale is present

dermal root sheath

the portion of the dermis that surrounds the epithelial root sheath

sebaceous glands

located in the dermis; produce sebum

release through duct in hair follicles (holocrine glands)

hyponychium

a thickened region of the stratum corneum beneath the free edge of the nail body

lunula

a small part of the nail matrix seen through the nail body and appears as a whitish-crescent at the base of the nail 

the major functions of the integumentary system

1. protection 

2. sensation 

3. temperature regulation 

4. vitamin D production 

5. excretion 

lamellae

thin sheet or layer of bone 

hyaline cartilage

has large amounts of collagen fibers and proteoglycans; found in places where strong support and some flexibility are needed 

lacunae

small space or cavity 

potential space between the matrix of bone or cartilage normally occupied by a cell 

smooth muscle

forms the walls of hollow organs; it is controlled involuntarily

perichondrium

double-layered connective tissue sheath surrounding cartilage

cartilage

firm, smooth, resilient, nonvascular connective tissue

mesenchyme

embryonic connective tissue

reticular tissue

characterized by a network of reticular fibers and cells; has the special property of predominating in areas of the body with high cellular content; found in lymphatic tissue, the liver, and bone marrow 

areolar tissue 

cushions most organs and other tissues; attaches skin to underlying tissues

adhesive molecules

present in the ground substance and hold the proteoglycan aggregates together

hyaluronic acid

good lubricant for joint cavities and present in large quantities in connective tissue