Anatomy Final Exam Review

hierarchy of structural organization in the body

atoms - molecules - organelles - cells - tissues - organs - organ system - organism

tissues

made of many cells functioning together

organs

made up of many tissues

organ systems

made up of many organs working together

organisms

made up of many organ systems working together

anatomical position

* body up right
* standing erect facing the observer
* heads and eyes facing forward
* feet flat on the floor and facing forward
* upper limbs to the sides
* palms turned forward

superior

toward the head, above

inferior

toward the feet, below

anterior/ventral

toward the front

posterior/dorsal

toward the back

medial

toward the midline

lateral

away from the midline

proximal

near the point of attachment to the body

distal

away from the point of attachment to the body

superficial

close to the surface

deep

far from the surface

ipsilateral

on the same side of the body

contralateral

on opposite side of the body

frontal/coronal plane

divides the body into anterior and posterior parts

horizontal/transverse plane

divides the body into superior and inferior parts

median/sagittal plane

divides the body into left and right parts

parasagittal plane

divides the body into left and right but not perfect halves, uneven

what are the smallest living units in the body?

cells

3 main structural components of cells

* plasma membrane
* cytoplasm
* nucleus

fluid mosaic model

the cell membrane is not a rigid structure but a fluid membrane of phospholipids and embedded proteins

phospholipids

amphipathic, bilayer, 75% of membrane lipids

cholesterol

helps maintain the proper membrane fluidity

glycolipids

assist in cell recognition and adhesion

tight junctions

connects two adjacent cells together with a nearly impenetrable barrier that prevents molecules from passing between them

desmosomes

filamentous junctions between two cells that provide a strong physical linkage between them and withstand stretching without tearing

gap junctions

when two adjacent cells are connected by membrane proteins (connexons) that form small channels between the cells that allow ions and small molecules to pass through

cilia

motile projections that assist in moving the cell or moving items along the surface of the cell, move objects across the surface using wiggling motions

flagella

motile projections that assist in moving the cell or moving items along the surface of the cell, use whip-like motions to move objects along the surface

microvilli

finger-like projections on the outside of the cells whose role is to increase the surface area

ribosomes

site of protein synthesis

mitochondria

the powerhouse of the cell, site of cellular respiration, converts energy stored in the bonds of organic molecules to ATP through redox reactions

endoplasmic reticulum

the network that extends from the nuclear envelope that comes in two forms

rough ER

studded with ribosomes and closest to the nucleus, involved in protein synthesis, cisternae

smooth ER

does not have ribosomes, making or breaking down fats and calcium storage, tubules

golgi apparatus

the part of the cells that receives the products of the ER, modifies, sorts and ships them to the rest of the cell or outside of the cell via transport vesicles

lysosomes

sacs of hydrolytic enzymes that break down large molecules and thus act as the site of intracellular digestion

peroxisomes

responsible for removing toxic wastes by using special enzymes

centrosome

the microtubule organizing center consisting of centrioles, the place where microtubules for cilia and flagella are formed, important role in cell division during mitosis

tissue

a group of cells that live and work together for a common function

extracellular matrix

component of all tissues that gives them their consistency, provides structural and biochemical support to surrounding cells

four main tissue types and their one word function

* epithelial - covering
* connective - support
* muscle - movement
* nervous - control

epithelial tissue

* found on body surfaces and linings, cells arranged in sheets
* a free surface - on surface is always exposed to an area of no cells
* cellularity - tightly packed, little extracellular matrix
* avascularity - no blood vessels, receives nutrients from other cells and tissues
* specialized contacts - specific proteins that allow them to link together tightly

simple squamous epithelium

a single layer of flattened cells with disk-shaped central nuclei and sparse cytoplasm allows passage of materials by diffusion and filtration in sites of no protection

* Kidneys, air sacs of lungs, blood vessels, the lining of the heart, lining of the ventral body cavity 

simple cuboidal epithelium

a single layer of cubelike cells with large spherical central nuclei, secretion, and absorption 

* Kidney tubules, ducts of glands, ovary surface

simple columnar epithelium

a single layer of tall cells with round to oval nuclei, some have cilia, a layer may contain goblet cells, absorption, secretion of mucus 

* nonciliated - lines the digestive tract, gallbladder, excretory ducts
* ciliated - lines small bronchi, uterine tubes, uterus

pseudostratified columnar epithelium

a single layer of cells of differing heights, may contain mucus-secreting goblet cells and bear cilia, secretion

* nonciliated - sperm-carrying ducts, ducts of large glands 
* ciliated - lines trachea and upper respiratory tract 

stratified squamous epithelium

thick membrane composed of several cell layers, the top layer is squamous, lower layers are active in mitosis, protects underlying tissues in abrasion areas

* nonkeratinized - esophagus, mouth, vagina 
* keratinized - forms the epidermis 

stratified cuboidal epithelium

generally two layers of cube-like cells, protection

* largest ducts of sweat glands, mammary glands, and salivary glands

stratified columnar epithelium

several cell layers, basal usually cuboidal, protection and secretion 

* rare in the body, small amounts in making urethra and in some large gland ducts

what is the most abundant and diverse type of tissue?

connective tissue

connective tissue

consists of a small number of cells and a large amount of extracellular matrix and the composition determines the properties

collagen fibers

large, thick, strong, rope-like fibers that provide tensile strength and withstand pulling forces, strongest, abundant, and widest type

elastic fibers

long fibers with intermediate diameter, branch off and form networks that make them stronger, allow the tissue to recoil

reticular fibers

smallest fibers, cluster into networks to become stronger, support

skeletal muscle

longest cells that run the length of the cell, striated, multiple nuclei, involved in voluntary body movements

cardiac muscle

striated, one nucleus, shorter, branched, high protein intercalated discs cellular junctions, only in the heart, involuntary

smooth muscles

not striated, arranged into sheets, center nuclei, propel things along internal pathways, walls of hollow organs, involuntary

nervous tissue

found in the brain, spinal cord and nerves, consists of two types of cells (neurons and neuroglia)

neurons

basic nervous cell, soma (cell body), axon and dendrites

neuroglia/glial cells

support cells for neurons

is the skin an organ?

yes, the skin is an organ because it consists of many types of tissues working together

layers of the skin

epidermis and dermis

epidermis

consists of epithelial tissue

dermis

consists of connective tissue

hypodermis

technically not a part of the skin, loose connective tissue lies deep to the dermis and primarily composed of adipose cells

what cells are hair and nails are made of?

keratinized epidermal cells, keratinocytes

hair shaft

visible portion of the hair

hair root

the portion that penetrates the skin and lies below the skin surface

hair follicle

the sheath surrounding the hair root in the skin

hair bulb

found at the base of the hair follicle

papilla of the hair

indentation of the hair bulb that consists of capillaries, connective tissue, and nervous tissue

arrector pili muscle

small, smooth muscle that attaches to the hair follicle

matrix of the hair follicle

the portion where the cells divide and produce new hair cells

sebaceous gland

skin glands that produce sebum (oily substance) on to the hairs, found a lot in the face and scalp but found everywhere but soles of feet and palms of hands

eccrine sweat glands

exist on the palms of the hands, soles of the feet, and forehead, produce true sweat directly onto the skin that serves to cool the skin during evaporation

apocrine sweat glands

found in anal, genital, and axillary areas, produce milky sweat that is viscous and odorous through the hair follicle ducts, used to neutralize harmful bacteria with its chemicals

periosteum

thick membrane found on the outside of bones that consists of two layers

* superficial layer - dense irregular connective tissue
* deep layer - osteogenic containing osteoblasts and osteoclasts

perforated fibers/sharpey’s fibers

collagen fibers that wedge themselves into bone tissue and attach the periosteum to the bone, found in greatest numbers where muscles attach

endosteum

thin membrane found on the inside of the bones lining the trabeculae of spongy bone in the medullary cavity, osteon central canals, and epiphyses, osteogenic, highly vascularized

epiphyseal plate

hyaline cartilage grows on the epiphysis side and then replace by bones on the diaphysis side until the cartilage stops growing and this structure is formed

joint

the point at which rigid elements of the skeleton come together