Anatomy Test 1

Anterior

Towards the front

Posterior

Towards the back

Ventral

Towards the stomach

Dorsal

Towards the back

Superior

Upwards

Inferior

Downwards

Cranial

Towards the head

Caudal

Towards the tail

Lateral

Away from the midline

Medial

Towards the midline

Proximal

Towards the point of attachment

Distal

Away from the point of attachment

Deep

Away from the surface

Superficial

Towards the surface

Coronal (frontal) Plane

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

Transverse (horizontal) Plane

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

Sagittal Plane

Divides body into left and right parts

Midsagittal Plane

Divides the body into equal left and right halves

Body Cavities

Spaces within the body that protect, separate, and support internal organs

Tissue

A group of cells that work together to perform a specific function

Epithelial Tissue

Tissue that lines walls of open tubes, provides secretory and absorptive surfaces

Connective Tissue

Tissue that provides support/integrity for other tissues/organs. Most diverse abundant widely distributed and structurally varied of the four tissue types

Muscle Tissue

Tissue that generates mechanical force- three kinds

Nervous Tissue

Tissue with glial cells that provide protection, nourishment and support to nerve cells, provide long-distance communication within the body

Functions of Epithelial Tissue

Physical protection, absorption, secretion, sensation

Main Characteristics of Epithelial Tissue

Tightly packed, organized assembly, exhibit polarity, highly regenerative

Basement Membrane

Support epithelial cells, provide surface for cell movement, restrict passage of substances

Basal Lamina

Found in basement membrane, formed by epithelial cells

Reticular Lamina

Found in basement membrane, formed by cells in connective tissue

Covering Epithelia

Cells arranged in layers that cover external surface or line body cavities

Glandular Epithelia

Cells specialized to produce secretion

Simple Epithelium

Single layer of cells with all cells attached to the basement membrane

Stratified Epithelium

Two of more layers of epithelial cells

Pseudostratified Epithelium

Single layer of cells but not all cells reach the apical surface, sporadic nuclei give the appearance of multilayered stratified epithelium

Squamous

Flattened, fried egg shape cells

Cubodial

Cube-like cell, all sides are about the same size, and nucleus is centrally located

Columnar

Cells that are taller than they are wide, nucleus is oval and located in the basal region

Simple Squamous Epithelia

Single layer of flat, disc-like cells with flattened nuclei, functions as surface for filtration and diffusion. Found in air sacs of lung, glomeruli, and body cavity linings

Simple Cuboidal Epithelia

Single layer of cube-like cells with large, round nuclei, responsible for secretion and absorption. Found in ducts and glands, kidney tubules, and ovaries

Simple Columnar Epithelia

Single layer of tall, rectangular cells with elongated nuclei. Microvilli and cilia common on apical surface, function in absorption and secretion. Found in digestive tract and respiratory tract lining

Pseudostratified Columnar Epithelia

Single layer of columnar cells of different heights, nuclei appear at different heights. Function in secretion and propulsion (can be ciliated), found in male sperm duct, respiratory tract and large glands

Stratified Squamous Epithelia

Multiple layers of squamous cells on a basement membrane, basal cells are cube/columnar-shaped and mitotically active. Form protection against abrasion and damage for tissue underneath. Found in skin and lining of esophagus, vagina, and mouth

Stratified Cuboidal/Columnar Epithelia

Two or more layers of cuboidal or columnar cells, function in secretion. Found in male sperm duct, sweat and mammary glands, pharynx, and male urethra

Transitional Epithelia

Appears to be stratified squamous or cuboidal, surface cells are rounded/squamous, stretch permitted. Found in lining of urinary tracts: ureter, bladder, urethra

Exocrine Glands

Cells secrete their products into ducts: leads to body surface or body cavity- mucous, sweat, oil, saliva

Goblet Cell

A unicellular exocrine gland that secretes mucous

Endocrine Glands

Do not possess ducts, secrete directly into the extracellular space or blood vessel, travels to specific targets (cells, tissues, organs)

Functions of Connective Tissue

Protection of tissues and organs, physical support, energy storage and insulation, transporting substances

Ground Substance

Interstitial fluid, a mixture of proteins and carbohydrates and variable amounts of salts and H₂O. Together with fibers makes up the extracellular matrix

Fibers

Provide support, depending on presence help determine structural properties of the tissue- 3 types

Collagen

Most common and strongest fiber type- resist being pulled apart

Elastic

Fiber that can stretch and return to original shape/length

Reticular

Thin branching collagen fibers that form extensive networks

Specific Cell “Blast”

Developing, active cell state

Specific Cell “Cyte”

Mature, less active cell state

Osteoblasts

Bone cells that actively lay down minerals

Osteocytes

Bone cells that are living but not as active

Fibroblasts

Very common cell type that secrete fibers

Macrophages

“Cleanup” cells that engulf bacteria and cellular debris

Plasma Cells

Cell type that secrete antibodies

Mast Cells

Cell type abundant by blood vessels and produce histamine

Adipocytes

Cell type involved in fat storage

Areolar Loose Connective Tissue

Loosely-packed assembly of all fiber types and immune cells that cushion organs. Contain key immune mediators to fight off infections. Found supporting under epithelial layers and surrounding organs

Adipose Loose Connective Tissue

Matrix crowded by tightly-packed adipocytes, serves to insulate and protect organs and provides energy storage depot. Found around major organs and within subcutaneous layer of skin

Reticular Loose Connective Tissue

Meshwork of reticular fibers loosely-organized, forms a flexible meshwork and supports tissue and immune cells. Found in lymph nodes, bone marrow, splenic pulp

Regular Dense Connective Tissue

Fibroblasts embedded within a regular ordered assembly of collagen fibers, functions to resist pulling stress. Attaches muscles to bone (tendon) and bone to bone (ligament)

Irregular Dense Connective Tissue

Irregularly-arranged collagen fibers with fibroblasts embedded within, resists force in many directions. Found in dermis, joint capsules, and underlying epithelial linings

Elastic Dense Connective Tissue

Dense regular connective tissue enriched with elastin fibers, ordered arrangement of elastin allows for stretch and recoil of tissue. Found in walls of arteries, and bronchial tubes and some ligaments

Cartilage

Collagen and elastic fibers in a specialized matrix, found in lacunae, provide support and withstand deformation

Hyaline Cartilage

Most abundant and weakest type of cartilage

Fibrocartilage

Strongest type of cartilage, contains lots of collagen

Elastic Cartilage

Type of cartilage that contains lots of elastic and maintains its shape

Bone Tissue

Similar to cartilage but has a solid matrix. Two types: compact and spongy

Lymph

Matrix similar to blood but fewer proteins, cellular composition varies

Cutaneous Membrane

Epithelial membrane that covers the surface of the body (the skin). Keratinized, stratified squamous epithelium attached to a thick layer of connective tissue

Mucous Membranes

Epithelial membrane that line passageways that open to body surface. Very important in defense, mucous traps particles and lubricates passages

Serous Mebranes

Epithelial membrane that lines body cavity that does not open to exterior- parietal and visceral layers. Pleura, pericardium, and peritoneum

Synovial Membranes

Found where two bones come together, consist of connective tissue only, cells secrete synovial fluid that acts as a lubricant

Skeletal Muscle Tissue

Formed from fused cells, multinucleated, has visible striations, voluntary movement. Found attached to bones

Cardiac Muscle Tissue

Greater degree of branching, specialized cell junctions, individual nuclei evident and visible striations. Found on heart wall only

Smooth Muscle Tissue

Spindle-shaped cells with central nucleus, found in layers that form sheets. Provide force and can accommodate stretch. Found in walls of hollow organs

Nervous Tissue

Neurons receive sensory information and carry it to the brain, transmit motor impulses from brain to effector organs. Glial cells provide support, protection, and nourishment for neurons. Found in brain, spinal cord, CNS and PNS

Functions of Skin

Thermoregulation, protection, sensation, excretion/absorption, vitamin D synthesis

Skin

Less complex than other organs, largest organ in the body, 7% of total body weight

Organ

A group of tissues working together to form certain functions

Epidermis

Stratified squamous epithelium, lacks blood vessels, surface consists of dead cells packed with keratin. Sparse nerve endings for touch and pain, 4 to 5 layers of distinct cell types

Keratinocytes

Main cell type of epidermis, produce keratin intermediate filaments, and structure to skin, hair and nails. Have a protective function (water-proofing)

Melanocytes

Produce pigments eumelanin/pheomelanin, giving skin and hair its color. Protects from harmful UV rays

Merkel Cells

Cell type in small numbers that are connected to nerve endings in the skin responsible for sense of touch

Langerhans Cells (dendritic cells)

Macrophages that originate in bone marrow, stand guard against toxins and pathogens and alert immune system

Stratum Basale

Single layer of cuboidal or columnar stem cells sitting on top of basement membrane. These cells continuously produce new keratinocytes, also find Merkel cells and melanocytes in this layer

Stratum Spinosum

Superficial to basale, consists of many layers of keratinocytes. Upper layers of cells become flattened and lose capacity to divide, produce lots of keratin. Langerhans cells found here

Stratum Granulosum

Middle layer of epidermis, consists of 3-5 layers of flattened keratinocytes undergoing apoptosis, secrete a substance between cells that acts as a waterproofing agent

Apoptosis

Programmed cell death

Stratum Lucidum

Found only in thickest skin, consists of a few rows of flattened keratinocytes

Stratum Corenum

Outermost layer of epidermis, many layers of dead keratinocytes. Cells are completely filled with keratin, protect skin against abrasion and penetration, also makes skin waterproof

Dermis

Layer of connective tissue well supplied with blood vessels, glands, and nerve endings. Hair follicles and nail roots embedded here, with smooth muscle attached to hair follicles

Papillary Region

Boundary between dermis and epidermis. Interacts with epidermis through dermal papillae and epidermal ridges, contains circulatory vessels and nerves that supply the epidermis

Reticular Region

Most of the dermis, toughest layer of skin, thick collagen bundles produce cleavage lines, contains blood vessels, nerves and other accessory structures

Friction Ridges

Result from epidermal ridges / dermal papillae (on fingers)