A&P Exam 2

Fibroblasts

Cells that produce fibers and ground substance that form the matrix of connective tissue

mast cells

Cells that secrete heparin (inhibits blood clotting) and histamine (dilates blood vessels)

collagenous fibers

fibers made of collagen

tough, flexible, resistant to stretching

reticular fibers

thin collagen fibers coated with glycoprotein

form spongelike framework for certain organs

elastic fibers

made of elastin coated with glycoprotein

stretches and recoils

simple squamous epithelium

-allows for rapid diffusion/transport of substances through membrane in alveoli, the inner lining of blood vessels, and Bowman’s capsule of kidneys

-mesothelium of serous membranes that secretes lubricating serous fluid

simple cuboidal epithelium

• absorption & excretion ; production of mucous coat ; movement of respiratory mucus

• bronchioles, most kidney tubules, glands such as mammary, thyroid, salivary, and liver

simple columnar epithelium

• rapid absorption and secretion of protective mucus

• inner lining of stomach, intestines, gallbladder, uterus, and uterine tubes

pseudostratified columnar epithelium

• propels and secretes mucus

• much of the inner lining of the airway including the nasal cavity, trachea, and bronchi

stratified squamous epithelium

• can be keratinized or unkeratinized (mucous membranes)

• keratinized: epidermis ; unkeratinized: oral cavity, vagina, esophagus, anal canal

stratified cuboidal epithelium

• contributes to sweat secretion, secretes ovarian hormones, produces sperm

• sweat gland ducts, egg-producing vesicles of ovaries, sperm-producing ducts of testes

transitional epithelium/urothelium

• can expand and retract; protects against osmotic damage

• urinary tract: bladder, ureters, urinary ducts, part of kidney, part of urethra

dense connective regular tissue

• densely packed collagen fibers and fibroblasts

• resists stress, transfers tension, and forms tight bonds

• tendons and ligaments

tendon

connects muscle to bone

ligament

connects bone to bone and stabilizes joints

joint

place where two bones meet

dense connective irregular tissue

• wavy, nonuniform collagen fibers

• imparts durability to tissues and resists stress in unpredictable directions

• deep dermis, capsules around viscera, fibrous sheaths around cartilage and bone

areolar tissue

• collagenous fibers, elastic fibers, and numerous blood vessels

• provides nutrients to overlying epithelia and allows nerves and blood vessels to penetrate into other tissue

• surrounds blood vessels and nerves and underlies almost all epithelia

adipose tissue

• dominated by adipocytes

• provides cushioning, energy storage, and thermal insulation

• subcutaneous fat, heart surface, breast

reticular tissue

• reticular fibers and lymphocytes

• forms supportive sponge-like framework in many lymph tissues (stroma)

• lymph nodes, spleen, bone marrow

hyaline cartilage

• fine, dispersed collagen fibers that are not usually visible

• allows smooth movement of joints and growth of long bones

• costal cartilage of rib cage, joints at the ends of bones, supportive rings of the trachea and bronchi

fibrocartilage

• many collagen fibers

• resists compression, absorbs shock in particular joints

• pubic symphysis, intervertebral discs, pads of shock-absorbing cartilage

elastic cartilage

• elastic fibers

• bendy and flexible

• outer ear and epiglottis

ectoderm

the outermost primary germ layer

gives rise to the epidermis and nervous system

endoderm

the innermost primary germ layer

gives rise to mucous membranes of digestive and respiratory tracts as well as digestive glands

mesoderm

middle primary germ layer

gives rise to mesenchyme

endosteum

reticular connective tissue that lines internal marrow cavity, the trabeculae of spongy bone, and the canal system of compact bone

marrow/medullary cavity

space in shaft of long bones enclosed by the outer shell of dense bone

contains bone marrow

diaphysis

the shaft of a long bone

epiphysis

the expanded head of long bones that contains spongy bone enclosed by the outer shell of dense bone

articular cartilage

layer of hyaline cartilage at the joint surface where one bone meets another in synovial joints

synovial membrane

lines the inner capsule of a joint and secretes slippery synovial fluid that promotes smooth movement

not true membrane → synoviocytes in place of epithelium

nutrient foramina

minute holes in bones where blood vessels penetrate and enter into perforating canals which travel to central canals

periosteum

tough outer covering of a bone formed by outer collagenous layer and inner osteogenic cell layer

osteogenic cells

stem cells that develop from mesenchyme and produce osteoblasts

in the endosteum and the inner layer of periosteum

osteoblasts

cells that synthesize the organic matter of the bone and promote its mineralization

form rows in endosteum and inner layer of periosteum

also function as endocrine cells

osteocytes

mature osteoblasts that have become embedded in matrix and live for decades

reside in lacunae

also function as endocrine cells

canaliculi

slender channels that connect lacunae which house osteocytes

osteoclasts

bone-dissolving cells on bone surfaces

dissolves hardened matrix

concentric lamellae

layers of matrix that surround a central canal

connected with e/o by canaliculi

osteon

a central canal and its lamellae

perforating canals

transverse passages that connect central canals along their length

lattice of spongy bone

consists of spicules and trabeculae

spongy bone

bone arranged in lattice-like structure, with spaces in between filled with bone marrow, reducing skeletal weight and absorbing shock

trabeculae develop along the bone’s line of stress

red bone marrow

bone marrow that produces blood cells

found in the marrow cavity of nearly every bone in children and in some of the spongy bone in adults

yellow bone marrow

fatty bone marrow

ossification

osteogenesis —> formation of bone

mesenchyme

embryonic loose connective tissue that develops into bones through both intramembranous and endochondral ossification

intramembranous ossification

produces flat bones of skull and parts of clavicle and mandible

bone arising directly from mesenchyme cells surrounding blood vessels

endochondral ossification

produces most bones of the body

bone arising from preexisting model of hyaline cartilage covered with fibrous perichondrium which produces chondrocytes/osteoblasts

epiphyseal plate

thin wall of cartilage that separates the primary and secondary marrow cavities at one or both ends of bone

growth zone for bone elongation through adolescence

metaphysis

transitional zone facing each marrow cavity where cartilage is replaced by bone

mineral deposition

crystallization process in which calcium, phosphate, and other ions are taken from blood plasma and are deposited onto collagen fibers

calcitriol

form of vitamin D produced by skin, liver, and kidneys

secreted into blood stream by kidneys

increases calcium absorption in stomach, increases osteoclast activity, decreases osteoblast activity, and prevents loss of calcium through kidney secretion

calcitonin

released by parafollicular cells of thyroid gland when they detect excess levels of calcium in the blood plasma

downregulates osteoclast activity and upregulates osteoblast activity to increase bone deposition and decrease resorption

parathyroid hormone

hormone released by parathyroid glands in response to low levels of calcium in blood plasma

upregulates osteoclast activity and downregulates osteoblast activity

also prevents loss of calcium in kidney excretion

merocrine/eccrine secretion

secretion through exocytosis

secretory vesicles merge with membrane and release product into duct/lumen

holocrine secretion

secretion by disintegration of cells

final product is substance produced by cell and dead cell fragments

apocrine secretion

secretion by release of vesicles with product into duct

final product contains substance as well as parts of the cell (i.e. plasma membrane)

mucous membranes

found in body cavities that open to outside (oral cavity, anal canal, etc.)

kept moist with secretion

epithelial tissue overlying connective tissue (usually areolar)

serous membrane

surrounds organs in motion, most commonly in closed cavities

double-layered membrane (simple squamous over areolar) with serous fluid in between

found in pleura, pericardium, and peritoneum

cutaneous membrane

the skin!

dry membrane with epithelium (epidermis) and dense irregular connective (dermis)

Lanherhan’s cell

immune system cell that resides in the epidermis with long projections between keratinocytes

mounts an immune system response if detects microbe that breached stratum corneum/granulosum

hirsutism

a condition marked by excessive hairiness in areas that are not usually hairy, most commonly in women and children

papillary layer of dermis

areolar tissue layer directly beneath dermal papillae

reticular layer of dermis

dense irregular tissue beneath papillary layer

hair dermal papilla

bud of vascular connective tissue that provides nutrient to hair

sudoriferous glands

sweat glands of two main types: eccrine and apocrine

eccrine glands

secretes sweat composed mostly of water and salts to cool down body

utilizes merocrine mechanism

apocrine glands

secretes sweat that includes many lipids

ducts directly to hair follicle in places where hair develops during puberty

under the control of sex hormones

utilizes merocrine secretion

sebaceous gland

secretes sebum that ducts onto hair follicle

locks in moisture and contributes to protection of skin

utilizes holocrine secretion

conditions under which bone remodeling occurs

in response to hormonal changes

in response to mechanical stress

turnover is constant

fibrodysplasia ossificans progressiva

genetic condition often triggered by trauma that involves soft tissue inappropriately forming into calcified bone tissue

accessory navicular syndrome

secondary ossification center begins to form own separate bone, commonly in the navicular tarsal bone

acromegaly

condition characterized by the excessive growth of cartilage after the epiphyseal plate has closed in adulthood

osteoporosis

a condition usually caused by the loss of estrogen during menopause

decreased amounts of estrogen results in osteoclast activity outworking osteoblast activity causing the loss of bone, mostly in spongy bone

Paget’s disease

condition marked by excess in deposit of bone causing a deformity in the bone which may lead to decreased function

when bones get thicker/wider, process is more similar to…

…intramembranous ossification

synostosis

bony, immobile joint that forms when a joint ossifies

form by the ossification of either fibrous or cartilaginous joints

includes the ossification of epiphyseal plates

synarthrosis

usually fibrous joint where bones are bound by collagen fibers that penetrate both bones

sutures, gomphoses

amphiarthrosis

usually cartilaginous joint

synchondrosis, symphysis, syndesmosis

synchondrosis

rigid joint in which bones are joined by a hyaline cartilage bridge

includes non-ossified epiphyseal plates

symphysis

joint in which bones are joined by fibrocartilage

diarthrosis/synovial joint

the most mobile joint, contains slippery synovial fluid in joint cavity

articular capsule

connective tissue of the synovial membrane that encloses the joint cavity and retains synovial fluid

outer fibrous capsule is continuous with periosteum of adjoining bones

articular disc

extension of fibrocartilage that forms a pad between two bones across the entire joint cavity

meniscus

extension of fibrocartilage that forms a pad between the femur and tib-fib but does not fully cross the joint cavity, resulting in a left and right pad

bursa

fibrous fluid-filled sacs usually found in places where bones are close to the surface

fibrous joints

joints in which the connecting tissue is dense connective tissue

sutures

joints in which there are very short fibers between the two bones, often in a wavy line to increase articulation surface area

found in the bones of the skull

syndesmosis

a joint where dense regular connective tissue keeps the radius/ulna and tib/fib oriented towards each other

gomphosis

found only between a tooth and its socket

periodontal ligament fibers hold tooth firmly in place

intracapsular ligaments

ligaments found within a joint capsule

generally take a long time to heal due to lack of blood vessels in area

ex: ACL and PCL

anterior cruciate ligament (ACL)

intracapsular ligament found in the joint capsule between the femur and the tibia

osteoarthritis

condition involving the degradation of a joint cavity, resulting in joints that can be bone-on-bone

generally found in bigger joints that undergo high mechanical stress

rheumatoid arthritis

autoimmune disease that often affects distal joints such as in the fingers

WBCs break down synoviocytes, causing swelling and joint deformity