In ______, zygotes divide by mitosis. The first tissues appear to organize themselves in the ________.
embryonic tissues; primary germ layers
What are the three primary germ layers?
the outer layer that forms the epidermis and nervous system
the inner layer that forms mucous membrane, lining GI tract, respiratory system, and digestive glands
in between the ectoderm and endoderm is the _______, which eventually turns into _______ with collagen fibers and fibroblasts.
(all connective tissues arrise from mesenchyme)
-Undifferentiated cells with potential to differentiate into one or more types of mature functional cells -growth and differentiation of tissues depends on them
cells formd in the early stages of development that have the potential to develop into any type of fully differentiated human cell; thus their plasticity is unlimited
cells in the inner cell mass that can still develop into any cell type of the embryo, but not into accessory organs of pregnancy; thus their plasticity is limited
cells that cover the body surface, line body cavities and organs, and make up most gland tissue
•Single layer of flat cells •Permits diffusion or filtration of substances •Secretes lubricating serous fluidAlveoli (air sacs) of lungs, kidney glomeruli, endothelium (lining of heart and blood vessels), and serosa (lining of ventral body cavity
simple squamous epithelium
•May contain microvilli (kidney tubules) or cilia (bronchioles) •Absorption and secretion, mucus production •Liver, thyroid, mammary & salivary glands, bronchioles, & kidney tubules
simple cuboidal epithelium
•Ciliated cells line small bronchi, uterine tubes, uterus •Nonciliated cells line digestive tract and gallbladder •Goblet cells (producing mucus) may be present •Absorption and secretion; Movement of egg/embryo in uterine tube •Lining of GI tract, uterus, kidney and uterine tubes
simple columnar epithelium
•Single row of cells, some not reaching free surface, but all touching basement membrane; Nuclei at different layers, giving a stratified look •Often contain goblet cells or bear cilia •Ciliated cells line trachea and most of upper respiratory tract
pseudostratified columnar epithelium
•Multilayered epithelium covered with dead squamous cells •On skin, especially thick on palms of hands, soles of feet •Retards water loss and acts as a barrier to organisms
stratified squamous epithelium
•Multilayered epithelium surface cells that change from round to flat when stretched -- allows for filling of urinary tract •Found in ureter and urinary bladder; one duct of umbilical cord
main cells of CT proper; produce fibers & ground substance that form the matrix of the tissue
form blood cells and platelets
eHematopoietic stem cells
phagocytes that destroy bacteria, other foreign particles, and dead or dying cells of our own body. they activate the immune system when they sense antigens and they arise from monocytes (a type of WBC)
most are neutrophils, which leave blood to wander through CT attacking bacteria. _______ are the dense patches of WBCs that react against bacteria, toxins, and other foreign agents.
leukocytes (white blood cells); lymphocytes
lymphocytes turn into ________ when they detect foreign agents, they then synthesize antibodies. found in walls of the intestines and in inflamed tissue
these cells, found alongside blood vessels, secrete heparin (inhibits blood clotting) and histamine (increases blood flow by dilating blood vessels)
fat cells that store triglycerides
______-form cartilage ______-cartilage cells ______-form bone ______-bone cells ______-break down bone
osteoblasts; osteocytes; osteoclasts
- tough, stretch resistant, yet flexible - most abundant protein in body (25%) - found in tendons, ligaments, bone and cartilage matrix, and deep layer of the skin
- thin, collagen fibers coated with glycoprotein - form spongelike framework in spleen and lymph nodes
- thin branching fibers of elastin protein that stretch and recoil like rubberband (elasticity) - found in skin, lungs and arteries
•Loosely arranged fibers & cells, mostly ground substance, blood vessels •Contains fibroblasts, macrophages, WBCs, plasma cells, mast cells •Underlies all epithelia, fascia between muscles, surrounds esophagus, trachea, nerves and blood vessels, mesenteries
CT proper: loose CT-areolar
•Loose network/mesh of reticular fibers and cells, houses blood cells •Forms supportive framework for lymphatic organs •Found in lymph nodes, spleen, thymus and bone marrow
CT Proper: Loose CT -- Reticular
•Cells filled with fat; nucleus pressed against cell membrane •Energy storage, insulation, cushioning, heat production •Found: hypodermis, breast, heart surface, mesenteries, surrounds organs
CT Proper: Loose CT -- Adipose
•Densely, packed, parallel, collagen fibers, fibroblast nuclei between fibers, very little ground substance, BVs scarce •Resists stress in one direction •Ligaments hold bones together; tendons attach muscles to bones
CT Proper: Dense Regular CT
•Densely packed fibers randomly arranged, few visible cells, scant ground substance, blood vessels scarce •Withstands stresses applied in different directions, durable, hard to tear •In deep skin layer; Around visceral organs, cartilages & bones
CT Proper: Dense Irregular CT
______ is a supportive CT with a flexible rubbery matrix _______ secrete matrix & become trapped in lacunae. Once enclosed, the cells become ______
cartilage; chondroblasts; chondrocytes
•Clear matrix; collagen fibers not visible; 2-4 chondrocytes per lacuna, covered by perichondrium (dense irregular CT) •Model for bone in fetus, present in growth plates of children’s long bones •Covers ends of bones at movable joints; sternal ends of ribs; larynx, trachea, bronchi
•Elastic fibers highly visible in matrix •Covered by perichondrium •Provides flexible, elastic support •Located in external ear and epiglottis
•Collagen fibers with parallel rows of chondrocytes in lacunae •No perichondrium •Resists compression, absorbs shock •pubic symphysis, knee menisci, intervertebral discs
there are two forms of osseous tissue, ______ fills the heads of long bones and forms the middle layer of flat bones and is covered by _______, composed of cells and matrix arranged in cylinders surrounding central canal filled with blood vessels & nerves
spongy bone; compact (dense) bone
Most compact bone is arranged in cylinders of tissue that surround _______ in which blood vessels and nerves travel through. The bone matrix is deposited in _______, onionlike layers around each central canal. Tiny lacunae between the lamellae are occupied by mature bone cells called _____. canals called _____ radiate from each lacuna to its neighbors and allow the osteocytes to contact each other. The bone as a whole is covered with a tough fibrous _______.
central canals; concentric lamellae; osteocytes; canaliculi; periosteum
blood is a fluid CT containing:
plasma, erythrocytes, leukocytes, and platelets
Nervous tissue consists of ______, large cells with cell processes specialized to detect stimuli, respond quickly, and transmit messages through the body; and ______, small cells specialized to protect and assist neurons •Found in brain, spinal cord, nerves and ganglia
•Elongated cells that contract when stimulated by a neuron •Exert physical force on other tissues and organs •Source of body heat, responsible for processes like digestion, breathing, speech, waste elimination
•Long, cylindrical cells with striations and multiple peripherally-located nuclei •Found in skeletal muscles attached to bones, tongue, esophagus, and voluntary sphincters
•Found only in heart •Contains short branched cells with striations, one centrally located nucleus per cell, and intercalated discs (junctions allowing electrical messages to travel quickly between cells and also hold neighboring cells together during heart contraction) •Pumps blood through body
•Short cells with tapered ends; nonstriated with only one centrally located nucleus per cell •Found in sheets of muscle in viscera walls; iris; hair follicles and involuntary sphincters •Functions: swallowing, GI tract functions, labor contractions, control of airflow, erection of hairs and control of pupil size
Cilia are most likely to be seen on ___ epithelium.
A tissue specialized for energy storage and thermal insulation is
Which of the following tissues is avascular?
epithelial and cartilage
Which of the following is not one of the four primary classes of tissue?
The only type of cell seen in a tendon is
The shape of a person's external ear is due mainly to
___ are single mucus-secreting cells found in the epithelia of many mucous membranes.
Hyaline cartilage is found in
All glands that release their products by way of ducts, rather than directly into the bloodstream, are called ___ glands.
The only type of muscle with multinucleated fibers is
Tendons and ligaments are made predominantly of the protein
Which type of epithelium is best suited for rapid filtration?
The nonliving material surrounding cells is called
The germ layer that gives rise to mucous membranes of the digestive and respiratory tracts is called
An individual was born with Marfan's syndrome, which is a hereditary defect on chromosome 15. Symptoms of this disease include unusually tall stature, long limbs, and an abnormal spinal curvature. Which germ layer is most likely affected by this hereditary disease?
This primary germ layer is the middle layer called _____ and gives rise to a gelatinous material called ____ that gives rise to the different types of connective tissue such as bone, muscle, and blood.
This tissue regulates what enters and what leaves the body.
Which of the following is not a characteristic of simple columnar epithelium?
cells appear cube shaped
The epithelium lining the trachea is capable of
producing mucus and moving material across its surface.
Simple cuboidal epithelium is found in _____ and its function is _____.
kidney tubules; absorption
The connective tissue that forms the framework of organs and tissue such as lymph nodes, spleen, and thymus is composed primarily of fibroblasts and
Which of the following tissues is found in the dermis of the skin?
The ground substance of blood is called
The area of the neuron which houses the nucleus is called the ______, while the long single extension that sends electrical signals to other cells is called the ______.
The electrical charge difference across plasma membranes of all cells is called the
The membrane that lines the outer wall of the heart is a ______ membrane, specifically called the _______.
serous; visceral pericardium
A chronic smoker can cause the normal ciliated pseudostratified epithelium in the bronchi to change to stratified squamous epithelium. You would expect this chronic smoker to
be less likely to warm and humidify the air and less likely to move filter particles towards the pharynx.
The most controversial stem cell is the embryonic stem cell. This cell, which is ethically very controversial, is most interesting to scientists because embryonic stem cells are