chapter 4 Flashcards
Tissue
A group of cells with similar structure and function is called a tissue
Epithelial tissues
found on surfaces as either coverings (outer surfaces) or linings (inner surfaces)
capable of secretion and may be called glandular epithelium or glands
Shape of squamous cells
flat cells
Shape of cuboidal cell
cubed shape
shape of columnar cells
tall and narrow cells
Simple cells
singe layer of cells
stratified cells
many layers of cells
simple squamous epithelium
single layer of flat cells
very thin and very smooth
Ex: Alveoli of the lungs- thin to permit diffusion of gases
Capillaries- thin to permit changes of materials; smooth to prevent abnormal blood clotting
Stratified squamous epithelium
many layers of cells; surface cells are flat; lower cells rounded; lowest layer undergoes mitosis
Barrier to microorganisms
Ex: Epidermis- surface cells are dead; excellent barrier to pathogens
Lining of esophagus, vagina, oral cavity- surface cells are living; a good barrier to pathogens
Transitional Epithelium
many layers of cells; surface cells change from rounded to flat
Ex:Lining of urinary bladder- permits expansion without tearing the lining
Simple cuboidal epithelium
single layer of cube-shaped cells
Function is secretion
Ex:Thyroid gland-Secretes thyroxine
Salivary glands-Secretes saliva
Kidney Tubules- permit reabsorption of useful materials back to the blood
Simple columnar epithelium
one layer of column-shaped cells
Goblet cells
Ex:Lining of stomach-Secretes gastric juice
Lining of small intestine-Secretes enzymes and absorbs end products of digestion (microvilli present)
Ciliated epithelium
one layer of columnar cells with motile cilia on their free surfaces
Ex:Lining of trachea-sweeps mucus and dust to the pharynx
Lining of fallopian tube-sweeps ovum toward uterus
Glands
cells or organs that secret something
Unicellular glands
One cell
Ex: Goblet cells-secret mucus
Multicellular glands
Dividing into two major groups: exocrine glands and endocrine glands
Exocrine glands
Have ducts (tubes) to take the secretion away from the gland to the site of its function
Ex: Salivary glands, for example, secret saliva that is carried by ducts to the oral cavity
Endocrine glands
Are ductless glands.
The secretions of endocrine glands are hormones, which enter capillaries and are circulated throughout the body.
Ex: thyroid gland, adrenal gland, pituitary gland
Both exocrine and endocrine gland
The pancreas.
Exocrine portion secretes digestive enzymes
endocrine portion secrete the hormones insulin and glucagon directly into the blood
Connective tissues
Hold things together
The matrix is a structural network or solution of non living intercellular material
Blood
Plasma (matrix) and red blood cells, white blood cells and platelets
Within blood vessels
Plasma-transports materials
RBCs-carry oxygen
WBCs- destroy pathogens
Platelets-prevent blood loss
Aerolar
made of fibroblasts
Contains mast cells
connects skin to muscles
wbc’s destroy pathogens
Adipose
Adipocytes that store fat (little matrix)
Stores energy and provides cushioning (white fat)
Brown fat generates heat
Fibrous
mostly collagen fibers (matrix) with few fibroblasts
Gives strength, yet flexible
Found in inner layer of skin, outer walls of arteries, and tendons/ligaments
Poor blood supply, makes repair a slow process
Elastic
more elastin, less fibroblasts
provides elasticity and stretch
found in walls of larger arteries-helps maintain blood pressure
around alveoli lungs- promotes normal exhalation
Bone
Osteocytes in a matrix of calcium, salts and collagen
Bones support the body and attach muscles
Cartilage
chondrocytes flexible protein matrix
helps prevent friction, absorbs shock and permits movement
within the wall of the trachea
on joint surfaces of bones
tip of nose and outer ear
between vertebrae
Muscle tissue
specialized for contractions
Contains skeletal muscle, smooth muscle and cardiac muscle
Skeletal Muscle
Large cylindrical cells with striations and several nuclei each.
Attached to bones
•moves the skeleton and produces heat
Essential to cause contraction (voluntary)
Smooth muscle
small tapered cells with no striations and one nucleus each
Within walls of arteries
•maintains blood pressure
Within the walls of stomach and intestines
•peristalsis (helps propel food through digestive tract)
Iris of the eye
•regulates size of pupil
Brings about contraction or regulate the rate of contraction (involuntary)
Cardiac Muscle
Branched cells with faint striations and one nucleus
Forms the walls of the chambers of the heart
*pumps blood
Regulate only the rate of contraction (involuntary)
Nerve tissue
consists of nerve cells called neurons and some specialized cells found only in the nervous system.
Central Nervous System (CNS)
The brain and spinal cord
Made of neurons and neuroglia
Peripheral Nervous System (PNS)
Consist of all the nerves that emerge from CNS and supply the rest of the body
Made of neurons and Schwann cells
Neuron (nerve cell)
Consist of a cell body, axon and dendrites
Cell body of neuron
Contains the nucleus
Regulates the functioning of the neuron
Axon
A cellular extension that carries electrical impulses away from the cell body
A neuron only has one Axon
Dendrites
A cellular extension that carry electrical impulses toward the cell of the body
A neuron may have several or many dendrites
Synapse
Space between axon of one neuron and the dendrite or cell body of the next neuron
Transmits impulses from one neuron to others by means of chemicals (neurotransmitters)
Neurotransmitters
Chemicals released by axons
Transmit impulses across synapses
Neuroglia
Specialized cells in the central nervous system
Form myelin sheaths and other functions
Schwann cells
Specialized cells in the peripheral nervous system
Dorm the myelin sheaths around neurons
Epithelial membranes
Two types of Epithelial membranes, serous and mucous
Serous membranes
Sheets of simple squamous epithelium that line some closed body cavities and cover the organs in these cavities
Pleural membranes
Serous membranes of the thoracic cavity
Parietal pleura-lines the chest wall
Visceral pleura- covers the lungs
Secrete serous fluid, which prevents friction between them as the lungs expand and recoil during breathing
The heart in the the thoracic cacity
Parietal pericardium- lines the fibrous pericardium
Visceral pericardium or epicardium- on the surface of the heart muscle
serous fluid is produced to prevents friction as the heart beats
Abdominal cavity
Peritoneum- serous membrane that lines the cavity
Mesentery- folded over and covers the abdominal organs
Serous fluid prevents friction as the stomach and intestines contract and slide against each other
Mucous membranes
lines the body tracts (systems) that have openings to the environment.
Respiratory, digestive, reproductive tracts.
The mucus secreted by these membranes keeps the lining of the epithelial wet.
Superficial fascia
Between the skin and muscles; adipose tissue stores fat; WBCs destroy pathogens that enter breaks in the skin
Periosteum
Covers each bone; contains blood vessels that enter the bone Anchors tendons from muscles and ligaments from other bones
Perichondrium
Covers cartilage; contains capillaries, the only blood supply for cartilage
Synovial
Lines joint cavities; secretes synovial fluid to prevent friction when joints move
Deep fascia
Covers each skeletal muscle; anchors tendons
Meninges
Cover the brain and spinal cord (line the cranial and spinal cavities); contain cerebrospinal fluid
Fibrous Pericardium
Forms a sac around the heart; lined by the serous parietal pericardium
