SPINAL CORD ANATOMY & PHYSIOLOGY HONORS ANATOMY & PHYSIOLOGY.
Anatomy and Physiology I
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Transcript of Anatomy and Physiology I
Anatomy and Physiology I
Tissue Types
Key Terms Histology:
the study of tissues.
Tissues: groups of cells which are similar in
structure and which perform common or related functions.
Four Basic Kinds of Tissues
Epithelial TissueConnective TissueMuscle TissueNervous Tissue
Epithelial Tissue
Epithelial Tissue Locations: Covers the body Lines the cavities, tubes, ducts and blood
vessels inside the body Covers the organs inside body cavities
Epithelial Tissue Functions: Protection from physical & chemical injury, Protection against microbial invasion, Contains receptors which respond to stimuli, Filters, secretes & reabsorbs materials and Secretes serous fluids to lubricate structures.
Examples of Epithelium Tissue Lines the respiratory tract Lines the digestive system Skin Surrounding internal organs
Characteristics of Epithelium Tissue1. Cells are tightly packed2. Regenerate easily3. Avascular – lack blood vessels4. apical surface – exposed surface5. Basement membrane – anchors down
cells
Connective Tissue
Connective Tissue: Most abundant & widely distributed
tissue Connective Tissue Functions:
Connects, binds and supports structures,
Tendons, ligaments, etc. Protects & cushions organs and tissues, Insulates (fat) and Transports substances (blood).
Examples of Connective Tissue Bones Cartilage Tendons Blood Fat
Characteristics of Connective Tissue1. Most are well vascularized – have a good
blood supply2. Some have very poor blood supply being
avascular.3. Extracellular matrix – nonliving substance
found outside the cells
Extracellular Matrix explained
Nonliving material between cells Produced by the cells and then
extruded Responsible for the strength Two components
1. Ground substance Of fluid, adhesion proteins, proteoglycans Liquid, semisolid, gel-like or very hard
2. Fibers: collagen, elastic or reticular
Epithelial Tissue in Detail
Classification of epithelia
According to thickness “simple” - one cell layer “stratified” – more than one layer of
cells (which are named according to the shape of the cells in the apical(base) layer)
According to shape “squamous” – wider than tall “cuboidal” – as tall as wide “columnar” - taller than wide
Human Anatomy, Larry M. Frolich, Ph.D.
Simple: just one layer or cell shape
Stratified: multiple layers and cell shapes
Classes of Epithelia
Human Anatomy, Larry M. Frolich, Ph.D.
Simple Epithelia
Type
Cell shape Example
Squamous Squashed Endothelium (lines blood vessels), mesothelium (serous lining of celom)
Cuboidal
Cubed Walls of glands
Columnar Columns Lining of gut tube; sometimes with cilia like lining of uterine tube
Pseudo-stratified Flat cells give rise to columns
With cilia in respiratory tubes to move mucous/particles out of lungs
to protect
where diffusion is important
where tissues are involved in secretion and absorption: larger cells because of the machinery of production, packaging, and energy requirements
Simple Squamous Epithelium Descriptions:
Single layer, flattened cells, simplest of epithelia
Function: Allows passage of materials by diffusion
and filtration Secretes lubricating substances
Location: Air sacs of lungs, lining of heart, blood
vessels, lining of ventral body cavity
Simple Cuboidal epithelium Descriptions:
Single layered, cube like, large spherical central nuclei
Function: Secretion and absorption
Location: Kidney tubules, ovary surfaces
“ciliated” literally = eyelashes(see next page)
Simple Columnar Epithelium Descriptions:
Single layer, tall, round or oval nuclei, some bear cilia,
may contain mucus-secreting glands(goblet cells)
Function: Absorption, secretion of mucus and
enzymes, cilia propels mucus Location:
Nonciliated lines the digestive tract Ciliated lines small bronchi, uterine tubes,
parts of uterus.
Pseudostratified Columnar Epithelium
Descriptions: Single layer w/ differing heights, nuclei at
different levels, may have goblet cells or cilia
Function: Secretion(especially mucus), propulsion of
mucus by ciliary action Location:
Nonciliated in sperm carrying ducts Ciliated lines the trachea and upper
respiratory tract.
Stratified: regenerate from below
Stratified Squamous Epithelium Descriptions: (most common stratified)
Several layers, surface cells are squamous, basal cells are cuboidal or columnar
Function: Protects underlying tissues in areas of
abrasion Location:
Esophagus, the mouth, outer portion of skin
Rare…
Stratified Cuboidal Epithelium Descriptions: (rare)
Usually two layers of cube-like cells Function:
Protection Location:
Rare Largest ducts of sweat glands,
mammary glands, and salivary glands.
Rare…
Stratified Columnar Epithelium Descriptions: (rare)
Several layers thick, columnar with varying in size and shape
Function: Protection, secretion
Location: Rare Large ducts of glands
Transitional Epithelium Descriptions:
Highly modified, several layers of cuboidal or columnar cells
Function: Stretches readily, allowing distention of
urinary organs Location:
Lines the ureters, bladder, parts of urethra
Human Anatomy, Larry M. Frolich, Ph.D.
Human Anatomy, Larry M. Frolich, Ph.D.
Can You Identify the Classes of Epithelium?
A BC
D
EQuiz!!
Specific Connective Tissue In Detail
Bone Descriptions: Aka: osseous tissue
Hard calcified matrix, surrounded by layers of calcium salts in additions to lots of collagen fibers
Cells sit in cavities called “lacunae” Function:
Protection and support Location:
Skeletal system
Hyaline Cartilage Descriptions: (hyalin=glass)
Most common and widespread type Collagen fibers with a rubbery matrix
Function: Supports/reinforces, resilient cushioning
Location: Covers ends of bones in joints, nose,
trachea, larynx, embryonic skeleton
Elastic Cartilage Descriptions:
Collagen fibers with a rubbery matrix Very elastic
Function: Maintains shape of structure gives flexibility
Location: External ear epiglottis
Fibrocartilage Descriptions:
Similar to hyaline but less firm Much like a cushion
Function: Absorbs compressive shock
Location: Intervertebral discs, discs of knee joint
Dense Connective Tissue Descriptions:
Collagen fibers, fibroblasts fill gaps between collagen
Strong ropelike structures like tendons and ligaments
Function: Connect muscles to bones, connect
bones at joints, lots of tensile strength Location:
joints
Vocab Fibroblasts – cells that make collagen
fibers Tendons – attach skeletal muscles to
bones Ligaments - connect bones to bones at
joints. More stretchy and contain more elastic fibers than tendon
Loose CT: Areolar Tissue Descriptions:
Gel-like matrix w/ all three fiber types Very loose network w/ lots of open space
Function: Wraps and cushions organs, a reservoir of
water and salts for surrounding tissues, important for swelling
Location: Under epithelia, around organs, surrounds
capillaries
Loose CT: Adipose Tissue Descriptions: (fat)
Very similar to areolar tissue Fat cells predominate
Function: Insulates against heat loss, supports and
protects organs, reserve food fuel Location:
Under skin, around kidneys and eyeballs, abdomen and breast
Loose CT: Reticular CT Descriptions:
Network of reticular fibers (similar to fibroblast)
Delicate network of interwoven fibers Function:
Form soft internal skeleton that supports other cells such as white blood cells, mast cells
Location: Lymphoid organs (lymph nodes, bone
marrow, spleen)
Blood Descriptions: (vascular tissue)
Red and white blood cells in a fluid matrix (plasma)
Fibers are soluble only seen during clotting
Function: Transportation of gases, nutrients,
wastes ect. Location:
Everywhere
Muscle Tissue Muscle Tissue:
Associated with the bones of the skeleton, the heart and in the walls of the hollow organs of the body.
Made to contract Called muscle fibers because they are elongated to
provide a long axis for contraction Muscle Tissue Functions:
Movement Maintains posture Produces heat Facial expressions Pumps blood Peristalsis
Specific Muscle Tissue Types: skeletal muscle Cardiac muscle Smooth muscle
Skeletal Muscle Descriptions:
Long, cylindrical, obvious striations, multinucleated
Function: Voluntary movement, manipulation of
the environment, facial expression Gross body movement
Location: Attached to bones
Cardiac Muscle Descriptions:
Branching, striated, uninucleated cells that fit tightly together at junctions called “intercalated disks”
Function: Involuntary control, propels blood into
circulation. Location:
Walls of the heart
Smooth Muscle Descriptions: (visceral)
No striations, spindle-shaped w/ central nuclei
Arranged closely to form sheets Function:
Propelles substances along internal passageways, involuntary control
Peristalsis – wavelike motion Location:
Walls of the stomach, bladder, uterus and blood vessels
Nervous Tissue
Nervous Tissue: Main component of the nervous system,
ie., brain, spinal cord & nerves. Nervous Tissue Functions:
Regulates & controls body functions Generates & transmits nerve impulses Supports, insulates and protects
impulse generating neurons.
Nervous Tissue Descriptions: (Neurons)
Branching cells, has long extended parts Irritability and conductivity Have “supporting cells” that insulate,
support and protect neurons. Function:
Transmits electrical signals from sensory receptors to effectors that control their activity
Location: Brain, Spinal cord and nerves
Muscle - Skeletal Muscle fibers (cells)
long, parallel & cylindrical
With many nuclei (multinucleate)
Striations (cross stripes run perpendicular to the cells
Produce voluntary movement
Locomotion Heat
Specific Nervous Tissue Types Nervous – Neuron
Branching cells with many long processes
Large central nucleus
Transmit impulses from one area of the body to other areas
Regulate activities through neuron impulses