Transcript 3 Cardiac muscle

The Tissue Level
of Organization
Ch 4
Instructor
presentation
Objectives
Describe the four major categories of
tissues and give general characteristics
of each
 Describe the function of epithelial tissue
depending on their location
 Describe the functions of connective
tissue and relate them to the function of
the body or an organ system

Objectives
Explain the basic differences between
smooth, skeletal and cardiac muscle
 Describe in brief nervous tissue
 Name the organs made of nerve tissue
 Describe the location of pleural
membranes, pericardial membranes,
and the peritoneum-mesentery

Objectives
State the location of mucous
membranes and state the function of
mucus
 Name some membranes made of
connective tissue

Introduction

In today’s modern medical practice it involves
aiding the body’s own homeostatic
mechanisms. The human body has a
tremendous capacity to heal itself. For
example, a child with a fix leg will be able to
bear full weight in 5-6 weeks. Within a year,
the fix site will no longer be visible on xrays.except for the liver, bone is unique
among all body tissues in that it will form new
bone, not scar tissue, when it heals after a fix.
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
Types of Tissues

Major Type
Epithelial
Tissue
types

Specific type

Simple squamous
Simple cubodial
Simple columnar
Pseudostratified
columnar
Stratified squmous
transitional
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
Types of Tissues

Major Type
Connective
Tissue
types

Specific type

Loose (areolar
Adipose
Dense fibrous
Reticular
Cartilage
Bone
Blood


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
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
Types of Tissues

Major Type
Nervous
Tissue
types


Specific type
Neurons
 Neuroglia
Types of Tissues

Major Type
Muscle
Tissue
types


Specific type
Skeletal
 Smooth
 Cardiac
Categories of Tissues

Epithelial tissue

Connective tissue

Muscle tissue

Nervous tissue
Tissue Levels
 The
study of
tissues is
called
histology
Properties of Epithelial Tissue
A layer of cells that forms a barrier with
specific properties
 A free surface exposed to the
environment or to some internal
chamber or passageway
 Attachment to underlying connective
tissue by a basement membrane
 The absence of blood vessels except to
the basement membrane

Surfaces of Epithelial Cells
Functions of Epithelial Tissues

Providing physical protection
– Protects internal body surfaces from
abrasion, dehydration, and destruction
from chemical or biological agents – aids in
the removal of foreign substances from
internal passageways

Controlling permeability
– Everything that enters or leaves the body
must cross an epithelium – some types
more permeable than others
Functions of Epithelial Tissues

Providing sensations
– Specialized cells that can detect
environmental changes and relay that
information to the nervous system
– Ex. Touch receptors in deep layers of the
epithelium of the skin respond by
stimulating neighboring sensory nerves.
Functions of Epithelial Tissues

Producing specialized secretions
– Gland cells
• Exocrine glands – secretions discharged onto
the surface of the epithelial tissue
• Ex. Enzymes entering the GI tract, perspiration
on the skin and milk produced by mammary gl.
• Endocrine glands – secretions discharged into
the surrounding tissues and blood
• Ex. The secretions are hormones, regulated by
tissues, organs, organ systems.
Classifying Epithelia
Epithelia are classified according to the
# of cell layers and the shape of the
exposed cells. 2 types: simple and
stratified with 3 shapes that are:
 1. Squamous
 2. Cuboidal
 3. Columnar

Squamous Epithelium

Areas of absorption or
to provide a slippery
surface to reduce
friction – exchange
surfaces of the lung,
interior of the heart
Simple Squamous Epithelium
The delicate cell type is found in
protected regions where absorption
takes place.
 Ex.

– Kidney tubules,
– Lungs
– Lining of body cavities
– Lining of blood vessels and the heart.
Simple Squamous Epithelium
pg 86
Cuboidal Epithelium

Limited protection,
secretion and absorption
– pancreas, salivary
glands, kidney tubules
Columnar Epithelium

Provides some protection and may
occur in areas of absorption or secretion

Lines the stomach, the intestinal tract,
and may excretory ducts
Columnar Epithelium
Columnar Epithelium (nasal
cavity, bronchi, trachea)
Name this type of tissue
Name this portion
What is this layer
Called beneath this line
What causes a bed sore?
A bed sore is another name for a
pressure ulcer, or a decubitus ulcer.
The ulcer is caused by an interruption of
blood supply to a tissue.
 Pressure ulcers frequently develop in
patients who have been bedridding for
long periods.

What causes a bed sore?

They are caused by the weight of the
body on the skin overlying a bony area
(ie, elbow, heel, hip). The weight of the
body compresses, or squeezes, the
blood vessels, cutting off the supply of
blood to the tissues. Deprived of its
blood supply, the tissues dies, forming
an ulcer.
Transitional Epithelium (bladder,
ureters)
Connective tissue
Pseudostratified Columnar
Epithelium
Nuclei at varying distances from the
surface gives a layered look.
 All cells still in contact with the
basement membrane
 Most are ciliated
 Line the nasal cavity, the trachea, the
bronchi, and part of the male
reproductive tract

Pseudostratified Columnar
Epithelium
– #3 Holocrine – the whole
cell is released –
sebaceous glands
– Endocrine – products are
released into the blood
stream (ductless)
Glands

Based on shape
– Cellular – (goblet cells) –
tubular sweat glands
– Alveolar – sebaceous
gland – attached to hair
follicles

Based on 3 methods
they release secretion:
– #1 Merocrine – release
fluid through their
membrane – sweat and
saliva glands
(exocytosis)
– #2 Apocrine – pinches
off the end of the cell and
releases it – milk,
apocrine sweat gland

Based on what they
secrete
– Serous – watery solution
containing enzymes –
parotid salivary gland
– Mucous – thick, slippery
mucous – sublingual
salivary gland
– Mixed – more than 1 type
– submandibular salivary
gland
Merocrine Glands
Apocrine and Holocrine Glands
Structural Classification of
Exocrine Glands
Connective Tissues
Are considered the deep tissues that
are never exposed to the environment
outside the body. Their functions
include:
 #1 Supporting and protecting
 #2 Transporting materials
 #3 Storing energy reserves
 #4 Defending the body

Functions of Connective Tissue

#1 Supporting and protecting
– Provide a bony structural framework, protect delicate
organs, and surround and interconnect other tissue
types

#2 Transporting materials
– Provides the means for transporting dissolved material
from one part of the body to another

#3 Storing energy reserves
– Fats stored in adipose tissue until needed

#4 Defending the body
– Cell-to-cell interactions and the creation of antibodies to
ward off bacterial invasion
Classifications of Connective
Tissue

Connective tissue proper
– Many types of cells and fibers surrounded
by a syrupy ground substance – tissue that
underlies the skin, fat, tendons, ligaments

Fluid connective tissue
– Blood and lymph

Supporting connective tissue
– Cartilage and bone
Connective Tissue Proper

Fibroblasts
– Most abundant – produce fibers and ground substance

Macrophages
– Phagocytes

Fat cells
– Large lipid-containing vacuoles dominate the
cytoplasm

Mast cells
– Mobile, found near blood vessels, packed with vesicles
filled with chemicals released in response to injury or
infection
Connective Tissue Proper
Connective Tissue Proper
Adipose Tissue
Question? Why do overweight men and
women “round out” into different shapes?
Overeating results in the storage of fat
in adipose tissue. Because fat
metabolism is affected by the sex
hormones estrogen and testosterone,
storage sites differ for males and
females.
 In males excess fat is stored primarily in
the abdomen region, while in the
female, excess fat is stored around the
breasts and hips.

Connective Tissue Proper
Fluid Connective Tissue

Blood and lymph
Supporting Connective Tissue

Cartilage
– Chondrocytes reside in the gel matrix

Types of cartilage
– Hyaline – most common – supports the respiratory
tract, lines bony articulations, connects the ribs to the
sternum
– Elastic – flexible – pinna of the ear, epiglottis, tip of the
nose
– Fibrocartilage – tough, less flexible – between the
vertebrae, some joints and tendons
Hyaline and Elastic Cartilage
Fibrocartilage
Fibrocartilage pg 94
Bone
Osteocytes within the matrix
 Fed by a rich blood supply
 Formed by a combination of hard
calcium compounds combined with
flexible collagen fibers

Bone
Membranes

Four types of membranes made of
connective tissue:
– #1 Mucous membranes
•
•
•
•
•
•
•
Line cavities that communicate with the exterior
Kept moist at all times
Combined epithelial and connective tissue
Line the: digestive
Respiratory
Reproductive
urinary tracts
Membranes
– #2 Cutaneous membrane
• The skin lining of the outer surface of the body
• Thick, usually dry, waterproof
Membranes
– #3 Serous membranes
• Consist of simple epithelium supported by
loose connective tissue
• Pleura line the lines the pleural cavity and
covers the lung
• Peritoneum lines the abdominal cavity and
covers the organs covered within the cavity
• Pericardium lines the pericardial cavity and
covers the heart (2 layers)
• Parietal layers (lines the cavity walls)
• Visceral layer (covers the internal organs)
Question? Why is pleurisy so
painful?

Pleurisy refers to an inflammation of the
pleura and decrease in serous fluid.
As the inflamed and “dry” pleural
membranes slide past one another
during breathing movements, the
person experiences pain.
Membranes
– #4 Synovial membranes
• Bones of the skeleton contact one another at
joints called articulations
• Creates a fluid that helps separate the
cartilage-covered bone ends of mobile joints
• Lines the joint capsule (lubricates joints to
provide smooth movement)
• Consists primarily of loose connective tissue,
the epithelial layer is incomplete
Membranes
Muscle Tissue

Muscle cell contraction involves
interaction between filaments referred to
as myosin and actin proteins found in
the cytoskeleton of many human body
cells. Muscle cells have numerous
filaments so that their interaction
produces a contraction of the entire
muscle cell.
Muscle Tissues

Three types, all specialized for
contraction
– #1 Skeletal muscle
– #2 Smooth muscle
– #3 Cardiac muscle
Muscle Tissue

#1 Skeletal muscle
• Striated
• under voluntary control from the nervous system
• Contractions of muscle tissue causes bones to
move
Muscle Tissue
– #2 Smooth Muscle
• Line all of the hollow structures of the body
such as:
• Urinary bladder
• Respiratory
• Circulatory
• Digestive reproductive
• Non-striated, involuntary control
Smooth Muscle
Muscle Tissue
– #3 Cardiac Muscle
• Found only in the heart
• Branched and connected cells joining at
intercalated discs give this muscle the principle
of conductivity
• Specialized pacemaker cells have the principle
of automaticity
• Striated, involuntary muscle, although the
nervous system can alter the rate
Skeletal and Cardiac Muscle
Neural Tissue

Specialized for the conduction of electrical
impulses to convey information from one part
of the body to another
 Two types of cells that make up both the CNS
and PNS organs
– Neurons
• Transmit the electrical impulse
• Soma – cell body, dendrites – receptor ends, axon –
effector end which ends at a synapse
– Neuralgia
• Provide physical support, defend from infection, maintain
chemical composition of tissue fluids
Nerve Cell
Disorders of Cellular Growth
Atrophy – Without nourishment,
atrophy is a decrease in the size,
shape, leading to a wasting away of
tissues and organs.
 Dysplasia – Abnormal growth.
Dysplasia is an alteration in cell size,
shape, and organization. The concern is
that these alterations can result in
cancer.

Disorders of Cellular Growth
Hyperplasia – Overgrowth. Hyperplasia
is an increase in the number of cells,
resulting in an increase in the size of
tissues and organs.
 Metaplasia – Transformation of one cell
type into another (ie, the change of
columnar cells in the breathing
passages of a smoker into a different
cell type)

Disorders of Cellular Growth
Necrosis – Death of cells or groups of
cells.
 Neoplasm – abnormal new growth, also
called a tumor. A malignant neoplasm is
a cancerous tumor. A benign neoplasm
is a noncancerous tumor. Malignant
neoplasms tend to metastasize, or
spread, from an orginal (primary site) to
another secondary site.

Any
questions