N - Cells and Tissues Flashcards
Chapter 3
1
Q
▪ They are the structural units of all living things
▪ The human body has 50 to 100 trillion ___
▪ Are about 60% water
A
Cells
2
Q
The Cell Theory
A
- A cell is the basic structural and functional unit of living organisms
- The activity of an organism depends on the collective activities of its cells
- According to the principle of complementarity, the biochemical activities of cells are dictated by their structure (anatomy) which determines their function (physiology).
- Continuity of life has a cellular basis
3
Q
Most cells are composed of four elements
A
▪ Carbon
▪ Hydrogen
▪ Oxygen
▪ Nitrogen
4
Q
Three Main Regions or Parts of the Cell
A
▪ Nucleus
▪ Cytoplasm
▪ Plasma membrane
5
Q
▪ Control center of the cell
▪ Contains genetic material known as
deoxyribonucleic acid, or DNA
A
Nucleus
6
Q
DNA is needed and necessary for
A
▪ Building proteins
▪ Cell reproduction
7
Q
Three Regions of the Nucleus
A
▪ Nuclear envelope (membrane)
▪ Nucleolus
▪ Chromatin
8
Q
▪ Consists of a double membrane that bounds the nucleus
▪ Contains nuclear pores that allow for an exchange of material with the rest of the cell
A
Nuclear envelope
9
Q
Encloses the jellylike fluid called the
A
Nucleoplasm
10
Q
▪ Nucleus contains one or more dark staining nucleoli
▪ Sites of ribosome assembly
▪ Ribosomes migrate into the cytoplasm through nuclear pores to serve as the site of protein synthesis
A
Nucleolus
11
Q
▪ Composed of DNA wound around histones (proteins)
▪ Scattered throughout the nucleus and present when the cell is not dividing
▪ Condenses to form dense, rodlike bodies called chromosomes when the cell divides
A
Chromatin
12
Q
▪ Transparent barrier for cell contents
▪ Contains cell contents
▪ Separates cell contents from the surrounding environment
A
Plasma Membrane
13
Q
Model that is constructed of two layers of phospholipids arranged “tail-to-tail”, cholesterol and proteins scattered among phospholipids, and sugar groups
A
Fluid Mosaic Model
14
Q
Sugar groups may be attached to the phospholipids, forming
A
Glycolipids
15
Q
What makes the phospholipids a good foundation for cell membrane?
A
Property of polarity
16
Q
▪ “water loving”
▪ polar “heads” are oriented
on the inner and outer surfaces of the membrane
A
Hydrophilic
17
Q
▪ “water fearing”
▪ nonpolar “tails” form the
center (interior) of the membrane
A
Hydrophobic
18
Q
Protein is responsible for specialized membrane functions
A
▪ Enzymes
▪ Receptors for hormones or other chemical messengers
▪ Transport as channels or carriers
19
Q
Branched sugars attached to proteins that abut the extracellular space
A
Glycoproteins
20
Q
The fuzzy, sticky, sugar-rich area on the cell’s surface
A
Glycocalyx
21
Q
Cells are bound together in three ways:
A
- Glycoproteins in the glycocalyx act as an adhesive or cellular glue
- Wavy contours of the membranes of adjacent cells fit together in a tongue and groove fashion
- Special cell membrane junctions are formed, which vary structurally depending on their roles.
22
Q
Cell Junctions
▪ Impermeable junctions
▪ Bind cells together into leakproof sheets
▪ Plasma membranes fuse like a zipper to prevent
substances from passing through extracellular space
between cells
A
Tight Junctions
23
Q
Cell Junctions
▪ Anchoring junctions, like rivets, that prevent cells from being pulled apart as a result of mechanical stress
▪ Created by buttonlike thickenings of adjacent plasma
membranes
A
Desmosomes
24
Q
Cell Junctions
▪ Allow communication between cells
▪ Hollow cylinders of proteins ( connexons ) span the width of the abutting membranes
▪ Molecules can travel directly from one cell to the next through these channels
A
Gap Junctions OR Communicating Junctions
25
▪ The cellular material outside the nucleus and
inside the plasma membrane
▪ Site of most cellular activities
▪ Includes cytosol, inclusions, and organelles
Cytoplasm
26
Fluid that suspends other elements and contains nutrients and electrolytes
Cytosol
27
Chemical substances, such as stored nutrients or cell products, that float in the cytosol
Inclusions
28
Metabolic machinery of the cell that performs functions for the cell
Organelles
29
▪ “Powerhouses” of the cell
▪ Mitochondrial wall consists of a double membrane with
cristae on the inner membrane
▪ Carry out reactions in which oxygen is used to break down food into ATP molecules
Mitochondria
30
```
▪ Made of protein and ribosomal RNA
▪ Sites of protein synthesis in the cell
▪ Found at two locations:
= Free in the cytoplasm
= As part of the rough endoplasmic reticulum
```
Ribosomes
31
▪ Fluid filled tunnels (or canals) that carry substances within the cell
▪ Continuous with the nuclear membrane
Endoplasmic Reticulum (ER)
32
ER
▪ Studded with ribosomes
▪ Synthesizes proteins
▪ Transport vesicles move proteins within the cell
▪ Abundant in cells that make and export proteins
Rough Endoplasmic Reticulum
33
ER
▪ Lacks ribosomes
▪ Functions in lipid metabolism
▪ Detoxification of drugs and pesticides
Smooth Endoplasmic Reticulum
34
▪ Appears as a stack of flattened membranes associated with tiny vesicles
▪ Modifies and packages proteins arriving from the rough ER via transport vesicles
▪ Produces different types of packages
Golgi Apparatus
35
Pathways of Golgi Apparatus
▪ Secretory vesicles (pathway 1)
▪ In house proteins and lipids (pathway 2)
▪ Lysosomes (pathway 3)
36
▪ Membranous “bags” that contain digestive enzymes
▪ Enzymes can digest worn out or nonusable cell structures
▪ House phagocytes that dispose of bacteria and cell debris
Lysosomes
37
▪ Membranous sacs of oxidase enzymes
▪ Detoxify harmful substances such as alcohol and formaldehyde
▪ Break down free radicals (highly reactive chemicals)
▪ Free radicals are converted to hydrogen peroxide and then to water
▪ Replicate by pinching in half or budding from the ER
Peroxisomes
38
▪ Network of protein structures that extend throughout the cytoplasm
▪ Provides the cell with an internal framework that determines cell shape, supports organelles, and provides the machinery for intracellular transport
Cytoskeleton
39
Three different types of elements form the
| cytoskeleton
▪ Microfilaments (largest)
▪ Intermediate filaments
▪ Microtubules (smallest)
40
▪ Rod-shaped bodies made of nine triplets of
microtubules
▪ Generate microtubules
▪ Direct the formation of the mitotic spindle during cell
division
Centrioles
41
Cell Extensions
▪ It moves materials across the cell surface
▪ Located in the respiratory system to move mucus
Cilia
42
Cell Extensions
▪ Propel the cell
▪ Sperm
Flagella
43
Cell Extensions
▪ Are tiny, fingerlike extensions of the plasma
membrane
▪ Increase surface area for absorption
Microvilli
44
Secretes cable like fibers
Fibroblast
45
Carries oxygen into the bloodstream
Erythrocyte (Red Blood Cell)
46
▪ Cells that cover and line body organs
▪ Packs together in sheets
▪ Intermediate fibers resist tearing during rubbing or
pulling
Epithelial Cell
47
▪ Cells that move organs and body parts
| ▪ Contractile filaments allow cells to shorten forcefully
▪ Skeletal Muscle Cells
| ▪ Smooth Muscle Cells
48
▪ Cell that stores nutrients
| ▪ Lipid droplets stored in the cytoplasm
Fat Cells
49
▪ Cell that fights disease
| ▪ Digests infectious microorganisms
White Blood Cells
Macrophage (phagocytic cell)
50
▪ Cell that gathers information and controls body functions
▪ Receives and transmits messages to other body
structures
Nerve Cell (neuron)
51
▪ Cells of reproduction
▪ Largest cell in the body
▪ Divides to become an embryo upon fertilization
Oocyte (female)
52
▪ Cells of reproduction
▪ Built for swimming to the egg for fertilization
▪ Flagellum acts as a motile whip
Sperm (male)
53
Cells have the ability to
```
Metabolize
Digest food
Dispose of wastes
Reproduce
Grow
Move
Respond to a stimulus
```
54
Homogeneous mixture of two or more components
Solution
55
▪ Dissolving medium present in the larger quantity
| ▪ The body’s main solvent is water
Solvent
56
Components in smaller quantities within a
| solution
Solutes
57
▪ Nucleoplasm and cytosol
| ▪ Solution containing gases, nutrients, and salts dissolved in water
Intracellular Fluid
58
▪ Fluid on the exterior of the cell
| ▪ Contains thousands of ingredients, such as nutrients, hormones, neurotransmitters, salts, waste products
Extracellular Fluid (interstitial fluid)
59
Methods of Transport
Substances are transported across the membrane without any input from the cell
Passive Processes
60
Passive Process
▪ Molecule movement is from high concentration to low concentration, down a concentration gradient
▪ Particles tend to distribute themselves evenly within a
solution
▪ Size of the molecule and temperature affect its speed
Diffusion
61
▪ Energy of motion
| ▪ Energy that causes the molecules to move about randomly
Kinetic Energy
62
Molecules will move by diffusion if the molecules are (3)
```
▪ small enough to pass through the membrane’s pores (channels formed by
membrane proteins)
▪ lipid-soluble
▪ assisted by a membrane
carrier
```
63
Types of Diffusion
▪ An unassisted process
▪ Solutes are lipid-soluble or small enough to pass
through membrane pores
Simple Diffusion
64
Types of Diffusion
▪ Simple diffusion of water across a selectively permeable membrane
▪ Highly polar water molecules easily cross the plasma membrane through aquaporins
▪ Water moves down its concentration gradient
Osmosis
65
Solutions have the same solute and water concentrations as cells and cause no visible changes
in the cell
Isotonic solutions
66
Solutions contain more solutes than the cells do; the cells will begin to shrink
Hypertonic solutions
67
Solutions contain fewer solutes (more water) than the cells do; cells will plump
Hypotonic solutions
68
Types of Diffusion
▪ Transports lipid insoluble and large substances
▪ Glucose
▪ Protein membrane channels or protein molecules that act as carriers are used
Facilitated Diffusion
69
Passive Process
▪ Water and solutes are forced through a membrane by fluid, or hydrostatic, pressure
▪ A pressure gradient must exist that pushes solute containing fluid (filtrate) from a high-pressure area to a lower pressure area
▪ It is critical for the kidneys to work properly
Filtration
70
Methods of Transport
▪ The cell provides the metabolic energy (ATP) to drive the transport process
▪ ATP is used to move substances across a membrane
▪ It is used when:
= Substances are too large to travel through membrane channels
= The membrane may lack special protein carriers for the transport of certain substances
= Substances may not be lipid-soluble
= Substances may have to move against a concentration gradient
Active Processes
71
Active Processes
▪ Amino acids, some sugars, and ions are transported by
protein carriers known as solute pumps
▪ ATP energizes solute pumps
▪ In most cases, substances are moved against concentration (or electrical) gradients
Active Transport
72
Example of Active Transport
Sodium-Potassium Pump
73
Purpose pf sodium-potassium pump
Necessary for nerve impulses
74
Sodium-Potassium Pump
Sodium is transported __ the cell
out
75
Sodium-Potassium Pump
Potassium is transported __ the cell
into
76
Active Processes
Substances are moved across the membrane “in bulk” without actually crossing the plasma membrane
Vesicular Transport
77
Types of Vesicular Transport
▪ Mechanism cells use to actively secrete hormones, mucus, and other products
▪ Material is carried in a membranous sac called a vesicle that migrates to and combines with the plasma membrane
▪ Contents of vesicle are emptied to the outside
Exocytosis
78
Types of Vesicular Transport
▪ Extracellular substances are enclosed (engulfed) in a membranous vesicle
▪ Vesicle detaches from the plasma membrane and moves into the cell
▪ Once in the cell, the vesicle typically fuses with a lysosome
▪ Contents are digested by lysosomal enzymes
▪ In some cases, the vesicle is released by exocytosis on the opposite side of the cell
Endocytosis
79
Types of Endocytosis
▪ Cell eating
▪ Cell engulfs large particles such as bacteria or dead body cells
▪ It is a protective mechanism, not a means of getting nutrients
Phagocytosis
80
Cytoplasmic extensions that separate substances (such as bacteria or dead body cells) from the external environment
Pseudopods
81
Types of Endocytosis
▪ Cell drinking
▪ Cell “gulps” droplets of extracellular fluid containing dissolved proteins or fats
▪ Plasma membrane forms a pit, and edges fuse around droplet of fluid
▪ Routine activity for most cells, such as those involved in absorption (small intestine)
Pinocytosis
82
Types of Endocytosis
▪ Method for taking up specific target molecules
▪ Receptor proteins on the membrane surface bind
only certain substances
▪ Highly selective process of taking in substances
such as enzymes, some hormones, cholesterol, and iron
Receptor Mediated Endocytosis
83
It is a series of changes the cell experiences from the time it is formed until it divides
Cell Life Cycle
84
Periods of Cell Life Cycle
▪ Cell grows and carries on metabolic processes
▪ Longer phase of the cell cycle
Interphase (Metabolic Phase)
85
Periods of Cell Life Cycle
Cell reproduces itself
Cell Division
86
Events of Cell Division
▪ Division of the nucleus
▪ Results in the formation of two daughter nuclei
Mitosis
87
Events of Cell Division
▪ Division of the cytoplasm
▪ Begins when mitosis is near completion
▪ Results in the formation of two daughter cells
Cytokinesis
88
Events of Mitosis
▪ Chromatin coils into chromosomes; identical strands called chromatids are held together by a centromere
▪ Centrioles direct the assembly of a mitotic spindle
▪ Nuclear envelope and nucleoli have broken down
Prophase
89
Events of Mitosis
▪ Chromosomes are aligned in the center of the cell on the metaphase plate (center of the spindle midway between the centrioles)
▪ Straight line of chromosomes is now seen
Metaphase
90
Events of Mitosis
▪ Centromere splits
▪ Chromatids move slowly apart and toward the opposite ends of the cell
▪ It is over when the chromosomes stop moving
Anaphase
91
Events of Mitosis
▪ Reverse of prophase
▪ Chromosomes uncoil to become chromatin
▪ Spindles break down and disappear
▪ Nuclear envelope reforms around chromatin
▪ Nucleoli appear in each of the daughter nuclei
Telophase
92
▪ Division of the cytoplasm
▪ Begins during late anaphase and completes during telophase
▪ A cleavage furrow (contractile ring of microfilaments) forms to pinch the cells into two parts
▪ Two daughter cells exist
Cytokinesis
93
▪ In some cases, the cytoplasm is not divided and the result is called
▪ Common in the liver and skeletal muscle
Binucleate or Multinucleate Cells
94
It serves as a blueprint for making proteins
DNA
95
DNA segment that carries a blueprint for building one protein or polypeptide chain
Gene
96
Proteins that are the building materials for cells
Fibrous (Structural) Proteins
97
Proteins that can act as enzymes (biological catalysts)
Globular (Functional) Proteins
98
Both the decoder and messenger functions are carried out by
RNA (Ribonucleic Acid)
99
RNA differs from DNA since it is (3)
▪ Single-stranded
▪ contains ribose sugar
▪ contains uracil (U) base
100
Three Varieties of RNA
Transfers appropriate amino acids to the ribosome for building the protein
Transfer RNA (tRNA)
101
Three Varieties of RNA
Helps form the ribosomes where proteins are built
Ribosomal RNA (rRNA)
102
Three Varieties of RNA
Carries the instructions for building a protein from the nucleus to the ribosome
Messenger RNA (mRNA)
103
Protein Synthesis
▪ Transfer of information from DNA’s base sequence to the complementary base sequence of mRNA
▪ DNA is the template for this; mRNA is the product
▪ Each DNA triplet corresponds to an mRNA codon
Transcription
104
Protein Synthesis
▪ Base sequence of nucleic acid is ____ to an amino acid sequence
▪ Occurs in the cytoplasm and involves three major
varieties of RNA
Translation
105
Groups of cells with similar structure and function
Tissues
106
4 Primary Body Tissues
1. Epithelial tissue (epithelium)
2. Connective tissue
3. Muscle tissue
4. Nervous tissue
107
Location of Epithelial Tissue
▪ Body coverings
▪ Body linings
▪ Glandular tissue
108
Function of Epithelial Tissue (PAFS)
▪ Protection
▪ Absorption
▪ Filtration
▪ Secretion
109
Tissue
▪ Cover and line body surfaces
▪ Often form sheets with one free surface, the apical surface, and an anchored surface, the basement membrane
▪ Avascular (no blood supply)
▪ Regenerate easily if well-nourished
Epithelial Tissue
110
Classification of Epithelia (number)
▪ One layer
▪ Functions in absorption, secretion, and filtration
▪ Very thin (so not suited for protection)
Simple Epithelium
111
Classification of Epithelia (number)
▪ More than one layer
▪ Function primarily in protection
Stratified Epithelium
112
Classification of Epithelia (shape)
Flattened, like fish scales
Squamous Epithelium
113
Classification of Epithelia (shape)
Cube shaped, like dice
Cuboidal Epithelium
114
Classification of Epithelia (shape)
Shaped like columns
Columnar Epithelium
115
Function of Epithelial Tissue related to Shape
▪ Diffusion, filtration, and secretion in serous membranes
▪ Single layer of flat cells
State its location (3)
Simple Squamous Epithelium
Location:
▪ Lines air sacs of the lungs
▪ Forms walls of capillaries
▪ Forms serous membranes (serosae) that line and cover organs in ventral cavity
116
Function of Epithelial Tissue related to Shape
▪ Secretion and absorption
▪ Ciliated types propel mucus or reproductive cells
▪ Simple Cuboidal Epithelium
| ▪ Simple Columnar Epithelium
117
Epithelial Tissue related to Shape
▪ Functions as a protective covering where friction is common
▪ Most common stratified epithelium
▪ Named for cells present at the free (apical) surface
State its location (3)
Stratified Squamous Epithelium
Location:
▪ Skin (outer portion)
▪ Mouth
▪ Esophagus
118
Function of Epithelial Tissue related to Shape
▪ Protection
▪ These tissue types are rare in humans
State its locations (2)
▪ Stratified Cuboidal Epithelium
▪ Stratified Columnar Epithelium
Location:
▪ Ducts
▪ Large glands
119
Function of Epithelial Tissue related to Shape
▪ Protection
▪ Stretching to accommodate distension of urinary structures
Stratified Transitional Epithelium
120
Epithelial Tissue related to Shape
Single-layer of cubelike cells
State its location (3)
Simple Cuboidal Epithelium
Location:
▪ Common in glands and their ducts
▪ Forms walls of kidney tubules
▪ Covers the surface of ovaries
121
Epithelial Tissue related to Shape
Single-layer of tall cells
State its location (2)
Simple Columnar Epithelium
Location:
▪ Lining of the digestive tract from stomach to the anus
▪ Mucous membranes (mucosae) line body cavities
opening to the exterior
122
The cell that secretes mucus
Goblet Cell
123
Epithelial Tissue related to Shape
▪ All cells rest on a basement membrane
▪ Single layer, but some cells are shorter than others giving a false impression of stratification
▪ Functions in absorption or secretion
State its location (1)
Pseudostratified (Ciliated) Columnar Epithelium
Location:
Respiratory tract, where it is ciliated
124
Epithelial Tissue related to Shape
Two layers of cuboidal cells
Stratified Cuboidal Epithelium
125
Epithelial Tissue related to Shape
Surface cells are columnar, and cells underneath vary in size and shape
Stratified Columnar Epithelium
126
Epithelial Tissue related to Shape
▪ Functions in stretching and the ability to return to
normal shape
▪ Composed of modified stratified squamous epithelium
▪ Shape of cells depends upon the amount of stretching
State its location (1)
Transitional Epithelium
Location:
Lining of urinary system organs
127
▪ One or more cells responsible for secreting a particular product
▪ Secretions contain protein molecules in an aqueous (water-based) fluid
▪ Secretion is an active process
Glandular Epithelia
128
Gland Type of Epithelium
▪ Ductless; secretions (hormones) diffuse into blood vessels
▪ Examples include thyroid, adrenals, and pituitary
Endocrine Glands
129
Gland Type of Epithelium
▪ Secretions empty through ducts to the epithelial surface
▪ Include sweat and oil glands, liver, and pancreas (both internal and external)
Exocrine Glands
130
Tissue
▪ Found everywhere in the body to connect body parts
▪ Includes the most abundant and widely distributed tissues
Connective Tissue
131
Function of Connective Tissue (PSB)
▪ Protection
▪ Support
▪ Binding
132
Nonliving material that surrounds living cells
Extracellular Matrix
133
2 Main Elements of the Extracellular Matrix
▪ Ground Substance
| ▪ Fibers
134
Types of Fibers of Matrix
▪ Collagen (white) fibers
▪ Elastic (yellow) fibers
▪ Reticular fibers (a type of collagen)
135
5 Types of Connective Tissue
From most rigid to
softest, or most fluid
```
▪ Bone
▪ Cartilage
▪ Dense connective tissue
▪ Loose connective tissue
▪ Blood
```
136
Types of Connective Tissue
▪ Functions to protect and support the body
▪ Composed of:
= Osteocytes (bone cells) sitting in lacunae (cavities)
= Hard matrix of calcium salts
= Large numbers of collagen fibers
Bone
137
Types of Connective Tissue
▪ Less hard and more flexible than bone
▪ Found in only a few places in the body
▪ Chondrocyte (cartilage cell) is the major cell type
Cartilage
138
3 Type of Cartilage
▪ Hyaline cartilage
▪ Fibrocartilage
▪ Elastic cartilage
139
Type of Cartilage
▪ Most widespread type of cartilage
▪ Abundant collagen fibers hidden by a glassy, rubbery
matrix
State its locations (5)
Hyaline Cartilage
```
Locations:
▪ Trachea
▪ Attaches ribs to the breastbone
▪ Covers ends of long bones
▪ Entire fetal skeleton prior to birth
▪ Epiphyseal (growth) plates in long bones
```
140
Type of Cartilage
Provides elasticity
State its location (1)
Elastic Cartilage
Location:
Supports the external ear
141
Type of Cartilage
Highly compressible
Fibrocartilage
Location:
Forms cushionlike discs between vertebrae of
the spinal column
142
Types of Connective Tissue
Main matrix element is collagen fiber
State its locations (3)
Dense Connective Tissue (dense fibrous tissue)
Location:
▪ Tendons
▪ Ligaments
▪ Dermis
143
Attach skeletal muscle to bone
Tendons
144
Attach bone to bone at joints and are more
| elastic than tendons
Ligaments
145
Cells that make fibers
Fibroblasts
146
Types of Connective Tissue
Softer, have more cells and fewer fibers than other connective tissues (except blood)
Loose Connective Tissue
147
Types of Loose Connective Tissue
▪ Most widely distributed connective tissue
▪ Soft, pliable tissue-like “cobwebs”
▪ Functions as a universal packing tissue and “glue” to hold organs in place
▪ Layer of this tissue called lamina propria underlies
all membranes
▪ All fiber types form a loose network
▪ Can soak up excess fluid (causes edema)
Areolar Connective Tissue
148
Types of Loose Connective Tissue
```
▪ An areolar tissue in which adipose (fat) cells dominate
▪ Functions
= Insulates the body
= Protects some organs
= Serves as a site of fuel storage
▪ Locations
= Subcutaneous tissue beneath the skin
= Protects organs, such as the kidneys
= Fat “depots” include hips, breasts, and belly
```
Adipose Connective Tissue
149
Types of Loose Connective Tissue
▪ Delicate network of interwoven fibers with reticular cells (like fibroblasts)
▪ Forms stroma (internal framework) of organs
State its location (3)
Reticular connective tissue
Locations
▪ Lymph nodes
▪ Spleen
▪ Bone marrow
150
Types of Connective Tissue
▪ Vascular tissue
▪ Its cells are surrounded by fluid matrix known as blood plasma
▪ Soluble fibers are visible only during clotting
▪ Functions as the transport vehicle for the cardiovascular system
Blood
151
The blood carries (3)
▪ Nutrients
▪ Wastes
▪ Respiratory gases
152
Types of Connective Tissue
Function is to contract, or shorten, to produce movement
Muscle Tissue
153
Types of Muscle Tissue
▪ Packaged by connective tissue sheets into skeletal muscles, which are attached to the skeleton and pull on bones or skin
▪ Voluntarily (consciously) controlled
▪ Produces gross body movements or facial expressions
Characteristics:
▪ Striations (stripes)
▪ Multinucleate (more than one nucleus)
▪ Long, cylindrical shape
Skeletal Muscle Tissue
154
Types of Muscle Tissue
▪ Involuntarily controlled
▪ Found only in the heart
▪ Pumps blood through blood vessels
```
Characteristics:
▪ Striations
▪ One nucleus per cell
▪ Short, branching cells
▪ Intercalated discs contain gap junctions to connect cells together
```
Cardiac Muscle Tissue
155
Types of Muscle Tissue
▪ Involuntarily controlled
▪ Found in walls of hollow organs such as stomach,
uterus, and blood vessels
Characteristics:
▪ No visible striations
▪ One nucleus per cell
▪ Spindle shaped cells
Smooth (visceral) Muscle Tissue
156
A wavelike activity, is a typical activity
Peristalsis
157
Tissue
▪ Function is to receive and conduct electrochemical impulses to and from body parts
= Irritability
= Conductivity
▪ Composed of neurons and nerve support cells
Nervous Tissue
158
It is support cells that insulate, protect, and support neurons
Neuroglia
159
Tissue Repair
Replacement of destroyed tissue by the same kind of cells
Regeneration
160
Tissue Repair
Repair by dense (fibrous) connective tissue (scar tissue)
Fibrosis
161
Regeneration or fibrosis occurs depends on (2)
▪ Type of tissue damaged
| ▪ Severity of the injury
162
Events of Tissue Repair
▪ Capillaries become very permeable
▪ Clotting proteins migrate into the area from the bloodstream
▪ A clot walls off the injured area
Inflammation
163
Events of Tissue Repair
▪ Growth of new capillaries
▪ Phagocytes dispose of blood clot and fibroblasts
▪ Rebuild collagen fibers
Granulation tissue forms
164
Events of Tissue Repair
▪ Scab detaches
▪ Whether scar is visible or invisible depends on severity of the wound
Regeneration and fibrosis affect permanent repair
165
Tissues that regenerate easily
▪ Epithelial tissue (skin and mucous membranes)
| ▪ Fibrous connective tissues and bone
166
Tissues that regenerate poorly
Skeletal Muscle
167
Tissues that are replaced largely with scar tissue
▪ Cardiac muscle
| ▪ Nervous tissue within the brain and spinal cord
168
Tissue that remains mitotic and forms repair (scar) tissue
Connective Tissue
169
Tissue that becomes
| amitotic by the end of puberty
Muscle Tissue
170
Tissue that becomes amitotic shortly after birth
Nervous Tissue
171
It is an increase in the size of a tissue or organ may occur when tissue is strongly stimulated or irritated
Hyperplasia
172
It is a decrease in size of a tissue or organ that occurs when the organ is no longer stimulated normally
Atrophy
