Chapter 4 Flashcards
1
Q
What are the four basic types of tissues?
A
Epithelial, Connective, Muscle, and Nervous tissue.
2
Q
What is histology?
A
The study of tissues.
3
Q
What are the functions of epithelial tissue?
A
Protection, absorption, filtration, excretion, secretion, and sensory reception.
4
Q
What are the functions of connective tissue?
A
Supports, protects, and binds other tissues together.
5
Q
What are the functions of muscle tissue?
A
Contracts to cause movement.
6
Q
What are the functions of nervous tissue?
A
Regulates and controls body functions through internal communication.
7
Q
What three steps are required to prepare tissues for microscopy?
A
Fixation (preservation), Sectioning (thin slicing), and Staining (enhancing contrast).
8
Q
What is the difference between light microscopy and electron microscopy?
A
Light microscopy uses colored dyes, while electron microscopy uses heavy metal coatings.
9
Q
What are artifacts in microscopy?
A
Distortions introduced during tissue preparation that can obscure details.
10
Q
What are the two main forms of epithelial tissue?
A
Covering and lining epithelia and glandular epithelia.
11
Q
What are the five distinguishing characteristics of epithelial tissues?
A
- Polarity
- Specialized contacts
- Supported by connective tissue
- Avascular but innervated
- Regeneration
12
Q
What are the apical and basal surfaces in epithelial tissue?
A
Apical is the free surface exposed to air or cavity, while basal is attached to the basal lamina.
13
Q
What is the basal lamina?
A
An adhesive sheet that holds epithelial cells to underlying structures.
14
Q
What is the reticular lamina?
A
A layer of collagen fibers deep to the basal lamina that supports epithelial tissue.
15
Q
What is the basement membrane?
A
A combination of the basal and reticular lamina that reinforces the epithelial sheet.
16
Q
What does it mean that epithelial tissue is avascular but innervated?
A
It has no blood vessels but contains nerve fibers.
17
Q
What are the three cell shapes in epithelial tissue?
A
- Squamous (flat)
- Cuboidal (box-like)
- Columnar (tall)
18
Q
What is the difference between simple and stratified epithelia?
A
Simple has one layer for absorption/secretion, while stratified has multiple layers for protection.
19
Q
Where is simple squamous epithelium found, and what is its function?
A
Found in lung alveoli, kidney glomeruli; functions in diffusion and filtration.
20
Q
Where is simple cuboidal epithelium found, and what is its function?
A
Found in kidney tubules, glands; functions in secretion and absorption.
21
Q
Where is simple columnar epithelium found, and what is its function?
A
Found in the digestive tract; functions in absorption and secretion.
22
Q
Where is pseudostratified columnar epithelium found, and what is its function?
A
Found in the trachea; functions in mucus secretion and propulsion.
23
Q
Where is stratified squamous epithelium found, and what is its function?
A
Found in the skin, esophagus; provides protection.
24
Q
Where is stratified cuboidal epithelium found, and what is its function?
A
Found in sweat and mammary glands; functions in protection and secretion.
25
Where is stratified columnar epithelium found, and what is its function?
Found in the pharynx, urethra; functions in protection and secretion.
26
What is transitional epithelium, and where is it found?
Found in the bladder; allows stretching.
27
What is the difference between endocrine and exocrine glands?
Endocrine glands secrete hormones into the blood; exocrine glands secrete substances through ducts.
28
What are merocrine, holocrine, and apocrine secretion methods?
* Merocrine (exocytosis)
* Holocrine (cell ruptures)
* Apocrine (part of cell pinches off)
29
What are the four main classes of connective tissue?
* Connective tissue proper
* Cartilage
* Bone
* Blood
30
What are the three main components of connective tissue?
* Ground substance
* Fibers
* Cells
31
What are the three types of connective tissue fibers?
* Collagen (strong)
* Elastic (stretchy)
* Reticular (supportive)
32
What are the 'blast' and 'cyte' cells in connective tissue?
'Blast' cells build tissue, 'cyte' cells maintain it.
33
What are the three types of muscle tissue?
* Skeletal (voluntary)
* Cardiac (involuntary)
* Smooth (involuntary)
34
What are intercalated discs in cardiac muscle?
Specialized junctions that connect cardiac cells.
35
What are the two types of cells in nervous tissue?
* Neurons (send signals)
* Glial cells (support neurons)
36
What are the two ways tissues repair?
* Regeneration (same tissue replaces damaged cells)
* Fibrosis (scar tissue forms)
37
What are the three steps of tissue repair?
* Inflammation
* Organization (restoring blood supply)
* Regeneration/Fibrosis
38
What are tight junctions in epithelial cells?
They are impermeable junctions that prevent molecules from passing between cells.
39
What are desmosomes?
Anchoring junctions that bind adjacent cells together like Velcro and prevent tearing.
40
What are gap junctions?
Communicating junctions that allow ions and small molecules to pass between adjacent cells.
41
What is the function of goblet cells?
They secrete mucus to protect and lubricate epithelial surfaces.
42
What is the difference between keratinized and non-keratinized stratified squamous epithelium?
Keratinized has a tough, waterproof layer (e.g., skin), while non-keratinized is moist (e.g., esophagus).
43
What is the function of cilia in epithelial tissue?
Cilia move mucus and trapped particles out of airways (e.g., respiratory tract).
44
What is the function of adipose tissue?
Stores energy, provides insulation, and cushions organs.
45
What is the perichondrium?
A dense layer of connective tissue that surrounds cartilage and provides nutrients.
46
What is the difference between hyaline cartilage and elastic cartilage?
Hyaline provides support with some flexibility (e.g., nose, joints), while elastic has more flexibility (e.g., ear, epiglottis).
47
What are the primary differences between compact and spongy bone?
Compact bone is dense and strong, while spongy bone is porous and contains marrow.
48
What is hematopoiesis, and where does it occur?
It is the formation of blood cells, occurring in the bone marrow.
49
What is the main function of skeletal muscle?
Voluntary movement, posture, and heat production.
50
What is the main function of cardiac muscle?
Involuntary contraction to pump blood through the heart.
51
What are myofilaments?
Actin and myosin proteins that enable muscle contraction.
52
What is the difference between voluntary and involuntary muscle?
Voluntary (skeletal) is consciously controlled, involuntary (cardiac & smooth) operates automatically.
53
What are the three main parts of a neuron?
Cell body, dendrites (receive signals), and axon (transmits signals).
54
What is the function of neuroglia?
Support, insulate, and protect neurons.
55
What is myelin, and what does it do?
A fatty sheath around axons that speeds up nerve impulse transmission.
56
What is granulation tissue?
A new capillary-rich tissue that replaces a blood clot during healing.
57
What is fibrosis?
The formation of scar tissue as part of the healing process.
58
What types of tissues regenerate well, and which do not?
Epithelial, bone, and connective tissues regenerate well; cardiac and nervous tissues do not.
59
What role do fibroblasts play in tissue repair?
They produce collagen fibers to form scar tissue.
60
What is the function of basal lamina in epithelial tissue?
It provides structural support and acts as a selective filter for molecules.
61
What type of epithelial tissue lines blood vessels and the heart?
Simple squamous epithelium, specifically called endothelium.
62
What is mesothelium, and where is it found?
It is the simple squamous epithelium that lines serous membranes, including pleura, pericardium, and peritoneum.
63
Why do stratified epithelia provide better protection than simple epithelia?
Because they have multiple layers, making them more resistant to mechanical stress and abrasion.
64
How does transitional epithelium accommodate stretching?
The cells change shape from cuboidal to squamous as the organ expands.
65
What are mesenchymal cells, and why are they important?
They are stem cells in connective tissue that can differentiate into various cell types, including fibroblasts and adipocytes.
66
What are the three types of dense connective tissue?
Dense regular, dense irregular, and elastic connective tissue.
67
What is the main function of reticular connective tissue?
It forms a supportive framework (stroma) for organs like the spleen and lymph nodes.
68
What is the perichondrium, and what is its role in cartilage?
It is a dense connective tissue layer surrounding cartilage that provides nutrients and allows growth.
69
Why does cartilage heal slowly compared to other connective tissues?
Because it is avascular and relies on diffusion from the perichondrium for nutrients.
70
What are sarcomeres, and why are they important in muscle tissue?
They are the contractile units of skeletal and cardiac muscle, made of actin and myosin.
71
What feature distinguishes cardiac muscle from skeletal muscle?
Cardiac muscle has intercalated discs, which help synchronize contractions.
72
How do smooth muscle contractions differ from skeletal muscle contractions?
Smooth muscle contracts more slowly and is involuntary, while skeletal muscle contracts rapidly and is voluntary.
73
What neurotransmitter is primarily responsible for skeletal muscle contraction?
Acetylcholine (ACh).
74
What is the role of calcium in muscle contraction?
Calcium binds to troponin, triggering muscle contraction by allowing myosin to interact with actin.
75
What are the three main types of neurons based on function?
Sensory (afferent), motor (efferent), and interneurons.
76
What is the role of Schwann cells and oligodendrocytes?
They produce myelin sheaths that insulate neurons; Schwann cells in the PNS, oligodendrocytes in the CNS.
77
What is the difference between white matter and gray matter in the nervous system?
White matter contains myelinated axons; gray matter contains neuron cell bodies and unmyelinated fibers.
78
What is the synapse, and why is it important?
It is the junction between two neurons or a neuron and a target cell, crucial for signal transmission.
79
What is the function of astrocytes in nervous tissue?
They support and regulate the blood-brain barrier and nutrient exchange in the CNS.
80
What is the role of platelets in tissue repair?
They initiate clotting and release growth factors to stimulate healing.
81
What happens during the inflammation phase of tissue repair?
Blood vessels dilate, immune cells arrive, and clotting occurs to seal the wound.
82
How does fibrosis differ from regeneration in tissue repair?
Fibrosis replaces damaged tissue with scar tissue, while regeneration restores original tissue type and function.
83
What is the significance of angiogenesis in tissue repair?
It is the formation of new blood vessels that supply nutrients and oxygen for healing.
84
Why do cardiac and nervous tissues have limited regeneration capacity?
Because they have few stem cells and a limited ability to undergo mitosis.
85
What type of epithelium is best suited for areas subject to friction and abrasion?
Stratified squamous epithelium.
86
What is the primary function of ciliated columnar epithelium in the respiratory tract?
It moves mucus and trapped particles out of the airways.
87
What epithelial tissue lines the urinary bladder?
Transitional epithelium.
88
Why do epithelial tissues have a high regeneration rate?
They are frequently exposed to damage and have stem cells that rapidly divide.
89
What is the difference between exocrine and endocrine glands?
Exocrine glands secrete through ducts, while endocrine glands secrete hormones directly into the bloodstream.
90
What are the three types of loose connective tissue?
Areolar, adipose, and reticular connective tissue.
91
What type of connective tissue is found in tendons and ligaments?
Dense regular connective tissue.
92
What is the function of brown adipose tissue?
It generates heat by burning fat, especially in infants.
93
What type of cartilage is found in intervertebral discs?
Fibrocartilage.
94
What is the main mineral component of bone matrix?
Calcium phosphate (hydroxyapatite).
95
What are lacunae in bone and cartilage?
Small spaces that house osteocytes in bone and chondrocytes in cartilage.
96
What type of muscle is found in the walls of blood vessels?
Smooth muscle.
97
What characteristic allows cardiac muscle to contract in a coordinated manner?
Intercalated discs containing gap junctions and desmosomes.
98
What protein blocks myosin binding sites on actin in resting muscle?
Tropomyosin.
99
What is the main function of skeletal muscle?
Voluntary movement and posture maintenance.
100
How does smooth muscle contraction differ from skeletal muscle contraction?
Smooth muscle contracts more slowly and can remain contracted for longer periods with less energy use.
101
What is the function of microglia in nervous tissue?
They act as immune cells, removing debris and pathogens.
102
What type of glial cell forms the myelin sheath in the central nervous system?
Oligodendrocytes.
103
What is the primary neurotransmitter at neuromuscular junctions?
Acetylcholine (ACh).
104
What is the resting membrane potential of most neurons?
Around -70 mV.
105
What is saltatory conduction, and how does it speed up nerve impulses?
It is the jumping of action potentials between nodes of Ranvier, increasing conduction speed.
106
What is the difference between primary and secondary intention healing?
Primary intention occurs in clean, closed wounds with minimal scarring; secondary intention occurs in large wounds with tissue loss and results in more scarring.
107
What is the role of fibroblasts in wound healing?
They produce collagen and extracellular matrix to help repair tissue.
108
How does vitamin C deficiency affect tissue repair?
It impairs collagen synthesis, leading to weak connective tissue and slow healing.
109
What factors can slow down tissue repair?
Poor blood supply, infection, malnutrition, and chronic diseases like diabetes.
110
What is the role of epidermal growth factor (EGF) in tissue repair?
It stimulates cell division and migration during wound healing.
