Histology- Study of Tissues

1
Histology- Study of Tissues
2

• Physiological systems are made up of organs that
  serve specific functions.
• Organs are made up of tissues, which are then
  made up of cells.

3

• Four types of tissue
• Epithelial
• Connective
• Muscle
• Nervous

4

• Epithelial tissues are sheets of tightly
  connected epithelial cells.
• The tissues form skin and line hollow organs.

5
Function of Epithelial cells

• Some epithelial cells can
• Secrete substances, like hormones
• Move substances with cilia
• Act as chemical receptors
• Create boundaries
• Control filtration and transport

6
Cells in Epithelial Tissue

• Squamous Cells- Simple /Stratified
• Columnar Cells- Simple/pseudostratified
• Cuboidal Cells- Simple/stratified
• Transitional Cells

7
Classification of Epithelial Tissue
8
(No Transcript)
9
Epithelial Tissue (A)
10
Stratified squamous epithelium, nonkeratinized,
from human mouth. LM, HE stain.
11
Simple Cuboidal Epithelium
12
Simple Columar Epithelium
13
Simple columnar epithelium from human
intrahepatic bile duct. LM, trichrome stain.
14
Simple cuboidal epithelium lining follicles of
human thyroid gland. LM, HE stain.
15
Pseudostratified columnar epithelium lining a
human bronchus cilia on many cells. LM.
16
Pseudostratified Columnar Epithelium
17
Transitional epithelium line the urethra of a
male infant. LM, HE stain.
18
Pigmented epithelium from a person of African
descent. LM, HE stain.
19
Keratinized Stratified Squamous Epithelium
20
Non-Keratinized Stratified Squamous Epithelium
21
Transitional Epithelium
22
Skin from human foot note thick keratin layer.
LM, HE stain.
23
Sweat glands in human skin. LM, HE stain.
24
Epithelial Tissue (B)

• Simple cuboidal epithelium is found in glandular
  tissue and in the kidney tubules.

25

• Muscle tissues consist of elongated cells that
  generate force and cause movement.
• Three types of muscle tissues
• Skeletal
• Cardiac
• Smooth

26

• Skeletal responsible for locomotion and other
  body movements (e.g., breathing, shivering).
• Cardiac makes up the heart and is responsible
  for the heartbeat and blood flow.
• Smooth involved in movement and generation of
  forces in internal organs (e.g., gut, blood
  vessels).

27
Figure 40.4 Filaments in Skeletal Muscle Cells
28
Types of Muscle Tissue
29
(No Transcript)
30
(No Transcript)
31
(No Transcript)
32

• Connective tissues are dispersed cells in an
  extracellular matrix that they secrete.
• The matrix contains protein fibers
• Collagen strong and resistant to stretch,
  supports skin and connections between muscles and
  bones
• Elastin can be stretched and then recoils found
  in tissues that stretch (e.g., lungs, arteries)

33
Diagram of Loose CT
34
(No Transcript)
35
(No Transcript)
36
Connective Tissue
37
Areolar connective tissue elastic and collagenic
fibers in a rat. LM, silver stain.
38
(No Transcript)
39
(No Transcript)
40

• Connective tissues
• Cartilage provides structural support and is
  flexible has chondrocytes cells that secrete
  the extracellular matrix.
• Bone provides support and is hardened by calcium
  phosphate deposition in the matrix. Bone cells
  are osteocytes.

41
Hyaline cartilage in cat larynx. LM, HE stain.
42
Cartilage
43
Fibrocartilage in a mammalian intervertebral
disc. LM, HE stain.
44
Elastic cartilage from a pig's ear.
45
(No Transcript)
46
(No Transcript)
47
(No Transcript)
48
Human compact bone, transverse section. LM,
Schmorl's stain.
49

• More connective tissues
• Adipose tissue includes adipose cells that form
  and store lipids. Cells are adipocytes.
• Blood consists of cells in a very liquid
  extracellular matrix, the blood plasma. There are
  red blood cells (erythrocytes), white blood cells
  (leukocytes), and platelets (thrombocytes).

50
Blood cells from domestic chicken (Gallus
gallus). LM, Giemsa stain.
51
(No Transcript)
52
Normal human adipose cells. LM, HE stain.
53
(No Transcript)
54

• Nervous tissues contain two basic cell types
  neurons and glia.
• Neurons encode information as electrical impulses
  that travel over axons to their targets.
• Chemical signals from the neuron stimulate a
  response in the target cell, via receptors.
• Glia provide support for neurons.

55
Neurons
56
Nervous Tissue Includes Neurons and Glia (A)
57

• Organs consist of multiple tissues.
• An organ system is a group of organs that
  function together.

58
Different Tissues make up an organ

• Example The stomach wall is arranged in layers
• Epithelial cells
• Connective tissue
• Smooth muscle
• Neurons
• Connective tissue

59
(No Transcript)
60
Figure 40.7 Tissues Form Organs
Fig 40.7 whole figure except stomach