Intro to Tissues and Clinical Anatomy Skills

Question 1

What are the 4 primary tissues of the body?

Answer 1

Epithelial

Connective

Muscular

Nervous

Question 2

What are the levels of organisation of the Human Body?

Answer 2

1. We come from simple molecules e.g. amino acids
2. This forms more complex molecules e.g. proteins, DNA
3. Cell organelles e.g. cell membrane, nucleus
4. Cells are formed by combining many different cell organelles
5. Similar cells combine to form tissues e.g. muscle, nerve, epithelium etc.
6. Several tissues are arranged together to form organs e.g. heart, lungs, brain
7. Organs are organised into systems e.g. cardiovascular system, digestive system
8. All systems put together forms the organism e.g. human

Question 3

Histology vs Anatomy vs Physiology vs Pathology

Answer 3

Histology = study of the tissue (parts of the body under the microscope) - this is the basis for the following:

Anatomy = study of the normal structure of the body

Physiology = normal functioning of the organs / systems / body

Pathology = disease processes / characteristics (can only understand once we know the normal structures of the body first)

Question 4

What is the light microscope and how is it used?

Answer 4

LM = uses visible light and lenses to magnify small objects, resolving power is about 0.2 micrometers

1. Sample the tissue and prepare it
2. Cut into thin slices
3. Stain
4. Mount on glass slide

Question 5

What is the TEM and why is it used?

Answer 5

TEM = Transmission electron microscope, beam of electrons transmitted through a specimen to form an image

Preparing specimen is time-consuming, lengthy and difficult

Expensive equipment

Higher resolution

Shows more details than the light microscope

Question 6

What are the 4 primary tissues in the body and describe their functions?

Answer 6

Connective - fills in the gaps between other organs or tissues

Epithelium - covers the sufarces / lines the cavities of certain body parts

Muscle - all the main muscles of the body and some viscera e.g. GI tract / stomach

Nerve - brain and spinal cord, and gut region

Question 7

What are the 3 germ layers of an embryo?

Where does connective tissue originate from, what they are composed of, and the different types of connective tissue?

Answer 7

In an embryo, there are 3 different primary germ layers, called the endo-, ecto-, and meso- derm, from which all the tissues of the body originate from

Connective tissue is derived from mesodermal layer of embryo

Composed of the extra cellular matrix and cells

Types: Loose areolar , dense, reticular and adipose (fat) connective tissues, cartilage and bone, and the blood and lymph

In the images, first image = white spots are fat, red / pink areas are connective tissue, bone tissue is mineralised, whereas cartilage is not

Question 8

Where does epithelial tissue originate from and what are the 2 groups of epithelial tissue?

Answer 8

Derived from all layers of embryonic tissue - endo-, ecto-, and meso- derms

2 groups: Lining / surface epithelia - e.g. skin, oral cavity, respiratory tract etc.

Glandular epithelia (gland tissues) - produces secretions e.g. salivary, mammary, sweat and endocrine glands etc.

Question 9

What are the 7 different types of surface epithelia and examples of where they are found?

Answer 9

Transitional - named because when the bladder is empty the epithelial surface is composed of several layers, when the bladder is full, the epithelial surface is composed of one or two layers

Question 10

Where does muscle tissue originate from, and what are the 3 types of muscle fibres?

Answer 10

Derived from the mesodermal layer of the embryo

Types: Skeletal muscle (voluntary - bulk of the body is composed of this), cardiac muscle (reserved only for the heart), smooth muscle (involuntary)

Important for movement

In the image: skeletal muscle fibres are long and so often known as striated muscle, and one cell may have several nuclei (multi-nucleated cell); smooth muscles are shorter in length and spindle shaped, one nucleus per cell and normally found in the walls of visceral structures; cardiac muscle is a mixture of both, long fibres and striations, but also branched

Question 11

What are the 3 types of muscle fibres?

Answer 11

Skeletal - voluntary, each fibre is very long, straight, not branched

Cardiac - branched fibres

Smooth - involuntary, single nuclei in each cell, spindle shaped fibres

Question 12

Where does nerve tissue originate from, and what are its main components?

Answer 12

Derived from the ectoderm layer of the embryo

Composed of neurones (excitable cell) and nerve fibres (AKA axons and dendrites), and neurolgia (these are connective tissue cells, which are supportive cells) from which the nerve cells get nutrients