draw and explain epithelial tissue connective tissue muscular tissue and nervous tissue with labelled
Answers
Tissues - Epithelium, Muscle, Connective Tissue and Nervous Tissue (Histology)
Tissues - Epithelium, Muscle, Connective Tissue and Nervous Tissue, histology
Tissues are groups of cells with a common structure (form) and function (job). There are four main tissues in the body – epithelium, muscle, connective tissue and nervous tissue.
I. EPITHELIUM (EPITHELIAL TISSUE)
Functions (jobs):
It protects us from the outside world - skin
Absorbs – stomach and intestinal lining (gut)
Filters – the kidney
Secretes – forms glands
Characteristics (Traits):
1) Closely attached to each other forming a protective barrier.
2) Always has one free (apical) surface open to outside the body or inside (cavity) an internal organ.
3) Always had one fixed (basal) section attached to underlying connective tissue.
4) Has no blood vessels but can soak up nutrients from blood vessels in connective tissue underneath.
5) Can have lots of nerves in it (innervated).
6) Very good at regenerating (fixing itself). i.e. sunburn, skinned knee.
Classifications (types):
1) By shape:
a) squamous - flat and scale-like
b) cuboidal - as tall as they are wide
c) columnar - tall, column-shaped
2) By cell arrangement:
a) simple epithelium - single layer of cells (usually for absorption and filtration)
b) stratified epithelium - stacked up cell layers (protection from abrasion - mouth, skin.)
There is also pseudostratified epithelium - looks like stacked cell layers, but is actually a single layer of cells (trachea and upper respiratory tract, it secretes muscous and its cilia helps to propel foreign material out of the body through coughing)
Tissues - Epithelium, Muscle, Connective Tissue and Nervous Tissue
II. CONNECTIVE TISSUE
Functions (jobs):
Wraps around and cushions and protects organs
Stores nutrients
Internal support for organs
As tendon and ligaments protects joints and attached muscles to bone and each other
Runs through organ capsules and in deep layers of skin giving strength
The 3 Elements of Connective Tissue:
1) Ground substance – gel around cells and fibers
2) Fibers – provide strength, elasticity and support
3) Cells
IIa. SPECIAL CONNECTIVE TISSUES
1) Cartilage
Functions (jobs):
provides strength with flexibility while resisting wear, i.e. epiglottis, external ear, larynx
cushions and shock absorbs where bones meet, i.e. intervertebral discs, joint capsules
2) Bone
Functions (jobs):
provides framework and strength for body
allows movement
stores calcium
contains blood-forming cells
More about Bone Tissue and Bone Structure: LINK
3) Blood
Functions (jobs):
transports oxygen, carbon dioxide, and nutrients around the body
immune response
Tissues - Epithelium, Muscle, Connective Tissue and Nervous Tissue
III. NERVOUS TISSUE
Functions (jobs):
Conducts impulses to and from body organs via neurons.
The 3 Elements of Nervous Tissue:
1) Brain
2) Spinal cord
3) Nerves
Answer:
connective tissue, epithelial tissue, muscle tissue, and nervous tissue.
Explanation: