Question

explanation:

Epithelia ?
Muscle ?
Connective tissue ?
Nervous tissue ?

compare the four tissue types?

Answer 1

A tissue is a group of cells that have a similar shape and function. Different types of tissues can be found in different organs. In humans, there are four basic types of tissue: epithelial, connective, muscular, and nervous tissue. There may be various sub-tissues within each of the primary tissues.

Epithelial tissue covers the body surface and forms the lining for most internal cavities. The major function of epithelial tissue includes protection, secretion, absorption, and filtration. The skin is an organ made up of epithelial tissue which protects the body from dirt, dust, bacteria and other microbes that may be harmful. Cells of the epithelial tissue have different shapes as shown on the student's worksheet. Cells can be thin, flat to cubic to elongated.

Connective tissue is the most abundant and the most widely distributed of the tissues. Connective tissues perform a variety of functions including support and protection. The following tissues are found in the human body, ordinary loose connective tissue, fat tissue, dense fibrous tissue, cartilage, bone, blood, and lymph, which are all considered connective tissue.

There are three types of muscle tissue: skeletal, smooth, and cardiac. Skeletal muscle is a voluntary type of muscle tissue that is used in the contraction of skeletal parts. Smooth muscle is found in the walls of internal organs and blood vessels. It is an involuntary type. The cardiac muscle is found only in the walls of the heart and is involuntary in nature.

Nerve tissue is composed of specialized cells which not only receive stimuli but also conduct impulses to and from all parts of the body. Nerve cells or neurons are long and string-like.

In tissues the simplest combination is called a membrane, or a sheet of tissues which cover or line the body surface or divide organs into parts. Examples include the mucous membrane which lines body cavities. Tissues combine to form organs. An organ is a part of the body which performs a definite function. The final units of organization in the body are called systems. A system is a group of organs each of which contributes its share to the function of the body as a whole.

Answer 2

thanks :D

Answer 3

could you help me with this question too: how each tissue type (connective tissue, epithelia tissue, nervous tissue and muscle tissue) explain how its structure enables it to carry out its function?

Answer 4

Epithelial cells join together to form epithelial membranes or tissue. At times called the epithelium, these sheets cover the outer surface of the body, helping create the form the body, as well as line body cavities. The primary job of epithelial tissue is to protect, but it is also involved in filtration, secretion, and absorption.


Types of Membranes
Epithelial membranes are classified as either cutaneous, meaning the skin, mucous, or serous. Mucous membranes, which line all cavities that are open to the outside, include the digestive and respiratory tract. Serous membranes, which are not open to the outside of the body, line the abdominal and thoracic cavities.

Protection
The skin, which is composed of epithelial cells, protects the body from invasion of germs, as well as from the sunlight.

Filtration
Epithelium of the respiratory tract protects the body by filtering out dirt and particles and cleaning the air that is inhaled.

Secretion
Epithelial cells form glands of the body. These glands secrete hormones and enzymes. Epithelium also may secrete wax, perspiration, digestive enzymes, and milk.

Absorption
The organs of the digestive tract have an abundance of epithelial cells, which function to absorb water and digested food. These cells play a large part in the proper digestion of food.

Answer 5

A nerve cell, or neuron, is the basic unit of the nervous system. It transmits information to and from the brain. The structure of a neuron allows the transmission to be quick.



Types
There are several types of nerve cells, including multipolar, bipolar and pseudounipolar. They can be classified as motor, sensory or interneurons.

Function
Motor neurons send information away from the central nervous system (CNS). Sensory neurons send information toward the CNS. Interneurons send information between motor and sensory neurons.

Structure
Nerve cells consist of a cell body, axon and dendrites. The cell body contains the nucleus and other cellular compartments. The axon is long and surrounded by a layer of fat. The dendrites are branches from the cell body.

Features
Axons carry information away from the cell body. Dendrites carry information toward the cell body. The cell body processes information and maintains the nerve cell by producing proteins.

Transmission
The space between nerve cells is called the synapse. For information to cross the synapse, chemicals are released from one nerve cell and interact with the next nerve cell.

Answer 6

Muscle cells

There are three different types of muscle cells in the human body: skeletal, smooth and cardiac. These are classified as either voluntary or involuntary, depending on whether we consciously control their movements. They are further classified by appearance, as either smooth or striated; striated muscle cells when viewed under a microscope have a striped appearance. Muscle cells are highly specialized, each optimally designed to perform its required function. As such, there is variation amongst muscle cells within each category.


Structure
Skeletal muscle cells are elongated, forming long fibers. They have multiple nuclei within each cell; this is in contrast to the majority of other cells in our bodies, according to BMH Linguistics. They also contain many mitochondria which are cellular organelles that produce adenosine triphosphate (ATP), the body's fuel. Smooth muscle cells are short, contain only one nucleus and are not striated in appearance, hence the term "smooth." Cardiac muscle cells are also striated in appearance though they appear less organized into stripes than skeletal muscle cells. These cells may be branched, forming physical connections with many surrounding cells.

Function
According to BMH Linguistics, skeletal muscle cells are the most abundant type in our bodies. These muscle fibers attach to our bones allowing movement in our joints. As well, we use skeletal muscles to maintain our posture. Smooth muscle cells are found lining our internal organs and blood vessels and are responsible for the contraction of organs, such as the bladder. Smooth muscles are considered involuntary. Cardiac muscle cells make up the heart and are responsible for pumping blood throughout our bodies. Cardiac muscle is generally thought of as involuntary

Answer 7

thanx again :D

Answer 8

Explain the relationship between cells, tissues, organs and organ systems in the organisation of the human body?

please help again

Answer 9

the connective tissue; explain how its structure enables it to carry out its function? please helppp