Tissues, Organs and Systems What do they all do? How do they all work together?

Tissues, Organs and Systems Humans are highly organized Composed of many cells = multicellular cellstissuesorgansorgan systems Organic molecules = carbon-containing building blocks of life

Tissue Structure and Function Cellular Components - Tissues A tissue is a group of similar cells specialized for performing a common function. Different types of tissues have different structures that are suited to their functions. Tissues are classified into four main categories: Epithelial Connective Muscle Nervous

Epithelial Tissue Definition Surface or coverings of organs and body parts, examples include skin, lining of the intestine, etc Purpose: Protection Secretion Absorption Filtration

1.Protection Skin protects you from external threats Stomach epithelial cells keep the acid inside the stomach to digest the food and not other internal organs!

2.Secretion Mammary glands secrete milk for nursing infants Salivary Glands allow saliva to be secreted into your mouth so that you can begin digesting food Mammary glands secrete milk for nursing infants

3. Absorption Food (nutrients) are mostly absorbed in the small intestine by the epithelial cells

4. Filtration Red Blood Cells Arteries bring oxygen and nutrients to cells and then exchange it for carbon dioxide and other wastes Waste carried to kidneys and liver via the veins

Connective Tissue Definition Supports, binds and connects tissues to one another. Can be physical or functional

1. Physical Connective Tissue a) Bone: physically supports the body c) Tendons: connects muscle and bone b) Ligaments: connects bone to bone to form a joint

2.Functional Connective Tissue Fat is a functional support because it stores fat to be used as energy as required Blood tissue is also functional because it supplies the body with….. OXYGEN

Muscle Tissue Definition Cells designed to contract and therefore allow movement

3 Main Types of Muscle cells Skeletal Smooth Cardiac

1.Skeletal Muscle Tissue Muscle attached to bone, For example, calf muscle, biceps, etc Muscles contract VOLUNTARILY (with nerve stimulation)

2. Smooth Muscle Muscle found within our internal organs such as the intestine, bladder and blood vessels Muscles contract INVOLUNTARILY (without nerve stimulation)

3. Cardiac Muscle Used to pump blood, therefore this muscle is INVOLUNTARY too

Nervous Tissue Definition Groups of nerve cells that send electrical impulses (signals) to the brain

The NEURON

How neurons work Neurons send signals for sensing and reacting to our environment (touch – hot or cold, pressure receptors, etc) They transmit messages to and from the brain

Organs Organs are made of 2 or more different types of tissue, working together to perform a specific function within the body. For example, the heart functions as a pump within the body.

ORGAN SYSTEMS DEFINITION 2 or more ORGANS working together to perform a specific function Examples include Circulatory System Respiratory System Digestive system Nervous system Reproductive system Skeletal system Urinary System

Digestive System Breaks down and absorbs food and nutrients and then helps get rid of the waste

Respiratory System The main function is the exchange of gases: Oxygen IN Carbon Dioxide OUT

Nervous System The main function to relay messages throughout your body

To Do Look through pages 58-60 and try to classify the specialized cells into the categories we just looked at. Answer #1, 4, 5, 6 on p.60 With the use of your notes and pages 73-76 answer #2 – 6 on p. 76