Anatomy and Physiology of Animals/Body Organisation - Wikibooks, open books for an open world
These are organized into tissues; the tissues into organs. View showing relationship between the apical and basolateral surfaces of epithelial cells and how. We will be examining human tissues as an example of animal tissues. Connective tissue assists in support and protection of organs and limbs and depending. Biologists refer to the relationship between cells, tissues and organs as the There are four basic types of tissue in the human body: epithelial.
Smooth muscle is not striped, striated, and it's involuntary, not under conscious control. That means you don't have to think about moving food through your digestive tract! Nervous tissue Nervous tissue is involved in sensing stimuli—external or internal cues—and processing and transmitting information.
It consists of two main types of cells: The neurons are the basic functional unit of the nervous system. They generate electrical signals called conducted nerve impulses or action potentials that allow the neurons to convey information very rapidly across long distances. The glia mainly act to support neuronal function. The neuron has projections called dendrites that receive signals and projections called axons that send signals.
Also shown are two types of glial cells: For example, the heart pumps blood, the lungs bring in oxygen and eliminate carbon dioxide, and the skin provides a barrier to protect internal structures from the external environment. Most organs contain all four tissue types.
How Are Cells, Tissues & Organs Related? | Sciencing
The layered walls of the small intestine provide a good example of how tissues form an organ. The inside of the intestine is lined by epithelial cells, some of which secrete hormones or digestive enzymes and others of which absorb nutrients. Around the epithelial layer are layers of connective tissue and smooth muscle, interspersed with glands, blood vessels, and neurons. The smooth muscle contracts to move food through the gut, under control of its associated networks of neurons.
From outside to inside: Blood vessels, networks of nerves in smooth muscle layers, connective tissue, more smooth muscle, another layer of connective tissue, epithelial tissue, and empty space in the middle as the path of digested food.
Tissues, organs, & organ systems
For example, the heart and the blood vessels make up the cardiovascular system. They work together to circulate the blood, bringing oxygen and nutrients to cells throughout the body and carrying away carbon dioxide and metabolic wastes.
Another example is the respiratory system, which brings oxygen into the body and gets rid of carbon dioxide. It includes the nose, mouth, pharynx, larynx, trachea, and lungs.
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On the left, a diagram of the respiratory system showing nasal passages, trachea, and lungs. On the right, a diagram of the circulatory system showing heart and blood vessels. Major organ systems of the human body Organ system Organs, tissues, and structures involved Cardiovascular Transports oxygen, nutrients, and other substances to the cells and transports wastes, carbon dioxide, and other substances away from the cells; it can also help stabilize body temperature and pH Heart, blood, and blood vessels Lymphatic Defends against infection and disease and transfers lymph between tissues and the blood stream Lymph, lymph nodes, and lymph vessels Digestive Processes foods and absorbs nutrients, minerals, vitamins, and water Mouth, salivary glands, esophagus, stomach, liver, gallbladder, exocrine pancreas, small intestine, and large intestine Endocrine Provides communication within the body via hormones and directs long-term change in other organ systems to maintain homeostasis Pituitary, pineal, thyroid, parathyroids, endocrine pancreas, adrenals, testes, and ovaries.
Although we often talk about the different organ systems as though they were distinct, parts of one system may play a role in another system. The mouth, for instance, belongs to both the respiratory system and the digestive system. There's also a lot of functional overlap among the different systems. For instance, while we tend to think of the cardiovascular system as delivering oxygen and nutrients to cells, it also plays a role in maintaining temperature.
The blood also transports hormones produced by the glands of the endocrine system, and white blood cells are a key component of the immune system.
Organs in a system work together. Just like workers on an assembly line, the organs of an organ system must work together for the system to function as a whole.
For instance, the function of the digestive system—taking in food, breaking it down into molecules small enough to be absorbed, absorbing it, and eliminating undigested waste products—depends on each successive organ doing its individual job.
Blood tissue contains red blood cells which are specialised to absorb, carry and release oxygen. We'll revisit blood later in this unit. Plants have cells, tissues and organs also. One example of a plant organ which is a leaf. A leaf is a collection of tissues which carry out the reactions of photosynthesis. We've mentioned the specialised cells found in a leaf in Unit 1but here's the same diagram labelled with the tissues instead.
Epidermis tissue is made up of epidermis cells. A leaf has two layers of epidermis tissue: Epidermis tissues contain and protect the leaf and therefore the cells are long and thin and do not contain many chloroplasts. The palisade mesophyll tissue is where the majority of photosynthesis occurs in the leaf. It is the uppermost of the two mesophyll tissues in order to absorb the majority of the light energy as it hits the leaf. It is made up of palisade mesophyll cells which have a large number of chloroplasts, are packed tightly together and are tall and thin in order to absorb as much light energy as possible.
There are two kinds found in mammals: The oil is confined within a single membrane-enclosed droplet. Virtually all of the "fat" in adult humans is white adipose tissue.
White adipose tissue and brown adipose tissue differ in function as well as cellular structure. These differences are described on a separate page. New adipocytes in white adipose tissue are formed throughout life from a pool of precursor cells.
These are needed to replace those that die after an average life span of 10 years. Whether the total number of these adipocytes increases in humans becoming fatter as adults is still uncertain. If not, why do so many of us get fatter as we age? Because of the increased size of individual adipocytes as they become filled with oil.