The Structural Organization of Animals• Individual cells are groupedinto tissues (cardiac muscle).• Tissues combine to formorgans (heart).• Organs are organized intoorgan systems (circulatorysystem).• Organ systems make upthe entire organism (thewoman!).
1. TISSUESIn most multicellular animals, cells are groupedinto tissues.A tissue is composed of similarly specializedcells that perform a common function in thebody
• 4 Types of Tissues in the Human Body – Epithelial: covers body surfaces and lines cavities – Connective: supports and binds body parts – Muscular: moves the body and its parts – Nervous: receives stimuli, processes that information, and conducts impulses
A. Epithelial Tissue– Consists of tightly packed cells that form a continuous layer– Numerous functions • Usually protective • Secretion • Absorption • Excretion • Filtration
Epithelial Tissue Can Be Classified according to: – Cell Shape: • Squamous: flattened cells • Cuboidal: cubed-shaped cells • Columnar: cells resembling rectangular pillars or columns – the Number of Layers in the Tissue • Simple: Single layer of cells • Stratified: Multiple cell layers • Pseudostratified: appears to be layered but each cell touches basement membrane
Glandular epithelium secretes a product• Gland: can be single or multiple cells – Exocrine glands – secrete products into ducts (“exit body”) – Endocrine glands – secrete product into bloodstream (stay in body) Example: Pancreas is both an exocrine and endocrine gland
B. Connective Tissue Functions– Binds organs together– Provides support and protection– Fills spaces– Produces blood cells– Stores fat
B. Connective TissueConnective tissues have a sparse populationof cells scattered through an extracellularmatrix.The matrix consists of a web of moleculesthat "glue" the cells together in the connectivetissuesThe structure of connective tissue correlateswith its function.It binds and supports other tissues.
Components of Connective Tissue– Matrix: noncellular material - solid, semisolid, or liquid– Fibers: collagen, elastic, reticular– Cells: various types
• Loose fibrous connective tissue – Supports epithelium and many internal organs – Forms a protective covering enclosing many internal organs• Dense fibrous connective tissue – Contains many collagen fibers – Found in structures such as tendons and ligaments• Both types have cells called fibroblasts separated by a jellylike matrix with collagen and elastic fibers
Loose connective tissue (under the skin) Blood Fibrous connective Tissue (tendons)Bone Cartilage (at the end of the bone) Adipose Tissue Fat droplets
1. Loose connective tissue: – is the most widespread connective tissue. – It binds epithelia to underlying tissues. – It holds organs in place.2. Blood: – is a connective tissue with a matrix of liquid. – Red and white blood cells are suspended in plasma.3. Fibrous connective tissue: – has a dense matrix of collagen. – It forms tendons and ligaments.
4. Adipose tissue stores fat: – It stockpiles energy. – It pads and insulates the body.5. Cartilage – Its matrix is strong but rubbery. – It functions as a flexible, boneless skeleton. – It forms the shock-absorbing pads that cushion the vertebrae of the spinal column.6. Bone: – is a rigid connective tissue with a matrix of rubbery fibers hardened with deposits of calcium.
Blood– Unlike other types of connective tissue in that the matrix (i.e., plasma) is not made by the cells– Functions 1. Transports nutrients and oxygen and removes carbon dioxide and wastes 2. Helps distribute heat 3. Plays role in fluid, ion and pH balance 4. Protects us from disease 5. Blood clotting protects against fluid loss
Components of Blood– Plasma – 55% of volume• Variety of inorganic and organic substances dissolved or suspended in water– Formed elements – 45% of volume • Red Blood Cells (erythrocytes) » Contain hemoglobin for transport of oxygen • White Blood Cells (leukocytes) » Fight infection • Platelets (thrombocytes) » Cell fragments involved with blood clotting
C. Muscular Tissue• Muscle tissue consists of bundles oflong, thin, cylindrical cells called musclefibers.• Each cell has specialized proteins thatcontract when the cell is stimulated by anerve. – Muscles fibers contain actin and myosin filaments • Interaction accounts for movements
There is 3 kinds of muscle Tissue: 1. Cardiac muscle 2. Skeletal muscle 3. Smooth muscle
1. Cardiac muscle: – is found only in heart tissue. – Its contraction accounts for the heartbeat.2. Skeletal muscle: – is attached to bones by tendons. – It is responsible for voluntary movements. – The contractile apparatus forms a banded pattern in each cell or fiber. – It is said to be striated, or striped.3. Smooth muscle – is named for its lack of obvious striations. – It is found in the walls of various organs. – It is involuntary.
D. Nervous TissueNervous tissue makes communication ofsensory information possible. • Sensory input is received and processed. • Motor output is then relayed to make body parts respond.Nervous tissue is found in the brain and spinalcord.The basic unit of nervoustissue is the neuron, ornerve cell. Neurons cantransmit electrical signalsrapidly over long distances.
Neuron structure• Dendrites• Cell body• Axon – may have myelin sheath to increase speed
2. Body Cavities– Ventral Cavity or Coelom • Thoracic cavity – Lungs and heart • Abdominal cavity – Separated from thoracic cavity by diaphragm – Stomach, liver, spleen, gallbladder, and most of the small and large intestines • Pelvic cavity – Bladder, rectum, internal reproductive organs– Dorsal Cavity • Cranial cavity - Brain • Vertebral canal - Spinal cord
Body MembranesLine cavities and the internal spaces of organsand tubes that open to the outside 1. Mucous membranes 2. Serous membranes 3. Synovial Membranes 4. Meninges
Mucous Membranes• Line tubes of the digestive, respiratory, urinary, and reproductive systems• Epithelium overlies loose fibrous connective tissue• Goblet cells produce mucus – Protective function
Serous Membranes• Line thoracic and abdominal cavities• Epithelium and loose fibrous connective tissue• Secrete watery fluid for lubrication• Specific names according to location – Pleurae- lines thoracic cavity and lungs – Pericardium-encloses heart – Peritoneum- lines abdominal cavity and covers organs • Mesentery supports abdominal organs and attaches them to abdominal wall
3. Synovial membranes• Loose connective tissue• Line freely movable joints• Secrete synovial fluid 4. Meninges• Line the dorsal cavity• Protect brain and spinal cord• Connective tissue
3. ORGANSThe next level in the structural hierarchy is theorgan. – An ORGAN consists of 2 or more tissues packaged into one working unit that performs a specific function. – Examples: heart, liver, stomach, brain, and lungs
Example of an Organ:THE SMALL INTESTINE Epithelial Tissue Connective Tissue(blood and lymph vessels) Smooth muscle Tissue (2 layers) Connective TissueEpithelial Tissue
4. ORGAN SYSTEMSThe organs of humans and most other animalsare organized into organ systems.Organ systems are teams of organs that worktogether to perform a vital bodily function.
Which of the following are listed in the correct hierarchical order, from leastcomplex to most complex?A) cell, tissue, organB) tissue, organ, cellC) organ, tissue, cellD) cell, organ, tissueE) tissue, cell, organ A
Groups of cells that perform a similar function are known as:A) organs.B) organ systems.C) control centers.D) organisms.E) tissues. A
Blood is a type of:A) epithelial tissue.B) muscle tissue.C) collagen.D) connective tissue.E) nerve tissue. D
Which organ system is NOT essential for survival of an individual?A) digestive systemB) respiratory systemC) muscular systemD) nervous systemE) reproductive system E
The skin is an example of a(n):A) organ.B) cell.C) ligament.D) tissue.E) organ system. A