Tissuesof vertabrates

Premedical 22

Tissues = cells of same shape and the same function

extracellular matrix

1. Epithelia – ectoderm,

mesoderm, endoderm

2. Connective tissue - mesoderm

3. Muscular tissue - mesoderm

4. Nervous tissue - ectoderm

1. By fusion of endothelial and epithelial cells / kidneys and alveoli

two laminae: lamina densa, lamina lucida

2. Epithelial cells with fibrous tissue: lamina densa and

reticularis

Basement membrane - thin sheet of fibers that underlies

the epithelium, which lines the cavities and surfaces of organs, or the

endothelium, which lines the interior surface of blood vessels

http://www.thefullwiki.org/Basement_membrane

1. Epithelia – form from one or more layers of cells

covering an external surface or lining a cavity

Single layer of squamous flat cells

Single layer of cuboidal cells (sweat, digested food)

Single layer of columnar cells - may function to absorb substances

Single layer of columnar cells with microvili - help move substances over their surface

Stratified e. of cuboidal cells

Stratified Squamous Epithelium (non-keratinized)

Stratified Squamous Epithelium (keratinized)

Transitional e. with cells range from flat to tall cells

Pseudostratified Ciliated Columnar Epithelial Tissue

http://www.thefullwiki.org/Squamous_epithelium

Simple squamous epithel (2) - capillary

Simple columnar epithel – gal gladder

Vesica fellea

Hematoxylin-Eozin

Single layer of columnar cells (2) with microvili (3)- oviduct

1 - lamina propria, 4 – gland cells

Stratified e. of cuboidal cells with microvilli (2) - trachea

1 - submucosa

Stratified Squamous Epithelium (1) (non-keratinized)

Uterus :2 - submucosa

Stratified Squamous Epithelium (keratinized) – Cutis- Skin

Transitional Epithelium (2) (urinary bladder)

1 – lumen of vesica urinaria, 3 - Lamina propria mucosae

Function of epithelial tissue

• protection and cover - the skin - protect underlying tissue from mechanical injury, harmful chemicals, invading

bacteria and from excessive loss of water

• sensation - specialized epithelial tissue containing sensory nerve endings is found in the skin, eyes, ears, nose and on the tongue

• secretion – glands - epithelial tissue is specialized to secrete specific chemical substances such as enzymes, hormones and lubricating fluids

• resorption, absorption - certain epithelial cells

lining the small intestine absorb nutrients from the

digestion of food [lining inside surface of hollow organs]

• respiratory, diffusion - simple epithelium promotes

the diffusion of gases, liquids and nutrients. Because

they form such a thin lining, they are ideal for the

diffusion of gases (eg. walls of capillaries and lungs).

Glands - secretionSecretion :

merocrine (pancreas) / exocytoseapocrine (lacteal gland)holocrine (sebaceous gland)

Gland:

•Exocrine - secrete chemicals into ducts

– outlets

•Endocrine–without outlets – directly to

body fluids

pancreas

lacteal gland

sebaceous gland

2. Connective tissue

play a central part in the support and repair of almost every

tissue and organ

and the adaptability of their differentiated character is an

important feature of the responses to many types of damage

Collagen is the main protein of connective tissue in

animals, making up about 25% of the total protein content

Proper fibrous tissue

Cartilage

Bone

Embryonic connective tissue

Connective-tissue cells:

Fibroblasts

Cartilage cells (chondrocytes)

Bone cells (osteoblasts and osteocytes)

Fat cells (adipocytes)

Mast cells

Macrophages

Leucocytes

Fiber types as follows:

collagenous fibers

elastic fibers

reticular fibers

Fibroblasts with dark nuclei [A] are seen here along with thick collagen fibers [B], thin elastic fibers [C] and very fine reticular fibers [D].

Loose fibrous tissue - Areolar loosely organized fibers

Fibers are collagenous, but elastic and reticular fibers are

also present, in many serous membranes

- Reticular a network of reticular fibers, made of type III

collagen

- Adipose white, brown

Dense fibrous tissue

Dense regular connective tissue (Ligament, Tendon,

Aponeurosis)

Dense irregular connective tissue (Submucosa, Dermis) 

Embryonic connective tissue - mesenchymal

Specialized

Bone

Cartilage

Vertical section of duodenum: 1 - Tunica mucosa, 2 - Tunica submucosa, 3 – Brunner gland Tendon

white, brown adipose tissue

Cartilage

– the joints between bones, the rib cage, the ear, the nose,

the elbow, the knee, the ankle, the bronchial tubes and

the intervertebral discs.

• chondrocytes that produce a large amount of ECM

composed of collagen fibers, rich in proteoglycan, and

elastin fibers

• elastic cartilage - epiglottis

• hyaline cartilage

• fibrocartilage

hyaline cartilage

elastic cartilage - epiglottis1 – elastic cartilage, 2 - perichondrium, 3 – seromucin glands, 4 - Tunica mucosa

Boneproduce red and white blood cells – red marrow - in long

bones store minerals and fatts (yellow) most notably calcium

and phosphorus (calcium phosphate 2/3, calcium

hydroxyapatit 1/3)

Ossification (or osteogenesis)

Intramembranous ossification is the direct laying down of

bone into the primitive connective tissue (mesenchyme),

while endochondral ossification involves cartilage as a

precursor.

1. periosteum2. compact bone3. spongy bone4. Bone marrow – medulla• Diaphysis• Epiphysis

http://doctorsgate.blogspot.com/2010/11/compact-vs-spongy-bones.html

3. Muscular tissue – contractility upon stimulation

skeletal musclelong, multinucleated syncytial

cells by fusion of myoblast cells

their nuclei are located peripherally adjacent to the

plasma membrane (sarcolemma).

Controll by our will, spinal (medullary) and cerebral

nerves, cortex

Skeletal and muscles of tongue and pharynx

smooth muscle

composed of sheets or bundles of relatively

short, spindle-shaped cells

not striated, and have a single central

nucleus are interconnected by gap junctions.

Muscles of digestive system, uteri, gall

bladder, dermis,

Controll by autonomic [vegetative] nerves

cardiac muscle

composed of branching and anastomosing chains of

cardiac muscle cells

are joined to their neighbours by intercalated discs,

which contain anchoring and gap junctions.

The anchoring junctions (adherens junctions and

desmosomes) physically connect the cytoskeletons

and contractile apparatuses of the neighboring cells.

Control by autonomic [vegetative] nerves

Muscle - structure

A.Muscle with fascia

e. tendon

f. bundle of fibers

B. Fiber

C. Myofibril from

sarcomers

g. actin

h. myosin

Composed of actin (thin) and myosin (thick)

filaments and associated proteins

is organized into myofibrils

The regular repeating segments (sarcomeres) of

myofibrils give skeletal and cardiac muscle cells

transverse striations. In smooth muscle cells, actin

and myosin filaments form contractile fibers, which

do not appear as highly organized as myofibrils

4. Nervous tissue

composed of cells with long

processes, which may run in

bundles of parallel fibers.

The cells are divided into excitable

cells (called neurons, lead

impulses ) and the more numerous

supporting cells (called neuroglia or

glial cells) Molecular Biology of the Cell. 4th edition.Alberts B, Johnson A, Lewis J, et al.

neuron • Centripetal fibers - dendrits• centrifugal fibers – neurits – axons

neuroglie

Schwann cells - origin of neurolemma which cohere with

sheath myelin

Nerve

grey and white fibers

with or without

Campbell, Neil A., Reece, Jane B., Cain Michael L., Jackson, Robert B., Minorsky, Peter V., Biology, Benjamin-Cummings Publishing Company, 1996 –2010.

Thank you for your attention