BIOSCI 107

Connective tissues and nerve and muscle tissues

What is the purpose of Connective tissue

Binds, supports and strengthens other tissues, major transport system (blood), stored energy reserves (fat or adipose )

How is connective tissue different to epithelia

Not found on body surfaces and has potential to be highly vascular (except cartilage and tendons)

How is connective tissue similar to epithelia?

is supplied by nerves (except cartilage)

What is connective tissue made from?

Cells and extracellular matrix (ECM)

What is Extracellular matrix made from?

Ground substances and protein fibres

What is Ground Substance made from and what is it?

Part of ECM, water, proteins and sugars (Polysaccharides)

How to make Proteoglycans?

Glycosaminoglycans join with proteins

Glycosaminoglycans (GAGS)

Long unbranched polysaccharides

What does hyaluronice acid do (GAGS)

Slippery substance that JOINS, cells together, LUBRICATES joints and MAINTAINS the shape of eyeball

What does Hyaluronidase do

Made by white blood cells, sperm and some bacteria, makes ground substance more liquid

Chondroitin Sulphate

Support and provide features of cartilage, bone, skin, blood vessels.

Keratan Sulphate

Bone, cartilage, cornea

Dermatan sulphate

Skin, tendons, blood vessels, heart valves

Abonormal perioorbital ECM and thyroid disease

Common in younger women, Goitre (Swollen thyroid gland), autoimmune action on fibroblasts and overaction of thyroid, swelling of ECM and increase muscle size and fat.

What increases orbital contents with thyroid disease and abnormal periorbital ECM?

Deposition of GAGS and influx of water

Collagen

Strong and flexible to resist pulling, 25%of body, found in bone, cartilages, tendons and ligaments, parallel bundles

Reticular Fibres

Fine bundles of collagen coated in glycoprotein, Strength and support, forms part of basement membrane, thinner branching to spread through tissue, makes networks in vessels and through tissues ( especially adipose tissue, smooth muscle tissue and nerve fibres)

What are reticular fibres made by?

Fibroblasts

Where does reticular fibres make networks in vessels and through tissue?

Adipose, nerve fibres, smooth muscle tissue.

Elastic Fibres

Fibrous network of thin fibres, can be stretched 150%, skin, blood vessels and lung

Where are elastic fibres found

Skin, Lungs, Blood Vessels

What are elastic fibres made up of?

The protein Elastin surrounded by the glycoprotein fibrillin, giving more strength and stability.

What are the three kinds of connective tissue fibres found in ECM?

Collagen, reticular, elastic

What is Marfan syndrome

A defect in the elastic fibres, resulting form a dominant mutation on chromosome 15, which codes for fibrillin. TGFb increases growth but doe snot bind noramlly to keep it inactive.

What is fibrillin?

Fibrillin is a large glycoprotein which contributes to the structural scaffold for elastin.

What are the two common cell types in connective tissue?

Fibroblasts and adipocytes

Where are fibroblasts located?

Distributed across a wide range of connective tissues (migratory)

What is the function of fibroblasts?

Secretes components of the matrix (fibres and ground substances)

Where are Adipocytes found?

Underneath skin and around organs

What is the function of adipocytes?

Stores fat (triglycerides)

What are the less common cells in connective tissue?

Macrophages, Plasma cells, Mast cells, Leucocytes

Two types of embryonic connective tissue

Mesenchyme and mucous

Two different kinds of connective tissue?

Embryonic and Mature

Mesenchyme CT

Allows other CT to fomr, make up of CT cells in a semi-fluid ground substance containing reticular fibres.

Mucous CT

Has fibroblasts scattered around embedded in jelly like ground substance, supports umbilical cord

What are the three kinds of Loose Connective tissue (MATURE)

Areolar, adipose, Reticular

What is the function of Areolar connective tissue?

Around almost every structure to provide strength, support, flexibility

What are the 3 types of fibres present in areolar connectivw tissue?

Collagen, Reticular, elastic

Where is Adipose CT found

with areolar CT

What does Adipose CT do

Insulation, energy source and temperature control

What do the brown and white adipose in adipose connective tissue do?

Energy storage, heat production

Where is reticular CT found

As a filter for RBC in spleen, and microbes in Lymph nodes

What does reticular CT form?

Reticular cells dominant

What does reticular CT do

acts as a scaffold of organs, binds smooth muscle

What are the 3 kinds of dense connective tissue?

Regular, Irregular, Elastic

What does regular dense connective tissue do?

Forms regularly arranged collagen, slow healing, tension strength along axis of fibres

Where is regular dense CT found

tendons, ligmanets, aponeuroses

Where is Irregular dense CT found?

In sheets called Fasciae

What deos Irregular dense CT do?

Form irregularly arranged collagen around a few cells, tensile strength in many directions.

Where is Elastic dense CT found?

Lung tissue, elastic arteries, bronchial tubes, true vocal cords, some interverbrael ligaments, penis ligament.

What does elastic dense CT do?

forms elastic fibres with fibroblasts between, enables stretching with recoil.

What are the 3 kinds of supporting CT cartilage?

Hyaline, Fibrocartilage, Elastic

Hyaline Cartilage (supporting CT)

Glistening and abundant, helps with felxibility and movement

Where is Fibrocartilage (supporting CT) found?

Pubic symphysis, intervertebral discs, menisci of the knee, and tendons that joing cartilage

Fibrocartilage (supporting CT) form?

Dense network of collagen fibres with scattered chondrocytes

What is the function ofFibrocartilage (supporting CT) ?

Support and joining of structures togetherm strongest type of cartilage

Where is Elastic cartilage (supporting CT) found?

Epiglottis, external ear, audiotory eustachian tubes

What is Elastic cartilages (supporting CT) form?

Chondrocytes in thread like networks of elastic fibers within extracurricular matrix

What is function of Elastic cartilage (supporting CT)?

Strength and elasticity, maintain shapes of structures

Two types of bone tissue

compact and spongey

Compact bone tissue

Contains osteons, stores calcium and phosophorus, protection and support

Spongey bone tissue

Lacks osteons, stores yellow bone marrow, produces red bone marrow

Four types of cells in Bone tissue

Osteogenic, Osteoblasts, Osteocytes, Osteoclasts

What does an Osteogenic cell turn into and how?

Mesenchyl stem cells, that develop lay down collagen, become trapped turn into osteoblasts

Osteoblasts are what kind of cells?

Bone forming

What cell does an osteoblast develop into and how?

Bone forming cells lay down more collagen and the mineralisation process begins, turning into Osteocytes

osteocytes process

Mature bone cells derived from osteoblasts trapped within the extracurricular matrix. Maintain bone tissue, involved in the exchange of nutrients and waste, have gap junctions.

Osteoclasts

large multinucleated cells formed from the fusion of blood monocytes, break down bone

The basic unit of compact bone is what

Osteon

What are the 4 parts of Osteon?

Lamellae, Lacunae, Canaliculi, Central (haversion) canal

Lamellae

Concentric rings of mineral salts which form hydroxapatite and collagen

Lacunae

Small spaces between lamellae that contain mature bone cells (osteocytes)

Canaliculi

“Minute Canals” that radiate fron lacunae and provide routes for oxygen, nutrients and waste

Central (haversion) canal

Blood, Lymph and nerves

What do Osteoclasts do

Reabsorb dead bown and remodel new bone

What do Chondroblasts do

Lay down hyaline cartilage callus

What do Osteoblasts do?

Lay down new bone

Liquid connective tissue

Blood

Blood

consists of plasma (a liquid extracellular matrix) and formed elements (red cells, white cells and platelets)

Ethrocytes (red blood cell)

Transport oxygen and carbon dioxide

The four different Leukocytes

Neutrophils, Basophils, eosinophils, Lymphocytes

Neutrophils and monocytes (Macrophages)

Phagocytic, engulfing bacteria

Basophils (mobile) and Mast cells (immature circulate, matire fixed in tissues)

Release substances that intensify the inflammatory reaction

Eosinophils

Effective against certain parasitic worms and in acute allergic response

Lymphocytes

Are involved in the immune response

Platelets (from Megakaryocytes in red marrow)

responsible for clotting

Muscle tissue

Muscle cells that use energy from the Hydrolysis of ATP to generate force. As a result of contraction, muscle tissue produces body movemtns, maintains posture and generates heat.

3 types of muscle tissue (50% of body tissue mass)

Skeletal, cardiac and smooth

How many named skeletal muscles

~650

Where is Skeletal muscle normally?

attacthed to bones via tendons

Smallest and largest skeletal muscles?

Smallest is stapedius (stabilises smallest bone in ear), 1.25mm

Largest is Sartorius (leg), up to 60cm

Is skeletal muscle tissue multi or single nucleated?

Multinucleated

Functions of skeletal muscle tissue

Posture, heat, protection, motion

Why are skeletal muscle tissues striated?

Due to highly organised arrangment of myofibrils within the cells

What are Myofibrils?

Fill the sarcoplasm of the muscle fibre and extend its entire length within the cell

What is this image, and name the tags

Muscle Fiber, Sarcolemma, Sarcoplasm, Myofibrils, Striations.

What makes up myofibrils?

Myofilament

What are the types of myofilament?

Thin (mostly actin), Thick (myosin)

Where are Myofilaments found?

Compartments called sarcomeres

what is a sarcomere?

Basic functional unit of a myofibril, seperated by z discs, contains myofilaments.