MANA S2 Integumentary system (Integument (Fascia: superficial - located…
Tissue types can be distinguished by:
1) amt of intercellular space (fibres)
2) Function & appearance
1) Epithelial tissue
2) connective tissue
3) Muscular tissue
4) Nervous tissue
F) to protect underlying tissue and structures that may be subjected to wear and tear, drying out or damage by other living organisms
C) - cells arranged to form covering sheets or lining membranes
cells are predominant. amt of inter-cellular substance at minimum.
a lining membrane of the body tracts that open to the exterior
e.g. digestive, respiratory, urogenital tracts
serous lining membrane for large cavities of the body (slippery=less friction)
eg. pleura, pericardium, peritoneum
inner lining of walls of blood and lymph vessels and heart, reduces friction, helps prevent blood clotting.
F) -packing and support material of the body
-plays an important role in repairing injuries by forming scar tissue to join injured parts
C) - cells far apart & separated by large amts of int substance
varying quantities of fibres present in int subs
Areolar connective tissue: fills empty spaces
adipose connective tissue: similar to areolar but has cells impregnated with fat
dense connective tissue: densely packed fibres that form elongated strands. e.g: tendons, ligaments, aponeurosis, deep fascia, intermuscular septa and neurovascular bundle.
cartilage: hyaline, fibrous and elastic
-haemopoetic tissue: forms red adn white blood cells. found in the red marrow of long bones and in internal organs like Liver.
F) consist of highly specialized elongated cells possessing the inherent power of contraction
Skeletal muscle (striated voluntary)
long threadlike cells with many striations
muscle cells=muscle fibres
each fibre has many myofibrils
-myofibril consists of overlapping filaments of the proteins myosin and actin whihc glide past each other when the fibre contracts.
fast and short duration contractions
most attatched to skeleton
Visceral muscle ( non-striated involuntary)
have long spindle shaped cells with no striations
slow and longer duration contractions
usually found in hollow organs eg blood vessels
Cardiac muscle (striated involuntary)
have branching striated cells
C) has specialized characteristic of excitability and conductivity
F) Nerve impulses: all the chemical and electrical changes accompanying the transmission of an impulse.
-often generated by the stimulation of a receptor at terminal end of dendrite
reaches axon and then transferred to next neuron via synapse.
neurotransmittors released into synapse
direction of impulse from dendrite to axon
support tissue for nervous system
cell consists of a cell body, axon and dendrite and their branches = nerve fibre
Macroscopic structure of nervous system:
-PNS: + autonomic
composition of peripheral nervous system:
somatic and autonomic component. Spinal and cranial nerves
somatic afferent and efferent nerve fibers
31 pairs of spinal nerves.
cranial (8), thoracic (12), Lumbar (5), sacral (5), coccygeal (1)
unilateral area of skin supplied by a particular spinal nerve is called a dermatome
unilateral group of skeletal muscles supplied by a particular spinal nerve = myotome
ectoderm = nervous system (neural tube and neural crest >brain, spinal cord & peripheral ns) and epidermis
mesoderm= muscles, bones and dermis layer
endoderm= intestinal canal
mesodermal layer>segments>paired blocks of mesoderm>somites. both sides of neural tube.
3 regions in somites:
dermatome=dermis of skin
-sclereotome=segmented parts of skeleton
-stratified, keratinized epithelium
-tough, horny superficial layer
thickness depends on location
-underlying layer of connective tissue
-dense layer of collagen and elastic fibres = skin tone
superficial - located between dermis and deep fascia.
-composed mostly of loose connective tissue and stored fat.
-fibrous bands extend through it.
dense organised connective tissue
fibers in intercellular substance in dermis have a prevailing direction in the different regions of the body.
lacerations // to tension lines = heal well. lacerations acroos tension line disrupts collagen fibers = keloid
eg. stretch marks from pregnancy
blood supply to the skin
Arteries to the skin form plexuses (network of nerves or blood vessels) in the dermis
From these plexuses capillary vessels originate and pass into the dermal papillae
Sympathetic nerve fibres present in the cutaneous nerves control the smooth muscle in the small arteries of the skin
vasoconstriction & vasodilation
Pleura - the covering of the lungs (visceral pleura) and of the inner chest wall (parietal pleura) which consists of a closed sac of serous membrane.
Pericardium - the membrane surrounding the heart. Consists of two parts – the outer fibrous pericardium and the internal serous pericardium.
Peritoneum - the serous membrane of the abdominal cavity. The parietal peritoneum lines the walls of the abdomen and the visceral peritoneum covers the abdominal organs.
Epidermis - the outermost layer of the skin which is divided into 4 layers.
Dermis - (corium) the true skin; the thick layer of living tissue that lies beneath the epidermis.
Mucosa - the moist membrane lining many tubular structures and cavities. Eg the nasal sinuses, respiratory tract.
Subcutaneous - beneath the skin
Skin ligaments - (L. Retinacula Curtis) numerous small fibrous bands, extend through subcutaneous tissue and attach the deep surface of the dermis to the underlying deep fascia.
Receptor - a cell or group of cells specialized to detect changes in the environment and in the sensory nervous system.
Effector - any structure or agent that brings about activity in a muscle or a gland, eg a motor nerve.
Nerve - a bundle of conducting nerve fibres that transmit impulses from the brain or spinal cord to the muscles and glands OR inwards from the sense organs to the brain and spinal cord.
Nerve fibre - the long fine process that extends from the cell body of a neuron and carries impulses.
Grey matter - nerve cell bodies