Muscle tissues

Muscle tissue

• Muscle cells (myocytes) are elongated and classified and or compatible as either striated muscle cells or smooth muscle cells depending on the presence or absence, respectively, of organized, regularly repeated arrangements of myofibrillar contractile proteins called myofilaments. Striated muscle is further classified as either skeletal or cardiac muscle.[1] Thus, muscle tissue can be described as being one of three different types:

Muscle tissue

• Skeletal muscle or "voluntary muscle" is anchored by tendons (or by aponeuroses at a few places) to bone and is used to effect skeletal movement such as locomotion and in maintaining posture.

• Though this postural control is generally maintained as an unconscious reflex (see proprioception), the muscles responsible react to conscious control like non-postural muscles.

• An average adult male is made up of 42% of skeletal muscle and an average adult female is made up of 36% (as a percentage of body mass).[2] It also has striations unlike smooth muscle.

• Smooth muscle or "involuntary muscle" is found within the walls of organs and structures such as the esophagus, stomach, intestines, bronchi, uterus, urethra, bladder, blood vessels, and the arrector pili in the skin (in which it controls erection of body hair).

• Unlike skeletal muscle, smooth muscle is not under conscious control.

Smooth muscle

Smooth muscle is an involuntary [non-[striated muscle]]. It is divided into two sub-groups; the single-unit (unitary) and

multiunit smooth muscle. Within single-unit smooth muscle tissues, the autonomic nervous

system innervates a single cell within a sheet or bundle and the action potential is propagated by gap junctions to neighboring cells such that the whole bundle or sheet contracts as a syncytium (i.e., a multinucleate mass of cytoplasm that is not separated into cells).

Multiunit smooth muscle tissues innervate individual cells; as such, they allow for fine control and gradual responses, much like motor unit recruitment in skeletal muscle.

http://en.wikipedia.org/wiki/Smooth_muscle_tissue

• Smooth muscle is found within the walls of blood vessels (such smooth muscle specifically being termed vascular smooth muscle) such as in the tunica media layer of large (aorta) and small arteries, arterioles and veins.

• Smooth muscle is also found in lymphatic vessels, the urinary bladder, uterus (termed uterine smooth muscle), male and female reproductive tracts, gastrointestinal tract, respiratory tract, arrector pili of skin, the ciliary muscle, and iris of the eye.

• The structure and function is basically the same in smooth muscle cells in different organs, but the inducing stimuli differ substantially, in order to perform individual effects in the body at individual times.

• • In addition, the glomeruli of the kidneys contain smooth

muscle-like cells called mesangial cells.

1.- gludā muskuļa šūnas, 2.- muskuļšūnas kodoli, 3.-saistaudi

1.

2.

3.

Morfoloģiskās pazīmes:

Vārpstveida šūnas, saplacināti kodoli, eozinofila citoplazma, bazofili kodoli

• Venules sieniņa L - lumens, E - endotelijs, M – gludo muskuļu šūna, C – kolagēna šķiedras. Mērgs = 2 µm. (Rabbit, neocortex.)

• http:// synapses.bu.edu/atlas/3_7.stm

Arteriolas sieniņa. L - lumens, E - endotelijs, M – gludo muskuļu šūna. Mērogs = 1 µm. (Rat, thalamus.)

http://synapses.bu.edu/atlas/3_8.stm

• Arteriolas sieniņa. B – bazālā plātnīte, E - endotelijs, M – gludo muskuļu šūna, C- kolagēna šķiedras. Mērogs = 200 nm. (Mouse, neocortex.)

• http://synapses.bu.edu/atlas/3_9.stm

Spraugveida kontakti gludo muskuļu šūnās.

• Smooth muscle is found within the walls of blood vessels (such smooth muscle specifically being termed vascular smooth muscle) such as in the tunica media layer of large (aorta) and small arteries, arterioles and veins.

• Smooth muscle is also found in lymphatic vessels, the urinary bladder, uterus (termed uterine smooth muscle), male and female reproductive tracts, gastrointestinal tract, respiratory tract, arrector pili of skin, the ciliary muscle, and iris of the eye.

• The structure and function is basically the same in smooth muscle cells in different organs, but the inducing stimuli differ substantially, in order to perform individual effects in the body at individual times.

• In addition, the glomeruli of the kidneys contain smooth muscle-like cells called mesangial cells.

• Bundles of actin microfilaments• Myosin miofilaments• Dense plaque• Dense boodies• Nucleus• Cytoplasm• Gap juctions

Smooth muscle

http://www.biochemj.org/csb/frame.htm

Cell Signalling Biology - Michael J. Cell Signalling Biology - Michael J. Berridge - Berridge - www.cellsignallingbiology.org - 2012www.cellsignallingbiology.org - 2012

Smooth muscle

http://www.biochemj.org/csb/007/Fig7_smooth_muscle_cell_EC-couplinga.jpg

Smooth muscle and plasma membrane

Module 7: Figure smooth muscle cell EC coupling

Smooth muscle

Gludo muskuļu kontrakcijas.MLCK-myosin, light chain kinase, Ca4CM – Ca and

calmodulin complex komplekss.

Sceletal striated muscle tissue

Muscle fibers

• Red Muscle fibers

• Red Muscle fibers : Mitochondria, Prolongated activity

• White Muscle fibers Anaerobic respiration• Short activity

M-M line, Z- Z line, I- I band, A- A band,H- H band

endomysium perimysium

• sarcomere.

• Thin and thick miofilaments

Triads

http://www.youtube.com/watch?v=WVuW560nRII

Cell Signalling Biology - Michael J. Berridge - www.cellsignallingbiology.org - 2012 Cell Signalling Biology - Michael J. Berridge - www.cellsignallingbiology.org - 2012

Cardiomiocytes

http://www.cellsalive.com/myocyte.htm

Muscle contractions