Lecture 4: Muscle and nerve tissue Flashcards

1
Q

What is muscle tissue

A

Consists of elongated muscle fibres that use energy from ATP to generate force.

By contraction, muscle tissue produces movement, holds posture and generates heat

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2
Q

What are the 3 types of muscle tisse

A

Skeletal muscle
Cardiac muscle
Smooth muscle

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3
Q

What are the features of skeletal muscle

A

Attached to bones via tendons
Striated
Very common throughout body
Multinucleate
Voluntary and involuntary (muscles related to posture)
Allow motion, hold posture, produce heat, and protection

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4
Q

What is stapedius?

A

The name of the smallest skeletal muscle located in the inner ear.

Helps prevent hearing disorders

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5
Q

What is sartorius?

A

Name of the longest skeletal muscle in the thigh

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6
Q

What are the parts of a muscle fibre

A

Also known as myocytes or muscle cells, muscle fibres are composed of:

Sarcolemma - cell membrane
Sarcoplasm - cell cytoplasm
Myofibrils

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7
Q

What are the two components of myofibrils?

A

Thin filament (Actin) and Thick filament (myosin)

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8
Q

What is a myofibril

A

Cynlindrical structures made of thick and thin filaments

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9
Q

What is epimysium

A

Surrounds the whole muscle

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10
Q

What is perimysium

A

Surrounds fascicles (bundles of muscle fibres)

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11
Q

What are fascicles

A

Bundles of muscle fibres

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12
Q

What is endomysium

A

Layer for capillaries and nerves around muscle fibres

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13
Q

What are the parts of myofibril?

A
A band
I band
H zone
M line
Z disc
Sarcomere
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14
Q

What is the A band

A

middle, dark part of myofibril which has overlap of actin and myosin filaments

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15
Q

What is I band

A

part containing only thin filaments

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16
Q

What is H zone

A

part containing only thick filaments

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17
Q

What is M line

A

Middle of sarcomere holding thick filaments together

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18
Q

What is Z disc

A

Located through the center of the I band made up of actinins that link filaments of adjacent sarcomeres

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19
Q

What is a sarcomere

A

Basic functional units of myofibrils that are separated by Z discs

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20
Q

What are the features of cardiac muscle

A
Striated
Branched
Single nucleus
Fibres join end to end through intercalated discs (contains desmosomes and gap junctions)
Found in the heart
Involuntary
21
Q

What are purkinje fibers?

A

Specialised muscle cells that conduct electrical activity around heart
Less myofibrils and more specialised connexins (gap junctions)

22
Q

What are the features of smooth muscle?

A

No striations
Found in the internal wall of hollow structures
Short, small, spindle-shaped
Involuntary
Can contain gap junctions (allowing peristalsis in small intestine for example)

23
Q

What are dense bodies?

A

Dense bodies - made up of actinin - exist around the smooth muscle providing anchoring points for contractile elements to bind to allowing muscle contraction.

They connect intermediate filaments

24
Q

What is the nervous system composed of

A

CNS : brain and spinal cord

PNS : all other nervous tissue

25
Q

What are the two divisions of PNS

A

Sensory/afferent divison : carry information to CNS

Motor/efferent divison : carry information from CNS to effectors

26
Q

What is the afferent divison

A

Sensory division of PNS which carry information to CNS

27
Q

What is the efferent division

A

Motor division carrying information from CNS to effectors

28
Q

What is the function of the nervous system

A

Sensory : detection of internal and external stimuli and transfer to CNS
Integrative : analysis and storing of information
Motor : stimulation of effectors (muscles and glands) through PNS

29
Q

What are the two types of nervous tissue cells?

A

Neurons and neuroglia

30
Q

What are features of neurons?

A

Longest cells in the body that make up nervous tissue
Involved in concious and unconscious control
Have a cell body
Have dendrites carrying information into neurons
Have axons carrying information from neuron to neuron
Do not divide
High metabolic rate

31
Q

What are dendrites?

A

Short, branched extensions of neurons which allow input of electrical impulses

32
Q

What are axons?

A

Long part of neuron that carries action potentials to adjacent neurons

33
Q

What are the 4 types of neurones?

A

Multipolar
Bipolar
Unipolar
Anaxonic

34
Q

What are multipolar neurons/

A

2 or more dendrites
1 axon
Most common
All motor neurons are multipolar

35
Q

What are bipolar neurons?

A

2 distinct processes - 1 dendritic and 1 axon
Cell body between dendritic part and axon part
Rare and small
Special sense organs

36
Q

What are unipolar neurons?

A
Dendrites and axons are continuous
Cell body off to one side
Point where dendrites converge is axon
Most sensory nerves are unipolar
Long
37
Q

What are anaxonic neurons?

A

Rare
Function idk?
Cannot distinguish between axon and dendrite
Found in brain and sense organs

38
Q

What are neuroglia?

A

Cells of nervous tissue
A sort of glue that holds nervous tissue together
Found in CNS and PNS
Do not propagate action potentials, but can communicate
Can divide

39
Q

What are functions of neuroglia (nervous cells)?

A

Hold physical structure of nervous tissue
Repair framework of nervous tissue
Undertake phagocytosis
Nutrient supply to neurons
Regulate interstitial fluid in neural tissue

40
Q

What are the types of neuroglia?

A
CNS
- astrocytes
- oligodendrocytes
- microglia
- ependymal cells
PNS
- schwann cells
- satellite cells
41
Q

What are astrocytes

A

Type of neuroglia cells found in CNS

Star shaped and large
Numerous
Form syncytium (large co-ordinated network of cells)
Function in supporting tissue and repairing
Communicate with neurons via gliotransmitters (glutamate)
Maintain environment around neuron
Maintain blood-barrier via endothelium (can alter permeability of endothelium in blood vessels)

42
Q

What are gliotransmitters?

A

Structures which allow astrocytes to communicate with neurons

43
Q

What are oligodendrocytes?

A

Type of neuroglia cells found in CNS
Form insulating myelin-sheath (protein-lipid layer) around CNS axons
Can myelinate more than one neuron cell’s axon

44
Q

What is the myelin sheath?

A

Lipid-protein layer around axons that accelerate action potentials

Secreted by oligodendrocytes in CNS and made up of schwann cells in PNS

45
Q

What are microglia?

A

Type of neuroglia cells found in CNS

Phagocytic cells of the nervous tissue

46
Q

What are ependymal cells

A

Type of neuroglia cells found in CNS
Produce cerebrospinal fluid (CSF)
Have cilia and microvilli
Cilia allow movement of nutrients and waste materials
Microvilli allow scanning and control of composition of cerebrospinal fluid

47
Q

What are schwann cells

A

Type of neuroglia found in PNS
Form insulating myelin sheath by wrapping around PNS axons
Support and surround non-myelinated axons also

48
Q

What are satellite cells

A

Glue-like role holding PNS nervous tissue together

Provide support and allow fluid exchange of PNS nervous tissue