Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biosci107 > lecture 4 > Flashcards

lecture 4 Flashcards

1
Q

What does muscle tissue consist of

A

Elongated cells (muscle cells or muscle fibres or myocytes that use energy from the hydrolysis of ATP to generate force

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

As a result of contraction, muscle tissue produces

A

Body movement, maintains posture and generates heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How many types of muscle

A

3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Name the three types of muscle

A

Skeletal
Cardiac
Smooth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Attachment of skeletal muscles

A

Attached to bones via tendons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How do skeletal muscles appear under microscope

A

Striated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Contraction of skeletal muscle is

A

Voluntary and usually under conscious control eg posture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Shape of fibres (cells) in skeletal muscle

A

Cylindrical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Smallest skeletal muscle

A

Stapedius

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What does the stapedius do

A

Smallest skeletal muscle and it stabilises the smallest human bone the stapes in the ear and prevents hyperacusis - damage to stapedius by extra loud sound perception- and tymapnic reflex by controlling the tension on bones to prevent becoming deaf when hearing loud noises and bells palsy which is caused by paralysis of facial nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How small is the stapedius

A

1.25mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How long is the sartorius

A

60cm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the name of the longest skeletal muscle

A

Sartorius

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How to look underneath sartorius

A

Twist foot and rotate leg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Hip functions

A

Flexor, abductor, lateral rotator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Functions of knee

A

Flexor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How far does sartorius extend

A

Hip to just above knee tibia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Structure of skeletal muscle

A

Long and can be up to 30cm
Striated
Multinucleated with many peripheral nuclei pushed to the sides so hard to tell which part of the cell is controlled by which nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Control of skeletal muscle

A

Voluntary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Function of skeletal muscle

A

Motion posture heat and protection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What causes skeletal muscle fibre striations

A

Due to highly organised arrangement of myofibrils within cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Cytoplasm if muscle fibre is called

A

Sarcoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are myofibrils and what do they do

A

They are 2 micrometers diameter and more or less fill the sarcoplasm of muscle fibre and extend its entire length within the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Skeletal muscle cell membrane

A

Sarcolemma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Name the two types of myofilaments that myofibrils are composed of

A

Thin filaments and thick filament

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are thin filaments made of

A

Mostly actin protein and are 8nm diameters in length which is half of the thick filaments and they are 1-2 micrometers long

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are thick filaments made of

A

Myosin and are 16nm diameter with 1-2 micrometer length

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Myofilaments do not extend the length of the muscle fibre but

A

Are arranged in compartments known as sarcomeres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is a sarcomere

A

Basic functional unit of a myofibril and sarcomeres are seperated by zig zag z discs or z lines
Sarcomeres are segmental batches of ordered blocks of filaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What do z lines di

A

Seperate sarcomeres and define the end point of a sarcomere where some proteins lock into it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Line of order of ct of skeletal muscles

A

Epimysium
Perimysium
Endomysium
Sarcolemma
Sarcoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Line of order of fascicle

A

Endomysium
Muscle fibre with striations
Sarcolemma and sarcoplasm
Myofibril inside sarcoplasm
Filament inside myofibril

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How are striations produced

A

Thick and thin myofilaments overlap to produce the striations in the myofibril

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the A band

A

Dark middle part which contains all the thick filaments and therefore is the length of the thick filament
Contractile length

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

I band

A

Thin filaments but no thick filaments - spans between and straddles sarcomeres

36
Q

H zone

A

Thick filaments but no thin filaments - decreases distance when muscle contracts
Dynamic space and end of overlap between thick and thin filaments

37
Q

M line

A

Middle of sarcomere and holds thick filaments together

38
Q

Z disk

A

Passes through centre of I band between sarcomeres in zigzag and is made up of actinins that link filaments of adjacent sarcomeres

39
Q

What and where is titin filament

A

Squiggly molecular spring shaped - links z disk to m line and provides resting tension in I bandfound between thin filaments

40
Q

What is thin filament made of

A

Actin

41
Q

What is thick filament made of

A

Myosin

42
Q

Features of cardiac muscle

A

Striated and branched
Single central nucleus
Fibres join end to end through junction comprised of intercalated disks
Sequential contraction for muscle coordination

43
Q

Intercalated disks contain

A

Desmosomes which bind intermediate filaments and provide adhesion in contraction
And gap junctions for communication which are coordinated for rapid conduction

44
Q

What are parkinje fibres

A

Specialised muscle cells which conduct electrical activity around the heart. They have less myofibrils and more specialised connexins from gap junction

45
Q

Increased coordinated contractions through

A

Fibres going in lots of different direction so when heart contracts it contracts effectively and layers are different in this

46
Q

Control of cardiac muscle tissue

A

Involuntary

47
Q

Smooth muscle features

A

Short spindle shaped and about 30-200 micrometers long with 3-8 micrometer thickest in middle
Non striated
Single central nucleus

48
Q

Smooth muscle movement

A

Involuntary

49
Q

Where is smooth muscle tissue located

A

Walls of hollow internal structures and organs
Intestines for peristalsis
Blood vessels walls for change of shape and constriction - needs to change diameter to control and direct blood flow
Also iris of eye
Reproductive and digestive and respiratory urinary system and skin erector pili

50
Q

Shape of smooth muscle tissue allows

A

Packing efficiency for muscle around cell

51
Q

Thin filaments in smooth muscle tissue

A

Actin and attached to dense bodies - similar function to z discs and in the dense body the main protein is actinin

52
Q

Intermediate filaments in smooth muscle tissue

A

Non contractile element and are also connected to dense body
Strong
Dont bend as much

53
Q

What happens during smooth muscle tissue contraction

A

Tension transmitted to intermediate filaments which dont contract and the cell twists
The dense bodies provide structural connections during contractions
Dense bodies come closer together whereas intermediate filaments dont really move and when tissue encircles another tube it shortens during contraction to change diameter of hollow tube

54
Q

For smooth muscle tissue where are lots of gap junctions and where are few

A

Gut - lots
Iris - few

55
Q

What system is the nervous tissue a part of

A

Nervous system

56
Q

Name the two subdivisions of the nervous system

A

Central nervous system and peripheral nervous system

57
Q

What does the central nervous system consist of

A

Brain and spinal cord and optic nerve

58
Q

Subdivisions of pns

A

Sensory/afferent division and motor/efferent division

59
Q

Sensory/afferent sends info to the

A

Cns

60
Q

Motor/efferent sends

A

Info from cns to organs (muscles and glands)

61
Q

What does pns consist of

A

All nervous tissue outside cns

62
Q

Three things nervous system helps with

A

Maintains homeostasis (along with endocrine system)
Initiates voluntary movements
Responsible for perception, behaviour and memory

63
Q

What are the three major functions that are grouped under activities

A
  • sensory which is detection of internal and external stimuli and transfer it to cns
  • integrative - the analysis of storing information and assembling so we can initiate action
  • motor - stimulation of effectors like muscle and glands through the pns - motor means effector (doing)
64
Q

Two types of cells in nervous tissue

A

Neurons - nerve cells that can be very large
Neuroglia - supportive cells of neurons and very small

65
Q

Size of neuron

A

Longest cell in body up to 1m from spinal cord to toe

66
Q

Control of neurons

A

Conscious and unconscious

67
Q

What is a dendrite

A

It is the receiving input part of the neuron and brings impulses into the cell body. Branched dendrites convey nerve impulses (action potential)

68
Q

What does an axon do

A

Carries nerve impulses away from the neurons cell body. It is the output portion of the neuron. Conducts nerve impulses to another neuron or tissue

69
Q

For our purposes neurons..

A

Dont divide and have a high metabolic rate meaning they die rapidly without O2.

70
Q

Myelin sheath

A

Waxy substance coating which helps with conduction

71
Q

Multipolar neuron

A

2 or more dendrites = multiple areas of info and a single axon leaving
Most common neurons in cns
All motor neurons (control skeletal muscle) are in this class
Some of the longest (spinal cord to toe muscles)

72
Q

Bipolar neurons

A

Two distinct processes
- 1 dendritic process (can branch at tip but not at cell body)
- 1 axon so info goes downwards
Has cell body between dendrite and axon
- small 30 micrometers
Special sense organs like sight smell hearing relay info from receptor to neuron
You see this type of neuron branching between neurons or involved in special sensory sight smell and hearing

73
Q

Unipolar neurons

A

Sensory nervous system - most sensory neurons are unipolar
Cell body is off to one side so dendrites and axon are connected and continuous
Very long 1m like motor nerves from cns to toe
Whole thing from where dendrites converge is axon

74
Q

Anaxonic neuron

A

Rare and function is poorly understood
Anatomy cannot distinguish axons from dendrites
Found in brain and special sense organs

75
Q

Neuroglia

A

Found in both cns and pns and makes a lot of tissue in cns
Makes up 50% of volume of cns glue
Smaller than neurons but more numerous 5-50x
Do not propogate action potentials but can communicate biochemically
Can divide within the mature nervous system

76
Q

Functions of neuroglia

A

Makes Physical structure if nervous tissue
Repairs the framework of nervous tissue by walling off damaged areas to enable scarring and prevents cavities from forming
Undertakes phagocytosis
Nutrient supply to neurons
Regulates intertitial fluid which is the environment in pns and cns in neural tissue

77
Q

Four classifications of cns Neuroglia

A

Astrocytes
Oligodendrocytes
Microglia
Ependymal cells

78
Q

5 functions and processes of astrocytes

A
  • star shaped and largest - most numerous of Neuroglia and has syncytium network which often links to itself via lots of different connections
  • support (have microfilaments) and repair by scarring
  • communicate with neurons via gliotransmitters like glutamate
  • maintain environment around neuron such as ion regulation
  • maintain blood brain barrier via the endothelium and wraps around vessels to influence permeability preventing some things from blood seeping into the brain
79
Q

Oligodendrocytes functions

A
  • form insulating multilayered myelin sheath which is a protein lipid layer) around cns axons which helps neurons conduct better and faster and less prone to interference - also can put out processes to make more than one neuron
  • can myelinate more than one neuron cells axon to accelerate action potential
80
Q

Function of microglia

A

Phagocytic (resident macrophages) for protection - engulfs materials
Removes damaged tissue of cns and is activated during infection

81
Q

Ependymal cells functions and processes

A
  • produce cerebrospinal fluid which bathes brain and spinal cord and provides nutrients and protection
  • line the cfs filled ventricles in brain and central canal of spinal cord
  • located in ventricles and in other locations where csf is found
  • csf mechanical buffer which moves nutrients and waste
  • single layer of predominately cuboidal cells have cilia flow and microvilli sampling
82
Q

Purpose of microvilli in ependymal cells

A

Make sure csf is in right conditions all the time and maintain composition

83
Q

Purpose of cilia flow in Ependymal cells

A

Need to move csf around openings in brain and spinal cord called ventricals which is where csf flows

84
Q

Two types of pns neuroglia

A

Schwann cells and satellite cells

85
Q

What are schwann cells

A

They are the pns version of cns Oligodendrocytes- they form insulating myelin sheath around axons or can support and surround several non myelinated axons
Note - one schwann cell per axon/neuron for myelination but more axons/cells if just support

86
Q

Purpose and function of satellite cells

A
  • surrounds neuron cell bodies and supports fluid - equivalent to astrocytes in cns

Biosci107 (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions