Lecture 3 - Organs and Tissues Flashcards

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1
Q

What is a tissue?

A

A collection of cells of the same type that perform a common function

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2
Q

Name the major tissue types within the body

A
  1. Connective
  2. Muscular
  3. Nervous
  4. Epithelial
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3
Q

What does connective tissue do?

A
  1. Binds and supports parts of the body
  2. All have specialised cells, ground substance and protein fibers
  3. Ground substance is noncellular and ranges from solid to fluid
  4. The ground substance and protein fibers together make up the matrix of the tissue
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4
Q

What are the 3 main types of connective tissue?

A
  1. Fibrous
  2. Supportive
  3. Fluid
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5
Q

Types of fibrous connective tissue?

A

2 types - dense or loose, but both contain fibroblasts cells with a matrix of collagen and elastic fibres

Loose fibrous tissue is found supporting epithelium and many internal organs

Adipose tissue is a special loose fibrous tissue where fat is stored

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6
Q

Types of supportive connective tissue?

A

Cartilage - cells are in chambers called lacunae
Matrix is solid but flexible

3 types are distinguished by types of fibres

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7
Q

Types of fluid connective tissue?

A

Blood - contained in blood vessels

Lymph - contained in lymphatic vessels

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8
Q

What do adipose cells release?

A

Hormone, Leptin which down-regulates appetite

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9
Q

Supportive connective tissue - Cartilage - What are the 3 types that are distinguished by types of fibres? and where are they located?

A
  1. Hyaline Cartilage - fine collagen fibres
    Located at the nose, ends of long bones and fetal skeleton
  2. Elastic cartilage - more elastic fibres than cartilage fibres
    Located at the outer ear
  3. Fibrocartilage - strong collagen fibres
    Located at disks between vertebrae
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10
Q

Properties of supportive connective tissue - bone?

A
  • Cells are in chambers called lacunae
  • Matrix is solid and rigid that is made of collagen and calcium salts

2 types are distinguished by types of fibres
Compact - made of repeating circular units called osteons which contain the hard matrix and living cells and blood vessels
Located in shafts of long bone

Spongy - an open, latticework with irregular spaces
Located at ends of long bones

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11
Q

Properties of fluid connective tissue - blood?

A
  • Made of fluid matrix called plasma and cellular components that are called formed elements:
  • 3 formed elements:
    1. Red blood cells - cells that carry oxygen
    2. White blood cells - cells that fight infection
    3. Platelets - pieces of cells that clot blood
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12
Q

Fluid connective tissue - Lymph

A
  • Matrix is a fluid called lymph

- White blood cells congregate in this tissue

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13
Q

Properties of muscle tissue?

A
  • Allows for movement in the body

- Made of muscle fibres/ cells and protein fibres called actin and myosin

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14
Q

Different types of muscle tissue in humans?

A

There are 3 different types of muscle tissue in humans

  1. Skeletal
  2. Smooth
  3. Cardiac
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15
Q

Muscle tissue - skeletal

A

Appearance: Long, cylindrical cells, multiple nuclei striated fibres

Location: Attached to bone for movement

Nature: Voluntary movement

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16
Q

Muscle tissue - smooth

A

Appearance: spindle-shaped cell with one nucleus, lacks striations

Location: walls of hollow organs and vessels

Nature: Involuntary movement

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17
Q

Muscle tissue - Cardiac

A

Appearance: branched cells with a single nucleus, striations called darker striations called intercalated disks between cells

Location: heart

Nature: Involuntary movement

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18
Q

Properties of nervous tissue?

A
  • Allows for communications between cells through sensory input, integration of data and motor output

Made of 2 major cells
A. neurons
B. Neuroglia

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19
Q

Properties of neurons (nervous tissue)?

A
  • Made of dendrites, a cell body and an axon
  • Dendrites carry information toward the cell body
  • Axons carry information towards a cell body
20
Q

Properties of neuroglia (nervous tissue)?

A
  • A collection of cells that support and nourish neurons
  • Outnumber neurons 9:1
  • Examples are oligodendrocytes, astrocytes and microglia
21
Q

Properties of epithelial tissue?

A
  1. A group of cells that forms a tight, continuous network
  2. Lines body cavities, covers body surfaces and found in glands
  3. Cells are anchored by a basement membrane on one side and free on the other side
  4. Named after the appearance of cell layers and the shape of the cells
  5. There is transitional epithelium that changes in appearance in response to tension
22
Q

How do we name epithelial tissue?

A
  1. Number of cells layers
    Simple - 1 layer of cells
    Stratified - More than 1 layer of cells
    Pseudostratified - Appears to have layers but only has one layer
  2. Shape of cell
    Cuboidal - cube-shaped
    Columnar - column-shaped
    Squamous - flattened
23
Q

The integumentary system

A
  1. Includes the skin and accessory organs such as hair, nails and glands
  2. The skin has two main regions called the epidermis and the dermis
  3. Under the skin there is a subcutaneous layer between the dermis and internal structures where fat is stored
  4. Is important for maintaining homeostasis
24
Q

What are the functions of the integumentary system?

A
  1. Protects the body from physical trauma, invasion by pathogens and water loss
  2. Helps regulate body temperature
  3. Allows us to be aware of our surroundings through sensory receptors
  4. Synthesises chemicals such as Melanin and Vitamin D
25
Q

Two regions of the skin?

A
  1. Epidermis

2. Dermis

26
Q

Properties of the epidermis?

A
  1. The thin, outermost layer of the skin
  2. Made of epithelial tissue
  3. Cells in the uppermost cells are dead and become filled with keratin thus acting as a waterproof barrier
  4. Langerhans cells are a type of white blood cells that help fight pathogens
  5. Melanocytes produce melanin that lend to skin colour and protection for UV light
  6. Some cells convert cholesterol to Vitamin D
27
Q

Properties of the dermis?

A
  1. The thick, inner layer of the skin
  2. Made of dense fibrous connective tissue
  3. Contains elastic and collagen fibres
  4. Contains blood vessels, many sensory receptors and glands
28
Q

What are the accessory organs of the skin and why are they important?

A
  1. Includes hair, nails and glands
  2. Nails are derived from the epidermis that offer a protective covering
  3. Hair follicles are derived from the dermis but hair grows from epidermal cells
  4. Oil glands are associated with hair and produce sebum that lubricates hair and skin as well as retards bacterial growth
  5. Sweat glands are derived from the dermis and help to regulate body temperature
29
Q

Moving from tissue to organs and organ systems

A
  • An organ is 2 or more tissue types working towards a particular function
  • An organ system s a combination of organs that work together to carry out a particular function
30
Q

Integumentary system

A
  1. Protects body
  2. Receives sensory input
  3. Helps control temperature
  4. Synthesises vitamin D
31
Q

Cardiovascular system

A
  1. Transports blood, nutrients, gases and wastes
  2. Defends against disease
  3. Helps control temperature, fluid and pH balance
32
Q

Lymphatic and immune systems

A
  1. Help control fluid balance
  2. Absorb fats
  3. Defend against infectious disease
33
Q

Digestive system

A
  1. Ingests food
  2. Digests food
  3. Absorbs nutrients
  4. Eliminates waste
34
Q

Urinary system

A
  1. excretes metabolic wastes
  2. helps control fluid balance
  3. helps control pH balance
35
Q

Skeletal system

A
  1. supports the body
  2. protects body parts
  3. helps move the body
  4. stores minerals
  5. produces blood cells
36
Q

Muscular system

A
  1. maintains posture
  2. moves body and internal organs
  3. produces heat
37
Q

Nervous system

A
  1. Receives sensory input
  2. Integrates and stores input
  3. Initiates motor output
  4. Helps coordinate organ systems
38
Q

Endocrine system

A
  1. Produces hormones
  2. Helps coordinate organ systems
  3. Responds to stress
  4. Helps regulate fluid and pH balance
  5. Helps regulate metabolism
39
Q

Reproductive system

A
  1. Produces gametes
  2. Transports gametes
  3. Produces sex hormones
  4. Nurtures and gives birth to offspring in females
40
Q

Respiratory system

A
  1. Maintains breathing
  2. Exchanges gases at lungs and tissues
  3. Helps control pH balance
41
Q

What about the body membranes that line the cavities?

A
  • Mucous membranes - lining of the digestive, respiratory, urinary and reproductive systems
  • Serous membranes - line lungs, heart, abdominal cavity and cover the internal organs; named after their location
    Pleura - lungs
    Peritoneum - abdominal cavity and organs
    Pericardium - heart
  • Synovial membrane - lines the cavities of freely movable joints
  • Meninges - Cover the brain and spinal cord
42
Q

What is homeostasis?

A
  • The ability to maintain a relatively constant internal environment in the body
  • The nervous and endocrine systems are key in maintaining homeostasis
  • Changes from the normal tolerance limits result in illness or even death
43
Q

What are the mechanisms for maintaining homeostasis?

A
  • Negative feedback

- Positive feedback

44
Q

What is negative feedback?

A

The primary mechanism for maintaining homeostasis

Has 2 components

  • Sensor
  • Control center
  • The output of the system dampens the original stimulus
45
Q

What is positive feedback?

A
  • A mechanism for increasing the change of the internal environment in one direction
  • An example is the secretion of oxytocin during birth to continually increase uterine contractions
  • Can be harmful such as when a fever is too high and continues to rise