Intro to physiology and homeostasis

Question 1

What are the components of connective tissues?

Answer 1

1. Cells such as fibroblasts, adipocytes, mast cells, plasma cells, macrophages and infiltrated white blood cells during inflammation
2. Matrix containing protein fibres and ground substances like water and a variety of small and large molecules

Question 2

What are the responses to heat exposure?

Answer 2

• Decreased muscle tone (micro constriction)
• Skin vasodilation
• Sweating

Question 3

What is positive feedback?

Answer 3

When change in controlled variable is further enhanced to accelerate the initial process

Question 4

What are the functions of the skin?

Answer 4

• Protection: skin barrier impedes passage of most materials into body
• Participate in immune response
• Melanin production by melanocytes
• Temperature regulation

Question 5

What are the 2 types of connective tissues?

Answer 5

1. Connective tissue proper
   - loose: more cells, less protein fibres
   - dense: mainly densely packed collagen fibres and fewer cells
2. Special connective tissues: bone, blood and cartilage

Question 6

What are the 4 physical processes of heat gain/loss?

Answer 6

Radiation, conduction, convection and evaporation

Question 7

What is the main structure of the skin?

Answer 7

1. Epidermis: epithelial cells
   - inner layer: rapidly dividing
   - outer layer: flattened and dead
2. Dermis: mainly irregular dense connective tissue
   - rich in collagen and elastin fibres, blood vessels and nerve endings
3. Hypodermis
   - loose layer of connective tissue
   - place where most body fats are stored

Question 8

What are the 3 types of epithelial tissues?

Answer 8

Squamous, columnar and cuboidal in simple or stratified arrangement

Question 9

What are the homeostatic conditions?

Answer 9

• Concentration of nutrients
• Concentration of waste products
• Concentration of O2 and Co2
• Concentration of salt and electrolyte
• pH
• Temperature
• Volume and pressure

Question 10

How is body temperature controlled?

Answer 10

By thermoregulatory center in the hypothalamus that operates on a set point

Question 11

What are the components of negative feedback?

Answer 11

Sensor > afferent pathway > integrating center > efferent pathway > effector

Question 12

What is the basement membrane made up of?

Answer 12

1. Basal lamina: rich in collagen, laminin, proteoglycan and glycoproteins secreted by epithelial cells
2. Reticular lamina: rich in collagen fibres secreted by fibroblasts

Question 13

What are the responses to cold exposure?

Answer 13

• Shivering
• Vasoconstriction
• Brown fat activity

Question 14

What is the function of the cuboidal epithelium?

Answer 14

• Cube shaped
• Function: absorption, secretion and excretion
• Lines kidney tubules, salivary and pancreatic ducts

Question 15

What are the 4 types of tissues?

Answer 15

Muscular, epithelial, connective and nervous

Question 16

What are the 3 sides of epithelial tissues?

Answer 16

1. Apical surface (open surface)
2. Basal surface: connected to basement membrane
3. Lateral surface: connected by tight junctions, adheren junctions and gap junctions

Question 17

What are the functions of connective tissues?

Answer 17

• Connect cells and organs together
• Provide strong flexible support to tissues
• Stores body fluids and nourishes cells and organs
• Fill spaces, stores body fats and provides cushion
• Site of immune response
• Involved in wound healing, tissue remodelling and cancer metastasis

Question 18

What is negative feedback?

Answer 18

When change in controlled variable triggers a response which opposes change, driving the variable in opposite direction of initial change to maintain dynamic constancy

Question 19

What are the components of neural tissues?

Answer 19

1. Neurons that function to generate and transmit electrical signals
2. Supporting cells

Question 20

What is the feed forward mechanism?

Answer 20

Change that occurs in anticipation of a change in a controlled variable

Question 21

What are the 3 types of muscle tissues?

Answer 21

1. Skeletal muscle: long striated cells with multiple nuclei
2. Cardiac muscle: branching, striated cells, fused at plasma membranes
3. Smooth muscle: long spindle shaped cells, each with one nucleus

Question 22

What is the function of squamous epithelium?

Answer 22

• Flattened with prominent, protruding nucleus
• Function for filtration and diffusion
• Lines oral cavity, pulmonary alveoli and glomerulus of kidney

Question 23

What is homeostasis?

Answer 23

The maintenance of stable conditions of internal environment to maintain dynamic constancy

Question 24

How does the skin take part in immune response?

Answer 24

• Keratinocytes produce inflammatory cytokines and kill microbes
• Langerhands and granstein cells serve as APCs
• Connective tissue important site for immune response

Question 25

What is the body organisation and tissue types?

Answer 25

• Cells: smallest unit of life
• Tissues: consist of cells with similar structures and functions
• Organs: Consist of at least 2 primary tissues with different functions
• System: when organs from different body regions perform related functions

Question 26

What is the difference between simple and stratified arrangement?

Answer 26

• Simple: one cell thick, specialised for transport
• Stratified: composed of number of layers; specialised for protection

Question 27

What is the function of the columnar epithelium?

Answer 27

• Taller column shaped cells
• Function for absorption, secretion and excretion
• Lines digestive track and uterine tubes

Question 28

What are the mechanisms regulating homeostasis?

Answer 28

• Intrinsic control: regulated within organ
• Extrinsic control: regulatory mechanisms initiated outside organ alters activity of organ; accomplished by endocrine and nervous systems
• Negative and positive feedback, feed forward