05. Animal Form and Function Flashcards

Question

What is thalamus comprised of?

Answer 1

Grey and white matter

Answer 2

It acts as the main input center of sensory information from special sense organs and special sense receptors in the skin and integral organs Sensory information is sorted and directed to specific locations in the cerebral cortex for processing and perception. It relates and distributes nerve impulses for most parts of the brain and cerebral cortex

Answer 3

Below and in front of the thalamus immediately above the pituitary gland.

Answer 4

Nerve fibers

Answer 5

A complex system of blood vessels (portal blood vessels)

Answer 6

Regulates body temperature Regulates thirst and water balance Regulates appetite Regulates sleep and wake cycles Controls the autonomic nervous system Initiates fight/flight response Source for posterior pituitary hormone and releasing hormones that act on the anterior pituitary Plays a role in sexual behavior

Answer 7

It is the upper part of the brainstem located in the cerebrum above and pons below surrounding the C.S.F fluid filled connection of third and fourth ventricles

Answer 8

Aggregates of nerve cell bodies and nerve tracts

Answer 9

Connects the cerebrum with the lower brain and spinal cord

Answer 10

Acts as a relay station for ascending and descending nerve fibers Receives and integrates sensory information (auditory and visual) and sends them to particular regions of the forebrain Coordinates auditory and visual reflexes

Answer 11

In front of cerebellum, below midbrain, above medulla oblongata

Answer 12

1. nerve fibers that form a bridge between two hemispheres of the cerebellum 2. nerve fibers passing between higher levels of the brain and spinal cord 3. groups of nerve cell bodies

Answer 13

centers that regulate respiration some act as relay stations

Answer 14

Transferring information between PNS and midbrain and forebrain Coordinating large scale body movements like running and climbing Together with medulla oblongata, helps regulate respiration

Answer 15

Lowest part of the brain stem which extends from the pons above and continuous with the spinal cord below

Answer 16

Respiratory center Cardiovascular center Reflex center

Answer 17

Transfers information between PNS and midbrain and forebrain Coordinates various body movements like running and climbing

Answer 18

It is located behind the pons varoli below the posterior portion of the cerebrum

Answer 19

Two hemispheres

Answer 20

coordinates voluntary muscle movements Maintains posture and balance Helps in learning and remembering motor skills

Answer 21

Coordinates large scale body movements like running and climbing Helps to regulate respiration

Answer 22

Act as a relay station

Answer 23

Links the central nervous system to sensory and motor neurons Facilitates nerve impulse propagation towards and away from the brain Coordinates and produces reflexes

Answer 24

central canal (surrounded by grey matter) outer region (made of white matter)

Answer 25

Cranial nerves Spinal nerves Autonomic nervous system (with ganglia)

Answer 26

It transmits impulses to and from the CNS Regulates both animal movement and its internal environment

Answer 27

Dealing with stressful or exciting situations and energy generating situations (Fight/Flight)

Answer 28

Only from the spinal cord

Answer 29

Norepinephrine

Answer 30

Causes opposite responses to sympathetic stimulations that promote calming or a return-to-self maintenance functions Rest and digest

Answer 31

Overall functions Organization Signal released

Answer 32

Spinal cord as spinal nerves or cranial nerves At the base of the brain

Answer 33

Acetylcholine

Answer 34

Bring about opposite effects in different organs such as lung, heart, intestine and bladder.

Answer 35

Constricts eye pupil Constricts bronchi in lungs Slows heart

Answer 36

Stimulates activity of stomach and intestines Stimulates activity of pancreas Stimulates gall bladder

Answer 37

Promotes emptying of bladder Promotes erection of genitalia

Answer 38

1. Dilates pupil eye 2, Inhibits salivary gland secretion 3. Relaxes bronchi in the lungs 4. Accelerates the heart rate 5. inhibits the activity of the stomach and the intestines 6. Inhibits the activity of pancreas 7. Stimulates glucose release from liver inhibits the gall bladder 8. Stimulates adrenal medulla 9. inhibits emptying the bladder 10. promotes ejaculation and vaginal contractions

Answer 39

1. Diameter of the axon- The conduction increases with increase in the axon diameter 2. Presence of myelinated axon- axon potential jumps from one node of Ranvier to next

Answer 40

1. Acetylcholine 2.some amino acids 3. Biogenic amines 4. Neuropeptides 5. Some gases

Answer 41

taste and olfactory receptors To Detect specific chemicals such as CO2 circulating in the blood

Answer 42

taste and olfactory receptors Detect specific chemicals such as CO2 circulating in the blood

Answer 43

Upper portion of the epithelium of the nasal cavity

Answer 44

Skin - detect the body surface temperature Hypothalamus - detects the temperature of the blood circulating through internal organs

Answer 45

Krause end bulbs detect cold Rufinicorpuscles detect warmth Free nerve endings detect both the warm and cold

Answer 46

Specialized neurons

Answer 47

Touch receptors Pressure receptors Vibration receptors

Answer 48

Meissner corpuscles - sensitive to light pressure Merkel disks - sensitive to light touch Free nerve endings

Answer 49

1. Epithelial tissue 2. Connective tissue 3. Muscle tissue 4. Nerve tissue

Answer 50

*It covers external or internal free surfaces and organs. *The cells of the tissues are closely packed. * Cells of epithelial tissue have both apical and basal surfaces where apical surface remains free and the basal surface attached to the basement membrane. *No blood vessels in the tissue. *Tissue gets nutrients and oxygen from the underneath connective tissue.

Answer 51

Protection (e.g. barrier against mechanical injury, pathogens, barrier against ﬂuid loss Secretion (e.g. enzymes, hormones, mucus, sweat) Absorption (e.g. nutrients, respiratory gases ) There are two general types according to the number

Answer 52

1. Simple epithelia 2. Compound epithelia

Answer 53

1. They are thin and leaky 2. Found in places where materials exchange by diffusion

Answer 54

Blood capillaries Alveoli

Answer 55

1. Dice shaped cells 2. Specialized for secretion 3.

Answer 56

Kidney tubules Glands like thyroid and salivary glands

Answer 57

Kidney tubules Glands like thyroid and salivary glands

Answer 58

1. Single cell layer 2. Large brick shaped cells 3. Found in places where secretion or active absorption is important

Answer 59

Intestinal lining

Answer 60

This tissue consists of a single cell layer. Cells are not of equal height. Nuclei of cells are located at different level. Appear as several layers. In many vertebrates this epithelium has ciliated cells that form a mucous membrane and the cilia help to sweep the mucous along the surface.

Answer 61

Nasal passage trachea

Answer 62

This tissue is composed of a number of layers of cells. This epithelium regenerates rapidly. Cell division produces new cells near the basement membrane. The old cells are sloughed off and replaced by the new cells .

Answer 63

on surfaces where they are subjected to abrasion such as outer skin, lining of mouth, anus, vagina

Answer 64

Connective tissues are the most abundant tissues in the body that help to connect organs and tissues together structurally and functionally. These types of tissue consist of different types of cells scattered in a large amount of extracellular matrix containing different types of ﬁbers. Matrix may be a semisolid (Jelly-like), liquid or solid (dense and rigid). Different types of cells can be found in the matrix such as ﬁbroblasts (secrete ﬁber proteins), macrophages (engulf foreign particles or any cell debris by phagocytosis) and mast cells ( secrete heparin and histamine) in addition fat cells (storage and insulation) and leukocytes (protection) are found in some connective tissues. There are three different types of ﬁbers. They are collagen ﬁbers (provide strength and ﬂexibility), reticular ﬁbers (join connective tissues to adjacent tissues) and elastic ﬁbers (make tissue elastic).

Answer 65

Binding and structural support Protection Transport of materials Insulation

Answer 66

loose connective tissue (Areolar tissue) Fibrous connective tissue (Dense connective tissue) adipose tissue, blood cartilage bone .

Answer 67

This tissue is the most widely distributed connective tissue type in the vertebrate body. This can be considered as the generalized type of connective tissue. Types of cells in this tissue are ﬁbroblasts, macrophages, mast cells, leukocytes and fat cells. All three types of ﬁbers are found in this tissue. Fibers are loosely arranged and wavy in nature

Answer 68

This tissue binds epithelia and the underlying tissue. Therefore this holds organs in place.

Answer 69

under the skin and throughout the body

Answer 70

This tissue is densely packed with collagen ﬁbers. Therefore the matrix is relatively reduced contains fewer cells (ﬁbrocytes)

Answer 71

tendons (attach muscle to bones) ligaments (connect bones and joints) (Here, the tensile strength is required)

Answer 72

This tissue is packed with adipose cells. Each adipose cell contains a large fat droplet. This is a specialized type of loose connective tissue which pads and insulates the body and stores fuel as fat molecules.

Answer 73

act as a thermal insulator energy store.

Answer 74

under the skin

Answer 75

Specialized connective tissue The matrix is not secreted by the cells Fibers are formed only during blood clotting process. The extracellular matrix of the blood is liquid. It is called as plasma. The blood plasma contains salts, water and dissolved proteins. Red blood cells (transport respiratory gases), white blood cells (defense) and platelets (blood clotting) are suspended in the blood plasma.

Answer 76

Transport of materials protection osmoregulation.

Answer 77

This tissue consists of a matrix composed of chondroitin sulphate which is a rubbery protein-carbohydrate complex. Collagen ﬁbers and chondrocytes are embedded in the matrix. Chondrocytes secrete chondroitin sulphate and collagen ﬁbers.

Answer 78

This tissue provides support and ﬂexibility in places such as trachea, intervertebral discs.

Answer 79

It is a mineralized connective tissue. Matrix consists of collagen ﬁbres and inorganic salts. Inorganic salts are Calcium, magnesium and phosphate ions. Cells are osteoblasts (bone forming cells) and osteocytes (mature bone cells that maintain bone tissue). Osteocytes are enclosed within lacunae. The mammalian hard bone has repeating units called osteons. Each osteons has a concentric layer of mineralized materials.

Answer 80

Each osteons has a concentric layer of mineralized materials. At the center of the osteon is a central canal containing blood vessels and nerves.

Answer 81

This tissue forms the endoskeleton of most vertebrates Provides support and strength to the body.

Answer 82

Muscle tissue is responsible for movement

Answer 83

The cells in the muscle tissue are composed of actin and myosin proteins. This tissue is able to contract and relax.

Answer 84

smooth muscle skeletal muscle cardiac muscle tissues.

Answer 85

The cells of the smooth muscle tissue are spindle shaped and uninucleated. Cells lack striations. This tissue is responsible for involuntary body functions (e.g. churning of stomach, constriction of arteries)

Answer 86

digestive tract urinary bladder arteries other internal organs.

Answer 87

They are composed of bundles of long cells with multi nuclei. Cells are striated. The contractile units of this muscle cells are called sarcomeres. The arrangement of the sarcomere gives the striated appearance The muscles are generally attached to the skeletal system

Answer 88

Helps in voluntary muscle movement

Answer 89

They are composed of uninucleated cells They are interconnected via intercalated discs. Cells are striated with sarcomeres. Intercalated disks help relay signals from cell to cell and synchronize heart contraction

Answer 90

Intercalated disks help relay signals from cell to cell and synchronize heart contraction

Answer 91

only found in the wall of the heart.

Answer 92

Neurons Glial cells

Answer 93

Neurons receive, process and transmit nerve impulses.

Answer 94

Cell body dendrites axon

Answer 95

Nervous tissue

Answer 96

Dendrites and cell body is used to receive nerve impulses from other neurons.

Answer 97

Axon is used to transmit impulses to other neurons, cells or muscles. Axons are bundled together into nerves

Answer 98

Neuroglial cells are supportive cells of neurons

Answer 99

nourishment of nerve cells insulation of nerve cells replenishing neurons and sometimes modulate neuron functions. (n i r s)

Answer 100

animals fungi majority of bacteria

Answer 101

1. Holozoic nutrition 2. Symbiosis

Answer 102

1. Ingestion 2. Digestion 3. Absorption 4. Assimilation 5. Egestion

Answer 103

1. Diet 2. environment

Answer 104

1. Mechanically (teeth or muscle contractions) 2. Chemically (by enzymes)

Answer 105

Clams Oysters

Answer 106

feed on small pieces of food in the water that passes over their gills. Cilia in the gills sweep the food particles to the animal’s mouth in a ﬁlm of mucus.

Answer 107

Mosquitoes-suck human blood Aphids- suck phloem sap of plants Bees and humming birds suck -honey from ﬂowers

Answer 108

Most animals including humans

Answer 109

jaws teeth tentacles claws poisonous fangs

Answer 110

*Cellulose digesting microorganisms in Ruminants and Termites

Answer 111

Tape worm and humans Lice and humans

Answer 112

Barnacles attached to the whales

Answer 113

Barnacles attached to the whales

Answer 114

Parasites live either within or on the host and derive its nourishment

Answer 115

Alimentary canal associated glands

Answer 116

Oral cavity pharynx esophagus stomach small intestine large intestine rectum anus

Answer 117

salivary glands pancreas liver

Answer 118

This makes it easier to swallow food increase the surface area for digestion.

Answer 119

This makes it easier to swallow food increase the surface area for digestion.

Answer 120

Releasing saliva into the oral cavity occurs when food enters the oral cavity due to a nervous reﬂex. Saliva is also released into the mouth before food is ingested due to various other stimuli. e.g. sight, odor of food, etc.

Answer 121

water, amylase, mucus (a viscous mixture of salts, cells and slippery glycoprotein called mucins), buffers and anti microbial components.

Answer 122

• Salivary amylase: Chemical digestion of polysaccharides (e.g. starch) into smaller polysaccharides and disaccharide maltose. • Water: Liquefy food and provide watery medium for chemical digestion. Aids in taste reception. • Mucus: Lubrication of food which makes it easier for swallowing. Clean the mouth and protects the lining of the mouth from abrasion. • Antimicrobial substances such as immunoglobulin and lysozymes: Protect against bacteria that enter the mouth. • Buffers prevent tooth decay by neutralizing acid

Answer 123

Helps to mix the food with saliva and make bolus of food that makes easier for swallowing. Then helps to push the bolus into the posterior part of the oral cavity and into the pharynx.

Answer 124

a common passage of the respiratory tract and the digestive tract. The pharynx leads to the esophagus.

Answer 125

Both skeletal and smooth muscles

Answer 126

located towards the uppermost part of the esophagus and these muscles function during swallowing

Answer 127

Smooth muscles that are involved in the process of peristalsis During this process the food bolus is pushed along the esophagus which is a alternative wave of rhythmic contractions and relaxations of the smooth muscles lining the esophagus.

Answer 128

The stomach is a J- shaped dilated sac in the abdominal cavity.

Answer 129

The inner surface of the stomach is highly folded and contains large number of pits that leads to gastric glands.

Answer 130

mucus cells chief cells parietal cells.

Answer 131

It is very elastic

Answer 132

With the small intestine

Answer 133

Sphincters are found at the junctions between esophagus and stomach (cardiac sphincter) Junction between the stomach and the small intestine(pyloric sphincter). They are made up of circular smooth muscles.

Answer 134

These sphincters help to regulate the passage of materials between these organs.

Answer 135

Gastric glands

Answer 136

mucus pepsinogen HCl

Answer 137

Mucus cells

Answer 138

Chief cells

Answer 139

Parietal cells release hydrogen ions and chloride ions separately into the stomach lumen where HCl is formed. Pepsinogen is initially converted into pepsin by HCl.

Answer 140

help to activate remaining pepsinogen molecules. This activated pepsin initiates the chemical digestion of proteins in the stomach.

Answer 141

It Initiates the chemical digestion of proteins in the stomach. The churning action of the stomach facilitates the chemical digestion. This is a series of muscle contraction and relaxation. This process mixes the swallowed food with gastric juice.

Answer 142

Into small polypeptides by pepsin

Answer 143

In the stomach food is mixed with gastric juice forming chyme (partially digested semisolid, acidic, food mass).

Answer 144

Enzymes are secreted in to the lumen as an inactive enzyme; Gastric glands secrete mucus that protect against self-digestion of the stomach lining ; Every three days, cell division adds a new epithelial cell layer which replaces the destroyed/ damaged cells in the lining of the stomach.

Answer 145

• Act as a temporary reservoir for food due to high convolution and very elastic wall. • Mechanical digestion of food by churning action due to muscular contraction. • Produce gastric juice which starts the chemical digestion of proteins to polypeptide by pepsin • Absorption of some materials such as water, alcohol and some drugs • Non speciﬁc defense-HCl kills microbes • Small jets of gastric contents push out through pyloric sphincter as chyme • Secretion of gastrin hormone which regulates digestion in the stomach.

Answer 146

Small intestine

Answer 147

1. C shaped curve, around the head of the pancreas. Most of the digestion is completed in the duodenum. 2. The jejunum is middle part of the small intestine. (The major sites for nutrient absorption are jejunum and ileum. ) 3. The ileum is the terminal part of the small intestine. (The major sites for nutrient absorption are jejunum and ileum.)

Answer 148

by permanent circular folds and villi. The villi are tiny ﬁnger like projections of the intestinal wall

Answer 149

Small intestine receives chyme from the stomach.

Answer 150

Peristaltic contractions

Answer 151

pyloric sphincter

Answer 152

The chyme is mixed with secretions of glands in intestinal wall and secretions of pancreas and liver.

Answer 153

several digestive enzymes. Glands of the intestinal wall secrete enzymes such as Disaccharidases, Dipeptidases, Carboxypeptidases, Aminopeptidases, Nucleotidases, Nucleosidases and Phosphotases. (CANCLT)

Answer 154

cholecystokinin secretin

Answer 155

release of pancreatic juice

Answer 156

Stimulates the bile secretion

Answer 157

enzymes such as Trypsin, Chymotrypsin , Pancreatic amylase , Pancreatic Carboxypeptidases, Pancreatic Nucleases and Pancreatic Lipases (CANCLT) ad bicarbonates in addition

Answer 158

Gall bladder, until released into the duodenum

Answer 159

Bile salts

Answer 160

act as emulsiﬁers that help in fat digestion and absorption.

Answer 161

Pancreatic amylase catalyze the conversion of polysaccharides (e.g. starch) into disaccharides. Intestinal disaccharidases catalyze the conversion of disaccharides into monosaccharides

Answer 162

Tripsin and Chymotripsin catalyse the conversion of small polypeptides into smaller polypeptides. These smaller polypeptides are converted to small peptides and amino acids by the catalytic action of Panceratic carboxypeptidases. Proteases secreted by the intestinal epithelium (Dipeptidases, Carboxypeptidases and Aminopeptidases) catalyse the conversion of small peptides into amino acids.

Answer 163

Digestion of fats (triglycerides) starts in the small intestine. First bile salts emulsify fats. Next Pancreatic lipase catalyse the conversion of these fats into fatty acids, glycerol and monoglycerides.

Answer 164

Digestion of nucleic acids start in the small intestine. Pancreatic nucleases catalyse the conversion of DNA and RNA into nucleotides. These nucleotides are eventually converted into nitrogenous bases, sugars and phosphates by the catalytic action of intestinal Nucleotidases, Nucleosidases and Phosphatases.

Answer 165

For effective absorption, the surface area of the intestinal wall has been increased with three structural modiﬁcations: *heavy permanent foldings, *ﬁnger like projections called villi in the intestinal wall *ﬁnger like microscopic projections called microvilli in the epithelial cells of the villi. These micro villi are exposed into the intestinal lumen, it gives the appearance of brush (brush border).

Answer 166

Active Passive

Answer 167

By facilitated diffusion

Answer 168

Amino acids Small peptides Vitamins Most glucose molecules

Answer 169

nutrients from the epithelial cells are transported into the blood capillaries in the villi blood capillaries are converged into the hepatic portal veins nutrients are carried in to the liver via the hepatic portal veins. from the liver, this nutrient ﬁlled blood is transported into the tissues. { Nutrients in the epithelial cells -> hepatic portal vein -> liver -> tissues }

Answer 170

Fatty acids and monoglycerides are absorbed into the cell through microvilli. Within the cells triglycerides are reformed and they are incorporated into water soluble globules called chylomicrons. These chylomicrons are transported into the lacteal and then into the blood vessels through lymph. Then they are transported throughout the body via the circulatory system. { fats and monoglycerides -> turns to water soluble globules called chylomicrons -> lacteals -> lymph -> blood vessels -> c.v.s }

Answer 171

The large intestine is the terminal end of the alimentary canal.

Answer 172

colon (proximal part) cecum rectum

Answer 173

at a ‘T’ shaped junction.

Answer 174

The colon leads to the rectum and anus.

Answer 175

for fermentation of indigested materials by microbes, especially in animals that eat large amount of plant matter.

Answer 176

completes the reabsorption of water synthesize some Vitamin B complexes Vitamin K and folic acid with the help of microbes move feces (consists of undigested matter such as ﬁbres) along the colon by peristalsis.

Answer 177

Stores feces until they are eliminated Presence of two sphincters between the rectum and anus can regulate feces movement Strong contractions in the colon trigger the defecation

Answer 178

The pancreas is a pale grey gland which consists of a broad head, a body and a narrow tail. Head is in the curve of the duodenum. Pancreas is both an exocrine and endocrine gland.

Answer 179

The exocrine part consists of a large number of lobules made up of small acini, the walls of which consist of secretary cells. Each lobule is drained by a tiny duct and these unite eventually to form the pancreatic duct which joins with bile duct to form hepato pancreatic duct and opens into the duodenum at its midpoint

Answer 180

Exocrine part of the pancreas secretes pancreatic juice. The components of the pancreatic juice are bicarbonate, carbohydrate digesting enzymes (pancreatic amylase), pancreatic lipase, nucleases and inactive form of protein digesting enzymes (trypsinogen and chymotrypsin). These inactive enzymes are converted to active enzymes(trypsin and chymotrypsin) upon secretion into the lumen of the duodenum.

Answer 181

Endocrine part of the pancreas is the islets of Langerhans, which consist of group of specialized cells. They do not have ducts

Answer 182

*Islets of Langerhans secrete hormones, glucagon and insulin which are involved in glucose homeostasis.

Answer 183

Its upper and anterior surfaces are smooth and convex. Its posterior surface is irregular in outline

Answer 184

lobules are made up of cuboidal cells called hepatocytes which are arranged in pairs of columns radiating from a central vein.

Answer 185

Between two pairs of column of cells there are sinusoids (blood vessels with incomplete walls) containing mixture of blood from the tiny branches of the portal vein and hepatic artery.

Answer 186

Hepatic macrophages (Kupffer cells)

Answer 187

Larger bile canals

Answer 188

a branch of hepatic artery a branch of the hepatic portal vein intra lobular bile duct

Answer 189

food digestion perform functions such as metabolism of carbohydrates, fats and proteins detoxiﬁcation of drugs and toxic substances defense against microbes, some hormone inactivation heat production.

Answer 190

The liver secretes bile which is stored in the gall bladder until released into the duodenum. The bile contains bile salts which act as emulsiﬁers that help in fat digestion and absorption. Most of the absorbed nutrients reach the liver and it regulates the distribution of nutrients to the rest of the body. Excess glucose is stored as glycogen in the liver cells. Glycogen deposition and break down in the liver cells are regulated by insulin and glucagon hormones. Fat soluble Vitamins (A,D,E and K) and some water soluble vitamins (B12), iron and copper are also stored in liver. (KADE)

Answer 191

1. Nervous regulation 2. Endocrine regulation

Answer 192

nervous reﬂex stimulates the release of saliva when food reach the mouth. Arrival of food in the stomach trigger churning and release of gastric juices.

Answer 193

*Endocrine system plays a critical role in digestion especially in the stomach and small intestine. *When food arrives the stomach, the stomach wall is stretched. This triggers to release the hormone gastrin. Gastrin circulates via the blood stream and arrives the stomach. Then gastrin stimulates the production of gastric juice at the stomach.

Answer 194

Fatty acids and amino acids in the chyme

Answer 195

Cholecystokinin triggers release of bile from the gall bladder and digestive enzymes from the pancreas

Answer 196

Secretin stimulates the release of bicarbonate from the pancreas.

Answer 197

Bicarbonate neutralize the chyme received from the stomach

Answer 198

Food digestion in the stomach slows down due to high levels of Cholecystokinin and Secretin secreted by duodenum. These hormones act on the stomach and inhibit peristalsis and gastric juice secretion.

Answer 199

*Carbohydrates • Proteins • Lipids • Vitamins • Mineral elements • water • ﬁbers

Answer 200

*sugars *polysaccharides (in rice and bread)

Answer 201

*Provide energy and heat: breakdown of carbohydrates provides ATP for body functions and generates heat. * Act as an energy stores. e.g. excess carbohydrates are converted into glycogen and fat * Facilitates protein sparing- proteins are not used to get energy when there is an adequate carbohydrates in the food

Answer 202

Amino acids

Answer 203

proteins are broken down into amino acids absorbed into the blood stream.

Answer 204

essential amino acids non essential amino acids

Answer 205

• are used for growth and repair of body cells and tissues • are used for synthesis of plasma proteins, enzymes, antibodies and some hormones (pahe) • Act as an energy source for body functions

Answer 206

Essential fatty acids Non essential fatty acids

Answer 207

• Provide energy and heat (on weight basis fats and oils provide more energy compared to carbohydrates and proteins) • Help in transport and storage of fat soluble vitamins such as Vitamin A, D, E and K • Store energy as fat in the adipose tissues • Help to synthesize steroid hormones from cholesterol. • Provide insulation: (ex. fat found in subcutaneous layer in the skin reduces heat loss , constituents of myelin sheath of neurons)

Answer 208

fat soluble vitamins (Vitamin A, D, E and K) water soluble vitamins (Vitamin B and C).

Answer 209

form visual pigments in the eye epithelial tissue maintenance, promotion of growth and immunity

Answer 210

components of coenzymes such as FAD and NAD, promote red blood cell production

Answer 211

act as an antioxidant used in collagen synthesis

Answer 212

aids in absorption and use of Calcium and Phosphorous

Answer 213

act as an antioxidant

Answer 214

It is important in blood clotting

Answer 215

form bones and teeth helps clotting blood nerve and muscle function

Answer 216

Vitamin C and vitamin E

Answer 217

form bones and teeth help maintain in acid base balance

Answer 218

components of some amino acids

Answer 219

help maintain in acid base balance and water balance nerve function

Answer 220

help maintain in acid base balance maintain osmotic balance nerve function

Answer 221

help maintain in acid base balance and water balance nerve function

Answer 222

act as enzyme cofactor

Answer 223

Components of hemoglobin electron carriers act as an enzyme cofactor

Answer 224

maintenance of tooth structure

Answer 225

component of thyroid hormone

Answer 226

Urine Sweating Feces

Answer 227

drinking food

Answer 228

• Provides the moist internal environment for all living cells. • Major component of blood and tissue ﬂuid therefore helps to transport materials around the body and to exchange materials between blood and tissues and body cells • Regulate body temperature mainly through evaporative cooling • Dilute waste products and toxins and provide a medium for their excretion • Moisten the food and that make easier to swallow

Answer 229

indigestible polysaccharides

Answer 230

indigestible polysaccharides

Answer 231

indigestible polysaccharides

Answer 232

• Provide bulk to the diet and satisfy the appetite. • Prevent constipation by attracting water to increase faecal bulk and stimulating peristalsis leading to defecation. • Adequate ﬁbres in the diet protect against some gastro-intestinal disorders such as cancers in the colon and rectum.

Answer 233

essential amino acids, essential fatty acids, vitamins minerals.

Answer 234

key functions in bio synthetic reaction in the body cells. If these essential nutrients are not supplied in correct proportions in the diet that will lead to malnutrition. Therefore it is essential to obtain them in correct amounts.

Answer 235

Leucine and methionine.

Answer 236

Diabetes mellitus cardiovascular diseases some cancers

Answer 237

Mass/ height^2(kg/ m2)

Answer 238

In gastritis, glands of the stomach wall are stimulated and secrete excess HCl causing damage to the mucosa. Due to the damages of mucosa layer of the stomach, blisters can be formed.

Answer 239

Prolonged starvation mental stress Some drugs like asprin

Answer 240

Helicobacter pylori

Answer 241

prolonged starvation

Answer 242

proper food habits should be practiced

Answer 243

Inhibition of the reﬂex action in defecation

Answer 244

pain in the anus and difﬁculty in defecating

Answer 245

by developing behavioral adjustments to carry out defecation properly

Answer 246

Intake of adequate ﬁber in the diet can help prevent constipation.

Answer 247

As organisms increase in size and complexity, the amount of materials moving in and out of the body also increases. The distance that materials have to be transported within the body also increases and many cells are not in direct contact with their external environment. Therefore diffusion is not sufﬁcient to transport materials throughout the body. Therefore circulatory systems have evolved

Answer 248

*A circulatory system is required in animals for transportation of materials within the body and exchange of materials with the external environment. *The simple animals (e.g. Cnidarians, Flat worms) lack specialized system for the transport and distribution of material because many or all cells are in direct contact with the external environment.

Answer 249

respiratory gases (oxygen, carbon dioxide) nutrients (glucose, amino acids, fatty acids, vitamins, etc.),-VAGF waste products of metabolism (urea, ammonia, etc) hormones antibodies

Answer 250

A muscular pumping device (heart), interconnected vessels circulatory ﬂuid (blood/ hemolymph).

Answer 251

1. Open CVS 2. Closed CVS

Answer 252

1. Open CVS 2. Closed CVS

Answer 253

Mollusca Arthropoda

Answer 254

Vertebrates Invertebrates like annelids

Answer 255

arteries veins capillaries.

Answer 256

Bony ﬁshes, Cartilagenous ﬁshes such as rays and sharks.

Answer 257

Amphibians, Reptiles, Aves, Mammals.

Answer 258

Amphibians and most reptiles

Answer 259

Birds Mammals

Answer 260

Double circulation is more effective in supplying blood to all body organs and tissues especially brain and muscles due to the higher pressure exerted by the heart in the systemic circulation. This in contrast to single circulation where blood ﬂows under reduced pressure from the gas exchange organs to other organs.

Answer 261

Oxygen poor blood from trunk and hind limbs is drained into the inferior vena cava and oxygen poor blood from the head, neck and fore limbs are directed into the superior vena cava.

Answer 262

capillary beds where O2 rich blood is diffused into the tissues while the CO2 rich blood diffused into the blood capillaries

Answer 263

The lymphatic system is closely connected with the blood circulatory system both structurally and functionally. It consists of lymph vessels through which lymph travels.

Answer 264

The lymphatic system is closely connected with the blood circulatory system both structurally and functionally. It consists of lymph vessels through which lymph travels.

Answer 265

lymph nodes lymphoid tissues (tonsils) lymphoid organs (e.g. spleen and thymus).

Answer 266

tiny vessels larger vessels.

Answer 267

tiny vessels (Tiny lymph vessels are in close contact with the capillaries of the blood circulatory system) larger vessels.

Answer 268

connective tissues white blood cells.

Answer 269

returns lost ﬂuid and proteins from the blood capillaries back into the blood tissue drainage to maintain the blood volume in the blood circulatory system - absorption of fat and fat soluble vitamins from the small intestine - for immune responses.

Answer 270

The lost ﬂuid from the blood capillaries is called lymph when they are inside the lymphatic system

Answer 271

same as interstitial ﬂuid

Answer 272

It prevents the backﬂow of the lymph

Answer 273

That prevents the backﬂow of the lymph.

Answer 274

The lymph is drained into veins at the base of the neck via two large ducts The rhythmic contraction of the lymph vessel walls and skeletal muscle contraction help to move the lymph.

Answer 275

Pericardium Myocardium Endocardium

Answer 276

outer ﬁbrous pericardium inner serous pericardium.

Answer 277

It is composed of specialized cardiac muscle found only in the heart

Answer 278

Two ventricles Two atria

Answer 279

takes oxygen poor blood to the respiratory surface, the lungs and returns the oxygen enriched blood back to the heart

Answer 280

Pulmonary circuit Systemic circuit

Answer 281

papillary muscles

Answer 282

prevents the valves from being turned inside out

Answer 283

found at the points where the pulmonary artery and aorta leave the right and left ventricles respectively.

Answer 284

These valves prevent the backﬂow of blood into the ventricles.

Answer 285

Two pulmonary arteries with oxygen poor blood leave the heart from the upper part of the right ventricle

Answer 286

Two pulmonary veins from each lung carry oxygen rich blood back to the left atrium.

Answer 287

The aorta with oxygen rich blood leaves from the upper part of the left ventricles.

Answer 288

The aorta with oxygen rich blood leaves from the upper part of the left ventricles.

Answer 289

The superior vena cava and inferior vena cava open into the right atrium and empty their contents into the right atrium

Answer 290

The heart is supplied with arterial blood by the right and left coronary arteries

Answer 291

the aorta immediately after the aortic valve

Answer 292

both sympathetic and parasympathetic nerve ﬁbers

Answer 293

adrenaline and thyroxine

Answer 294

Small group of specialized neuromuscular cells in the myocardium

Answer 295

• SA node (Sinoatrial node) • AV node (Atrioventricular node) • Atrioventricular bundle (bundle of His), bundle branches and Purkinje ﬁbres

Answer 296

The stimulus for contraction of the heart originates in the ‘SA node’. The SA node initiates the heart beat and sets the rhythm of the heart beat so it is called the pace maker.

Answer 297

It lies in the myocardium of the right atrium near the opening of the superior vena cava

Answer 298

by the stimulation from the autonomic nervous system, hormones such as adrenaline, thyroxine temperature.

Answer 299

between wall of the left and right atria

Answer 300

transmits the electrical signals from the atria into the ventricles

Answer 301

from the AV node

Answer 302

ﬁbrous rings that separate atria and ventricle at the upper end of the ventricular septum

Answer 303

transmit electrical impulse from the AV node to the apex of the myocardium. As a result of this impulse, wave of ventricular contractions begin. Then the contraction sweeps upwards and outwards pumping blood simultaneously into the pulmonary artery and the aorta.

Answer 304

1. Atrial systole – Contraction of the atria 2. Ventricular systole - Contraction of the ventricles 3. Complete cardiac diastole – Relaxation of the atria and ventricles

Answer 305

The superior vena cava the inferior vena cava

Answer 306

4 pulmonary veins

Answer 307

the ventricular muscles via the AV bundle the bundle branches, and Purkinje ﬁbers

Answer 308

The sequence of opening and closing of valves ensure that blood ﬂows only in one direction.

Answer 309

the spread of the electrical signal generated by the SA node as it travels throughout the heart.

Answer 310

It represents the impulse from the SA node as it sweeps over the atria (atrial depolarization).

Answer 311

It represents rapid spread of impulse from the AV node throughout the ventricles and electrical activity of the ventricular muscles.( ventricular depolarization)

Answer 312

Represents ventricular repolarization and relaxation of the ventricular muscles.

Answer 313

atrial repolarization which occurs during ventricular contraction

Answer 314

Information about the heart function of a person ( state of the myocardium and the cardiac conduction system)

Answer 315

the essential ﬂow of blood into and out of the organs of the body

Answer 316

High blood pressure could lead to damage blood vessels resulting in formation of clots or bleeding from damaged sites. If the blood pressure falls too low, there will be inadequate blood ﬂow through tissue capillary beds. This will adversely affects the normal functioning of vital organs such as the brain, heart and kidneys.

Answer 317

according to: the time of day the posture gender age activity exercise stress (Emotional states) of an individual

Answer 318

Blood pressure falls at rest and during sleep

Answer 319

Blood pressure increases during excitement, fear or anxiety

Answer 320

sphygmomanometer

Answer 321

Systolic pressure (mm Hg) / Diastobic pressure (mm Hg)

Answer 322

kidney damage adrenal gland disorders heart attack (because of the increased heart rate and cardiac contraction) stroke(caused by cerebral hemorrhage) damaged blood vessels which can lead to death

Answer 323

• Obesity • Diabetes mellitus • Family history • Smoking • A sedentary life style • High intake of salts • High intake of alcohol • Stress • Deposition of low density lipoprotein (LDL) on artery walls

Answer 324

shock dengue hemorrhage fever standing up suddenly from sitting or lying position over bleeding/ hemorrhage condition fasting low nutrition

Answer 325

inadequate blood supply to the brain depending on the cause unconsciousness may be brief (fainting) or prolonged possibly causing death

Answer 326

Atherosclerosis -> Thrombosis -> heart muscle will be deprived of oxygen and nutrients -> chest pain (angina) -> myocardial infarction

Answer 327

Depending on the place (s) of the block in the coronary arteries and the degree of blockage related parts of the heart muscle

Answer 328

Heart beat rhythm may be abnormal and the heart may cease to be an effective pump. The other vital organs such as brain may be deprived of inadequate supply of oxygen rich blood and heart attack may be fatal if not treated on time.

Answer 329

Since oxygen is less soluble in watery medium including blood, transportation of oxygen from respiratory surface to the tissues/ organs is a problem for complex animals

Answer 330

Present in blood of human, other vertebrate and annelids

Answer 331

present in hemolymph of arthropods and molluscs.

Answer 332

present in the blood of many annelids

Answer 333

present in the blood of marine invertebrates (some annelids)

Answer 334

present in vertebrate muscles

Answer 335

Haemoglobin Chlorocruorin Haemoerythrin

Answer 336

Haemoglobin Myoglobin

Answer 337

transport oxygen from respiratory surfaces to the tissues and organs while transporting carbon dioxide from tissue/ organs to the respiratory surface for elimination

Answer 338

transport oxygen from respiratory surfaces to the tissues and organs while transporting carbon dioxide from tissue/ organs to the respiratory surface for elimination

Answer 339

oxygen storage function

Answer 340

globin protein haem group

Answer 341

Erythrocytes

Answer 342

responsible for the transport of oxygen around the body

Answer 343

Haem groups

Answer 344

A ferrous(iron) atom each hemoglobin molecule can carry up to four oxygen molecules.

Answer 345

Hb + 4O2 ========> HbO8 (Hemoglobin molecules)

Answer 346

• As HCO3- ions in the plasma (about 70%): When CO2 diffuses into the red blood cells the enzyme carbonic anhydrase catalyze the combination of CO2 with water to form bicarbonate ( HCO3- ) and H+ ions. The HCO3- moves out of the erythrocytes into the plasma • As carbaminohemoglobin (about 23%): CO2 combined with protein group of hemoglobin and form carbaminohemoglobin. Therefore CO2 does not compete with oxygen binding sites in hemoglobin. • Dissolved in plasma (about 7%): as free gas.

Answer 347

red blood cells white blood cells platelets

Answer 348

bone marrow in the bones such as (vpsr) ribs, vertebrae, sternum pelvis

Answer 349

Erythropoietin hormone (from kidneys) stimulates the generation of red blood cells

Answer 350

cells plasma

Answer 351

small biconcave disk-like cells

Answer 352

This character helps to carry more hemoglobin molecules within the cell

Answer 353

via anaerobic respiration. If they produce ATP by aerobic respiration that will reduce the O2 transport efﬁciency

Answer 354

gender health status.

Answer 355

Transportation of O2 molecules. They also transport CO2 molecules.

Answer 356

Basophils, Lymphocytes, Eosinophils, Neutrophils and monocytes (NEVER LET MONKEYS EAT BANANAS)

Answer 357

body defense phagocytic engulﬁng digesting microorganisms increase immune response against foreign substances.

Answer 358

T cells B cells

Answer 359

Bone marrow

Answer 360

play a major role in blood clotting

Answer 361

Around 7.4

Answer 362

in plasma (higher than in interstitial ﬂuid)

Answer 363

buffer and maintain the osmotic balance in the blood

Answer 364

buffers the blood

Answer 365

Involved in defense

Answer 366

aids in blood clotting

Answer 367

• Transport of oxygen to organs and removal of carbon dioxide from the organs and tissues • Transport of soluble excretory materials to organs of excretion • Transport of nutrients • Transport of hormones from the glands where they are produced to target organs • Defense against foreign invasions • Aids in osmoregulation

Answer 368

This prevents further blood loss This prevents the entry of pathogenic micro organisms which is of clear survival value

Answer 369

When the blood vessel is damaged the connective tissues of the vessel wall is exposed. Therefore platelets in the blood adhere to the collagen ﬁbers in the connective tissue and release substance that makes close by platelets sticky, forming a platelet plug.

Answer 370

provides instant protection against blood loss

Answer 371

They trigger the formation of thrombin. Then thrombin converts ﬁbrinogen into ﬁ brin. Next this ﬁ brin aggregates into threads that form a network of the clot. The activated thrombin is also involved in formation of more thrombin which completes the formation of blood clot.

Answer 372

Pacinian corpuscles which are present in the deep skin. They are sensitive to deep pressure.

Answer 373

Meissner corpuscles, Pacinian corpuscles) Speciﬁc hair cells in the organ of Corti in the inner ear detect sound vibrations. Hair cells of the vestibule of the inner ear detect the gravity whereas hair cells of the semicircular canals detect the motion

Answer 374

reﬂect harmful conditions that could arise from extreme pressure or temperature and certain chemicals that could damage the tissues.

Answer 375

Special nerve endings in diﬀerent parts of the body can detect the tissue damage. Ultimately the pain is perceived by the brain.

Answer 376

The outer ﬁbrous layer (sclera and cornea), the middle vascular layer (choroid, cilliary body and iris) and the inner nervous layer (Retina)

Answer 377

lens, aqueous ﬂuid and vitreous body.

Answer 378

Sclera is white and opaque. It is the outermost layer of the posterior and lateral aspects of the eye ball. It connects anteriorly with the clear transparent epithelial membrane called cornea.

Answer 379

Sclera maintains the shape of the eye and gives attachment of the extrinsic muscles of the eye.

Answer 380

Cornea is the passage through which light rays reach the retina. It is devoid of blood vessels. The cornea is convex anteriorly

Answer 381

involved in refracting light rays to focus on the retina.

Answer 382

Choroid is located just beneath the sclera. It is a thin pigmented layer and rich with blood vessels.

Answer 383

Cilliary body is the anterior continuation of the choroid layer consisting of smooth muscle ﬁbers (ciliary muscle) and sensory epithelial cells. Most of these smooth muscle ﬁbers are circular.

Answer 384

ciliary muscles act as a sphincter. The ciliary body holds the lens in place by suspensory ligaments

Answer 385

The size and thickness of the lens can be controlled by contraction and relaxation of the ciliary muscle ﬁbers attached to these suspensory ligaments

Answer 386

Epithelial cells secrete aqueous humor

Answer 387

Iris is a circular coloured body composed of pigment cells. It is located at the front of the eye. It extends anteriorly from the ciliary body and present behind the cornea and in front of the lens

Answer 388

two layers of smooth muscle ﬁbers which are arranged as circular and radial bundles. In the center of iris is a hole called pupil.

Answer 389

Iris controls amount of light entering the pupil by changing size which is mediated by the autonomic nervous system. Pigments prevent penetration of excessive light.

Answer 390

The lens is lying immediately behind the pupil.

Answer 391

It is an elastic, biconvex transparent disc made up of protein enclosed within a transparent capsule.

Answer 392

It refracts light rays reﬂected by objects in front of the eye and focuses them on the retina to form the image. By changing the thickness, the lens can vary its refractive power in order to focus rays on the retina.

Answer 393

Aqueous ﬂuid supplies nutrients and removes wastes from the cornea, lens and lens capsule which have no blood supply. (Blockage of ducts that drain this ﬂuid can produce glaucoma causing vision loss) :(

Answer 394

Behind the lens a colourless and transparent jelly like vitreous humour is present.

Answer 395

Behind the lens a colourless and transparent jelly like vitreous humour is present.

Answer 396

It maintains enough intra ocular pressure to support the retina against choroid and prevents the eye ball from collapsing.

Answer 397

Outer pigmented epithelium middle photoreceptive layer inner layer with neurons

Answer 398

sensory cells (rods and cones) which contain photosensory pigments that can convert light rays into nerve impulses.

Answer 399

Retina is thickest at the back. At the centre of the posterior part of the retina, macula lutea (yellow spot) is present. In the center of the yellow spot there is a little depression called the fovea centralis which contains only cones. Towards the anterior part of the retina there are fewer cones than rods. About 0.5 cm to the nasal side of the macula lutea all the nerve ﬁbers of the retina converge to form the optic nerve. The small area of retina where the optic nerve leaves eye is the blind spot (optic disk). It lacks photoreceptors.

Answer 400

In the rods visual pigment is rhodopsin. They are sensitive to light but do not distinguish colours. They enable us to see at night but only in black and white.

Answer 401

visual pigment is photopsin. They provide colour vision. They contribute very little to night vision as they are less sensitive.

Answer 402

There are three types of cones each of which has a diﬀ erent sensitivity across the visible spectrum providing an optimal response to red, green or blue light.

Answer 403

bipolar cells and ganglion cells.

Answer 404

Light rays coming from the visual ﬁ eld pass through the conjunctiva ﬁ rst, then successively through cornea, aqueous ﬂ uid, lens and vitreous body before reaching the retina

Answer 405

Lens has changing refractory power while all the other parts (conjunctiva, cornea, aqueous ﬂuid and vitreous body) have constant refractory powers. Light rays are mostly refracted by the biconvex lens.

Answer 406

autonomic nervous system

Answer 407

Constriction of the pupil Movement of the eye ball (convergence) Changing the refractory power of the lens

Answer 408

Monocular vision: it is possible to see visual ﬁ elds with one eye. Seeing the visual ﬁeld using only one eye is called monocular vision Binocular vision: Seeing the visual ﬁeld using two eyes with greater overlapping ﬁelds of view is called binocular vision. *The left eye views more on the left of the visual ﬁelds. *The right eye views more on the right of the visual fields. Even though each eye views a scene from a slightly diﬀerent angle, in the middle the visual ﬁelds are overlapped. *However only one image is perceived due to the fusion of left, middle and right of the visual ﬁeld images from the two eyes in the occipital lobe of the cerebrum.

Answer 409

However when one eye is used, three dimensional vision is impaired especially in relation to the judgment of speed and distance.

Answer 410

Unlike monocular vision, binocular vision enables three dimensional views. * So binocular vision is very important in judging the speed and distance of an approaching object such as a vehicle. *It gives more accurate assessment of one object relative to another in relation to distance, depth, height and width. *In some individuals, binocular vision may be impaired. Such individuals face diﬃculties to judge the speed and distance of an approaching object

Answer 411

outer ear middle ear inner ear.

Answer 412

Semicircular canals and vestibule located in the inner ear provide information about the position of the head in space and contribute to maintain the posture and balance. Utricle and saccule of the vestibule perceive position with respect to gravity or linear movements.

Answer 413

*Semicircular canals and vestibule located in the inner ear provide information about the position of the head in space and contribute to maintain the posture and balance. *Utricle and saccule of the vestibule perceive position with respect to gravity or linear movements.

Answer 414

palms and ﬁngers of the hand, sole of the foot

Answer 415

a dark pigment called melanin contribute to the skin colour.

Answer 416

Circulating blood in the dermis, excessive levels of bile pigments and carotenes in the fat layer

Answer 417

Fibroblasts, macrophages and mast cells

Answer 418

blood and lymph vessels sensory nerve endings sweat glands sebaceous glands hair, arrector pili muscles sensory receptors (Meissner’s corpuscle, Pacinian corpuscle, free nerve endings, bulb of Krause, organ of Ruﬃni, Merkle discs)

Answer 419

1. protection 2. regulation of the body temperature 3. cutaneous sensation 4. Synthesis of vitamin D 5. Excretion

Answer 420

hypothalamus, pituitary gland, thyroid gland, parathyroid glands, adrenal glands, islets of Langerhans (in the pancreas), gonads, thymus gland and pineal gland

Answer 421

in some organs and tissues (e.g. stomach, small intestine, kidneys etc.) which secrete speciﬁc hormones (e.g. isolated endocrine cells in the stomach secrete the hormone, gastrin).

Answer 422

(ﬁve releasing hormones and two release inhibiting hormones), act on the anterior pituitary (target site)

Answer 423

(oxytocin and antidiuretic hormone) are stored in the posterior pituitary until they are released into the bloodstream and act on speciﬁc target sites.

Answer 424

Stimulates the secretion of growth hormone (GH) from anterior pituitary

Answer 425

Stimulates the secretion of thyroid stimulating hormone (TSH) from anterior pituitary

Answer 426

Stimulates the secretion of adrenocorticotropic hormone (ACTH) from anterior pituitary

Answer 427

Stimulates the secretion of follicle stimulating hormone (FSH) and luteinizing hormone (LH) from anterior pituitary

Answer 428

Stimulates the secretion of prolactin hormone from anterior pituitary

Answer 429

Inhibits the secretion of prolactin hormone from anterior pituitary Inhibits the secretion of GH and TSH from the anterior pituitary

Answer 430

Inhibits the secretion of prolactin hormone from anterior pituitary Inhibits the secretion of GH and TSH from the anterior pituitary

Answer 431

TSH, ACTH, FSH and LH

Answer 432

prolactin he hormone prolactin which is secreted by the anterior pituitary is not a tropic hormone as its target sites are non-endocrine tissues. Prolactin promotes only non-tropic eﬀects.

Answer 433

Growth hormone (GH) secreted by the anterior pituitary has a “tropic as well as non-tropic eﬀ ects” as its target sites can be endocrine cells as well as non- endocrine cells. GH is the most abundant hormone synthesized by the anterior pituitary. All body cells

Answer 434

Stimulates secretion of thyroid hormones (triiodothyronine and thyroxin); Stimulates growth of thyroid gland Thyroid

Answer 435

Mammary gland Stimulates milk production; Together with other hormones promotes milk secretion by the mammary glands.

Answer 436

Ovary Ovulation; promote formation of corpus luteum in the ovary (structure formed after ovulation) and stimulates progesterone hormone secretion by the corpus luteum. Testis Stimulate spermatogenesis

Answer 437

ovary: Ovulation; promote formation of corpus luteum in the ovary (structure formed after ovulation) and stimulates progesterone hormone secretion by the corpus luteum Testis Stimulates secretion of testosterone hormone

Answer 438

The posterior pituitary which is an extension of the hypothalamus connecting via axons, does not synthesize hormones but secretes two hypothalamic hormones (oxytocin and antidiuretic hormone) to the bloodstream

Answer 439

Distal convoluted tubules of the nephrons and collecting ducts in the kidney Stimulates resorption of water by increasing permeability to water

Answer 440

Mammary gland Stimulates milk ejection by stimulating contraction of smooth muscles Uterine muscles Promotes parturition by contraction of smooth muscles

Answer 441

help maintain normal blood pressure, heart rate and muscle tone and regulate digestive and reproductive functions. also help maintain normal blood pressure, heart rate and muscle tone and regulate digestive and reproductive functions Thyroid gland is located in the neck just below the larynx and in front of the trachea (T3 and T4 proteins)

Answer 442

Calcitonin is another hormone secreted by the thyroid gland. Calcitonin helps to lower blood calcium ion level if it is raised above the normal limit. This hormone acts on bone cells and promotes storage of calcium within bone tissues. The hormone also acts on kidney tubules and inhibit calcium reabsorption enhancing calcium excretion.

Answer 443

Parathyroid glands (a set four small glands) are embedded in the posterior surface of the thyroid gland located in the neck

Answer 444

Main function of the PTH is to promote high calcium levels in the blood by stimulating calcium reabsorption from the kidney tubules and calcium absorption through the small intestine. If these sources supply inadequate calcium, PTH acts on bone destroying cells and promotes release of calcium from the bones into the blood. PTH has the opposite eﬀect of calcitonin hormone (released by the thyroid gland) on the blood calcium level.

Answer 445

Thymus gland is located in the upper part of the chest, directly behind the sternum and between the lungs.

Answer 446

Thymosin acts on the lymphocytes (originated from the stem cells in the bone marrow) and regulates development and maturation of T lymphocytes which are important components of speciﬁ c immunity.

Answer 447

Melatonin secreted by the pineal gland is involved in the regulation of biological rhythms related to reproduction and daily activity levels. Melatonin seems to be associated with coordination of circadian and diurnal rhythms of many tissues and inhibition of growth and development of sex organs before puberty.

Answer 448

Adrenal glands are paired structures, one of which lies superior to each kidney. Each gland is consists of two parts: adrenal cortex (outer) and adrenal medulla (inner).

Answer 449

The structure and functions of these two parts are diﬀ erent. Hormones secreted by the adrenal cortex and the adrenal medulla can mediate the stress responses in the body.

Answer 450

glucocorticoids and mineralocorticoids.

Answer 451

maintaining water and electrolyte balance. stimulates the reabsorption of sodium ions by the kidney tubules and excretion of potassium ions in the urine. As sodium reabsorption is accompanied by the water retention, blood volume and blood pressure can be increased. Hence aldosterone hormone is also involved in the regulation of blood volume and blood pressure.