05. Animal Form and Function Flashcards
What are differences between nervous and endocrine systems?
TNRTD
What is nervous organization of cnidaria and an example?
Nerve net, Hydra
Nervous organization of platyhelminthese and an example
Brain and longitudinal nerve cord
Planaria
What is the common nervous organization of snnelid and arthropod?
Brain
Ventral nerve cord
Segmented ganglia
Ex1-leech
Ex2 cockroach
What is the nervous prganization of echnodermata and an example
Nerve ring and radial nerves
Sea star
What I the nervous organization of chordata
Brain
Spinal cord
Nerves and ganglia
Ex.gecko
What does the central nervous system consist of
Brain
Spinal cord
What does the anterior part of the nervous system enlarge and form?
Forebrain
Midbrain
Hindbrain
What is the location of the ventricles?
3 ventricles in the forebrain
1 ventricle in the hindbrain
What is the function of C.S.F?
It helps maintain uniform pressure within the central nervous system
Acts as a shock absorber between the brain and skull
Helps circulate nutrients and hormones
Removes waste products
How is the brain protected from physical injuries?
The brain is enclosed by the skull
How is the spinal cord protected from physical injuries?
It is surrounded by vertebrae which forms the vertebral column
How is the central nervous system protected?
By 3 layers of tissues called meninges
They are dura mater (outermost layer), pia mater(innermost layer) and the arachnoid mater(the layer in-between these two layers)
What does the forebrain give rise to?
Cerebrum
Thalamus
Hypothalamus
Pineal Body
What does the midbrain give rise to?
Part of the brainstem
What does the hindbrain give rise to?
Cerebellum
Pons varolii
Medulla oblongata
What is the largest part of the human brain?
Cerebrum
What is the cerebrum composed of?
Nerve cell bodies (grey matter) forming the cerebral cortex
Deeper layers consist of nerve fibers (white matter)
What connects the 2 cerebral hemispheres?
Corpus Callosum
What is the corpus callosum made up of?
White matter
What do the infoldings of the cerebral cortex do?
It increases the area of the cerebrum
What are the 4 lobes of the cerebral hemisphere?
Frontal Lobe
Temporal Lobe
Parietal Lobe
Occipital Lobe
What are the main functions of the cerebral cortex?
Sensory areas RECIEVE and PROCESS sensory information including the perception of pain, temperature, touch, taste, smell, sight and hearing
Association areas are responsible for recognition, integration , and interpretation of sensory information and the processing of complex mental functions such as MEMORY, INTELLIGENCE, REASONING, JUDGEMENT and EMOTIONS.
Motor areas are responsible for directing skeletal (voluntary) muscle movement through the initiation and control of voluntary muscle contraction
What is the location of thalamus?
Within the cerebral hemisphere just below the corpus callosum
What is thalamus comprised of?
Grey and white matter
What are the functions of the thalamus?
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
What is the location of the hypothalamus?
Below and in front of the thalamus immediately above the pituitary gland.
What links the hypothalamus to the posterior lobe of pituitary gland?
Nerve fibers
What links the hypothalamus to the anterior lobe of the pituitary gland?
A complex system of blood vessels (portal blood vessels)
What are the functions of the hypothalamus?
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
Where is the midbrain located?
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
What does the midbrain contain?
Aggregates of nerve cell bodies and nerve tracts
What is function of nerve tracts of the midbrain?
Connects the cerebrum with the lower brain and spinal cord
What are the functions of the midbrain?
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
What is the location of pons varolii?
In front of cerebellum, below midbrain, above medulla oblongata
What does the pons varolii contain?
- nerve fibers that form a bridge between two hemispheres of the cerebellum
- nerve fibers passing between higher levels of the brain and spinal cord
- groups of nerve cell bodies
What do groups of cell bodies form?
centers that regulate respiration
some act as relay stations
What are the functions of pons varolii?
Transferring information between PNS and midbrain and forebrain
Coordinating large scale body movements like running and climbing
Together with medulla oblongata, helps regulate respiration
Where is medulla oblongata?
Lowest part of the brain stem which extends from the pons above and continuous with the spinal cord below
What are the centers the medulla oblongata contains?
Respiratory center
Cardiovascular center
Reflex center
What are the functions of the medulla oblongata?
Transfers information between PNS and midbrain and forebrain
Coordinates various body movements like running and climbing
What is the location of the cerebellum?
It is located behind the pons varoli
below the posterior portion of the cerebrum
What is cerebellum made of?
Two hemispheres
What are the functions of the cerebellum?
coordinates voluntary muscle movements
Maintains posture and balance
Helps in learning and remembering motor skills
What are the common functions of the medulla oblangata and the pons varolii?
Coordinates large scale body movements like running and climbing
Helps to regulate respiration
What are the common functions of thalamus and midbrain?
Act as a relay station
What are the functions of the spinal cord?
Links the central nervous system to sensory and motor neurons
Facilitates nerve impulse propagation towards and away from the brain
Coordinates and produces reflexes
What does the center of the spinal cord contain?
central canal (surrounded by grey matter)
outer region (made of white matter)
What is the peripheral nervous system made up of?
Cranial nerves
Spinal nerves
Autonomic nervous system (with ganglia)
What is the function of PNS?
It transmits impulses to and from the CNS
Regulates both animal movement and its internal environment
What does the sympathetic stimulation prepare the body for?
Dealing with stressful or exciting situations and energy generating situations (Fight/Flight)
Where do sympathetic nerves exit from?
Only from the spinal cord
What neurotransmitter is secreted by sympathetic nerve system?
Norepinephrine
What does the parasympathetic stimulation prepare the body for?
Causes opposite responses to sympathetic stimulations that promote calming or a return-to-self maintenance functions
Rest and digest
What makes sympathetic and parasympathetic nervous systems differ from each other?
Overall functions
Organization
Signal released
Where do parasympathetic nerves exit from?
Spinal cord as spinal nerves or cranial nerves
At the base of the brain
What is the neurotransmitter secreted by parasympathetic division?
Acetylcholine
What do different neurotransmitters enable sympathetic and parasympathetic nervous systems to do?
Bring about opposite effects in different organs such as lung, heart, intestine and bladder.
Name examples for parasympathetic division
Constricts eye pupil
Constricts bronchi in lungs
Slows heart
How does the parasympathetic nervous system help in digestion?
Stimulates activity of stomach and intestines
Stimulates activity of pancreas
Stimulates gall bladder
How does the parasympathetic nervous system function in rest?
Promotes emptying of bladder
Promotes erection of genitalia
What are the functions of the sympathetic nervous system?
- Dilates pupil eye
2, Inhibits salivary gland secretion - Relaxes bronchi in the lungs
- Accelerates the heart rate
- inhibits the activity of the stomach and the intestines
- Inhibits the activity of pancreas
- Stimulates glucose release from liver inhibits the gall bladder
- Stimulates adrenal medulla
- inhibits emptying the bladder
- promotes ejaculation and vaginal contractions
What does the speed of the conduction depend on?
- Diameter of the axon- The conduction increases with increase in the axon diameter
- Presence of myelinated axon- axon potential jumps from one node of Ranvier to next
What are examples if neurotransmitters?
- Acetylcholine
2.some amino acids - Biogenic amines
- Neuropeptides
- Some gases
What are examples of chemoreceptors?
taste and olfactory receptors
To Detect specific chemicals such as CO2 circulating in the blood
What are examples of chemoreceptors?
taste and olfactory receptors
Detect specific chemicals such as CO2 circulating in the blood
Where are the olfactory receptors?
Upper portion of the epithelium of the nasal cavity
What are locations of thermo receptors?
Skin - detect the body surface temperature
Hypothalamus - detects the temperature of the blood circulating through internal organs
What are the thermal receptors found in the skin?
Krause end bulbs detect cold
Rufinicorpuscles detect warmth
Free nerve endings detect both the warm and cold
What are the thermoreceptors found in the hypothalamus?
Specialized neurons
What are examples for mechanoreceptors?
Touch receptors
Pressure receptors
Vibration receptors
What are examples for touch receptors?
Meissner corpuscles - sensitive to light pressure
Merkel disks - sensitive to light touch
Free nerve endings
What are the four main types of tissues?
- Epithelial tissue
- Connective tissue
- Muscle tissue
- Nerve tissue
What are the characteristics of epithelial tissues?
*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.
What are the functions of epithelial tissues?
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
What are the general types of tissues according to the number of cell layers on the basement layers?
- Simple epithelia
- Compound epithelia
What are the features of simple squamous epithelium?
- They are thin and leaky
- Found in places where materials exchange by diffusion
What are the examples for simple squamous epithelium?
Blood capillaries
Alveoli
What are the features of cuboidal epithelium?
- Dice shaped cells
- Specialized for secretion
3.
Where are simple cuboidal epithelial cells are found?
Kidney tubules
Glands like thyroid and salivary glands
Where are simple cuboidal epithelial cells are found?
Kidney tubules
Glands like thyroid and salivary glands
What are the features of simple columnar epithelium?
- Single cell layer
- Large brick shaped cells
- Found in places where secretion or active absorption is important
What are examples for simple columnar epithelial cells?
Intestinal lining
What are the features of the pseudostratified columnar epithelium?
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.
What are the examples of pseudostratified epithelial tissues?
Nasal passage
trachea
What are the features of the stratified squamous epithelium?
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 .
Where are stratified squamous epithelium found in?
on surfaces where they are subjected to abrasion such as outer skin, lining of mouth, anus, vagina
What are the features of the connective tissue?
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).
What are the common functions of the connective tissues?
Binding and structural support
Protection
Transport of materials
Insulation
What are the different types of the connective tissue?
loose connective tissue (Areolar tissue)
Fibrous connective tissue (Dense connective tissue)
adipose tissue,
blood
cartilage
bone .
What are the features of the loose connective tissue?
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
What is the function of loose connective tissue?
This tissue binds epithelia and the underlying tissue.
Therefore this holds organs in place.
Where is the loose connective tissue is located in?
under the skin and throughout the body
What are the common features of the fibrous connective tissue?
This tissue is densely packed with collagen fibers.
Therefore the matrix is relatively reduced
contains fewer cells (fibrocytes)
Where are the fibrous connective tissues found in?
tendons (attach muscle to bones)
ligaments (connect bones and joints)
(Here, the tensile strength is required)
What are the features of the adipose tissue?
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.
What is the function of the adipose tissue?
act as a thermal insulator
energy store.
Where is the adipose tissue located in?
under the skin
What are the features of the blood tissue?
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.
What are the main functions of the blood tissue?
Transport of materials
protection
osmoregulation.
What are the features of the cartilage?
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.
What does the cartilage do?
This tissue provides support and flexibility in places such as trachea, intervertebral discs.
What are the features of the bone tissue?
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.
What is the repeating unit of the mammalian hard bone?
Osteon
Describe the structure of the osteon
Each osteons has a concentric layer of mineralized materials.
At the center of the osteon is a central canal containing blood vessels and nerves.
What is the function of the bone?
This tissue forms the endoskeleton of most vertebrates
Provides support and strength to the body.
What is the function of the muscle tissue?
Muscle tissue is responsible for movement
What are the features of the muscle tissue?
The cells in the muscle tissue are composed of actin and myosin proteins.
This tissue is able to contract and relax.
What are the three basic types of muscle tissues?
smooth muscle
skeletal muscle
cardiac muscle tissues.
What are the features of the smooth muscle tissue?
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)
Where can we find the smooth muscle tissue?
digestive tract
urinary bladder
arteries
other internal organs.
What are the features of the skeletal muscle tissue?
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
What is the function of the skeletal muscle tissue?
Helps in voluntary muscle movement
What are the features of the cardiac muscle tissue?
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
Where can we find the cardiac muscle tissue?
Intercalated disks help relay signals from cell to cell and synchronize heart contraction
Where can we find the cardiac muscle tissues?
only found in the wall of the heart.
What are the two types of cells of the nervous tissue?
Neurons
Glial cells
What is the function of the nervous tissue?
Neurons receive, process and transmit nerve impulses.
What are the parts of the neuron?
Cell body
dendrites
axon
What is the structural unit of the nervous system?
Nervous tissue
What is the function of dendrites?
Dendrites and cell body is used to receive nerve impulses from other neurons.
What is the axon used for?
Axon is used to transmit impulses to other neurons, cells or muscles.
Axons are bundled together into nerves
What are neuroglia?
Neuroglial cells are supportive cells of neurons
What are the functions of the neuroglia?
nourishment of nerve cells
insulation of nerve cells
replenishing neurons and
sometimes modulate neuron functions.
(n i r s)
What are examples of heterotrophs?
animals
fungi
majority of bacteria
What are the two types of heterotrophic nutrition?
- Holozoic nutrition
- Symbiosis
What are the five main stages of the holozoic nutrition?
- Ingestion
- Digestion
- Absorption
- Assimilation
- Egestion
According to what do different animals have different mode of nutrition?
- Diet
- environment
How can digestion occur during the holozoic mode of nutrition?
- Mechanically (teeth or muscle contractions)
- Chemically (by enzymes)
What are examples of filter feeders?
Clams
Oysters
How do clams and oysters feed themselves?
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.
What are the examples for fluid feeders?
Mosquitoes-suck human blood
Aphids- suck phloem sap of plants
Bees and humming birds suck -honey from flowers
What are examples for bulk feeders?
Most animals including humans
What are the different types of adaptations used by bulk feeders to tear and capture prey?
jaws
teeth
tentacles
claws
poisonous fangs
Give an example for mutualistic association of heterotrophic organisms
*Cellulose digesting microorganisms in Ruminants and Termites
Give an example for parasitism association of heterotrophic organisms
Tape worm and humans
Lice and humans
Name an example for commensalism of heterotrophic organisms
Barnacles attached to the whales
Name an example for commensalism of heterotrophic organisms
Barnacles attached to the whales
Where do parasites live in?
Parasites live either within
or on the host and derive its nourishment
What does the digestive system consist of?
Alimentary canal
associated glands
What does the alimentary canal include of human digestive system?
Oral cavity
pharynx
esophagus
stomach
small intestine
large intestine
rectum
anus
What are the associated glands of the human digestive system?
salivary glands
pancreas
liver
Why is the food cut, mashed and grounded easily?
This makes it easier to swallow food
increase the surface area for digestion.
Why is the food cut, mashed and grounded easily?
This makes it easier to swallow food
increase the surface area for digestion.
What are the two ways by which the saliva entered into the mouth?
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.
What do the saliva contain?
water, amylase, mucus (a viscous mixture of salts, cells and slippery glycoprotein called mucins), buffers and anti
microbial components.
What are the functions of the saliva
• 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
What is the function of the tongue?
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.
What is the function of the pharynx?
a common passage of the respiratory tract and the digestive tract. The pharynx leads to the esophagus.
What does the wall of esophagus contain ?
Both skeletal and smooth muscles
What is the location of skeletal muscles and their function?
located towards the uppermost part of the esophagus and these muscles function during swallowing
What does the rest of esophagus contain?
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.
What is the stomach?
The stomach is a J- shaped dilated sac in the abdominal cavity.
Describe the nature of the inner surface of the stomach
The inner surface of the stomach is highly folded and contains large number of pits that leads to gastric glands.
What are the three types of cells of the gastric gland?
mucus cells
chief cells
parietal cells.
Describe the nature of the stomach wall
It is very elastic
What does the distal part of the stomach connect with?
With the small intestine
Where are the stomach sphincters found in?
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.
What does these sphincters regulate?
These sphincters help to regulate the passage of materials between these organs.
What secretes gastric juice of the stomach?
Gastric glands
What does the gastric juice consist of?
mucus
pepsinogen
HCl
Mucus is secreted by what cells of stomach?
Mucus cells
Pepsinogen(inactive form of pepsin) is secreted by what cells in the stomach?
Chief cells
What do parietal cells of the stomach do?
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.
What do the activated pepsin of the stomach do?
help to activate remaining pepsinogen molecules.
This activated pepsin initiates the chemical digestion of proteins in the stomach.
What does the churning action of the stomach do?
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.
What are proteins hydrolyzed into in the stomach?
Into small polypeptides by pepsin
What does the food mixed with gastric juice form?
In the stomach food is mixed with gastric juice forming chyme (partially digested semisolid, acidic, food mass).
How is the stomach lining protected from the digestion of HCl and pepsin?
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.
What are the functions of the stomach?
• 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.
What is the longest organ in the human alimentary canal?
Small intestine
What is the duodenum? Function?
What is the jejunum? Function?
What is the ileum? Function?
- C shaped curve, around the head of the pancreas. Most of the digestion is completed in the duodenum.
- The jejunum is middle part of the small intestine. (The major sites for nutrient absorption are jejunum and ileum. )
- The ileum is the terminal part of the small intestine. (The major sites for nutrient absorption are jejunum and ileum.)
How is the surface area of the small intestine increased?
by permanent circular folds and villi.
The villi are tiny finger like projections of the intestinal wall
From what does the small intestine receive chyme from?
Small intestine receives chyme from the stomach.
What aids in receiving the chyme?
Peristaltic contractions
What sphincter regulates the passing of the chyme into the small intestine?
pyloric sphincter
What is the chyme of the small intestine mixed with?
The chyme is mixed with secretions of glands in intestinal wall and secretions of pancreas and liver.
What does the epithelium and the duodenum secrete?
several digestive enzymes. Glands of the intestinal wall secrete enzymes such as Disaccharidases, Dipeptidases, Carboxypeptidases, Aminopeptidases, Nucleotidases, Nucleosidases and Phosphotases. (CANCLT)
What are the two hormones secreted by the duodenum?
cholecystokinin
secretin
What does the cholecystokinin stimulate?
release of pancreatic juice
What does secretin stimulate?
Stimulates the bile secretion
What does the pancreatic juice contain?
enzymes such as Trypsin, Chymotrypsin , Pancreatic amylase , Pancreatic Carboxypeptidases, Pancreatic Nucleases and Pancreatic Lipases (CANCLT) ad bicarbonates in addition
What does the liver secrete?
Bile
What is bile stored in?
Gall bladder, until released into the duodenum
What does the bile contain?
Bile salts
What do the bile salts do?
act as emulsifiers that help in fat digestion and absorption.
How does the carbohydrate digestion occur in the small intestine?
Pancreatic amylase catalyze the conversion of polysaccharides (e.g. starch) into disaccharides.
Intestinal disaccharidases catalyze the conversion of disaccharides into monosaccharides
How does protein digestion take place in the small intestine?
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.
How does fat digestion take place in the stomach?
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.
How does nucleic acid digestion take place in the small intestine?
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.
What are the adaptations of the small intestine for effective digestion?
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).
How does the transportation
What are the two ways of transport across the small intestine?
Active
Passive
How is fructose absorbed by the small intestine?
By facilitated diffusion
What are actively transported into the epithelial cells of the small intestine?
Amino acids
Small peptides
Vitamins
Most glucose molecules
Name the pathway of nutrients after the absorption process of the small intestine?
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 }
What is the different pathway in which the absorption of some products of fat take place?
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 }
What is the large intestine?
The large intestine is the terminal end of the alimentary canal.
What are the three regions of the large intestine?
colon (proximal part)
cecum
rectum
How is the small intestine connected to the large intestine?
at a ‘T’ shaped junction.
What is the finger like projection in the cecum?
appendix
What does the colon leads to?
The colon leads to the rectum and anus.
Why is the caecum important?
for fermentation of indigested materials by microbes, especially in animals that eat large amount of plant matter.
Name the functions of the colon of the large intestine?
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.
What are the functions of the rectum in the large intestine?
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
Name the nature of the structure of the pancreas
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.
What is the exocrine part of the pancreas consisted of?
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
What does the exocrine part of the pancreas secrete and what does it include?
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.
What does the endocrine part of the pancreas contain?
Endocrine part of the pancreas is the islets of Langerhans, which consist of group of specialized cells. They do not have ducts
What does the islets of the Langerhans do?
*Islets of Langerhans secrete hormones, glucagon and insulin which are involved in glucose homeostasis.
What is the largest gland in the body?
Liver
Describe the nature of the liver
Its upper and anterior surfaces are smooth and convex.
Its posterior surface is irregular in outline
How many lobes are there in the liver
4
What are lobules of liver made up of?
lobules are made up of cuboidal cells called hepatocytes which are arranged in pairs of columns radiating from a central vein.
Between two pairs of columns of cells, what are there in the liver lobules?
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.
In the lining of the sinusoids, what can be found?
Hepatic macrophages (Kupffer cells)
What do canaliculi form after joining up?
Larger bile canals
What can be found in the corner of the hexagonal structure?
a branch of hepatic artery
a branch of the hepatic portal vein
intra lobular bile duct
What are the functions of the liver?
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.
What are the functions of the liver related to digestion?
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)
What are the two ways of regulation of digestion of man?
- Nervous regulation
- Endocrine regulation
How does nervous regulation help in regulation digestion in man?
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.
How does endocrine system play a role in digestion?
*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.
What stimulate the release of cholecystokinin and secretin from duodenum?
Fatty acids and amino acids in the chyme
What does cholecystokinin trigger?
Cholecystokinin triggers release of bile from the gall bladder and digestive enzymes from the pancreas
What does secretin stimulate?
Secretin stimulates the release of bicarbonate from the pancreas.
What is the function of HCO3- in the pancreas?
Bicarbonate neutralize the chyme received from the stomach
What happens when the chyme is rich in fat?
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.
What are the main components of food in a balanced diert?
*Carbohydrates
• Proteins
• Lipids
• Vitamins
• Mineral elements
• water
• fibers
What are the two types of carbohydrates?
*sugars
*polysaccharides
(in rice and bread)
What are the functions of digestible carbohydrates?
*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
What are proteins made up of?
Amino acids
What happens to proteins during digestion?
proteins are broken down into amino acids
absorbed into the blood stream.
What are the two types of amino acids?
essential amino acids
non essential amino acids
What are the functions of proteins in the diet?
• 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
What are lipids made out of?
Fats
Oils
What are the two types of fats in lipids?
Essential fatty acids
Non essential fatty acids
What are the functions of lipids in the diet?
• 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)
What are the two types vitamins?
fat soluble vitamins (Vitamin A, D, E and K)
water soluble vitamins (Vitamin B and C).
What is the function of vitamin A?
form visual pigments in the eye
epithelial tissue maintenance,
promotion of growth and immunity
What is the function of vitamin B?
components of coenzymes such as FAD and NAD, promote red blood cell production
What is the function of vitamin C?
act as an antioxidant
used in collagen synthesis
What is the function of vitamin D?
aids in absorption and use of Calcium and Phosphorous
What is the function of vitamin E?
act as an antioxidant
What is the function of vitamin K?
It is important in blood clotting
What is the function of the Ca mineral?
form bones and teeth
helps clotting blood
nerve and muscle function
What are 2 anti oxidants as vitamins?
Vitamin C and vitamin E
What are the functions of P mineral?
form bones and teeth
help maintain in acid base balance
What are the two minerals forming bones and teeth?
Ca and P
What is the function of S?
components of some amino acids
What is the function of K?
help maintain in acid base balance and water balance
nerve function
What is the function of Cl?
help maintain in acid base balance
maintain osmotic balance
nerve function
What is the function of Na?
help maintain in acid base balance and water balance
nerve function
What minerals maintain acid base balance?
Na
K
cl
P
What minerals help in water balance?
Na
K
What is the function of the mineral Mg?
act as enzyme cofactor
What is the function of the mineral Fe?
Components of hemoglobin
electron carriers
act as an enzyme cofactor
What is the function of the mineral F?
maintenance of tooth structure
What is the function of the mineral I?
component of thyroid hormone
What act as enzyme cofactors?
Mg and Fe
What are the ways by which water is lost in the human body?
Urine
Sweating
Feces
Why is the amount if water taken into the body balanced?
drinking
food
What are the functions of water?
• 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
What are fibers made out of?
indigestible polysaccharides
What are fibers made out of?
indigestible polysaccharides
What are fibers made out of?
indigestible polysaccharides
What are the functions of dietary fibers?
• 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.
What are examples of essential nutrients?
essential amino acids,
essential fatty acids,
vitamins
minerals.
Why is it essential to intake essential nutrients?
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.
What are essential amino acid examples?
Leucine
and methionine.
What does obesity lead to?
Diabetes mellitus
cardiovascular diseases
some cancers
BMI equation?
Mass/ height^2(kg/ m2)
What occurs in gastritis?
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.
What are the reasons for the secretion of HCL?
Prolonged starvation
mental stress
Some drugs like asprin
What bacteria is long lasting bacteria associated with?
Helicobacter pylori
What is the reason for gastritis?
prolonged starvation
What should be practiced for gastritis?
proper food habits should be practiced
What leads to constipation?
Inhibition of the reflex action in defecation
What does constipation lead to?
pain in the anus and difficulty in defecating
How can constipation controlled by?
by developing behavioral adjustments to carry out defecation properly
What can prevent constipation?
Intake of adequate fiber in the diet can help prevent constipation.
Describe the need of the circulatory system.
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
Describe why a circulatory system for simple organisms is not needed?
*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.
What are the substances that are transported in the body
respiratory gases (oxygen, carbon dioxide)
nutrients (glucose, amino acids, fatty acids, vitamins, etc.),-VAGF
waste products of metabolism (urea, ammonia, etc)
hormones
antibodies
What are the components of the animal circulatory system
A muscular pumping device (heart),
interconnected vessels
circulatory fluid (blood/ hemolymph).
What are the two types of circulatory systems in animals?
- Open CVS
- Closed CVS
What are the two types of circulatory systems in animals?
- Open CVS
- Closed CVS
What are the two groups of animals that have the open cvs?
Mollusca
Arthropoda
What are the organisms that show closed CVS?
Vertebrates
Invertebrates like annelids
What are the three main types of blood vessels in CVS?
arteries
veins
capillaries.
What organisms show single circulation?
Bony fishes, Cartilagenous fishes
such as rays and sharks.
what organisms show double circulation?
Amphibians, Reptiles, Aves, Mammals.
Who has three chambers of the heart?
Amphibians and most reptiles
What organisms have four chambers of heart?
Birds
Mammals
What is the difference between double circulation and single circulation?
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.
Where does oxygen poor blood drain into?
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.
Where does the gas exchange occur in the CVS?
capillary beds where O2 rich blood is diffused into the tissues while the CO2 rich blood diffused into the blood capillaries
What are the features of the lymphatic system?
The lymphatic system is closely connected with the blood circulatory system both structurally and functionally.
It consists of lymph vessels through which lymph travels.
What are the features of the lymphatic system?
The lymphatic system is closely connected with the blood circulatory system both structurally and functionally.
It consists of lymph vessels through which lymph travels.
What does the lymphatic system include?
lymph nodes
lymphoid tissues (tonsils)
lymphoid organs (e.g. spleen and thymus).
What does lymph vessels consist of?
tiny vessels
larger vessels.
What does lymph vessels consist of?
tiny vessels (Tiny lymph vessels are in close contact with the capillaries of the blood circulatory system)
larger vessels.
What are lymph nodes composed of?
connective tissues
white blood cells.
What is the function of the lymphatic system?
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.
What is lymph?
The lost fluid from the blood capillaries is called lymph when they are inside the lymphatic system
What is the composition of the lymph?
same as interstitial fluid
What is the function of lymph vessel valves?
It prevents the backflow of the lymph
What is the function of valves in the lymphatic system?
That prevents the backflow of the lymph.
To where is lymph drained into?
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.
What are the three layers of tissues heart wall is composed of?
Pericardium
Myocardium
Endocardium
What are the two sacs which the pericardium is made out of?
outer fibrous pericardium
inner serous pericardium.
What is the special feature of myocardium?
It is composed of specialized cardiac muscle found only in the heart
What are the four chambers of the human circulatory system?
Two ventricles
Two atria
What takes place during the pulmonary circulatory system?
takes oxygen poor blood to the respiratory surface, the lungs and returns the oxygen enriched blood back to
the heart
What are the two different types of circulatory systrmd
Pulmonary circuit
Systemic circuit
By what is the heart completely divided into right and left sides?
By septum
By what is the atrium and ventricle divided by?
AV valve
How many flaps does the right AV valve have?
3 flaps
How many flaps does the left ventricular valve has?
2 flaps
What are the extensions of the inner wall of ventricles?
papillary muscles
What is the function of chordae tendinea?
prevents the valves from being turned inside out
Where can we find semilunar valves?
found at the points where the pulmonary artery and aorta leave the right and left ventricles respectively.
What is the function of semi lunar valves?
These valves prevent the backflow of blood into the ventricles.
From where does the pulmonary arteries with oxygen poor blood leave from?
Two pulmonary arteries with oxygen poor blood leave the heart from the upper part of the right ventricle
To where does pulmonary veins give blood to?
Two pulmonary veins from each lung carry oxygen rich blood back to the left atrium.
Where does the aorta leaves from?
The aorta with oxygen rich blood leaves from the upper part of the left ventricles.
Where does the aorta leave from in the CVS?
The aorta with oxygen rich blood leaves from the upper part of the left ventricles.
What does the superior and the inferior vena cava open into?
The superior vena cava and inferior vena cava open into the right atrium and empty their contents into the right atrium
By what blood supply is the heart supplied with?
The heart is supplied with arterial blood by the right and left coronary arteries
From what does the left and right coronary arteries branch from?
the aorta immediately after the aortic valve
By what nerve fibers is the heart supplied with?
both sympathetic and parasympathetic nerve fibers
What two hormones does the heart respond to?
adrenaline and
thyroxine
What initiate and conduct impulses?
Small group of specialized neuromuscular cells in the myocardium
What does the conducting system of the heart consists of?
• SA node (Sinoatrial node)
• AV node (Atrioventricular node)
• Atrioventricular bundle (bundle of His), bundle branches and Purkinje fibres
What happens in the SA node? What is the function?
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.
What is the location of the SA node?
It lies in the myocardium of the right atrium near the opening of the superior vena cava
How can the heart rate be varied?
by the stimulation from the autonomic nervous system,
hormones such as adrenaline, thyroxine
temperature.
Where is the AV node located in?
between wall of the left and right atria
What is the function of AV node?
transmits the electrical signals from the atria into the ventricles
Where does the AV bundle originate from?
from the AV node
What does the AV bundle cross?
fibrous rings that separate atria and ventricle at the upper end of the ventricular septum
What is the function of the purkinje fibers and bundle branches?
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.
What does the cardiac cycle involve?
- Atrial systole – Contraction of the atria
- Ventricular systole - Contraction of the ventricles
- Complete cardiac diastole – Relaxation of the atria and ventricles
What transports poor oxygen blood :( to right atrium?
The superior vena cava
the inferior vena cava
What brings oxygen rich blood to the left atrium?
4 pulmonary veins
What triggers a wave of contractions that spread across the myocardium of both atrium?
SA node
To where are the electrical impulses generated by the AV node spread to?
the ventricular muscles via the AV bundle
the bundle branches, and Purkinje fibers
How is it ensured that blood only flows in one direction in the body?
The sequence of opening and closing of valves ensure that blood flows only in one direction.
What does an ECG indicate?
the spread of the electrical signal generated by the SA node as it travels throughout the heart.
What does the P wave represent in an ECG?
It represents the impulse from the SA node as it sweeps over the atria (atrial depolarization).
What does QRS wave complex represent?
It represents rapid spread of impulse from the AV node throughout the ventricles and electrical activity of the ventricular muscles.( ventricular depolarization)
What does the T wave represent in an ECG?
Represents ventricular repolarization and relaxation of the ventricular muscles.
Due to a larger QRS complex, what cannot be seen?
atrial repolarization which occurs during ventricular contraction
what can be obtained by examining the pattern of waves and the time interval between cycles and parts of cycles?
Information about the heart function of a person ( state of the myocardium and the cardiac conduction system)
What does blood pressure in the arteries of systemic circulation maintain?
the essential flow of blood into and out of the organs of the body
Why is it important to keep the blood pressure in normal limits?
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.
What does the blood pressure vary according to?
according to:
the time of day
the posture
gender
age
activity
exercise
stress (Emotional states) of an individual
When does blood pressure drop?
Blood pressure falls at rest and during sleep
When does blood pressure rise?
Blood pressure increases during excitement, fear or anxiety
By what equipment is atrial blood pressure measured?
sphygmomanometer
What is the equation for atrial blood pressure?
Systolic pressure (mm Hg) / Diastobic pressure (mm Hg)
What are the consequences of hypertension?
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
What are the risk factors for hypotension?
• 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
What is hypotension as a result of?
shock
dengue hemorrhage fever
standing up suddenly from sitting or lying position
over bleeding/ hemorrhage condition
fasting
low nutrition
What does low blood pressure lead to?
inadequate blood supply to the brain
depending on the cause unconsciousness may be brief (fainting) or prolonged possibly causing death
What are the consequences of the blockage of coronary arteries?
Atherosclerosis -> Thrombosis -> heart muscle will be deprived of oxygen and nutrients -> chest pain (angina) -> myocardial infarction
Depending on what conditions will the heart muscle be deprived of oxygen and nutrients?
Depending on the place (s) of the block in the coronary arteries and the degree of blockage related parts of the heart muscle
What are the results of myocardial infarction?
What are the results of myocardial infarction?
What are the results of myocardial infarction?
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.
Why are respiratory pigments necessary?
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
What organisms use hemoglobin as the respiratory pigment?
Present in blood of human, other vertebrate and annelids
What organisms use Haemocyanin as the respiratory pigment?
present in hemolymph of arthropods and molluscs.
What organisms use Chlorocruorin as a respiratory pigment?
present in the blood of many annelids
What organisms use Haemoerythrin as the respiratory pigment?
present in the blood of marine invertebrates (some annelids)
What organisms use myoglobin as a respiratory pigment?
present in vertebrate muscles
What are the respiratory pigments seen in annelids?
Haemoglobin
Chlorocruorin
Haemoerythrin
What are the respiratory pigments seen in vertebrates?
Haemoglobin
Myoglobin
What are the functions of the respiratory pigments except myoglobin?
transport oxygen from respiratory surfaces to the tissues and organs
while transporting carbon dioxide from tissue/ organs to the respiratory surface for elimination
What are the functions of the respiratory pigments except myoglobin?
transport oxygen from respiratory surfaces to the tissues and organs
while transporting carbon dioxide from tissue/ organs to the respiratory surface for elimination
What is the function of the myoglobin respiratory pigment?
oxygen storage function
What is hemoglobin composed of?
globin protein
haem group
Where can the hemoglobin molecule found in?
Erythrocytes
What is the function of hemoglobin molecule?
responsible for the transport of oxygen around the body
What is responsible for the characteristic red colour of the blood of the hemoglobin molecule?
Haem groups
What combine reversibly with one molecule of oxygen?
A ferrous(iron) atom
each hemoglobin molecule can carry up to four oxygen molecules.
Explain the equation for the formation of Combination of oxygen with hemoglobin to from oxyhemoglobin
Hb + 4O2 ========> HbO8
(Hemoglobin molecules)
What are the different ways of transportation of CO2 in the blood
• 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.
What are the cellular components of blood?
red blood cells
white blood cells
platelets
What are Red blood cells, leukocytes and platelets developed from?
bone marrow in the bones such as (vpsr)
ribs,
vertebrae,
sternum
pelvis
What does the erythropoietin hormone stimulate?
Erythropoietin hormone (from kidneys) stimulates the generation of red blood cells
What is cells composed of?
cells
plasma
What is the shape of the RBC?
small biconcave disk-like cells
What do mature erythrocytes lack?
Nuclei
What is the advantage of mature erythrocytes lacking nuclei?
This character helps to carry more hemoglobin molecules within the cell
RBC lack mitochondria. Then, how do they produce ATP?
via anaerobic respiration.
If they produce ATP by
aerobic respiration that will reduce the O2 transport efficiency
Depending on what factors do the number of RBC vary?
gender
health status.
What is the main function of RBC?
Transportation of O2 molecules.
They also transport CO2 molecules.
What are the five types of leukocytes?
Basophils, Lymphocytes, Eosinophils,
Neutrophils and monocytes
(NEVER LET MONKEYS EAT BANANAS)
What are the main functions of leukocytes
body defense
phagocytic engulfing
digesting microorganisms
increase immune response against foreign substances.
What do lymphocytes develop into?
T cells
B cells
Where are platelets developed from?
Bone marrow
Do platelets have nuclei?
No
What is the function of platelets?
play a major role in blood clotting
What is the Ph of blood?
Around 7.4
Where can we find a high protein concentration?
in plasma (higher than in interstitial fluid)
What is the function of dissolved ions in the plasma?
buffer and maintain the osmotic balance in the blood
What is the function of albumin in the blood plasma?
buffers the blood
What is the function of antibodies?
Involved in defense
What is the function of fibrinogen?
aids in blood clotting
What is blood called when all the clotting factors are removed?
serum
What are the main functions of the blood?
• 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
What is the function of the blood clot?
This prevents further blood loss
This prevents the entry of pathogenic micro organisms which is of clear survival value
What happens when a blood vessel is damaged?
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.
What is the function of the platelet plug during blood clotting?
provides instant protection against blood loss
What takes place after the platelets release clotting factors?
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.
What are examples for pressure receptors?
Pacinian corpuscles which are
present in the deep skin. They are sensitive to deep pressure.
Examples for vibration corpuscles?
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
What kind of stimuli do the pain receptors detect?
reflect harmful conditions that could arise from extreme
pressure or temperature and certain chemicals that could damage the tissues.
Examples of pain receptors?
Special
nerve endings in different parts of the body can detect the tissue damage. Ultimately the
pain is perceived by the brain.
Three layers of tissues of the eye wall?
The outer fibrous layer (sclera and cornea), the middle vascular layer (choroid, cilliary body and iris) and the inner nervous layer (Retina)
What does the eye ball contain?
lens,
aqueous fluid and vitreous body.
What is the structure of the sclera?
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.
What is the function of the sclera?
Sclera maintains the shape of the eye and gives attachment of the extrinsic muscles of the eye.
Describe the structure of the cornea?
Cornea is the passage through which light rays reach the retina. It is devoid of blood
vessels. The cornea is convex anteriorly
What is the function of the cornea?
involved in refracting light rays to focus on
the retina.
Describe the structure and the location of the choroid layer?
Choroid is located just beneath the sclera. It is a thin pigmented layer and rich with blood
vessels.
What is the structure of the ciliary body?
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.
What is the function of the ciliary body?
ciliary muscles act as a sphincter. The ciliary body holds the lens
in place by suspensory ligaments
What is the function of the ciliary muscle fibers?
The size and thickness of the lens can be controlled
by contraction and relaxation of the ciliary muscle fibers attached to these suspensory ligaments
What do the epithelial cells of aq humour secrete?
Epithelial cells secrete aqueous humor
Describe the structure of the iris
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
What does the iris contain?
two layers of smooth muscle fibers which are arranged as circular
and radial bundles.
In the center of iris is a hole called pupil.
What is the function of the iris?
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.
What is the location of the lens?
The lens is lying immediately behind the pupil.
Describe the structure of the lens?
It is an elastic, biconvex transparent disc made up
of protein enclosed within a transparent capsule.
What is the function of the lens?
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.
What is the function of the aq fluid?
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) :(
What is the location of the vitreous body?
Behind the lens a colourless and transparent jelly like vitreous humour is present.
What is the location of the vitreous body?
Behind the lens a colourless and transparent jelly like vitreous humour is present.
What is the function of the vitreous body?
It maintains enough intra ocular pressure to support the retina against choroid and prevents the eye ball from collapsing.
What are the three layers of the retina?
Outer pigmented epithelium
middle photoreceptive layer
inner layer with neurons
What does the photoreceptive layer contain?
sensory cells (rods and cones) which contain photosensory pigments that
can convert light rays into nerve impulses.
describe the structure of the retina
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.
Function of rhodopsin?
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.
Function of photopsin?
visual pigment is photopsin.
They provide colour vision.
They contribute very little to night vision as they are less sensitive.
What is the function of cones?
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.
What do the neurons in the retina contain?
bipolar cells and
ganglion cells.
What is the pathway of refraction of the light rays?
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
What structures of the eye have
- constant refractive power
- changing refractive power?
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.
What is the size of the pupil controlled by?
autonomic nervous system
What are the three main adjustments of the eye?
Constriction of the pupil
Movement of the eye ball (convergence)
Changing the refractory power of the lens
What is the difference between the monocular and binocular vision?
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.
What is the disadvantage of monocular vision?
However when one eye is used, three dimensional vision
is impaired especially in relation to the judgment of speed and distance.
What are the advantages of the binocular vision?
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
What is the three parts of the human ear?
outer ear
middle ear
inner ear.
Function of the semicircular canals?
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.
Function of the semicircular canals?
*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.
What are the areas subjected to wear and tear?
palms and fingers of the hand, sole of the foot
Describe about the function of melanin?
a dark pigment called melanin contribute to
the skin colour.
What can affect the skin colour?
Circulating blood in the dermis,
excessive levels of bile pigments and carotenes in the fat layer
What are the main cells of the dermis?
Fibroblasts, macrophages and mast cells
What are the structures present in the dermis?
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)
What are the functions of the skin?
- protection
- regulation of the body temperature
- cutaneous sensation
- Synthesis of vitamin D
- Excretion
What are the endocrine glands of the human body?
hypothalamus, pituitary gland, thyroid gland, parathyroid glands, adrenal glands, islets of Langerhans (in the pancreas), gonads, thymus gland and pineal gland
What are the isolated endocrine cells?
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).
What are the hormones that are produces and released by the hypothalamus?
(five releasing hormones and two release inhibiting hormones), act on the anterior pituitary (target site)
What are the hormones produced by the hypothalamus?
(oxytocin and antidiuretic hormone) are stored in the posterior pituitary until they are released into the bloodstream and act on specific target sites.
Function of GHRH
Stimulates the secretion of growth hormone (GH)
from anterior pituitary
Function of TRH
Stimulates the secretion of thyroid stimulating
hormone (TSH) from anterior pituitary
CRH function
Stimulates the secretion of adrenocorticotropic
hormone (ACTH) from anterior pituitary
GnRH function
Stimulates the secretion of follicle stimulating
hormone (FSH) and luteinizing hormone (LH) from
anterior pituitary
PRH function
Stimulates the secretion of prolactin hormone from
anterior pituitary
PIH and GHRIH function?
Inhibits the secretion of prolactin hormone from
anterior pituitary
Inhibits the secretion of GH and TSH from the
anterior pituitary
PIH and GHRIH function?
Inhibits the secretion of prolactin hormone from
anterior pituitary
Inhibits the secretion of GH and TSH from the
anterior pituitary
Tropic hormones?
TSH, ACTH, FSH and LH
non tropic effect hormone?
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.
GH function
target site
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
TSH function
target site
Stimulates secretion of thyroid
hormones (triiodothyronine and
thyroxin); Stimulates growth of
thyroid gland
Thyroid
Prolactin function
target site
Mammary gland
Stimulates milk production;
Together with other hormones
promotes milk secretion by the
mammary glands.
Follicle stimulating
hormone (FSH)
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
LH
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
How does the posterior connect with the hypothalamus?
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
ADH function and target site?
Distal convoluted tubules of
the nephrons and collecting
ducts in the kidney
Stimulates resorption of water by
increasing permeability to water
What is the function of oxytocin hormone and the target site?
Mammary gland
Stimulates milk ejection by
stimulating contraction of smooth
muscles
Uterine muscles
Promotes parturition by contraction
of smooth muscles
Thyroid gland functions and location
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)
Calcitonin function?
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.
parathyroid gland location
Parathyroid glands (a set four small glands) are embedded in the posterior surface of the thyroid
gland located in the neck
Parathyroid glabd funtion
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.
Thymus gland location
Thymus gland is located in the upper part of the chest, directly behind the sternum and between the lungs.
Thymosin function?
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.
Pineal gland location
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.
Adrenal gland location
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).
Adrenal gland function
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.
Hormones of the adrenal cortex?
glucocorticoids and mineralocorticoids.
aldesterone function?
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.