Bio exam 3

Tissue

A group of similar cells

that performs a specialized

function.

Animal tissue types:

Epithelial

Connective

Muscle

Nervous

Epithelial tissue

Protects and interfaces with environment

Covers outside of body and lines organs and

cavities within body. Different cell types (cuboidal,

columnar, squamous) and cell arrangement

• Simple: Single layer

• Stratified: Multiple layers

• Pseudostratified: Single layer of varying length

Connective tissue

Binds plus supports other tissues and has

many functions.

• Contains sparsely packed cells scattered

throughout an extracellular matrix.

• Matrix consists of fibers in a

liquid, jelly-like, or solid foundation.

Muscle tissue

Responsible for movement.

Long cells (muscle fibers) that contract in

response to nerve signals.

Nervous tissue

Receives, processes, and transmits information.

What do most animals need to

keep their tissues healthy and to

perform their functions?

Oxygen

How do animals get oxygen?

Gills and lungs

Getting water?

Drinking

Food

Metabolic water

Getting nutrients?

Food has different size, structure, form, and

composition. Animals obtain it in diffferent

ways.

Suspension feeders?

Sift-filter small food particles from the water.

Substrate feeders?

Live in or on their food source.

Fluid feeders?

Get nutrient-rich fluids from a

living host.

Bulk feeders?

Eat relatively large pieces of food

Teeth in mammals

Set into sockets within the jaw.

Vary in the size, shape and cutting

surfaces.

Homodont

Teeth are uniform

(most reptiles).

Heterodont

Teeth specialized.

Incisors, canines, premolars, molars

Digestion

Breaking food down into molecules small

enough to be absorbed.

Enzymatic hydrolysis splits bonds within

molecules

what organs make up our digestive system?

Alimentary canal and

accessory glands: salivary,

pancreas, liver,

gallbladder.

Ruminant herbivore digestion

Cellulases of anaerobic bacteria and ciliates

help them digest

organs in ruminant digestion

Rumen:the largest stomach compartment in beef cattle, acting as a massive fermentation vat

Reticulum: Honeycomb, sorts the food from the mess (nails, wire)

Omasum: “tripe”, regulates flow into true stomach

Abomasum: True chemical digestion, where the acid is

Destination of nutrients

Proteins (aminoacids)

Sugars

Mitochondria

Perform cellular respiration. A complex

oxidation-reduction reaction (involves

transfer of electrons).

Our cells generate and use billions of ATPs

per day.

Oxygen (O2) consumption by animals

Two main sources:

Aquatic animals extract oxygen from water

while land living animals take up oxygen from

air.

Usually oxygen consumption increases when

temperature increases

Aerobic cellular respiration

Overall chemical reaction: The cell uses O2

and glucose to generate ATP.

Releases chemical energy to fuel cellular

activity and all our functions.

Aerobic cellular respiration formula

Glucose + Oxygen Carbon dioxide + water + ATP

Important molecules in Cellular respiration

Molecules that can accept electrons from other molecules.:

NAD+, FAD

Molecules that have accepted electrons from other

molecules:

NADH , FADH2

Glycolysis

A six carbon glucose molecule

splits into two three-carbon pyruvate molecules.

Transition step

Produces Acetyl CoA

Krebs cycle

Releases CO

Electron transport chain

Transfers energy-rich electrons

from NADH and FADH2. Produces most of the ATP

molecules.

What does Glycolysis Need/Produce?

Doesn’t need O2.

Electrons from glucose are transferred

to electron carrier molecules (NADH)

Generates 2 ATPs. Occurs in the

cytoplasm.

What does Krebs Need/Produce?

Requires O2.

Produces CO2 and 2 ATPs;

Occurs in the mitochondrial

matrix.

What does ETC Need/Produce?

Requires O2, produces water.

Primary source of ATP.

Occurs in the inner mitochondrial

membrane.

what is the net gain of Glycosis?

Produces 4 ATPs, 2 NADHs

and 2 pyruvates. Spends 2 ATPs.

Net gain: 2 ATPs, 2 NADHs

After glycolysis: Transition step

Each pyruvate molecule moves into the

mitochondrial matrix and it is oxidized to Acetyl CoA.

A molecule of CO2 is removed.

NAD+ is reduced to NADH.

The remaining two-Carbon molecule (acetyl group) is

transferred to a coenzyme to form Acetyl CoA:

Acetyl Coenzyme A enters the Krebs cycle

what does etc do ?

Passing of electrons along a series of

proteins embedded in the inner mitochondrial

membrane

The Immune System

A network of cells, tissues, organs,

chemicals, and fluids.

- Recognizes its own cells.

- Defends against infectious agents, foreign

substances, abnormal cellular growths, etc

Immunity

A condition of being able to

resist or tolerate a particular pathogen

that causes disease especially through

preventing development of the pathogen

or its products.

In humans, immune function is usually more efficient

during the middle of life than during early or old ages.

Immune system in humans

Innate defenses

Adaptive (Acquired) immunity

Innate defenses

Nonspecific

Are nonspecific and act early, they are always

present. Act against a broad spectrum agents.

Adaptive (Acquired) immunity:

Specific to particular pathogens.

Recognizes and acts against individual

specific targets and keeps in the memory

previous encounters.

Lymphatic system

A bridge between the circulatory

and the immune system.

Lymphoid organs

Red bone

marrow, thymus, spleen.

Lymph node

Small organs located

along the lymph vessels. They have millions

of white blood cells and release B and T

cells to the lymph.

White blood cells (Innate)

Participate in the immune response.

EX:

•Monocytes

•Neutrophils

•Eosinophils

•Basophils

•Natural killer cells

•Lymphocytes

Physical barriers (innate)

Skin,

mucus, wax, tears.

Normal microbiota (innate)

Help

prevent colonization by

pathogens.

Macrophages (innate)

Engulf and

can destroy invaders.

Inflammation (innate)

Immediate localized reaction to an

injury or to pathogens. Basophils release

histamine that dilates blood vessels. White blood

cells engulf and destroy pathogens and damaged

cells.

Fever (innate)

Increased metabolic heat production.

In the hypothalamus cytokines can trigger

a rise in the body’s temperature.

Normal: 98.6 °F, 37°C.

Fever: 100 °F, 38°C or higher.

Antigen (adaptive)

Molecule that stimulates an

immune reaction by B and T cells. Most

antigens are carbohydrates and proteins.

Examples: Part of a bacterial cell, proteins on

the surface of a mold spore or pollen grain.

Two types of adaptive (acquired)

immune responses

Macrophages in both Helper T cells secrete

cytokines that activate cytotoxic T cells or B cells.

Cell mediated immunity (adaptive)

Cytotoxic T cells

have receptors, bind and destroy body cells

that are defective or infected.

Humoral immunity

by B cells which relies

primarily on antibodies.

humoral immunity examples

Primary immune response:

Response of the

body to an antigen that occurs on the first occasion

it is encountered.

Secondary immune response:

Fast and

strong. Observed following subsequent encounter

with the same antigen, leads to the activation of

previously generated

memory cells.

General ways to acquire passive immunity

One individual acquires antibodies from

another individual (human or other species).

- Antibodies can be acquired from the mother via placenta or milk.

- By direct injection of antibodies (e.g. rabies vaccine after dog bite).

- Direct intravenous antivenom with antibodies (e.g. after snake bite).

General ways to acquire active immunity

Individual produces antibodies to an antigen.

- After having chickenpox the individual acquires natural future

immunity to that disease.

- Vaccines trigger production of memory cells specific to

certain antigens

Vaccine

A substance that stimulates immunity against

a pathogen without actually causing illness:

Memory cells linger after this initial exposure,

ensuring that a subsequent encounter triggers

a rapid secondary immune response.

Adaptice immunity close up (study steps)

Endocrine system

Endocrine glands: Ductless organs that

produce and secrete hormones into the

bloodstream or into their surrounding fluid.

Do not act with the high speed of neural impulses,

but the chemical messages and responses can

last longer.

Hormone

A biochemical messenger released by one part of

the body (endocrine cells) that affects another

part of the body (target cells).

Circulate throughout the body in blood vessels or other ducts.

Major classes of hormones

Peptide and most amine hormones are water-soluble.

Steroid hormones are lipid-soluble.

Thyroid gland

Thyroid hormone

Calcitonin

Parathyroid glands

Parathyroid hormone

Adrenal glands

Adrenal medulla (organ)

Epinephrine

Norepinephrine

Adrenal cortex

Glucocorticoids (e.g. Cortisol)

Mineralocorticoids

Pineal gland

Melatonin

Hypothalamus

Many releasing

and inhibiting

hormones

targeting

anterior pituitary

Pituitary gland

Anterior pituitary

Adrenocorticotropin

Prolactin

Growth hormone

Follicle-stimulating

hormone

Luteinizing

hormone + others!

Posterior pituitary

Oxytocin

Vasopressin

Pancreas

Insulin

Glucagon

Ovaries

Estrogens

Progesterone

Testes

Androgens

placenta

a major source

of hormones

Important role of hormones

Can trigger the development of secondary sex characteristics, and metamorphasis

Regulation of sexual reproduction

Mainly done by estrogen and testoterone

Regulation of kidney function

Hypothalamus → Pituitary

gland Antidiuretic hormone

(ADH): balance of solutes:

Blood reabsorbs more or less

water.

Weight balance

Fat metabolism is under different controls: genes,

hormones, nervous system, digestion etc

Regulation of hunger and fat

Balancing:

•Hunger. Physiological need to eat food.

•Metabolism. Chemical reactions that

build and break down molecules.

An animal’s metabolic rate usually

determines its need for food

Obesity and hormones

Obesity in humans is common and it increases

frequency of diabetes, heart disease, back pain,

stroke, and other problems.

Combines action of genes, hormones, diet,

behavior, and environment.

Leptin ghrelin

Leptin Vs. ghrelin

ghrelin: start eating

Leptin: stop eating

Hormonal regulation of fat

One cell may have receptors for many hormones,

each of which initiates a unique response

Hormonal regulation of fat

Leptin

Protein with 167 amino acids → it’s a peptide

hormone.

Regulates adipose-tissue mass through

hypothalamic effects on satiety-fullness and

energy expenditure.

Leptin hormone and its properties

Secreted by adipose-fat tissue (fat

cells): Beneath skin, between muscles,

around heart, and joints.

- Increases metabolism

- Decreases hunger

- Binds to MC4 (melanocortin 4)

receptor (protein) in the hypothalamus,

region of the brain, then goes to pituatary, then thyroid

Mechanisms of leptin

Leptin levels increase with an increase of food

consumption or fat tissue.

Fat tissue releases leptin

into the bloodstream.

what does leptin interact with

Leptin interacts with

receptors MC4 and triggers

a signal cascade that inhibits

food intake and increases

metabolic activity

What about plants?

bullshit lmao

what are the kinds of Sexual reproduction

• Isogamous (same size gametes)

• Anisogamous (different size gametes)

what are the different kinds of Anisogamous animals?

Dioecious VS Hermaphroditic (monoecious)

kinds of Asexual reproduction

Fission, budding,

parthenogenesis

Sexual anisogamous involves

Recombination of genetic material from

gametes of different sizes to create a

third individual.

In humans:

Eggs fertilized by X-bearing sperm become

females (XX).

Eggs fertilized by Y-bearing sperm become

males (XY).

reproduction in mammals

Copulatory organ in males (penis)

Testis usually in scrotum (suspended

sack of skin and smooth muscle)

-Internal fertilization

-Most viviparous

-Amnion, chorion and allantoids

Chorion

Outermost embryonic membrane

allantoids

It primarily handles liquid waste and gas exchange, and in humans, it develops into the umbilical cord and the urinary bladder

Chordate

Member of Bilateria Deuterostomata defined by a set

of derived characters.

In many species, some of these characters are only

expressed during embryonic development

Notochord

• Anterior-posterior.

• Semirigid elongated structure

of fluid-filled cells enclosed

by a fibrous sheath.

•Supports.

•Allows for lateral bending.

•Muscle attachment.

Cord present in early development or throughout life.

May be partly replaced

by cartilaginous or bony vertebra

Dorsal hollow Nerve Cord

•Single, dorsal, parallel to the digestive

tract and notochord.

•The anterior end forms the brain in

vertebrates, connected to the spinal cord.

Pharyngeal pouches or slits

•Openings that lead from the pharyngeal

cavity to the outside.

Protochordates: Filter feeding apparatus.

Aquatic vertebrates: Give rise to gills.

Tetrapodes: Give rise to different structures

(middle ear, tonsils, glands)

Postanal tail

•Probably evolved for propulsion

in water.

•Vestige in adult humans = coccyx

Subphylum Urochordata

Tunicates, sea squirts

Subphylum Urochordata exhibits more

Chordate characteristics in the larval stage

Subphylum Cephalochordata:

Lancelets